Beyond Bands: The Immature Granulocyte Count

In today’s clinical laboratories there are an increasing number of tests available for physicians to order. In a constant effort to provide the best tools for patient care, laboratories typically issue a Laboratory Technical Bulletin when new platforms or new testing is available. These help introduce physicians to or update them on the ever changing array of test availability. In Hematology, Advanced Clinical Parameters are an extension of the traditional CBC and Automated Differential. Used appropriately, these new tests can provide a wealth of knowledge that can be available to physicians in making diagnoses. In my July post, (Beyond the CBC and Reticulocyte Count: Early Detection of Iron Deficiency Anemia), I discussed the Reticulocyte Hemoglobin (RetHe) and it’s uses in early detection and better management of iron deficiency anemia. In this blog I will explore the Immature Granulocyte Count (IG%), another of the Advanced Clinical Parameters.

Historically, the 100 cell manual differential has been used to enumerate percentages of each cell type present and to detect the presence of abnormal cells, including immature granulocytes. An increase in band count >10 %, was, and is still often used with other screening tests as an indicator of infection or sepsis. The first microscopic image analyzer, the Perkin-Elmer Cellscan in 1966, could recognize neutrophils, lymphocytes and monocytes with 90% accuracy, and a 100 cell differential could be completed overnight. With improved, faster computers this instrument was marketed in the mid 1970’s and then purchased by Coulter Electronics in 1977 to become the Coulter Diff 3. These first hematology analyzers to provide an automated differential yielded a 3 part differential, and then more sophisticated instrumentation gave us the 5 part diff. In the beginning, an automated differential only counted 100-200 cells and manual diffs performed by a trained technologist were still considered superior. Today’s hematology analyzers count over 30,000 cells using impedance and flow cytometry to give us a statistically superior automated differential.

An automated 5 part differential will flag a ‘Left Shift’ when bands are seen. Many laboratories then perform a scan or manual diff. However, bands are very subjective and therefore it has been questioned if the band count is truly useful as a clinical indicator of sepsis. If a band count >10% is an indicator of sepsis, what happens when 2 or 3 technologists perform diffs on the same slide and get a band % range between 5% and 19%? 5% would not indicate sepsis, whereas 19% exceeds the 10% cutoff almost twofold. Two experienced technologists can perform a manual diff on the same slide and get band counts in a fairly wide range depending on their training and which definition of bands they use and which 100 cells they see in their count. On the other hand, a 6 part automated differential counts and differentiates over 30,000 neutrophils, lymphocytes, monocytes, eosinophils, basophils and immature granulocytes. The auto diff separates bands and immature granulocytes. Band cells are considered mature and included in the neutrophil count. The Advanced Clinical Parameter, Immature granulocytes (IG%) include metamyelocytes, myelocytes and promyelocytes. In the peripheral blood these immature granulocytes are an indicator of leukopoiesis, cells just coming out of the bone marrow and represent the earliest information possible and an earlier indication of inflammation and infection than a band count. The example below illustrates this concept.
Case Study 1

A patient admitted to the ER with high fever and chills has a CBC and auto diff ordered. His WBC is elevated and percent neutrophils are high. The physician suspects sepsis despite the normal WBC and orders a CRP and blood cultures. CRP results are within normal limits. The immature granulocyte counts are shown below on admission and in 4 subsequent phlebotomies. Antibiotics were started 3 hours after initial triage. The patient was admitted to the hospital and Streptococcus pneumoniae was isolated from the blood cultures at 48 hours.

left shift 1

The IG% and absolute counts are increased in this patient when other markers of infection are not. An IG% of >1% is indicative of a true left shit and >3% may predict positive blood cultures. The ED can also use the IG to determine that the infection is community acquired and not nosocomial if the IG% is high on admission. Note the band counts here that could be high or low depending on who performed the diff. This demonstrates the inherent subjectivity and imprecision of band counts and manual differential counts because they are done on only 100 cells. The immature granulocyte count is automated, not subjective. In checking the slide for correlation, we see the presence of these immature granulocytes. The IG% is thought to be better as a predictor of sepsis than the WBC and band count. For this reason, with the availability of a 6 part diff, labs have encouraged physicians to order and use the automated differential.
Another application of the utility of the IG% is seen in comparing IG% and ITR, immature to total neutrophil ratio. ITR is used by neonatologists to determine infection. The ITR is a calculation based on a 100 cell manual differential. In this formula, the immature neutrophils are bands, myelos, metas and pros. An ITR <0.2% is a negative predictive value for sepsis.
Immature neutrophils/Total neutrophils=bands+myelos+metas+pros/total neutrophils= ITR

Case Study 2

left shift 2

In 2 babies less than 30 days old, we see again here the phenomenon of a wide variety of bands counted by 2 techs. In the ITR, bands are counted as immature cells. Despite the imprecision of the band count, Baby A has >10% bands counted by both techs and the ITR range is >0.2% in both calculations. However, in Baby B, we see that the band count from one differential was 5% and the second tech counted 17% bands. Since the bands are used to calculate the ITR, one calculation gives an ITR of 0.06%, a negative predictor of infection, and the second count gives an ITR of 0.22%, above the 0.2% threshold. At the same time, if physicians are looking at an absolute neutrophil count(ANC), the number of neutrophils available to fight off infection, this number is calculated using bands and neutrophils. In one formula, bands are lumped with immature cells, and in the other, bands are included with mature cells. This can be confusing information. If we were instead to rely on the automated differential, the IG% gives us a more clear and precise measure of sepsis. Using the previously stated criteria for infection, the IG% of Baby A is clearly above 3% and in Baby B is well below 1%.

How do band counts compare to the IG%? Should bands be eliminated as an indicator of infection? Studies have been done that suggest that the WBC and band counts are not as reliable in predicting infection as the IG% and ANC. Suggestions have been made that the left shift should be redefined with IG% rather than bands. Bands may be too subjective to be the best indicator of infection and they lead to an imprecision in the ITR. The IG count can highlight potential acute infection or inflammation at its earliest stages, even when other parameters are still within normal ranges. IG counts (% and #), reported with the automated differential, reduce turnaround time and are valuable for clinicians to use in conjunction with other current indicators for the diagnosis of infection and inflammation.

References

  1. Ansari-Lari, M.Ali et al. Immature Granulocyte Measurement Using the Sysmex XE-2100 Relationship to Infection and Sepsis Am. J Clin Pathol. 2003,Nov;120(5):795-9.
  2. Balamurugan Senthilnayagam, et al. Automated Measurement of Immature Granulocytes: Performance Characteristics and Utility in Routine Clinical Practice. Patholog Res Int. 2012: 483670. Published online 2012 Feb 15. doi: 10.1155/2012/483670
  3. Cavallazzi, R et al. Is the band count useful in the diagnosis of infection? An accuracy study in critically ill patients. J Intensive Care Med. 2010, Nov-Dec;25(6):353-7.
    Dutcher, Thomas F. Automated Leukocyte Differentials: A Review and Prospectus. Laboratory Medicine, Volume 14, Issue 8, 1 August 1983, Pages 483–487, https://doi.org/10.1093/labmed/14.8.483
  4. McDaniel, Holly. Ban the Bands. Sysmex News, 2013. https://www.sysmex.com/crc/ACP/IG_Ban_the_Bands.pdf
  5. Sysmex America White Paper. Getting Beyond the Flags: Quantitative assessment of immature granulocyte (IG) populations may improve the assessment of sepsis and inflammation. http://www.sysmex.com/us

 

Socha-small

-Becky Socha, MS, MLS(ASCP)CM BB CM graduated from Merrimack College in N. Andover, Massachusetts with a BS in Medical Technology and completed her MS in Clinical Laboratory Sciences at the University of Massachusetts, Lowell. She has worked as a Medical Technologist for over 30 years. She’s worked in all areas of the clinical laboratory, but has a special interest in Hematology and Blood Banking. When she’s not busy being a mad scientist, she can be found outside riding her bicycle.

Hematopathology Case Study: A 48 Year Old Woman with Left Upper Quadrant Pain

Case History

A 48-year-old female presents with a one-month history of left upper quadrant pain. Laboratory investigation reveals pancytopenia. Radiology work-up demonstrates splenomegaly. CT scan confirms splenomegaly at 22 cm. There is no lymphadenopathy appreciated in the abdomen. A bone marrow biopsy is performed.

Figure HSTCL
Image 1. H&E and CD3 stains at varying magnification.

Bone Marrow Findings

The bone marrow core biopsy reveals a normocellular marrow space (approximately 50% cellular marrow) with progressive trilineage hematopoiesis. Clusters of small, slightly irregular, mature-appearing lymphocytes are seen within the sinusoids. The marrow aspirate smears reveal mild erythroid hyperplasia without morphologic evidence of dysplasia. There is no increase in blasts. Lymphocytes comprise 18% of a 500-cell differential count on the marrow aspirate smears.

The sinusoidally distributed lymphocytes demonstrate immunopositivity (flow and/or IHC) for CD2, CD3, CD7, CD16, CD56, and γδ. These neoplastic lymphocytes are negative for granzyme B, CD4, CD5, CD8, CD57, and αβ.  PCR for T-cell receptor clonality was positive. Cytogenetics revealed a normal female karyotype. FISH for 5p/5q and 7p11/7q31 was normal.

Diagnosis

Taken together, the patient’s clinical presentation along with the presence of an abnormal gamma-delta population of T cells in a sinusoidal distribution with PCR evidence of T-cell clonality is diagnostic of a T-cell lymphoma. The pattern of distribution, granzyme B negativity, lack of concurrent adenopathy favor a diagnosis of Hepatosplenic T-cell lymphoma.

Discussion

Hepatosplenic T-cell lymphoma (HSTCL) is an uncommon entity that represents <1% of all non-Hodgkin lymphomas and 1%-2% of all T/natural killer cell lymphomas. It most commonly affects young adult men, with a median age of 35 years. This high-grade malignancy is most often characterized by γδ T-cells. The most consistent symptoms among patients are fever, splenomegaly, hepatomegaly, bone marrow involvement, peripheral blood cytopenia, and less commonly, adenopathy. Hepatosplenic T-cell lymphoma has a poor prognosis with median survival rates varying from a few months to 16 months in different studies.

Immune suppression (such as solid- organ transplant, or immune dysregulation secondary to malignancy or infection) is thought to play a role in the lymphomagenesis in around 20% of cases. Inflammatory bowel disease and the use of immunosuppressive agents (e.g., antitumor necrosis- α agents) and antimetabolite therapy (e.g., 6TG, 6MP) had also been associated with development of HSTCL.

HSTCL initially infiltrates the cords and sinusoids of the splenic red pulp. The white pulp is often atrophic or absent. Eventually, the neoplastic T cells diffusely replace the spleen. The lymphoma cells often involve the liver and bone marrow sinusoids. At the time of diagnosis, the bone marrow is almost always involved and commonly hypercellular. The neoplastic cells are mostly intermediate in size, with pale agranular cytoplasm and round nuclei with condensed chromatin and inconspicuous nucleoli.

Cytogenetic studies in HSTCL most commonly show isochromosome 7q and trisomy 8. Molecular analysis of HSTCL characteristically shows expression of a γδ T-cell type and flow cytometric analysis typically reveals a CD2+, CD3+, CD7+/−, CD4−, CD5−, and CD8− phenotype with positivity for natural killer cell-associated markers CD11b, CD16, and CD56.

Activating mutations in PI3KCD and STAT signaling genes have also been described in HSTCL, providing potential molecular target therapies for this aggressive lymphoma.

The differential diagnosis of HSTCL includes other types of T-cell lymphoma and leukemia, and non-neoplastic such as immune thrombocytopenia or acute hepatitis. In most instances, the distinctive presentation of spleen, liver and bone marrow involvement, the immunophenotype and T-cell monoclonality distinguishes HSTCL from other entities.

The outcomes of the patients using standard chemotherapy regimens are dismal, and allogeneic SCT appears to be a reasonable approach to achieve the best possible patient outcome.

References

  1. Yabe M, Miranda RN, Medeiros LJ. Hepatosplenic T-cell Lymphoma: a review of clinicopathologic features, pathogenesis, and prognostic factors. Hum Pathol. 2018 Apr; 74:5-16.
  2. McThenia SS, Rawwas J, Oliveira JL, Khan SP, Rodriguez V. Hepatosplenic γδ T-cell lymphoma of two adolescents: Case report and retrospective literature review in children, adolescents, and young adults. Pediatr Transplant. 2018 Aug;22(5): e13213.

 

levent photo

-Levent Trabzonlu, MD is a postdoctoral researcher in the department of pathology at Johns Hopkins University in Baltimore, MD. Follow Dr. Trabzonlu on twitter @aflevent

Mirza-small

-Kamran M. Mirza, MD PhD is an Assistant Professor of Pathology and Medical Director of Molecular Pathology at Loyola University Medical Center. He was a top 5 honoree in ASCP’s Forty Under 40 2017. Follow Dr. Mirza on twitter @kmirza.

Hematopathology Case Study: A 55 Year Old Woman with Fatigue, Nausea, and Vomiting

Case History

55 year old woman with no significant past medical history presented with two weeks of increasing fatigue, nausea and vomiting. She was subsequently found to have a leukocytosis (WBC = 31.1) and marked splenomegaly (19 cm).

Peripheral Blood

mcl-peri-1

mcl-peri-2

 

Bone Marrow Biopsy 

mcl-bm-20x
aspirate 20X
mcl-bm-40
aspirate 40X
mcl-bm-core-10
core biopsy 10X
mcl-bm-core-40
core biopsy 40X

 

mcl-core-cd20
core biopsy CD20
mcl-core-bcl1
core biopsy BCL1 (CCND1)

 

Flow Cytometry

mcl-flow

 

Cytogenetics

mcl-cyto-kary
Karyotype
mcl-cyto-IGH
IGH/CCND1 gene rearrangement
mcl-cyto-deletion
deletion of TP53
mcl-cyto-MYC
MYC amplification

 

Diagnosis

The peripheral blood shows a population of atypical cells that at first may look like blasts. However, the variable size, round to markedly irregular nuclear contours, large prominent nucleoli and mild to moderate amounts of cytoplasm favor lymphoma cells.

The bone marrow aspirate shows the vast majority of the cellularity is composed of a pleomorphic population of lymphoma cells that are varied in size from small to large with mild to moderate cytoplasm, round to irregular nuclear contours and prominent nucleoli. Occasional maturing erythroid and myeloid precursors are present.

The core biopsy shows a marrow with a cellularity of approximately 70%. There is an interstitial infiltrate of atypical mononuclear cells with frequent scattered mitoses occupying 70% of the overall cellularity. By immunohistochemistry performed on the core biopsy, B-cell marker CD20 highlights the majority of the infiltrating lymphocytes, which co-express BCL1 (CCND1).

Flow cytometry revealed a population of CD19 and CD20 positive kappa (bright) restricted B-cells that were also positive for CD23 in a subset. They did not express any other characteristic antigens including CD5, CD10 and CD11c. Importantly, as there was initial concern for acute myeloid or lymphoblastic leukemia, no abnormal events were identified in the CD45 dim “blast” gate, with CD34 positive blasts showing normal maturation.

Cytogenetics revealed a complex abnormal karyotype. The most important finding was a translocation involving the long arms of chromosome 11 and 14 resulting in the IGH/CCND1 translocation that is characteristic of mantle cell lymphoma. Interestingly, the FISH probe showed that there were 4 IGH/CCND1 fusions indicating an extra copy of the derivative chromosome 14. Additional FISH probes showed a deletion of the TP53 gene on 17p13 and greater than 10 copies of the MYC gene on chromosome 8, consistent with MYC amplification.

Overall, the findings are consistent with a pleomorphic variant of mantle cell lymphoma with leukemic peripheral blood involvement. The cytogenetic findings portend an unfavorable prognosis.

Discussion

Mantle cell lymphoma is generally characterized as an aggressive lymphoma of mature B-cells. It accounts for approximately 3-10% of non-Hodgkin lymphomas and tends to occur in older men. Lymph nodes are the most commonly involved site; however the bone marrow and peripheral blood are frequently involved as well. There are multiple morphologic variants of mantle cell lymphoma. The two aggressive variants include blastoid and pleomorphic. The blastoid variant has cells that resemble lymphoblasts with dispersed chromatin and large prominent nucleoli. The pleomorphic variant is characterized by a spectrum of cells, with many large cells with irregular nuclear contours, pale cytoplasm and variably prominent nucleoli. These two variants are clinically significant because they portend a worse prognosis. 1

The patient’s cytogenetic findings also portend a poor prognosis. IGH/CCND1 is a translocation between the immunoglobulin heavy chain on chromosome 14 and cyclin D1 on chromosome 11. This translocation leads to the overexpression of cyclin D1. However, Cyclin D1 is a “weak” oncogene and is not sufficient by itself to lead to the development of lymphoma. There are numerous secondary chromosomal aberrations and mutations that must occur to result in the presentation of mantle cell lymphoma. A paper by Beà et al. performed whole genome and/or whole exome sequencing on 29 cases of mantle cell lymphoma. They detected around 3,700 somatic mutations per tumor. ATM, CCND1 and TP53, which have previously been described as drivers in mantle cell lymphoma, were found frequently mutated. TP53 mutations were found in 28% of the lymphomas.2

MYC is a potent proto-oncogene located on chromosome 8. It mainly functions as a transcription factor and its activation leads to increased DNA replication, protein synthesis and alterations in cell metabolism among many other changes. The ultimate effect is increased cell proliferation and tumorigenesis. MYC amplification or translocation was shown to occur more often in blastoid/pleomorphic mantle cell lymphoma variants. This finding was associated with a shortened overall survival and progression-free survival. 3

References

  1. Swerdlow, Steven H. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Revised 4th ed., International Agency for Research on Cancer, 2017.
  2. Beà S, Valdés-Mas R, Navarro A, et al. Landscape of somatic mutations and clonal evolution in mantle cell lymphoma. Proceedings of the National Academy of Sciences of the United States of America. 2013;110(45):18250-18255. doi:10.1073/pnas.1314608110.
  3. Choe, JY, Yun, JY, Na, HY, et al. MYC overexpression correlates with MYC amplification or translocation, and is associated with poor prognosis in mantle cell lymphoma. 2016 Feb;68(3):442-9. doi: 10.1111/his.12760. Epub 2015 Jul 28.

 

Marcus, Chelsea_099-Edit

Chelsea Marcus, MD is a third year resident in anatomic and clinical pathology at Beth Israel Deaconess Medical Center in Boston, MA and will be starting her fellowship in Hematopathology at BIDMC in July. She has a particular interest in High-grade B-Cell lymphomas and the genetic alterations of these lymphomas.

Hematopathology Case Study: An 85 Year Old Man with Pancytopenia

Case History

An 85 year old man presented with pancytopenia and weakness. His labs include WBC of 3.2, HgB of 9.9 and platelets of 137.

Bone Marrow Biopsy

hairycellbm10x
Bone Marrow Aspirate, 10x
hairycellbm40x
Bone Marrow Aspirate, 40x
hairycellcore10x
Core Biopsy, 10x
hairycellcore40x
Core Biopsy, 40x

Flow Cytometry

hairycellflow

hairycellplasmacell

hairycellplasmacellgate

Diagnosis

The bone marrow aspirate shows multiple cellular spicules with a prominent population of lymphoid cells with oval to reniform nuclei, dispersed chromatin and abundant pale cytoplasm. Scattered plasma cells are also present.

The core biopsy shows an infiltrating population of atypical lymphocytes with moderate amounts of pale eosinophilic cytoplasm and mature chromatin that stain positive for CD20. Frequent mononuclear cells consistent with plasma cells are also seen scattered throughout the bone marrow and stain positive for CD138.

Flow cytometry revealed that 80% of the lymphoid gate represented a kappa light chain restricted population that co-expressed B-cell markers CD19, CD20 and CD22 along with classic hairy cell leukemia specific markers CD11c, CD25 and CD103. A second population of kappa restricted cells fell in the plasma cell gate. The cells co-expressed CD138, CD56 and were largely negative for CD19 and CD20.

Overall, there is a hypercellular bone marrow with a prominent mononuclear lymphoid infiltrate consistent with hairy cell leukemia and a concurrent population of plasma cells consistent with plasma cell neoplasm.

Discussion

Hairy cell leukemia is a rare lymphoid neoplasm that accounts for only 2% of lymphoid leukemias. Patients tend to be in their 50s-60s with a 4:1 male predominance. The tumor is generally found in the bone marrow and spleen with rare circulating cells in the peripheral blood. Patients are generally cytopenic at presentation and symptoms include weakness and fatigue. Splenomegaly is common and hepatomegaly can also be seen.. 1

Hairy cell leukemia involves the clonal expansion of B-cells with a unique immunophenotypic profile. They are bright for CD19, CD20, CD22 and CD200, negative or dim for CD5, CD23 and CD10 and positive for CD11c, CD103, CD123 and CD25. Hairy cell leukemia must be distinguished from two provisional entities, hairy cell leukemia-variant and splenic diffuse red pulp lymphoma. These two entities do not have the classic morphology or staining profile of hairy cell leukemia.2

BRAF V600E mutations are detected in more than 80% of cases of classic hairy cell leukemia. The mutation is considered to be a driver mutation, but additional mutations are usually present that lead to disease progression. Hairy cell leukemia-variant is usually negative for BRAF mutations and has a more aggressive clinical course.3

Patients with hairy cell leukemia are given purine analogues as first line treatment and generally do well. However, patients who do not respond or who undergo relapse have few options. Increasingly, BRAF V600E inhibitors are being used for patients with hairy cell leukemia. Multiple studies have now confirmed the efficacy of vemurafenib and dabrafenib, however patients can be quick to relapse once off the drugs. Combination approaches should be considered for the most effective treatment. 4

References

  1. Swerdlow SH, Campo E, Harris NL, et al. WHO Classification of Tumours of Haematopoetic and Lymphoid Tissues (Revised 4th edition). IARC: Lyon 2017.
  2. Troussard X, Cornet E. Hairy cell leukemia 2018: Update on diagnosis, risk‐stratification, and treatment. American Journal of Hematology. 2017;92(12):1382-1390. doi:10.1002/ajh.24936.
  3. Maitre E, Bertrand P, Maingonnat C, et al. New generation sequencing of targeted genes in the classical and the variant form of hairy cell leukemia highlights mutations in epigenetic regulation genes. Oncotarget. 2018;9(48):28866-28876. doi:10.18632/oncotarget.25601.
  4. Roider T, Falini B, Dietrich S. Recent advances in understanding and managing hairy cell leukemia. F1000Research. 2018;7:F1000 Faculty Rev-509. doi:10.12688/f1000research.13265.1.

 

Marcus, Chelsea_099-Edit

Chelsea Marcus, MD is a third year resident in anatomic and clinical pathology at Beth Israel Deaconess Medical Center in Boston, MA and will be starting her fellowship in Hematopathology at BIDMC in July. She has a particular interest in High-grade B-Cell lymphomas and the genetic alterations of these lymphomas.

Beyond the CBC and Reticulocyte Count: Early Detection of Iron Deficiency Anemia

In my May 2018 post (Not your Grandmother’s Hematology), I discussed the history of hematology and chronicled how far we have come in the last 60 years. We have progressed from manual counting of cells to the first Coulter Counter in 1956, which revolutionized hematology by being able to automate the counting of red blood cells, to modern instruments that can report up to 30 parameters and perform up to 400 CBCs an hour. Among these parameters are what are termed advanced clinical parameters, new parameters which provide physicians with additional information about the state of blood cells. In this blog I will explore how one of these advanced clinical parameters, the Reticulocyte Hemoglobin content, can provide physicians with information that can assist them with earlier detection, differential diagnosis and better management of iron deficiency and iron deficiency anemia. 

Case Study 

A 29 year old female was seen by her gynecologist reporting a history of heavy menstrual bleeding with current bleeding lasting 15 days. The doctor discussed various treatment options with the patient and a CBC was performed. CBC results are shown below.

Test Result Flags Reference
WBC 7.23   4.5-10.5 K/CMM
RBC 4.38   3.70-5.30 M/CMM
HGB 12.0   12.0-15.5 GM/DL
HCT 36.2   36.0-46.0 %
MCV 82.6   80-100 FL
MCH 27.4   27.0-34.0 PG
MCHC 33.1   32.0-36.0 %
PLT 243   150-450 K/CMM
MPV 11.0   9.6-12.0 FL
RDW 12.5   0-15.1 %

This CBC shows no abnormal flags. Based on patient history and presentation, the physician questioned iron deficiency despite normal hemoglobin and hematocrit, MCV and MCHC. He ordered a reticulocyte profile on the same specimen with the following results:

Test Result Flags Reference Range
Retic 1.55   0.5-2.0 %
Abs Retic 0.0679 H 0.0391-0.057 M/CMM
Imm Retic Frac 14.9   2.3-15.9 %
Ret-Hgb 24.6 L 30-35 PG

Reticulocyte counts are the quantity of the youngest red blood cells released from the bone marrow into the peripheral blood. Reticulocytes are reported as a % and the absolute reticulocyte count is calculated by multiplying the Retic% by the RBC. The immature reticulocyte fraction (IRF) is the rate of production of reticulocytes and depends largely on the ability of the bone marrow to respond to erythropoietin. The reticulocyte hemoglobin (Ret-He) content is the amount of hemoglobin in newly formed red blood cells. (There are two different hematology systems that report reticulocyte hemoglobin content. The two nomenclatures used for reticulocyte hemoglobin are Ret-He and CHr and studies have been done that demonstrate their equivalence)

Note that the Ret-He reflects the quality of the newly formed reticulocytes. Ret-He is a direct measurement of the amount of hemoglobin in each reticulocyte, which indicates the amount of iron available for incorporation into the precursors of mature red cells. This patient’s retic% and IRF are within normal ranges, but her absolute reticulocyte count is high. A Ret-He less than 29 pg in an adult is indicative of iron deficiency. With a normal CBC and low Ret-He, this is an early indication that iron deficiency is indeed present. With the absence of sufficient iron, this patient would eventually develop a microcytic, hypochromic anemia. Therefore, Ret-He can measure and indicate inadequate hemoglobin production before the hemoglobin and hematocrit decrease.

In this case the importance of clinical awareness is illustrated. This physician remembered a recent laboratory technical bulletin announcing implementation of a new hematology analyzer system with the availability of new parameters for reticulocyte counts. When the CBC results came back from the laboratory, the patient had already gone home, and no serum had been drawn to perform a ferritin level. Rather than calling the patient back to have another sample drawn, the Ret-He could be done from the same blood sample already in the lab. Ret-He is a faster, easier and less expensive test than additional iron studies and bone marrow iron stains. Ret-He can easily be used at a very low cost to get that first piece of information to decide whether or not iron deficiency is a concern. A high or normal Ret-He would have ruled out an iron deficiency with a fairly high confidence level. In this case, the low Ret-He could be used to guide further workups. A subsequent blood drawn revealed a low ferritin and iron deficiency was confirmed. The patient was advised to take an iron supplement along with ongoing treatment for the bleeding.

This case is just one example of the clinical utility of the Ret-He. Using the Ret-He, physicians can determine iron deficiency before iron deficiency IDA develops. A low Ret-He can alert a physician to iron deficiency without the presence of anemia, microcytosis or hypochromia. Ret-He can also be used to monitor and show early response to iron therapy before any other parameters change. A case example is that of a 5 month old who was brought to the emergency room with a Hgb of 7 g/dl and a Ret-He of 11.9 pg. In pediatric patients, a Ret-He less than 27.5 is an indicator of IDA. In this child, treatment with oral iron showed that the Ret-He had risen to 24.6 pg seven days after the onset of iron therapy, while the CBC remained virtually the same. This provided a very early indication that the iron therapy was effective.1 The Ret-He can also been used to minimize transfusions. The AABB Choosing Wisely Campaign lists 5 things that physicians and patients should questions before transfusion. One of the guidelines states “Don’t transfuse red blood cells for iron deficiency without hemodynamic instability.“2 Historically, physicians have used a ‘wait and see’ approach and watched Hgb levels drop before they start looking at iron. Using a Ret-He, iron deficiency could be determined, for example, in a patient with a Hgb of 11 g/dl. Oral or intravenous iron could be started before the Hgb drops below 7 g/dl and transfusion becomes necessary. The AABB Choosing Wisely Campaign emphasizes this by stating that patients with chronic iron deficiency or pre-operative patients with iron deficiency should be given iron therapy before transfusion is considered.2 Ret-He can give the earliest indication of iron deficiency and can be used to monitor the response to iron therapy. Another clinical utility of Ret-He has been to help diagnose or rule out iron deficiency in oncology patients. Additionally, Ret-He has been included in guidelines for anemia management in end stage renal disease patients on dialysis and who get erythropoietin.

The Ret-He parameter has proved clinically useful in early determination of functional iron deficiency. Traditionally ordered chemistry iron studies are indirect measures that have certain inherent inaccuracies due to the presence of inflammation and infection, or in patients on iron therapy. Ret-He is a direct and very effective screening tool and physicians can use Ret-He with other RBC indicies to improve anemia diagnosis and management in many patient populations. Ret-He can be used as a screening measure, and used to reflex for iron studies. Therefore, laboratories who have instruments that can report Ret-He and CHr should develop an education program to help clinicians effectively use Ret-He. Together physicians and laboratorians can develop their own guidelines for reflex testing and improvement for patient care.

References

  1. Case Studies Demonstrating the Clinical Application of the Advanced Clinical Parameters (1/20/2016) Chantale Pambrun, MD, FRCPC, Head of Division of Hematopathology and Assistant Professor of Pathology and Laboratory Medicine, IWK Children’s & Women’s Health Centre and Dalhousie University
  2. https://www.aabb.org/pbm/Documents/Choosing-Wisely-Five-Things-Physicians-and-Patients-Should-Question.PDF
  3. Advanced parameters offer faster, surer guidance to cancer care. Anne Paxton. CAP Today. Sept 2017
  4. The Value-driven Laboratory. Reticulocyte Hemoglobin Content (Ret-He): A Parameter Well-Established Clinical Value. Sysmex America White Paper.
  5. Sysmex Clinical Support Team. Utility of RET-He, August 10. 2015
  6. Brugnara C, Schiller B, Moran J. Reticulocyte hemoglobin equivalent (Ret-He) and assessment of iron-deficient states. Clinical Laboratory Hematology 2006;28:303 – 308.

 

Socha-small

-Becky Socha, MS, MLS(ASCP)CM BB CM graduated from Merrimack College in N. Andover, Massachusetts with a BS in Medical Technology and completed her MS in Clinical Laboratory Sciences at the University of Massachusetts, Lowell. She has worked as a Medical Technologist for over 30 years. She’s worked in all areas of the clinical laboratory, but has a special interest in Hematology and Blood Banking. When she’s not busy being a mad scientist, she can be found outside riding her bicycle.

Hematopathology Case Study: A 67 Year Old Female with a Sore Throat

History 

A 67 year old female presents with a two-month history of sore throat. She endorses dysphagia and left-sided otalgia but denies voice changes, shortness of breath, hemoptysis, weight loss, fever or night sweats. She has smoked 1 pack/day for 41 years and occasionally drinks alcohol. Her past medical history is notable for systemic lupus erythematosus for which she takes Plaquenil.

Physical examination slightly elevated systolic blood pressure. She is afebrile. Pertinent neck exam findings include mild tonsillar asymmetry (left slightly larger than right), and a firm mass at left base of tongue, and a 3 cm lymph node in the neck (left level III). A biopsy sample was taken from the tongue mass. 

Biopsy

EBV-1

H&E stained sections reveal sheets of large lymphocytes. The lymphoid cells are medium to large in size with irregular nuclear contours and prominent nuclei. Areas of necrosis are prominent. No specific areas of epithelial ulceration are noted. Immunophenotypic characterization of the larger cells reveals positivity for CD20, CD30, CD79a, PAX5, MUM1, Epstein Barr virus encoded RNA (EBER) and a variable Ki-67 proliferation index, which is up to 60-70% in the larger cells, but around 20-30% overall. Only rare cells are positive for BCL-2 and BCL-6. The lymphoma cells are negative for keratin AE1/AE3, CD10, CD4, CD8, CD21, CD23, CD7, CD5, Cyclin D1, CD68, CD56, and CD43. The background T cells express CD5 and CD7 and are a mixture of CD4 and CD8 with CD4 predominance.

We considered the diagnosis of EBV-positive mucocutaneous ulcer (a more indolent entity); however, the lack of history of an ulcer/ulceration and the presence of a mass-lesion (with additional adenopathy) does not support this diagnosis.

The findings are most consistent with EBV-positive DLBCL, NOS (WHO 2017), previously known as EBV positive DLBCL of the elderly (WHO 2008). 

Discussion 

Epstein Barr Virus, a member of the Herpesviridae family is mostly known for causing Infectious Mononucleosis. However, the ubiquitous virus which is present in about 90% of adults but often asymptomatic1, has a predilection for epithelial cells including B-cells.2 Incorporation of the viral genome and viral takeover of the cells proliferative machinery underlies the pathogenesis of any EBV-related disease/malignancy. It has been associated with a gastric carcinoma, fulminant hepatitis, undifferentiated nasopharyngeal carcinoma, and B cell, T cell and NK cell lymphomas3, including EBV+ diffuse large B-cell lymphoma, not otherwise specified (DLBCL-NOS).

EBV-positive diffuse large B-cell lymphoma, not otherwise specified (EBV+ DLBCL-NOS) was formerly known as EBV-positive diffuse large B-cell lymphoma (DLBCL) of the elderly. The WHO classification substituted “not otherwise specified” in place of “for the elderly” to reflect two things: 1) EBV is associated with other specific neoplastic Large B-Cell diseases such as lymphomatoid granulomatosis, and 2) EBV+DLBCL can affect younger individuals as well as the elderly. 2

EBV+DLBCL-NOS patients may occur in nodal or extranodal sites, with up to 40% presenting with extranodal sites at least in the early stages. Patients may be asymptomatic with or without B symptoms but usually, patients present with rapidly enlarging tumors at single or multinodal sites, as well as at extranodal sites. 4

The patient’s presentation with sore throat and the finding of neck mass with EBV-positive large B-cells associated with ulcer-like necrosis raises a differential diagnosis that ranges from reactive to malignant. Table 1 shows a comparison between three differential diagnoses: EBV+DLBCL-NOS; EBV-positive mucocutaneous ulcer; and infectious mononucleosis.

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Table 1. Comparison of 3 EBV-positive differentials in the head and neck

Unfortunately, there is currently no uniformly agreed standard of treatment for EBV+DLBCL which has a worse prognosis than EBV negative DLBCL.2 The standard treatment for DLBCL (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone- R-CHOP) is used but it responds poorly to treatment, with a median survival of 2 years.

Therefore, early detection by clinical suspicion and testing all DLBCL patients for EBV is very important.2 

 References

  1. Tsuchiya S. Diagnosis of Epstein–Barr virus-associated diseases. Critical Reviews in Oncology and Hematology. 2002;44(3):227-238. https://www.sciencedirect.com/science/article/pii/S1040842802001142. doi: 10.1016/S1040-8428(02)00114-2.
  2. Murthy SL, Hitchcock MA, Endicott-Yazdani T, Watson JT, Krause JR. Epstein-barr virus–positive diffuse large B-cell lymphoma. Proceedings (Baylor University.Medical Center). 2017;30(4):443-444. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5595389/.
  3. Okano, Motohiko, MD, PhD|Gross, Thomas G., MD, PhD. Acute or chronic life-threatening diseases associated with epstein-barr virus infection. American Journal of the Medical Sciences, The. 2012;343(6):483-489. https://www.clinicalkey.es/playcontent/1-s2.0-S0002962915309435. doi: 10.1097/MAJ.0b013e318236e02d.
  4. Swerdlow S, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J, Arber D, Hasserjian R, Le Beau M. WHO classification of tumours of haematopoietic and lymphoid tissues. 2017.
  5. Dunmire SK, Hogquist KA, Balfour HH. Infectious Mononucleosis. Current topics in microbiology and immunology. 2015;390:211-240. doi:10.1007/978-3-319-22822-8_9.

 

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-Adesola Akinyemi, M.D., MPH, recently earned his MPH-Health Policy and Management from New York Medical College. He plans on pursuing residency training in pathology. His interests include cytopathology, neuropathology, and health outcomes improvement through systems thinking and design.

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-Kamran M. Mirza, MD PhD is an Assistant Professor of Pathology and Medical Director of Molecular Pathology at Loyola University Medical Center. He was a top 5 honoree in ASCP’s Forty Under 40 2017. Follow Dr. Mirza on twitter @kmirza.

Hematopathology Case Study: Two Cases with Surprising Hematopoetic Elements

Case 1 History

Sixty-one year old man with new diagnosis of Bud-Chiari syndrome and extensive peripheral, splenic and hepatic venous thrombosis with increasing fatigue, abdominal discomfort and abnormal liver function tests. A liver biopsy was performed and a hypercoagulability work-up, including JAK2 mutation analysis was initiated.

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Liver core biopsy 2X
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Liver core biopsy 10X

Diagnosis

The liver biopsy showed extensive hemorrhage, hepatocellular necrosis and collapse with mild portal and lobular mixed inflammation. Occasional megakaryocytes and nucleated red blood cell precursors were noted. The case was sent to hematopathology for further review.

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Liver core biopsy 40X
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Liver core biopsy 40X
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JAK2 Mutations Analysis

Hematopathology Diagnosis

Sections show liver parenchyma with changes of the patient’s known history of venous outflow obstruction, as well as extramedullary hematopoiesis, including scattered megakaryocytes (arrows) and erythroid precursors (circle). In the setting of a positive JAK2 V617F mutation, this constellation of findings is consistent with a myeloproliferative neoplasm.

Case 2 History

Fifty-nine year old man with a history of hypertension and alcohol abuse with posterior mediastinal lymphadenopathy. Recent bone marrow biopsy showed mildly hypercellular bone marrow with megakaryocytic and myeloid hyperplasia, and increased stromal reticulin with concern for primary myelofibrosis. A lymph node biopsy was performed.

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Lymph node biopsy 10X
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Lymph node biopsy 40X
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Myeloperoxidase
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CD71
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CD61
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CD34
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CD3
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CD20

Diagnosis

The lymph node biopsy shows fragments composed of adipocytes and maturing trilineage hematopoiesis. Multiple small to medium sized lymphoid aggregates are also seen, composed of small and mature appearing lymphocytes. The lymphocytes are a mixture of CD3 positive T cells and CD20 positive B cells with focal B cell predominance. Myeloperoxidase highlights myeloid precursors, which comprise 70-80% of the cellularity. CD71 highlights erythroid precursors, which comprise 20-30% of the cellularity. CD61 highlights megakaryocytes. CD34 highlights vessels and only rare CD34-positive cells are seen. Taken together, the findings are consistent with extramedullary hematopoiesis.

Discussion

Extramedullary hematopoiesis (EMH) is defined as hematopoiesis that occurs outside of the bone marrow. It can occur in both normal and pathologic states and has been seen in several hematologic disorders including chronic myeloproliferative neoplasms. Myeloproliferative neoplasms (MPN) are a group of clonal hematopoetic stem cell disorders that include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF).1 JAK2V617F mutation is the most frequent mutation associated with MPNs, found in roughly 96% of patients with PV and 65% of patients with ET and PMF. This mutation leads to constitutive activation of the JAK/STAT pathway and is a driver of myeloproliferation.2  The patient in case 1 was found to have a JAK2 mutation during the work-up for hypercoagulability. This suggests that he may have an underlying MPN, however JAK2 mutations have been found in patients with venous thrombosis, but without overt evidence of MPNs.3 The patient in case 2 had a bone marrow biopsy with features concerning for primary myelofibrosis. In PMF, there is generally a proliferation of myeloid cells in addition to marrow fibrosis. Increasing fibrosis can eventually result in pancytopenia as the fibrosis takes over the marrow space in addition to altering the bone marrow environment so that it is unable to support normal hematopoiesis. Ultimately, this can lead to extramedullary hematopoesis. EMH most commonly occurs in the spleen and liver, but has been described in many other sites including the mediastinum and lymph nodes. In addition to being a driver of proliferation, it is thought that JAK2 mutations make hematopoetic stem and progenitor cells more sensitive to growth factors and can cause the cells to mobilize to the liver and spleen.4  Patients with EMH can have symptoms related to the site of involvement. Depending on the extent of involvement and location, EMH may require treatment with low dose radiation. While EMH is a rare finding, it should prompt an investigation for an underlying MPN.

References

  1. Imai K, Aoi T, Kitai H,et al. A case of perirenal extramedullary hematopoiesis in a patient with primary myelofibrosis. CEN Case Reports. 2017;6(2):194-199. doi:10.1007/s13730-017-0274-1.
  2. Kim CH. Homeostatic and pathogenic extramedullary hematopoiesis. Journal of blood medicine. 2010;1:13-19.3https://www.ncbi.nlm.nih.gov/pubmed/17263783.
  3. De Stefano, V, Fiorini, A, Rossi, E, et al. Incidence of JAK2 V617F mutation among patients with splanchnic or cerebral venous thrombosis and without overt chronic myeloproliferative disorders. Journal of Thrombosis and Haemostasis. 2007;5(4):708-14. https://www.ncbi.nlm.nih.gov/pubmed/17263783.
  4. Passamonti F, Maffioli M, Caramazza D, et al. Myeloproliferative neoplasms: From JAK2 mutations discovery to JAK2 inhibitor therapies. Oncotarget. 2011;2(6):485-490.

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Chelsea Marcus, MD is a third year resident in anatomic and clinical pathology at Beth Israel Deaconess Medical Center in Boston, MA and will be starting her fellowship in Hematopathology at BIDMC in July. She has a particular interest in High-grade B-Cell lymphomas and the genetic alterations of these lymphomas.