Relationships between HLA-A, -B, -DQ and -DR antigens and interstitial fibrosis in renal allografts.

Although renal transplant recipients tend to exhibit similar clinical and immunological changes over time, some allograft biopsies show early IF. To evaluate the relationship between HLA antigens and IF in renal allografts, we reviewed for HLA-A, -B, -DQ, and -DR antigens in 88 renal transplant recipients. For each antigen type, we determined the numbers of patients who did and did not possess the antigen. We then determined the mean time to onset of IF for each of these two groups, and statistically compared the means. In the second part of the analysis, we divided the 88 patients into those who did and did not show IF at 6 months posttransplantation, and then calculated the prevalence of each antigen type in the IF (+) and IF (-) groups. This same procedure was repeated with the patients grouped according to presence of IF at 12 months posttransplantation. The patient groups with HLA-B8, -B27, -DQ2, -DQ5, -DQ6, -DQ7, -DR4, -DR13, and -DR15, respectively, had significantly shorter times to IF onset after transplantation than the corresponding groups without these antigens (p<0.05). The groups that were IF (+) at 6 and 12 months posttransplantation had significantly higher frequencies of HLA-B8, -B27, -DQ2, and -DR4 than the corresponding IF (-) groups at these two time points (p<0.05). The results indicated that any kidney recipient with these antigens is predisposed to developing diffuse IF in their graft relatively soon after transplantation. We conclude that although there are multiple etiological agents in the pathogenesis of interstitial fibrosis, one cannot exclude an HLA association in these cases.