HLA-Bw4-B57 and Cw18 alleles are associated with plasma viral load modulation in HIV-1 infected individuals in Salvador, Brazil

• Published in: The Brazilian journal of infectious diseases 2010-09, Vol.14 (5), p.468-475
• Main Authors: da Silva, Edinete Melo, Acosta, Angelina Xavier, Melo Santos, Eduardo José, Netto, Eduardo Martins, Lemaire, Denise Carneiro, Oliveira, Adriano Silva, Barbosa, Carolina Matos, Bendicho, Maria Teresita, Galvão-Castro, Bernardo, Brites, Carlos
• Format: Article
• Language: English
• Subjects: Adult; Aged; AIDS; AIDS (Disease); Alleles; Allelomorphism; Analysis; Antigenic determinants; CD4 Lymphocyte Count; Development and progression; Disease Progression; Female; Genetic Markers; Genotype; Health aspects; Histocompatibility antigens; HIV; HIV (Viruses); HIV Infections - blood; HIV Infections - virology; HIV patients; HIV-1 - genetics; HIV-1 - immunology; HLA; HLA histocompatibility antigens; HLA-B Antigens - blood; Humans; Immunoglobulins; Infection; Male; MHC; Middle Aged; polymorphism; Prognosis; Viral Load; Viremia - blood; Young Adult
• ISSN: 1413-8670; 1678-4391
• DOI: 10.1016/S1413-8670(10)70095-7

Host genetic factors play an important role in mediating resistance to HIV-1 infection and may modify the course of infection. HLA-B alleles (Bw4 epitope; B*27 and B*57) as well as killer cell immunoglobulin-like receptors have been associated with slow progression of HIV-1 infection. Objective: To evaluate the association between serological epitopes HLA-Bw4 and HLA-Bw6 and prognostic markers in AIDS. Methods: 147 HIV-infected individuals in Bahia, Northeast Brazil, were genotyped for HLA class I locus. HLA class I genotyping was performed by hybridization with sequence-specific oligonucleotide probes following amplification of the corresponding HLA-A, HLA-B and HLA-C genes. Statistical analysis was performed using Fisheŕs exact and ANOVA tests for categorical and continuous variables, respectively. Results: We detected a significant association (χ2 = 4.856; p = 0.018) between the presence of HLA-Bw4 and low levels of viremia. Eighteen out of the 147 HIV-infected individuals presented viremia ≤ 1,800 copies/mL and 129 presented viremia > 2,000 copies/mL. Ninety and four percent (17/18) of all individuals with viremia ≤ 1,800 copies/ mL carried HLA-Bw4, compared to 67.4% (87/129) of individuals with viremia > 2,000 copies/mL. Additionally, we found a significantly higher frequency of B*57 (OR = 13.94; 95% CI = 4.19-46.38; p < 0.0001) and Cw*18 (OR = 16.15; 95% CI = 3.46-75.43; p ≤ 0.0001) alleles, favoring the group with lower viremia levels, in comparison with those with higher viral load. Conclusion: HLA-Bw4-B*57 and Cw*18 alleles are associated with lower level of viral load in HIV-infected Brazilian patients. These findings may help us in understanding the determinants of HIV evolution in Brazilian patients, as well as in providing important information on immune response correlates of protection for such population.