Role of Molecular Typing in Live Related Donor Renal Transplantation

In renal transplantation, a good HLA-DR match is associated with higher success rate of graft outcome. It is particularly so In high risk recipients. Serological HLA-DR typing is not always easy due to a number of technical problems. In view of this, a comparison of serological and molecular typing was done in our institutions. A total of 64 live related donor patients of renal transplantation were studied. Serological typing was done by conventional methods. Molecular HLA class II typing was done by polymerase chain reaction (PCR) based sequence specific oligonucleotide probe (SSOP) hybridization technique. An overall discrepancy of 19.5% was observed in the DR typing obtained by serology and PCR-SSOP of all the recipients and donors. 14.5% of cases showed discrepancy in the results of only one DR antigen. Serological typing failure was seen in 10.9% of total cases. In 19.5% cases, only one DR antigen was assigned by PCR-SSOP as compared to two antigens by serological methods. Maximum number of discrepancies were seen in DR 2 antigens. There was no appreciable difference of graft survival shown in the patients typed by both methods. However, higher incidence of acute graft rejection episodes were seen in patients with 1 antigen mismatch as compared to zero mismatch. It is concluded that HLA-DR typing should be carried out by molecular methods as these have been found to be more specific and accurate.