MCrosby

My Reference Lab’s practice is to honor c if the patient demonstrates an anti-E (and they are Rh positive) and they are antigen negative for c, regardless of sex or age. Since c is so antigenic, it’s just good practice. Do you really want to run the risk of them forming an anti-c? And if their immune system is ramping up to form anti-c, would it run be reasonable to believe that it may start forming antibodies to other blood group antigens as well? An interesting article in Immunohematology (Vol 21,No3,2005) finds that anti-c in R1R1 patients with anti-E is higher than one would think. I believe anti-c showed up in Gel or enzyme treated panels, where it wasn’t showing in tube (I’ll have to find the article), but in any case no one wants to work up a transfusion reaction if it could have been prevented.

Dr. George Garratty is currently involved with a similar project. He gave a short lecture about it at the AABB conference in Anaheim last year. If you would like, I could send you a PDF file from it. PM your e-mail to me if you want to see it.