Objective: Our aim was to study the relationship between virological and/or immunological markers during the first month of life in vertically HIV-1 infected infants without prior antiviral treatment.
Patients and methods: Thirty HIV-1 infected infants that had not received prior antiviral therapy, nor had their mother during pregnancy, were studied. Viral load was quantified using standard molecular assays. Viral isolation and phenotype were carried out by using viral co-cultures. Subpopulations of lymphocytes were determined by flow cytometry.
Results: We have found an inverse correlation between log10 CD4+ cells/mm3, as well as CD4+ percentage with log10 viral load, with a slope of -0.266 (CI95%: -0.459 to -0.074) and -6.648 (CI95%: -12.815 to -0.471), respectively. When the influence of viral phenotype on the log10 viral load or the percent of CD4+ T cells standardized according to age (Z-score) with the log10 of the viral load was determined, it was found that infants having syncytium inducing (SI) virus had 12.355% (CI95%: 2.336 to 22.373) less CD4+ cells and 4.530 standard deviations (IC95%: 0.448 to 8.613) than infants with non syncytium inducing (NSI) isolates.
Conclusions: Our results suggest that a particular biological phenotype of viral isolates (SI and those with rapid/high replication) and high plasma viral loads have a statistically significant tendency to be associated. Viral load is the marker that shows the best inverse correlation with the level of CD4+ cells normalized according to the infant's age. This correlation shows a different value in infants with SI and NSI isolates.