Definition of allele specific HLA antibodies using luminex technology
L. Syme1, M. Davies1, K. Stewart1, S. Malone2, L. Jack2, D. McKenzie2, I. Galbraith2,
A-M. Little2, D. Turner1
1
H&I Dept, South-East Scotland Blood Transfusion Service, Royal Infirmary of
Edinburgh, Edinburgh, UK, and 2H&I Service, Gartnavel General Hospital, Glasgow,
UK
We describe two cases that have led to patients’ own HLA antigens being listed as
unacceptable with ODT.
Patient 1 typed as HLA-A2,3; B8,35; DR17,10 prior to receiving a renal transplant
from a ‘100’ mismatch donor (HLA-A3,11; B8; DR17) in 1997. The patient represented in 2009, and SAB (One Lambda) HLA antibody testing identified multiple
specificities including A0301. The patient was re-typed by PCR-SSO (Luminex,
Tepnel) and HLA-A*02, A*0302/31 were identified. The patient has been re-listed
with HLA-A3 as an unacceptable antigen.
Patient 2 typed as HLA-A2,11; B22,75; DR4,12 prior to receiving a transplant from a
‘110’ mismatched donor (HLA-A1,2; B22,62; DR4) in 1992. The patient represented in 2004 with a failing graft. Regular antibody monitoring was implemented,
more recently including SAB (One Lambda). Multiple specificities were identified
including HLA-A0201 and A0206. Repeat patient typing using PCR-SSO (Luminex,
Tepnel) and PCR-SSP A*02 subtyping (Olerup, Genovision) identified A*0203. A
mock CDC crossmatch performed with an A*0201 donor and post-transplant patient
serum was positive. HLA-A2 has been listed as an unacceptable antigen for this
patient.
Conclusion:
SAB testing and high resolution HLA typing are necessary tools for identification of
allele specific antibodies in patients being listed for transplant. Both patients possess
rare (in the UK donor population) alleles and have made antibodies against common
alleles. Identification of these antibody specificities and listing the antigens as
unacceptable is necessary to reduce probable positive crossmatches. The matchability
score for these patients has been reduced due to the presence of these common
unacceptable antigens.