Evaluating the contribution of APOBEC3G haplotypes, on influencing HIV infection in a Zimbabwean paediatric population.

BACKGROUND: Apolipoprotein B mRNA-editing catalytic polypeptide like-3G (APOBEC3G) is an antiviral enzyme that reduces viral fitness by introducing uracil to thymidine hypermutations in viral genomes. Thus, polymorphisms in the APOBEC3G gene have been implicated in differential outcomes of HIV infection and disease progression. However, there is insufficient evidence on the role of APOBEC3G gene variants on HIV infection, especially in African populations. This study therefore describes polymorphisms in the APOBEC3G gene in a Zimbabwean paediatric population and evaluates their effects on susceptibility to HIV infection among children born to HIV-infected mothers. Methods. A total of 104 children aged between 7 and 9 years, comprising 68 perinatally exposed to HIV (32 born infected (EI) and 36 born uninfected (EU)) and 36 unexposed and uninfected (UEUI) controls were recruited. Allelic variants (n=5) in the APOBEC3G gene were characterised. Results. Frequencies for minor APOBEC3G alleles in the HIV-uninfected groups (EU and UEUI) were c.557G (40%), g.-90C (32%), g.-571C (12%), c.467-85C (42%), and c.582-162G (6%). APOBEC3G c.467-85C frequency was statistically significantly different when compared to the Masai of Kinyawa, Kenya population (42% v. 18%). None of the single nucleotide polymorphisms individually or as part of haplotypes were significantly associated with HIV infection when comparing the EI and EU groups. Conclusions. Our findings suggest that APOBEC3G polymorphisms alone may not have significant predictive power for inferring genetic susceptibility to vertical transmission of HIV in children perinatally exposed to HIV.

Risk factors of HIV vertical transmission in a cohort of women under a PMTCT program at three peri-urban clinics in a resource-poor setting.

OBJECTIVE: To identify the risk factors of HIV vertical transmission in pregnant women. STUDY DESIGN: Observational cohort study. Between 2002 and 2003, 479 HIV-infected pregnant women in a PMTCT (prevention of the mother-to-child transmission) program were followed up with their infants at delivery, until 15 months with infant HIV testing. RESULTS: Of these 281 infants had a definitive HIV result by 15 months of age, and 31.7% of the infants become HIV infected. In univariate analysis the risk factor identified were presence of vaginal discharge, genital itchiness, genital ulcers, dysuria, abnormal breast and vaginal infections (Trichomonas, Bacteria vaginosis and Candida) in the mother at enrolment. In multivariate analysis vaginal infections risk ratio (RR) 1.72(1.03-2.88) and abnormal breast RR 4.36(2.89-6.58) were predictors of HIV vertical transmission. CONCLUSION: There is need to screen for vaginal infections (Trichomonas, Bacteria vaginosis and Candida) and examine pregnant women for mastitis to identify women at risk of HIV vertical transmission for prevention.