Primary or Secondary?

[butlermom]

12-year old patient who had never been transfused had a type and screen in December, and was group A positive with a negative screen by gel (ProVue).  She returned in early April, still showing a negative antibody screen and received one packed cell, after which we learned she had thalassemia and needed Rh and Kell phenotypically matched blood.  The unit she received was c negative and K negative, but was E positive (she is c neg., E neg., and K neg.). 

 

She returned approximately one month later, antibody screen still negative, and received two units that were c, E, and K negative.  She left the hospital with a hemoglobin of 10.6.  Exactly 6 days later she returned to the hospital with a 4.9 hemoglobin, positive antibody screen, all panel cells positive of varying strength (all 2+ and 3+), a positive auto control, DAT weakly positive for both IgG and complement.  The eluate was reactive with all cells tested.  

 

We sent samples to our reference lab and they identified a cold autoantibody that is IgM in nature plus 4 other antibodies: Anti-E, Anti-K, Anti-Jkb, and Anti-S. We were thinking this was a delayed transfusion reaction from blood received elsewhere, but the physician questioned the family again and they insisted that she has never received a blood transfusion anywhere else. 

 

6 days just seems like too short a time-frame for this to be a primary immune response with this much reactivity, and we have only transfused K negative blood and yet she exhibits an anti-K!  Our reference lab indicated that autoantibodies can demonstrate specificiy to antigens that the patient does not possess.  I have heard of this as well, but am only familiar with it as far as Rh antigens.  Two of her previous transfusions were with units that were Jkb positive and one was S positive so I think she has so much circulating anti-Jkb, that it is destroying the transfused cells.  Her hemoglobin dropped to 4.0 by the time we were able to find antigen negative units for her 4 antibodies and have given her 2 units in the past 3 days.

 

She appears to be improving, although still clearing some of the transfused cells.  Urine is dark yellow.  Her plasma has always been icteric, even prior to transfusions, and has never looked hemolyzed. So, back to my original query:  is it possible we are truly seeing a primary immune response here?  (Sorry this is so lengthy, but I've lost a good bit of sleep over this one!)  

 

Thanks!

[Malcolm Needs ☆]

The bad news about thalassaemic patients is that the tend either to make no antibodies, or they make every specificity under the sun!

 

I also remember a lecture given at the BBTS ASM a few years back now by Dr Ed Synder (a quite brilliant speaker) where he talked about the ability of people to make antibodies.  It has been known for some time that about 20% of people never seem to make antibodies, how ever often their immune system is challenged, about 60% have a "normal" immune system, and make antibodies as do everyone else, and about 20% of people are, for want of a better way of putting it, super responders.  Ed Synder put it as something along the lines of, you can show these people a photograph of a red cell and they will make an antibody.  He referred to this as a "virtual" transfusion!

 

I wouldn't mind betting that your patient is amongst this latter group, and that what you have is a primary response, but with auto-antibodies also present that are mimicking other specificities.  As I recently posted elsewhere, Joyce Poole, late of the International Blood Group Reference Laboratory (and one of my mentors) introduced me to the concept of an "auto-anti-K-like" antibody, that mimicked anti-K, and yet could be eluted from the K- patient's own red cells, having never been given K+ blood in their life, although, of course, most mimicking antibodies mimic specificities within the Rh Blood Group System.

 

Auto-antibodies or not, however, just to be on the safe side, I would honour them.

 

Others, of course, may have different views.

[David Saikin]

I've seen super-responders in the past:  one day p tx a new ab, next day 2 more, 3rd day 2 more.  We required a new sample for every transfusion.

[tbostock]

I once had a patient that received 2 units of blood and a month later came back with 8 alloantibodies.  Insisted she was never transfused elsewhere.