HLA class I and II antigens expression in patients with renal cell carcinoma.

An optimal antitumoral immune response requires the activation of both CD8(+) and CD4(+) T lymphocytes by the peptide antigen presentation via the human leukocyte antigen (HLA) class I and class II molecules, respectively. The frequency of A1, A26, DR11 alleles are signifi­cantly elevated and seem to be the predisposing alleles in RCC, while HLA A29 and DQ1 are the protective alleles and are found more frequently in the healthy group. To investigate the association between renal cell carcinoma (RCC) and the host's immune system, we immunohistochemically examined RCCs in 44 Turkish patients for the expression of class I and class II antigens. We found a significantly higher frequency of the alleles HLA-A1 (p= 0.001), HLA-A26 (p=0.047) and HLA­DR11 (p= 0.03) in RCC patients compared to the control group. The most frequent alleles in the control population were A29, DQ1 (p= 0.004 and 0.002 respectively). We observed no significant difference between patients and controls in HLA-B and HLA-C allele frequency. We conclude that our study found an association between HLA antigens and RCC in Turkish patients. We found a significantly higher frequency of the alleles HLA-A1, HLA-A26 and HLA-DR11in RCC patients compared to the control group. Larger studies are required to confirm these results.