This is an archive from the old ASHI Forum
Posted: Mon Oct 30, 2006 2:22 am
We are reporting HLA typing of Kidney patient as serological level even if we do it by Molecular SSP. My question is, If we have an allele that do not have a serological equivalent, shall we report it as blank or report that particular allele?
Fadi Al Zayer. CHT.CHS(ABHI)
Posted: Thu Nov 02, 2006 12:40 pm
I believe labs should report all alleles they detect. Like you, our lab reports serological equivalents for solid organ transplantation, however, if an allele has no serological equivalent, we then report the low resolution allele. This makes a big difference for HLA-C, where Cw*12-18 have no serological equivalents. Our lab assigns unacceptable antigens for Cw12-18, based on screening with single antigen beads, and we have several times received imported kidneys that were incompatible for patients with Cw12-18 antibodies, but these patients did not get ruled out for these kidneys because the originating lab did not report Cw12-18 even though they detected it, because these alleles have “no serological equivalent”. I believe the original point of serological equivalents was to provide a way for labs to report things like B62, B63, DQ7, etc. that would be more informative than the corresponding low-resolution molecular results of B*15, B*63, DQB1*03. Cw12-18 will never have “serological equivalents”, but we can’t pretend that donors don’t have the corresponding antigens, especially when patients can clearly make antibodies to these antigens.
Posted: Fri Nov 03, 2006 2:26 am
What going to be the case for the alleles that the serological specificity is different than the first 2 digits (eg. B*4026=B21).
If we are going to report the B*40, can we accept patient with Anti B21(which is B50)?!
Fadi Al Zayer. CHT.CHS(ABHI)
Posted: Mon Nov 06, 2006 11:19 am
That’s a more difficult question. Just because your patient has anti-B49, B50, doesn’t mean she also has anti-B*4026. Donors with unusual antigens not represented on a screening panel will always be problematic. These rare antigens could cause a crossmatch to be unexpectedly positive or unexpectedly negative. In the end, I suppose your approach should depend on whether your center thinks it better to potentially and unnecessarily exclude a patient from receiving that donor’s kidney, or whether it’s better to bring the patient in and potentially have a positive crossmatch. My inclination would have been to run the crossmatch. If it’s negative, good. If it’s positive, now you know to avoid B*4026 the next time.
Posted: Tue Nov 07, 2006 1:51 pm
As suggested, single antigen beads are very helpful. There are articles regarding the use of single antigen beads vs a crossmatch. A positive crossmatch, depending on methods, etc should be interpreted with the patient’s sensitization and antibody characterization history. Of course, your patient/donor population comes into this also. As the commercial beads don’t have the rarer antigens.
HLA Lab @SW