Naive B Cell Output in HIV-Infected and HIV-Uninfected Children

Area of Science:

• Immunology
• Pediatrics
• Virology

Background:

• Naive B cell output is crucial for adaptive immunity.
• Understanding B cell dynamics in pediatric HIV is essential for treatment strategies.
• Kappa-deleting recombination excision circles (TRECs) serve as a marker for recent thymic emigrants and B cell production.

Purpose of the Study:

• To quantify TREC levels and naive B cell output in healthy and HIV-infected South African children.
• To establish reference ranges for TRECs and naive B cell output in pediatric populations.
• To compare naive B cell output between HIV-uninfected and HIV-infected children, with and without ART.

Main Methods:

• Mathematical modeling integrating TREC levels, flow cytometry data (naive unswitched B cells), and Ki67 proliferation marker.
• Analysis of samples from 288 HIV-uninfected and 153 HIV-infected South African children.
• Comparison of TREC levels and naive B cell output across age groups and HIV status.

Main Results:

• Naive B cell output follows a pattern of increase from birth to one year, followed by a decline.
• HIV-infected children, both on and off ART, exhibited higher naive B cell outputs compared to HIV-uninfected children.
• This study presents the first reference ranges for TRECs and naive B cell output in children.

Conclusions:

• HIV infection in children appears to be associated with an increased naive B cell output.
• Further research is needed to elucidate the mechanisms driving increased naive B cell output in pediatric HIV.
• The clinical utility of measuring naive B cell output in pediatric HIV management warrants further investigation.