Impact of HLA allele mismatching between recipients and donors on subclinical acute rejection after renal trans-plantation

Objective To evaluate the impact of HLA allele mismatching between recipients and donors on subclinical acute rejection (SAR). Methods A total of 56 kidney allograft recipients negative for PRA before transplantation were treated with a combination of CSA, MMF and prednisone and underwent anallograft biopsy at 3rd month after transplantation. The biopsies were scored by a blinded pathologist accor-ding to the Banff criteria (Canada,1997). Results SAR was seen in 12 patients (21.5%). These 6 patientswith 2 HLA-DR mismatching had all met the criteria of SAR, whereas SAR was present in only O (0/9) and14.6%(6/41) of patients with respectively 0 and 1 HLA-DR mismatching (P<0.01). 9.1% (1/11),8.8%(3/34) and 72.7% (8/11) of patients with 0, land 2 HLA-B mismatches had met SAR, with thedifference being repectively between 0,2 HLA-B mismatches and 1,2 HLA-B mismatches (P<0.01). Alsorespectively 27.3% (3/11), 18.8% (6/23) and 23.1%(3/13) of patients with 0, 1 and 2 HLA-A mis-matches had SAR (P0.05), with the difference being not significant among them Conclusion Thisretrospective study suggest that HLA-DR and HLA-B mismatching plays an important role in the occurrenceof SAR, the extent of impact is observed as HLA-DRHLA-B. On the other hand, HLA-A has nosignificant impact on the occurrence of SAR. Key words: DNA probes,HLA; Kidney transplantation,Grft rejection; Biopsy,needle