Laboratory and Hospital Ebola Response

Laboratories are currently scrambling to define and put into place procedures for dealing with processing and testing of samples from highly infectious patients. The CDC has guidelines for healthcare workers and for laboratories specifically (http://www.cdc.gov/vhf/ebola/hcp/index.html). They also are very willing to help. Because Dallas had actual cases of Ebola, our hospital in Dallas mounted a hospital-wide response, in which the CDC and Texas State and County Health Departments were involved early on and throughout. This blog post describes the plans we instituted.

It quickly became clear that we did not want to transport infectious material through the hospital if we could avoid it, keeping everything infectious isolated in a single area. The hospital cleared an ICU wing which contained two negative pressure rooms, and the laboratory used an ICU room two doors away to create a mini-lab. The entire ICU wing was closed off as an isolation zone. No samples will leave the isolation zone unless they are headed for the CDC or State lab, and those will be couriered directly from the isolation zone.

All testing that can be, will be done on the I-stat in the patient room, including electrolytes, BUN, creatinine, ionized calcium and blood gases. A meeting was held with the ICU physicians who will be treating patients, to ask what testing they could foresee requiring other than those available on the I-stat. Their final list included platelets, CBC and coag tests, and originally also asked for ammonia and liver function tests. The only test we could not provide for them was ammonia. We couldn’t find a way to perform ammonia on a whole blood sample and had decided not to centrifuge any samples due to the possible risks of aerosolizing the sample and additional risks associated with aliquotting samples.

For the coag tests, we chose to use the I-stat PT/INR. Knowing that PT/INR on the I-stat is not FDA approved for anything other than Coumadin monitoring, we performed a full CLIA validation of the PT/INR in order to be able to use it for Ebola patients. Using the I-stat this way causes the PT/INR to become a high-complexity test, therefore only those individuals with appropriate licensure, training and competency will be performing the test at bedside.

Testing other than what is available on the I-stat will be done in the mini-lab set up in the nearby ICU room. It will be performed by lab personnel in full PPE, including PAPR (powered air purifying respirators), 3 layers of gloves, etc, all within the isolation zone. Lab testing in the mini-lab will occur once a day, with a possibility of twice a day. We purchased an Abaxis Piccolo for performing the liver enzymes and a Sysmex pocH-100i for the CBC and platelets. Both these analyzers will be run in the mini-lab room. The piccolo will be run inside a biosafety cabinet (BSC) which was put in the room because the piccolo is not a closed system. Sample pipetting into the piccolo carousel will occur in the BSC.

As far as blood utilization, the plan is to perform a one time, ABO only, blood typing on admission of a patient. A blood bank technologist in full PPE will perform the ABO only blood type manually in the BSC in the mini-lab. This ABO only typing has also been validated on samples allowed to settle rather than being centrifuged. The plan is for any patients to receive type O-negative blood if transfusions are required. However if they should require type-specific blood products for any reason (i.e. shortage of O-negative), it was felt that performing the blood type early before viral titers are really high would be better than waiting.

To work in the isolation wing, personnel must don full isolation PPE, including PAPR, etc, with a multi-step system in place for both donning and doffing the equipment. A buddy system is used throughout, with training on all procedures being continuous. The lab personnel who have volunteered to staff the mini-lab have undergone the PPE training. All of this perhaps excessive care is being taken in order to protect all other patients, as well as all healthcare team members, both lab and non-lab. Although Ebola may never reach our hospital, we live in a world where global travel makes if very likely that we will see patients with this or other highly infectious diseases appear in our facilities. It’s important to be as prepared as possible.

 

-Patti Jones PhD, DABCC, FACB, is the Clinical Director of the Chemistry and Metabolic Disease Laboratories at Children’s Medical Center in Dallas, TX and a Professor of Pathology at University of Texas Southwestern Medical Center in Dallas.

 

Name That Cytogenetic Abnormality

A 36-year-old male presents with recurrent epistaxis and fatigue of several days’ duration. Physical examination reveals numerous ecchymoses scattered over his limbs and trunk. A CBC shows the following:

  • Hgb 9.2 g/dL (normal = 13.5 – 17.5 g/dL)
  • WBC 31×109/L (normal = 4.5 – 11 x 109/L)
  • Platelet count 23 x 109/L (normal = 150 – 450 x 109/L)

Review of the blood smear shows numerous hypergranulated immature myeloid cells. Rare cells like the cell below are also present.

auer-rod

What cytogenetic abnormality is most likely present in the abnormal cells?

  1. inv(16)
  2. t(8;21)
  3. t(14;18)
  4. t(15;17)
  5. t(11;14)

The answer is D, t(15;17). This is a case of acute promyelocytic leukemia (or AML-M3 in the old FAB classification). The key to the diagnosis is the cell in the image above, which is an immature myeloid cell containing innumerable Auer rods. This cell is called a faggot cell because the Auer rods resemble a bundle of sticks (or faggot). Faggot cells are specific for acute promyelocytic leukemia; they are not seen in any other hematologic malignancy.

Other clues to the diagnosis which are not entirely specific for acute promyelocytic leukemia include the anemia and thrombocytopenia (which point towards bone marrow failure), and the leukocytosis (which presumably is comprised mostly of the hypergranular myeloid cells noted on the blood smear).

Acute promyelocytic leukemia (APL) is a type of acute leukemia in which the predominant cell type is the promyelocyte. The malignant promyelocytes in APL have a distinctive appearance which is different from that of normal promyelocytes. In most cases, the malignant promyelocytes in APL contain innumerable small azurophilic granules – but in rare cases, the promyelocytes are hypogranular.

The characteristic morphologic finding in APL is the faggot cell, as shown above. When you see faggot cells, you can make the diagnosis of APL based on morphology alone, without waiting for molecular or cytogenetic studies (which will show the characteristic t(15;17) of APL – but which take some time to perform).

Making an immediate, morphologic diagnosis is critical in cases of APL, because patients with APL cannot be given routine acute myeloid leukemia chemotherapeutic agents. The granules in the malignant promyelocytes contain substances which quickly activate the coagulation system. Traditional chemotherapeutic agents cause cell lysis and release of the procoagulant substances, which puts the patient at high risk for disseminated intravascular coagulation (DIC).

Patients with APL are given a drug called all-trans retinoic acid (ATRA) that overcomes the maturation block caused by the translocation between chromosomes 15 and 17. Following ATRA therapy, the malignant promyelocytes mature into segmented neutrophils, and the risk of DIC diminishes.

The other cytogenetic translocations in this question are seen in different disorders: inv(16) is seen in some cases of acute myelomonocytic leukemia (AML-M4); t(8;21) is seen in some cases of acute myeloblastic leukemia with maturation (AML-M2); t(14;18) is seen in follicular lymphoma; and t(11;14) is seen in mantle cell lymphoma.

Krafts

-Kristine Krafts, MD, is an Assistant Professor of Pathology at the University of Minnesota School of Medicine and School of Dentistry and the founder of the educational website Pathology Student.

Internationally Safe

With the serious and concerning news about international contagious disease, it’s always appropriate to remind ourselves of safety, both personal and protective. What laboratory professional has not donned the gown, the mask, the gloves…in an effort to protect ourselves, and also protect the patients we serve? We all have…but we all have also occasionally been cavalier about it.

In these times of viruses and antibiotic-resistant strains of microbes—and who knows what iterations of the above are in the “evolutionary muck” of the future—we stand in the cautionary shadow of the devastation they can cause. The invention of the microscope only served to give us a view of our un-seeable enemies, and they are countless.

I travel extensively, internationally and within the USA, and the risks of contagion are all around. It helps to keep yourself personally prepared by encouraging a robust immune system, eating/sleeping and hydrating well, and staying as healthy as is possible—but as we all know that is not always enough. It will also serve us well, as laboratory professionals, to both practice and teach personal protection in compromised situations. When at work, it’s obvious…but when in someone else’s lab, or hospital, or clinic, or even railway station, we must be diligent and alert to the unseen dangers of contagious disease contamination. Laboratory scientists are trained to treat every single action, specimen, and encounter as if it were a threat to health and safety, and yet…do we?

Life is short, disease is inevitable, and safety precautions are a must…but also a choice. Choose wisely, and don’t compromise! If your hospital/laboratory/healthcare system is following PPE and international safety regulatory compliance, good for you and those around you. We are the most knowledgeable infectious control specialists on the planet, and we have the obligation to lead the way in international and personal safety.

And as I mentioned in my last blog, let’s roll up our lab coat sleeves—and put those gloves and masks on…we have a lot of work to do!

 

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Beverly Sumwalt, MA, DLM, CLS, MT(ASCP) is an ASCP Global Outreach Volunteer Consultant.

 

Dilutions: How Are You Doing Yours?

If you ask someone to dilute a sample in half, pretty much everyone will do it the same way – add an equal volume of sample to an equal volume of diluent, whether that’s 1 mL to 1 mL or 100 µL to 100 µL. But if you ask people to do a 1 to 2 dilution, you may be surprised to get different results. That’s because I’ve found that the convention for writing dilutions is taught differently at different Medical Laboratory Science (MLS) schools.

A 1 to 2 dilution should be written as ½. It means to dilute something in half. But many times it will be written as 1:2. These two forms are actually not equal, despite the fact that they are used interchangeably in the laboratory. One is a dilution and the other is a ratio. In the scientific literature, if you see “1:2”, it means to add 1part to 2 parts. That will be 1 mL added to 2 mL, for a total of 3 mL, or a 1/3 dilution.

Unfortunately, this problem is prevalent in the laboratory. I’ve seen 1 to 10 dilutions written both as 1/10 and 1:10.   It’s very important to know how the technologists in the lab are performing that 1 to 10 dilution. Are they doing a true 1/10 (1 mL sample plus 9 mL diluent) or are they actually doing a 1 to 11 dilution (1 mL sample plus 10 mL diluent)? Your patient results may be different depending on who does the dilution!

Coming into this field from a scientific background rather than an MLS background, I prefer the convention of writing a dilution as 1 over something, ½, 1/10, rather than as a ratio, 1:2, 1:10. However, perhaps the majority of medical laboratory scientists are taught the ratio. Either convention works fine as long as it is clear to everyone in the lab what dilution they are actually performing and being asked to perform.  You might want to just check your own MLS and see how they do their dilutions.

 

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-Patti Jones PhD, DABCC, FACB, is the Clinical Director of the Chemistry and Metabolic Disease Laboratories at Children’s Medical Center in Dallas, TX and a Professor of Pathology at University of Texas Southwestern Medical Center in Dallas.