HLA-C Alleles and Cytomegalovirus Retinitis in Brazilian Patients with AIDS

Variability at the 3' untranslated region of the HLA-G gene: a study on patients with AIDS and cytomegalovirus retinochoroiditis

Cytomegalovirus retinochoroiditis (CMV-R) is the primary cause of blindness among AIDS patients. Since HLA-G is associated with the modulation of the immune response, we hypothesized that variability at the 3′ untraslated region (3′UTR) of the gene could be implicated on the predisposition to CMV-R. We evaluated whether HLA-G 3′UTR influences CMV-R development in Brazilian AIDS patients. Peripheral blood DNA was obtained from two groups of patients: (1) AIDS exhibiting CMV-R (n = 40) and (2) AIDS without CMV-R (n = 147). HLA-G 3′UTR typing was performed using sequencing analysis. Allele, genotype and haplotype frequencies were evaluated using Fisher’s exact test accompanied by the calculation of the odds ratio and its 95% confidence interval (95% CI). The etiologic (EF) and preventive fractions were also estimated. Compared to AIDS patients without CMV-R, AIDS patients with CMV-R showed increased frequencies of the: (1) + 3001T allele, (2) the + 3001C/T genotype and (3) the UTR-17 (InsTTCCGTGACG) haplotype (EFs = 0.02–0.04). The UTR-3 (DelTCCGCGACG) haplotype was associated with protection against CMV-R development. Although the risk for developing CMR-V at the population level was relatively low (EF), the identification of HLA-G 3′UTR variation sites may help to further evaluate the role of post-transcriptional factors that may contribute to the existent immunosuppresion caused by HIV per se.

Clinical and genetic markers associated with tuberculosis, HIV-1 infection, and TB/HIV-immune reconstitution inflammatory syndrome outcomes

BACKGROUND

Tuberculosis (TB) and AIDS are the leading causes of infectious disease death worldwide. In some TB-HIV co-infected individuals treated for both diseases simultaneously, a pathological inflammatory reaction termed immune reconstitution inflammatory syndrome (IRIS) may occur. The risk factors for IRIS are not fully defined. We investigated the association of HLA-B, HLA-C, and KIR genotypes with TB, HIV-1 infection, and IRIS onset.

METHODS

Patients were divided into four groups: Group 1- TB+/HIV+ (n = 88; 11 of them with IRIS), Group 2- HIV+ (n = 24), Group 3- TB+ (n = 24) and Group 4- healthy volunteers (n = 26). Patients were followed up at INI/FIOCRUZ and HGNI (Rio de Janeiro/Brazil) from 2006 to 2016. The HLA-B and HLA-C loci were typed using SBT, NGS, and KIR genes by PCR-SSP. Unconditional logistic regression models were performed for Protection/risk estimation.

RESULTS

Among the individuals with TB as the outcome, KIR2DS2 was associated with increased risk for TB onset (aOR = 2.39, P = 0.04), whereas HLA-B*08 and female gender were associated with protection against TB onset (aOR = 0.23, P = 0.03, and aOR = 0.33, P = 0.01, respectively). Not carrying KIR2DL3 (aOR = 0.18, P = 0.03) and carrying HLA-C*07 (aOR = 0.32, P = 0.04) were associated with protection against TB onset among HIV-infected patients. An increased risk for IRIS onset was associated with having a CD8 count ≤500 cells/mm3 (aOR = 18.23, P = 0.016); carrying the KIR2DS2 gene (aOR = 27.22, P = 0.032), the HLA-B*41 allele (aOR = 68.84, P = 0.033), the KIR2DS1 + HLA-C2 pair (aOR = 28.58, P = 0.024); and not carrying the KIR2DL3 + HLA-C1/C2 pair (aOR = 43.04, P = 0.034), and the KIR2DL1 + HLA-C1/C2 pair (aOR = 43.04, P = 0.034), CONCLUSIONS: These results suggest the participation of these genes in the immunopathogenic mechanisms related to the conditions studied. This is the first study demonstrating an association of HLA-B*41, KIR2DS2, and KIR + HLA-C pairs with IRIS onset among TB-HIV co-infected individuals.