Serology superstars Brooke Stuber, MT, ASCP; Karen Rodberg, MBA, MT(ASCP)SBB; and Susan Johnson, SBB, broke all the rules Monday in a case study-based workshop aimed at challenging longtime blood bank dogma, or established opinions and definite authoritative tenets. Kicking off the Wacky and Weird RBC Serology (9314-TC) session was Stuber, who introduced why blood bankers must question the long-held beliefs, principles and rules of serology in order to resolve unusual patient cases.

“When we ask for patient history, we assume what we’re getting is complete and accurate,” she said, adding that this is often not the case. Learning the details about a patient’s past medical history is critical to making an accurate diagnosis and providing the right units of blood for transfusion since alloantibodies and autoantibodies may not always be easy to distinguish, passively acquired and reagent-dependent antibodies may mimic other specificities, and antigen typing may not always be clear cut.

As such, Stuber encouraged her reference lab colleagues to challenge the following dogmas:

·          Alloantibodies are non-reactive with autologous RBCs. The patient’s RBCs are antigen-negative.

·          An antigen-positive individual will not produce an alloantibody with that specificity. 

With this in mind, Stuber guided attendees through two case studies. One involved an 84-year-old male diagnosed with anemia. A blood sample taken two weeks earlier revealed that the patient was group A, Rh positive and had a negative antibody screen. Results of selected cell panels run on two manufacturers’ equipment led lab technicians to wonder if the man’s pattern fit an anti-D profile. They questioned whether he could have a partial/variant D, whether he could have an anti-LW, whether he had received IVIG/RhIVIG/RHIG or whether he could have an auto anti-D. Although initial patient questioning did not find anything unusual, a second follow-up inquiry found that the diagnosis was really ITP and the man had received WinRho one week before. As a result, additional cells were run to rule out all other common antibodies and the patient was given two units of A-negative, crossmatch-compatible units.

Building on the dogmas Stuber presented, Rodberg offered additional beliefs that must always be questioned in order to provide the best patient care possible:

·          Antibody exclusion is performed by finding one non-reactive example of antigen-positive RBCs (preferably from a presumed homozygote).

·          Alloantibody specificity is confirmed with a minimum of two antigen-positive and two antigen-negative RBCs.

·          Autoantibodies are reactive with autologous RBCs. The patient’s RBCs are antigen-positive.

·          An antigen-negative individual will not produce an autoantibody to this antigen.

·          IgM antibodies react as direct agglutinins at room temperature.

·          IgG antibodies react by the indirect antiglobulin test.

Offering three case studies as examples of why it is important to look beyond initial impressions, Rodberg shared one that involved a type and screen request for a 28-year-old Caucasian female in labor with placenta previa. The patient had one living child, no history of HDFN and had never been transfused. Initial impressions showed group A, Rh positive and a positive antibody screen. The case was resolved when it became apparent that the patient’s serum contained anti-IH, an autoantibody, even though the patient’s RBCs were non-reactive with her own serum. Because blood had been requested for the woman’s delivery, an additional concern was the clinical significance of anti-IH, because DTT treatment of serum will reduce IgM molecules but not IgG molecules.  Ultimately, DTT treatment abolished the reactivity, so this example of anti-IH was IgM antibody only.

Anchoring the session with additional dogmas and case studies, Johnson reminded attendees to think beyond the “rule” that the following is always true:

·          FDA-licensed antisera will detect said antigen present on all individuals who possess the antigen.

·          All FDA-licensed antisera of labeled specificity show equal reactivity.

To illustrate, she shared an experience of a women with no prenatal care who had given birth at home to a baby who had to be rushed to the hospital in distress. “The baby was A, the mom was an O, but the eluate was all negative. That’s weird. It doesn’t look like anti-A or anti-B so we looked at another eluate, which is always a good idea. When those results came back, we saw we had an anti-D. But, we just typed this baby and she was negative, so why are we seeing anti-D in eluate?” Johnson asked. “What we’ve all learned about it—but it doesn’t happen often, keep in mind— is the blocking phenomenon. If a mom has a lot of antibody, it can coat the baby’s red cells to the extent that the anti-D we added to the test cannot get to them.” The way to resolve this issue, she said, is to treat the cells. “When you treat RBCs you are removing mom’s antibody, exposing the D antigen present on the baby’s red cells, so now when you add anti-D, you should see a positive.”

Asking attendees to use all their available clues to interpret serologic puzzles, Johnson reassured them that even experienced problem solvers expect to see specific clues to guide them to a particular resolution, but the results could lead them down the wrong path.

“Review dogma. We’ve held these established opinions thinking they were always accurate and relevant, but sometimes you have to ignore the textbooks,” Johnson said. “We’re aware of these things that break the rules, and it’s a challenge to teach our students and our new techs in the lab that these things can happen, and we have to do it in a way that won’t confuse them. Try to remember, that with all of our resources, we have to look hard to challenge the dogma. Points made to the contrary are in the textbooks, but they are in one short paragraph. We hope we have made you aware of things to think about.  When you see something that’s wacky or weird, believe it.”

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