HLA Class I Profile in Patients with AIDS and Toxoplasma gondii Chorioretinitis

Abstract

Abstract: : Purpose: Studies carried out in different populations reported association between some HLA specificities and increased susceptibility to infections. Taking in account that patients with AIDS present different evolutions, the aim of this study was to investigate the class I HLA profile in Brazilian patients with AIDS and previous evidence of Toxoplasma gondii infection, in order to verify differences between patients with and without chorioretinitis, and if HLA markers associated with progression to AIDS are, also, associated with susceptibility to chorioretinitis. Methods: The study population was composed by 25 patients with AIDS and Toxoplasma gondii chorioretinitis (TgCR), 41 patients with AIDS and neurotoxoplasmosis (NT), without TgCR, and 43 patients with AIDS and positive anti–T. gondii circulating antibodies, without NT and TgCR (AbTg). The diagnosis of HIV infection was made by an immunoenzymatic method (Abbott Recombinant HIV–1/HIV–2 IEA) and confirmed by the gelatin particle agglutination tests (Serodia ® , Fujerebio Inc., Tokyo, Japan). The TgCR was diagnosed clinically using indirect binocular ophthalmoscopy. HLA class I alleles were typed using classical serologic methods. Statistical analysis was performed using the chi–square or Fisher exact test; for the significant associations it was calculated the odds ratio (OR) and the attributable risk (AR). Results: In our population, the only HLA antigen with frequency significantly different in the TgCR group was HLA–B35 (TgCR X NT: p<0.001, OR=7.27, AR=45.58; and TgCR X NT+AbTg: p<0.001, OR=5.81, and AR=27.94). Conclusions: HLA–B35 antigen might be associate with susceptibility to Toxoplasma gondii chorioretinitis; and subtypes related with progression to AIDS are not over represented in Brazilian patients with AIDS and anti–T. gondii circulating antibodies, presenting or not choriorretinitis.

Keywords: chorioretinitis • AIDS/HIV • gene screening