The Italian Register for HIV Infection in Children. Rapid disease progression in HIV-1 perinatally infected children born to mothers receiving zidovudine monotherapy during pregnancy.

To investigate the outcome in children perinatally infected with HIV-1 whose mothers received zidovudine (ZDV) monotherapy in pregnancy. Observational retrospective study of a prospectively recruited cohort. Italian Register for HIV Infection in Children. A group of 216 children perinatally infected with HIV-1, born in 1992-1997 and derived prospectively from birth: 38 children had mothers receiving ZDV monotherapy and for 178 children the mothers received no antiretroviral treatment during pregnancy. The estimated probability of developing severe disease or severe immune suppression, survival probability [95% confidence interval (CI)] within 3 years, and the hazard ratio (95% CI), adjusted for year of birth, maternal clinical condition at delivery, birthweight and treatments (Pneumocystis carinii pneumonia chemoprophylaxis and/or antiretroviral therapy before the onset of severe disease, severe immune suppression or death) were compared. Comparison of HIV-1-infected children whose mothers were treated with ZDV with children whose mothers were not treated showed that the former group had a higher probability of developing severe disease [57.3% (95% CI 40.9-74.3) versus 37.2% (95% CI 30.0-45.4); log-rank test 7.83, P = 0.005; adjusted hazard ratio 1.8 (95% CI 1.1-3.1)] or severe immune suppression [53.9% (95% CI 36.3-73.5) versus 37.5% (95% CI 30.0-46.2); log-rank test 5.58, P = 0.018; adjusted hazard ratio 2.4, (95% CI: 1.3-4.3)] and a lower survival [72.2% (95% CI 50.4-85.7) versus 81.0% (95% CI 73.7-86.5); log-rank test 4.23, P = 0.039; adjusted hazard ratio of death 1.9 (95% CI 1.1-3.6)]. This epidemiological observation could stimulate virologic studies to elucidate whether this rapid progression depends on in utero infection or transmission of resistant virus. Findings may suggest a need to hasten HIV-1 diagnosis in infants of ZDV-treated mothers and undertake an aggressive antiretroviral therapy in those found to be infected.