CCR5 chemokine receptor variant in HIV-1 mother-to-child transmission and disease progression in children. French Pediatric HIV Infection Study Group

Abstract

Context: Studies suggest that adults with the CCR5delta32 deletion are less likely to become infected with the human immunodeficiency virus (HIV) and to develop HIV-related disease progression, but the effect of the mutation in children is not known.

Objective: To study the effect of the CCR5 chemokine receptor mutant allele on mother-to-child transmission of HIV type 1 (HIV-1) and subsequent disease progression in infected children.

Design: Multicenter, prospective study of infants born to mothers seropositive for HIV-1.

Setting: A total of 52 medical centers participating in the French Pediatric HIV Cohort studies.

Participants: The CCR5delta32 deletion was studied in 512 non-African children, born between 1983 and 1996 to HIV-1-infected mothers. Among them, 276 children were infected and 236 were not.

Main outcome measures: HIV-1 infection status and, in infected children followed up since birth, incidence of category B and C disease events and severe immunosuppression as defined in the new pediatric Centers for Disease Control and Prevention (CDC) classification, according to CCR5 genotype.

Results: The 32-base pair deleted allele was detected at a frequency of 0.05. Only 1 infant, not infected by HIV-1, was homozygous for the delta32 deletion. The 49 heterozygous children (9.6% of the total; 95% confidence interval [CI], 7.1-12.2) were equally distributed into the infected (9.8%) and uninfected (9.3%) groups. The incidence of stage C symptoms in heterozygous infected children was 9% at 36 months vs 28% in children homozygous for the normal allele (P<.004). The proportion of children at 8 years old with no stage B or C symptoms was 49% for heterozygous children and 11% for children homozygous for the normal allele (P<.003). The progression of severe immune deficiency (CD4 <15%, CDC stage 3) was also significantly different between the 2 groups (P<.001).

Conclusions: Heterozygosity for the CCR5delta32 deletion does not protect children from infection by the maternal virus but substantially reduces the progression of the disease in HIV-1-infected children.