ABSTRACT
Human T cell lymphotropic virus type I [HTLV-I]-associated rnyelopa-thy/tropical spastic paraparesis [HAM/TSP] is an inflammatory disease which occurs in less than 2% of HTLV-I -infected individuals. High proviral load, high HTLV-I-specific CD8[+] cytotoxic T lymphocyte frequency [CTL] and host genetic factors such as HLA all appear to be associated with HTLV-I infection. Previous studies have shown that HLA-DRB1*01 increases the risk of HAM/TSP in Japanese HTLV-1 infected individuals. To investigate the association between HLA class II DRB1 alleles and HLA class I alleles [HLA-Cw*08, B54, A*02 and A-30] in HTLV-I infected individuals in Mashhad. Here we determined the frequency of HLA class II DRBl, using INNO-LIPA reverse hybridization line probe assay, and HLA class I alleles [HLA-Cw*08,B54, A*02 and A-30] by PCR-SSCP method in healthy controls, HAM/TSP patients and HTLV-I infected individuals born and resident in Mashhad. The frequency of HLA-DRB1*01 alleles in this population was different from other areas of Iran. The frequency of HLA-DRB1*01 was significantly increased in HAM/TSP patients compared with carriers [p 0.028; OR=9.4]. The frequency of HLA-Cw*08 was also significantly increased in HAM/TSP patients compared with controls [p=0.03; OR=13.5]. Our results may suggest that possession of HLA-DRB1*01 increases the risk of HAM/TSP in HTLV-I-infected individuals and HLA-Cw*08 correlates with low CTL immune response in HAM/TSP patients