Abstract
Abstract: :
Purpose: Previous studies have suggested that specific clinical presentations of toxoplasmosis and severity of disease may be related to human leukocyte antigen (HLA) types, such as HLA-Bw62 in patients with severe toxoplasmic retinochoroiditis attributable to congenital infection and HLA-DQ3 in immunosuppressed individuals with encephalitis. In this study we sought to determine whether specific HLA types were associated with the development of, or the severity of, ocular disease in Toxoplasma gondii-infected individuals. Methods: Definitions of ocular disease severity were determined prospectively. Subjects were recruited from Clinica Silveira in Erechim, Brazil. Twenty adults were included in each of the following three groups of otherwise healthy individuals with serum antibodies against T. gondii: (1) individuals without ocular toxoplasmosis; (2) patients with mild ocular toxoplasmosis; and (3) patients with severe ocular toxoplasmosis. Blood specimens were sent to the UCLA Immunogenetics Laboratory, where HLA-A, -B, and -C specificities were determined by serologic techniques, and HLA-DR and -DQ genotypes were determined by polymerase chain reaction techniques. Results: There was no difference in the frequency of HLA types between the groups with ocular toxoplasmosis and the group without ocular toxoplasmosis, nor was there a difference between the groups with severe vs. mild ocular toxoplasmosis. Specifically, there was no increase in the frequency of HLA-Bw62 in the group with severe ocular toxoplasmosis. The rates of HLA-DQ3 and HLA-DR11 (which is linked to HLA-DQ3) were higher in all three groups than published rates for the general Caucasian population in Brazil, but there were no differences in the rates of these HLA types between the three groups. Conclusions: Our results fail to support a strong relationship between specific HLA types and either the presence of, or severity of, ocular toxoplasmosis in adult seropositive individuals.
Keywords: 600 toxoplasmosis