A total of 220 individuals were included in this study, 112 HIV-seronegative healthy individuals and 108 HIV-1-infected patients involving: 18 AIDS patients with Toxoplasmic encephalitis (AIDS-TE), 49 AIDS patients without TE, and 41 asymptomatic patients, were genotyping for DR and DQ loci by molecular biology techniques. Fisher's Exact test was used for statistical analysis. HLA-DQB*0402 and DRB1*08 alleles were associated with a high risk to develop opportunistic infections with neurological involvement, mainly Toxoplasma encephalitis in relationship with subjects healthy (OR = 20.43; Pc = 7.0 x 10(-6) and OR = 11; Pc = 2.6 x 10(-4), respectively); in relationship with AIDS no TE (OR = 6.98; Pc = 0.028 and OR = 4.85; P = 0.012, Pc = 0.14) and with patients in asymptomatic stage (OR = 61.50, Pc = 8.4 x 10(-6) and OR = 19.38; Pc = 3.9 x 10(-4)), respectively.
Conclusions: It was concluded that the presence of HLA-DQB*0402 and DRB1*08 alleles in HIV-1-positive patients could be considered risk factors for developing neurological opportunistic infections, mainly Toxoplasmic encephalitis.