Chemistry Case Study: Hypercalcemia in Sarcoidosis

Our patient is a 47-year-old female with a history of type II diabetes mellitus, hypertension, pancreatic insufficiency, systemic sarcoidosis with lung and liver involvement. She was admitted into the ED for severe hypercalcemia, hypokalemia and hypomagnesemia. Her total calcium concentration was at 15.1 mg/dL (ref range: 8.3-10.2 mg/dL, critical: >13.0) at admission and albumin was low. Further testing revealed 25-hydroxy vitamin D (25(OH)D) of 23.2 ng/mL, which is considered insufficient, and decreased PTH of < 15 pg/mL (ref range: 15 – 65). From these results, primary hyperparathyroidism was ruled out. PTH related peptide (PTHrp) was tested given her sarcoidosis history.

PTHrp is produced by some cancers, especially kidney, breast and lung cancers, and as well as lymphoma and leukemia. It has the same N-terminal and binds to the same receptor as PTH, therefore sharing some functions of PTH. In patients with hypercalcemia associated with malignancy, PTHrP may be evaluated. There are also case reported sarcoidosis-related hypercalcemia due to production of PTHrp. In the case, PTHrp was normal at 0.4 pmol/L (ref range: < 2.0).

Further tests showed that 1, 25-dihydroxyvitamin D (DHVD) was elevated at a concentration of 93.3 pg/mL (ref: 18.0 – 78.0). In the presence of decreased 25(OH)D, this result suggested that the 1-alpha-hydroxylase could be the cause of hypercalcemia. DHVD is the active form of vitamin D. It promotes intestinal calcium absorption and, in concert with PTH, skeletal calcium deposition. 25(OH)D converts to DHVD via 1-alpha-hydroxylase, which is almost exclusively expressed in the kidney, but can also be found in some extrarenal tissues, including inflammatory cells of the monocyte/macrophage lineage commonly seen in sarcoidosis and other granulomatous diseases. DHVD produced in extrarenal tissues is PTH-independent, and moreover, elevated calcium induced by extrarenal DHVD can inhibit PTH production via calcium-sensing receptor (CaSR) on parathyroid cells.

Sarcoidosis is a multisystem inflammatory disease of unknown etiology manifests as granulomas found predominantly in the lungs and lymph nodes. Hypercalcemia is seen in about 10-13% of patients. Overproduction of 1-alpha-hydroxylase and production of PTHrp can both contribute to the hypercalcemia in some patients with sarcoidosis. In this case, PTHrp was normal and elevated 1-alpha-hydroxylase was found to be the cause of hypercalcemia.

In addition to treatment of the underlying disorder, treatment of hypercalcemia in sarcoidosis is aimed at reducing intestinal calcium absorption and DHVD synthesis. Besides dietary interventions, glucocorticoids and bisphosphonates have also been used successfully to treat hypercalcemia in sarcoidosis:

  • Glucocorticoids: inhibit DHVD synthesis by the activated mononuclear cells (major contribution), inhibit intestinal calcium absorption and osteoclast activity
  • Bisphosphonates: inhibit the resorption of bone by osteoclasts

 

References

  1. https://emedicine.medscape.com/article/301914-overview
  2. https://www.uptodate.com/contents/hypercalcemia-in-granulomatous-diseases
  3. https://www.uptodate.com/contents/diagnostic-approach-to-hypercalcemia
  4. https://www.ncbi.nlm.nih.gov/books/NBK109831/

 

Huang

-Rongrong Huang, PhD is a first year clinical chemistry fellow at Houston Methodist Hospital. Her interests include general clinical chemistry, genetic biochemistry and applications of mass spectrometry in clinical laboratories.

Xin-small

-Xin Yi, PhD, DABCC, FACB, is a board-certified clinical chemist, currently serving as the Co-director of Clinical Chemistry at Houston Methodist Hospital in Houston, TX and an Assistant Professor of Clinical Pathology and Laboratory Medicine at Weill Cornell Medical College.

Chemistry Case Study: Conjugated Bilirubin in Neonatal Jaundice

Case History

Patient was a 1-week-old infant in the level 2 NICU born at 37 weeks. This infant was initially born with indirect hyperbilirubinemia but now also has increasingly elevated level of direct bilirubin (see measurements in table below). Neonatologist requested conjugated and unconjugated bilirubin test due to increasing elevated level of direct bilirubin. Conjugated bilirubin test is not routinely performed in our hospital laboratory and needs to be send out.

Question: What’s the difference between conjugated bilirubin and direct bilirubin? When does conjugated bilirubin need to be assessed?

Ref Range 3/6/18 3/7/18 3/9/18 3/10/18 3/12/18
Bilirubin total, neonatal 1.0-10.5 mg/dL 9.2 8.7 10.8 10.2 8.6
Bilirubin direct, neonatal 0.0 – 0.6 mg/dL 0.5 0.7 1.8 1.8 2.1

Discussion

Neonatal jaundice is commonly seen in newborns in the first few days of life, mainly due to increased bilirubin formation from break down of red blood cells and limited conjugation of bilirubin. Total bilirubin normally peaks at day 2-3 and should decline by day 4-5. Sample is collected via heelstick in green top tube and protected from light. Measurement of total bilirubin is interpreted based on the Bhutani Nomogram to assess risk of hyperbilirubinemia. Most often, unconjugated bilirubin is elevated in neonatal jaundice owing to hemolytic causes. In cases with prolonged jaundice, conjugated bilirubin needs to be determined to rule out cholestasis.

Conjugated bilirubin refers to bilirubin conjugated with one or two glucuronic acid, and this term “conjugated bilirubin” is often used interchangeably with direct bilirubin. Direct bilirubin refers to bilirubin fractions that can directly react with diazo reagent without the addition of accelerator, such as methanol or ethanol. This fraction usually includes conjugated bilirubin and delta bilirubin. Delta bilirubin is formed by covalent bonding between conjugated bilirubin and albumin, and has a similar half-life as albumin, 21 days. Therefore, direct bilirubin measurement overestimate conjugated bilirubin and in cases with persist or atypical jaundice, clear differentiation between conjugated and direct bilirubin is important. Clinician should know what the laboratory is measuring when interpreting the bilirubin fraction results.

In laboratories, conjugated bilirubin can be assessed by the VITROS BuBc dry slide, which simultaneously measures unconjugated (Bu) and conjugated (Bc) bilirubin by use of a mordant. In the presence of the mordant, the visible spectra of conjugated and unconjugated bilirubin are different, allowing measurement of both species from a single slide. Fractions of bilirubin can also be separated by HPLC, but this is not practical to use in a routine clinical laboratory. In this case, conjugated bilirubin was measured by VITROS BuBc slide test, and result came back elevated at 1.0 mg/dL (ref range: < 0.3 mg/dL).

 

Ketcham

-Megan Ketcham, MD is a 4th year anatomic and clinical pathology resident at Houston Methodist Hospital. She will be completing both hematopathology and dermatopathology fellowships. Her interests include pathology resident and medical student education and skin lymphomas.

Xin-small

-Xin Yi, PhD, DABCC, FACB, is a board-certified clinical chemist, currently serving as the Co-director of Clinical Chemistry at Houston Methodist Hospital in Houston, TX and an Assistant Professor of Clinical Pathology and Laboratory Medicine at Weill Cornell Medical College.

Is It Possible to Have Coexistence of Hepatitis B Surface Antigen and Antibody?

Hepatitis B surface antigen (HBsAg) is the serologic hallmark of acute Hepatitis B virus (HBV) infection. It can be detected in serum using immunoassays a few weeks after HBV infection, and normally disappears after 4-6 months in recovered patients (1). Antibodies against HBsAg (anti-HBs) appears as a response from the host immune system, and these antibodies neutralize HBV infectivity and clear circulating HBsAg (2). Anti-HBs generally persist in life, indicating recovery and immunity from HBV infection.

Some of us may simply assume that the presence of anti-HBs should always associated with the loss of HBsAg. However, it is possible to see concurrent anti-HBs and HBsAg in patients. In fact, coexistence of HBsAg and anti-HBs is not rare, and has been reported in 10 to 25 percent of HBV chronic carriers in previous studies (3-4).  The underlying mechanism is not fully understood but several reports explained it as HBsAg mutants escaping the immune system (2-4). HBsAg mutants are believed to arise under the selective pressure from the host immune system, or from vaccinations (4-6).

“a” determinant in HBsAg is one of the main target of anti-HBs. It has been reported that mutations in the “a” determinant of the surface gene (S-gene) result in amino acid substitutions in HBsAg, and reduce the binding of anti-HBs to HBsAg, leading to immune escape (4). The first HBV mutant was reported by Zanetti et al in 1988 as G145R mutation. In their report, infants born to HBsAg carrier mothers developed breakthrough infections despite receiving HBIG and HBV vaccine at birth (5). Since this report, several other HBsAg mutations have been reported (4, 6).

Currently, there is no easily available assay to diagnose individuals who are suspected of harboring HBsAg escape mutants. Moreover, mutated HBsAg may leads to false negativity in some serologic assays, leading to a missed diagnosis of chronic HBV infection (6). Another concern is the potential risk of transmission to others, as vaccination does not provide protection from these mutated viruses (8); this is especially important in liver transplant recipient and newborns from HBsAg positive mothers.

References

  1. Lok A, Esteban R, Mitty J. Hepatitis B virus: Screening and diagnosis. UpToDate. Retrieved Feb 2018 from https://www.uptodate.com/contents/hepatitis-b-virus-screening-and-diagnosis#H3
  2. Liu W, Hu T, Wang X, Chen Y, Huang M, Yuan C, Guan M. Coexistence of hepatitis B surface antigen and anti-HBs in Chinese chronic hepatitis B virus patients relating to genotype C and mutations in the S and P gene reverse transcriptase region. Arch Virol 2012;157:627–34.
  3. Colson P, Borentain P, Motte A, Henry M, Moal V, Botta-Fridlund D, Tamalet C, Gérolami R. Clinical and virological significance of the co-existence of HBsAg and anti-HBs antibodies in hepatitis B chronic carriers. Virology 2007;367:30–40.
  4. Lada O, Benhamou Y, Poynard T, Thibault V. Coexistence of hepatitis B surface antigen (HBs Ag) and anti-HBs antibodies in chronic hepatitis B virus carriers: influence of “a” determinant variants. J Virol. 2006 Mar;80(6):2968-75.
  5. Zanetti AR, Tanzi E, Manzillo G, Maio G, Sbreglia C, Caporaso N, Thomas H, Zuckerman AJ. Hepatitis B variant in Europe. 1988 Nov 12; 2(8620):1132-3.
  6. Leong J, Lin D, Nguyen M. Hepatitis B surface antigen escape mutations: Indications for initiation of antiviral therapy revisited. World J Clin Cases 2016;4:71.
  7. Colson P, Borentain P, Motte A, Henry M, Moal V, Botta-Fridlund D, Tamalet C, Gérolami R. Clinical and virological significance of the co-existence of HBsAg and anti-HBs antibodies in hepatitis B chronic carriers. 2007;367:30–40.
  8. Thakur V, Kazim S, Guptan R, Hasnain S, Bartholomeusz A, Malhotra V, Sarin S. Transmission of G145R mutant of HBV to an unrelated contact. J Med Virol 2005;76:40–6.

 

Xin-small

-Xin Yi, PhD, DABCC, FACB, is a board-certified clinical chemist, currently serving as the Co-director of Clinical Chemistry at Houston Methodist Hospital in Houston, TX and an Assistant Professor of Clinical Pathology and Laboratory Medicine at Weill Cornell Medical College.

A Laboratory Professional’s Perspective on the Opioid Crisis

It was in the 1980s that physicians first explored the use of narcotics/opioids for the treatment of pain associated with non-terminal illnesses, including chronic and “mild to moderate” pain. In 2012, opioid prescriptions for outpatients were common, and some states had as many as 143 opioid prescriptions for every 100 people. Today, more than 6 out of 10 drug overdoses involve an opioid. The CDC states that 91 Americans die every day from an opioid overdose. This situation has been called “the opioid crisis” and the “opioid epidemic.” It is a public health emergency.

The landscape is characterized by new trends in both the drugs involved and drug user demographics. Current data indicates that prescription opioids are not the main problem. In fact, from 2015 to 2016, prescription opioid overdoses decreased from 17,539 to 16,800. The decrease in prescription overdose may indicate that efforts to reduce over-prescribing may be working. Or, drug users may be abandoning high cost prescription opioids for illicit drugs.

While prescription opioid overdoses have been decreasing, the incidence of heroin overdose has tripled. The incidence of fentanyl overdose has increased 196%, and the incidence of overdose due to non-methadone synthetic opioids has increased by 72%. Fentanyl is available both legally by prescription, and illegally from illicit sources. It is frequently combined with or sold as other drugs such as heroin, cocaine, and alprazolam. Fentanyl is 100 times more potent than morphine, and 50-100 times more potent than heroin. Even more dangerous are the fentanyl analogs, carfetanil(yl) sufentanil, acry and acetyl fentanyl, and furanyl fentanyl, to name a few. Sufentanil is 1000 times more potent than morphine, and carfentanil – sometimes called elephant tranquilizer – is 10,000 times more potent than morphine. Opioid abuse now spans nearly all demographics. In fact, NCHS Data Brief in 2017 disclosed that the age group with the most rapid rise in opioid overdose is adults ages 55-64 years. Some of the greatest increases in heroin related deaths have been among women, privately insured, and those with higher incomes – demographic groups that historically have had low rates of heroin abuse.

Laboratory professionals can help fight this crisis by providing relevant testing, and billing for the testing appropriately. Most hospitals are ill equipped to test for the synthetic opioid analogs. For many hospitals, the drug testing capabilities consists of an immunoassay based urine drug screen. These screens can detect many of the “classic” drugs of abuse like morphine (heroin), cocaine, amphetamines, PCP, and benzodiazepines. These screens do not differentiate individual drugs in a drug class, and they can’t detect fentanyl or fentanyl analogs, even with high degrees of cross-reactivity. As our Vice President of Laboratories expressed it to me, “our emergency rooms are full of overdose patients with negative drug screens.” Unfortunately, the culprit drug is not identified until a medical examiner orders forensic toxicology. More comprehensive and confirmatory testing like mass-spectrometry based testing provides more accurate information.

Mass spectrometers are not cheap, and many laboratory professionals are challenged with obtaining funding for them. The challenge is not lessened by the bad taste left in Medicaid’s mouth by code-stacking when billing for drug testing in the pain management patient population. This practice was, unfortunately, exploited by some physicians running office-based drug testing labs. Large multi-drug LCMS based panels were used in routine monitoring of pain management testing but instead of billing per panel, the test was billed by drug (analyte) in the panel. This practice led to CMS scrutinizing the use of mass spec testing alone and recommending the limited immunoassays. Laboratory professionals have the responsibility to advocate for the appropriate use of this powerful testing, and fortunately we are doing that – the Academy of AACC in collaboration with American Academy of Pain Medicine just released guidelines for the use of laboratory tests in monitoring pain management patients. We need to be trusted to do the right test, at the right time, for the right patient.

Forensic pathologists and toxicologists also face big challenges related to the opioid crisis. Forensic toxicologists are challenged to keep up analytically with synthetic and novel drugs entering the market while dealing with the pressure of limited budgets and client frustration with long turnaround times. Forensic pathologists are challenged by the sheer volume of overdose-related deaths. The National Academy of Medical Examiners (NAME) limits the number of autopsies to 325/pathologist/year. There are currently only around 500 board certified forensic pathologists in the US and the future doesn’t look great – only 3% of graduating medical students choose to enter pathology and only 7% of those will enter forensic pathology.

 

Sarah Brown Headshot_small

Sarah Riley, PhD, DABCC, is an Assistant Professor of Pediatrics and Pathology and Immunology at Washington University in St. Louis School of Medicine. She is passionate about bringing the lab out of the basement and into the forefront of global health.  

Which Potassium Do You Believe?

A patient presented to the Emergency Department at the St. Paul’s Hospital. Initial blood was collected by phlebotomy staff (one poke) at 6:55 am in the morning and the specimen was received in the lab at 7:11 am.

Venous blood gases: Potassium  7.3 mmol/L
Plasma Lytes: Potassium  3.3 mmol/L

Emergency phoned the lab about these discrepant potassium results. What is going on?! The venous gas specimen was centrifuged and appeared hemolysed (3+), while the plasma sample had no evidence of hemolysis.

The phlebotomist indicated there was no problem with the collection. Repeat testing was initiated an hour later.

Venous blood gases: Potassium  6.4 mmol/L
Plasma Lytes: Potassium  3.6 mmol/L

The venous gas specimen was centrifuged and appeared hemolysed (3+).

Because the venous gas specimens were transported on ice and the other tubes of blood collected were sent at room temperature, the biochemist discussed the possibility of a red cell cold agglutinin with the ER physicians. The ER physicians requested evaluation for a cold agglutinin (the EDTA tube collected for early hematology was used for this analysis). Lab staff performed the screen and it was 4+ for cold agglutinin.  ER physicians were advised to believe the lower potassium results and to avoid sending further specimens on ice for this patient.

 

Lyon-small

-Dr. Andrew Lyon, PhD, FCACB, DABCC is a clinical chemist and clinical toxicologist. He is the current past-president of the Canadian Society of Clinical Chemists. He is currently Division Head of Clinical Biochemistry of the Saskatoon Health Region and teaches general pathology residents as a clinical associate professor of Pathology and Laboratory Medicine at the University of Saskatchewan.

Pitfalls of Prolactin Biochemistry Assay

Laboratories occasionally get questions from clinicians about prolactin results, mainly to either rule out high-dose hook effect or assess interference from macroprolactin. In most laboratories, sandwich immunoassay is used to measure prolactin concentration and it is widely known that older generations of prolactin assays suffer from hook effect and interference from macroprolactin. In the presence of extremely high concentration of prolactin, antibodies can be saturated, resulting in falsely low results, which is known as high-dose hook effect. Multiple cases have been reported in patients with giant prolactinomas, that their prolactin results were measured as normal or moderately elevated. In order to rule out high-dose hook effect, clinicians normally request laboratories to perform appropriate dilutions for prolactin in patients with large pituitary tumors. Newer generation of prolactin assays have better performance in this aspect, and most assays nowadays have no hook effect up to concentrations of 10,000 ng/mL, claimed by manufactures.

Another pitfall of prolactin assay is the interference from macroprolactin. Macroprolactin is a complex of prolactin bound to immunoglobulin, and thought to be biologically inactive. In the presence of elevated macroprolactin, patient is asymptomatic. However, macroprolactin can be picked up by prolactin immunoassays to some extent, and results in misdiagnosis as hyperprolactinemia. Reports showed that 15-20% of cases with hyperprolactinemia was due to elevated macroprolactin. Therefore, macroprolactinemia should be considered while evaluating hyperprolactinemia cases in the absence of symptoms or pituitary imaging evidence. Laboratories could easily perform dilution study to test if interference exists. To confirm the presence of macroprolactin, polyethylene glycol (PEG) 6000 can be used to precipitate macroprolactin followed by prolactin measurement in the supernatant. The presence of macroprolactin is suggested when the pull-down percentage is greater than 40-50%. This test is offered by many reference laboratories.

These two pitfalls of prolactin biochemistry assays should always be kept in mind by laboratorians, to provide better guidance to clinicians’ concern and workups on prolactin related cases.   

 

Xin-small

-Xin Yi, PhD, DABCC, FACB, is a board-certified clinical chemist, currently serving as the Co-director of Clinical Chemistry at Houston Methodist Hospital in Houston, TX and an Assistant Professor of Clinical Pathology and Laboratory Medicine at Weill Cornell Medical College.

Pathologist on Call: There Is No Perfect Lab Test for Smoking Assessment

Cigarette smoking can affect both innate and adaptive immunity, and introduces concerns when evaluating a patient’s eligibility for surgery. It has been shown to hinder time required for healing and long-term survival of patients. It can promote vascular complications, increase the rates of hepatocellular carcinoma and reduce lung function.1 For lung transplantation, one of the common requirements of eligibility is smoking abstinence for at least 6 months. Smoking post-surgery is associated with worse outcomes for the patients including complications and higher rates of mortality.2 Relapse to smoking post lung transplantation has been reported to range from 11% to 23% in various patient populations.3 As a result, clinical testing for cigarette smoking abstinence is an important part of initial workup and follow-up of transplant patients.

In some situations, the burden of lung allocation weighs heavily on a single clinical laboratory result that is perceived to definitively confirm or exclude active cigarette smoking. This subsequently factors into the decision by the physicians to deem the patient eligible to receive a lung transplant. The perception of nicotine testing as definitive proof of smoking is misleading and does not reflect the complexity of situations that can lead to a positive test result.

How can we assess smoking?

Ideally, many factors should weigh into the final smoking status determination including self-reporting (used historically), witnesses to behavior, odor, and past history including cessation attempts. Clinical laboratory testing is important and thought to be more reliable means for smoking assessment. It can involve testing for nicotine (originating from tobacco or nicotine replacement therapy, NRT) and its metabolites: cotinine, 3-hydroxycotinine (3-OH-cotinine), and nornicotine. Moreover, nicotine contains a number of alkaloids that are not usually present in nicotine-replacement therapies (NRTs) including anatabine and anabasine.4 Nicotine testing can involve a combination of metabolites such as cotinine as well as alkaloids like anabasine. Various sample types have been used including saliva, blood and urine.5 In addition, measurements of the exhaled carbon monoxide (CO) have been used to assess recent smoking status (within the last 8 hours).6

Clinical case: patient with detectable nicotine metabolites

A case involving a patient being considered for lung transplantation was received by our department. The patient had been tested for anabasine, nicotine, and its metabolites in urine. Testing of random urine specimens was performed by liquid chromatography tandem mass spectrometry (LC-MS/MS) at different time points from samples collected during hospital visits (days 0, 38, and 62). The urine contained variable concentrations of nicotine and its metabolites, with anabasine concentrations below the detection limit in 2 out of the 3 testing instances. Testing at day 0 showed an interfering substance that prevented the determination of accurate anabasine concentration. The nicotine and its metabolite concentrations in the random urine specimens were lower from day 0 to day 38, but a noticeable increase of 3-OH-cotinine and cotinine concentrations was observed in the specimen collected on day 62. The physician was seeking information about the current smoking status of the patient and was planning to use this information to determine the patient’s lung transplant eligibility.

smoking-1

 

Days 0 38 62
Analyte concentration (ng/mL)
3-OH-cotinine 4074 89 603
Anabasine interf. subst. < 3 < 3
Cotinine 1404 47 425
Nicotine 241 < 2 72
Nornicotine 58 < 2 6

 

Figure and table 1. Nicotine, metabolite and anabasine concentrations (ng/mL) at different time points for a patient evaluated for lung transplantation eligibility. Anabasine was not detected on days 38 and 62, with an interfering substance preventing quantitation on day 0.

How definitive are these results?

No information was available regarding self-reported smoking or NRT use history for this patient. The physician had high suspicion that the patient was an active smoker and was attempting to use higher concentrations of nicotine and metabolites observed on day 62 as evidence of recent tobacco use.

For cotinine, values can range from 20-550 ng/mL for daily tobacco use.5 Nicotine concentrations in urine can approach over 5000 ng/mL with daily use. Together, high nicotine and cotinine can support tobacco or high-dose nicotine patch use. Furthermore, presence of nornicotine above 30 ng/mL along with anabasine greater than 10 ng/mL would be consistent with current tobacco use rather than NRT.7

Given that these were random urine specimen and the urinary creatinine values are not routinely measured, it’s important to consider the possible contributions of the variable urine concentration to the analyte concentrations. It has previously been reported that individuals abstaining from smoking for at least two weeks should present with nicotine of <30 ng/mL, cotinine of < 23 ng/mL, 3-OH-cotinine of <120 ng/mL, nornicotine < 3 ng/mL, and anabasine of < 2 ng/mL in urine.7 Based on these cut-offs, all analytes except anabasine would suggest new nicotine intake within the last two weeks.

In general, a positive anabasine result, in combination with the presence of nicotine metabolites, is consistent with active use of a tobacco product, whereas anabasine values of < 2ng/mL may suggest that NRT is the likely source.8 This can imply that the patient is abstinent from smoked or chewed tobacco if anabasine is not detected. However, anabasine is not a sensitive marker of smoked tobacco. It has been reported that the compound may not be detectable in 60% of self-reported smokers (N=51; 3 ng/mL cut-off in urine)9  and its urinary concentrations do not correlate well with self-reported tobacco use.8

As a result, anabasine has low sensitivity for determining eligibility for UNOS (United network for organ sharing) listing. There are some recommendations that this marker should not be used alone. Given that other alkaloids can originate from tobacco plant, it has been proposed that anatabine should be added to analysis due to higher expected concentration.9 However, this alkaloid is not completely specific to tobacco as it has been proposed to also arise from other plant sources 10,11  leading to possible implications for the patient that may be misclassified. In addition, anatabine sensitivity in detecting smoked tobacco use varies depending on the tobacco source and the clinical cut-off used. Clinical tests that include anatabine are not routinely available.

Can we improve this process?

Unfortunately, there is no definitive marker distinguishing smoking from NRT.

The determination of smoking status has advanced from reliance on self-reporting to quantitative and specific measurements of metabolites of nicotine and minor components of tobacco. Additional analyte incorporation into a test panel leads to additional complexities and considerations in interpretation of the results. Therefore, it is important to educate the physicians about various nicotine sources causing a positive nicotine and/or metabolite test result including NRT or e-cigarettes. It is also important to convey the limitations of tobacco alkaloid testing in such scenarios. Both the lab and the physician need to be cautious about implying active smoking in the absence of indirect supporting evidence and/or positive clinical test results.

At the same time, there is a need to improve the utility and availability of other tobacco alkaloid testing in distinguishing cigarette smoking from NRT in specific transplant populations and consider the value of testing alternative specimens. This may lead to a more effective implementation of secondary markers of tobacco use.

References

  1. Qiu, F.; Fan, P.; Nie, G. D.; Liu, H.; Liang, C.-L.; Yu, W.; Dai, Z., Effects of Cigarette Smoking on Transplant Survival: Extending or Shortening It? Frontiers in Immunology 2017, 8, 127.
  2. Zmeskal, M.; Kralikova, E.; Kurcova, I.; Pafko, P.; Lischke, R.; Fila, L.; Valentova Bartakova, L.; Fraser, K., Continued Smoking in Lung Transplant Patients: A Cross Sectional Survey. Zdravstveno varstvo 2016, 55 (1), 29-35.
  3. Vos, R.; De Vusser, K.; Schaevers, V.; Schoonis, A.; Lemaigre, V.; Dobbels, F.; Desmet, K.; Vanaudenaerde, B. M.; Van Raemdonck, D. E.; Dupont, L. J.; Verleden, G. M., Smoking resumption after lung transplantation: a sobering truth. The European respiratory journal 2010, 35 (6), 1411-3.
  4. Hukkanen, J.; Jacob, P., 3rd; Benowitz, N. L., Metabolism and disposition kinetics of nicotine. Pharmacological reviews 2005, 57 (1), 79-115.
  5. Raja, M.; Garg, A.; Yadav, P.; Jha, K.; Handa, S., Diagnostic Methods for Detection of Cotinine Level in Tobacco Users: A Review. Journal of clinical and diagnostic research : JCDR 2016, 10 (3), Ze04-6.
  6. Sandberg, A.; Skold, C. M.; Grunewald, J.; Eklund, A.; Wheelock, A. M., Assessing recent smoking status by measuring exhaled carbon monoxide levels. PloS one 2011, 6 (12), e28864.
  7. Moyer, T. P.; Charlson, J. R.; Enger, R. J.; Dale, L. C.; Ebbert, J. O.; Schroeder, D. R.; Hurt, R. D., Simultaneous analysis of nicotine, nicotine metabolites, and tobacco alkaloids in serum or urine by tandem mass spectrometry, with clinically relevant metabolic profiles. Clinical chemistry 2002, 48 (9), 1460-71.
  8. Jacob, P., 3rd; Hatsukami, D.; Severson, H.; Hall, S.; Yu, L.; Benowitz, N. L., Anabasine and anatabine as biomarkers for tobacco use during nicotine replacement therapy. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 2002, 11 (12), 1668-73.
  9. Feldhammer, M.; Ritchie, J. C., Anabasine Is a Poor Marker for Determining Smoking Status of Transplant Patients. Clinical chemistry 2017, 63 (2), 604-606.
  10. Lanier, R. K.; Gibson, K. D.; Cohen, A. E.; Varga, M., Effects of dietary supplementation with the solanaceae plant alkaloid anatabine on joint pain and stiffness: results from an internet-based survey study. Clinical medicine insights. Arthritis and musculoskeletal disorders 2013, 6, 73-84.
  11. von Weymarn, L. B.; Thomson, N. M.; Donny, E. C.; Hatsukami, D. K.; Murphy, S. E., Quantitation of the minor tobacco alkaloids nornicotine, anatabine, and anabasine in smokers’ urine by high throughput liquid chromatography mass spectrometry. Chemical research in toxicology 2016, 29 (3), 390-397.

 

VG

-Dr. Valentinas Gruzdys developed interest in clinical chemistry early in his academic training which led him to pursue and obtain a PhD in Clinical and Bioanalytical Chemistry at Cleveland State University. Valentinas is enthusiastic about teaching and helping improve the understanding of limitations and utility of clinical laboratory testing. He is currently enrolled in a clinical chemistry fellowship program at the University of Utah. He enjoys learning more about various aspects of clinical chemistry and cannot wait to make his own contributions to the field after his training.