Characterising B cell numbers and memory B cells in HIV infected and uninfected Malawian adults.
BACKGROUND
Untreated human immunodeficiency virus (HIV) disease disrupts B cell populations causing reduced memory and reduced naïve resting B cells leading to increases in specific co-infections and impaired responses to vaccines. To what extent antiretroviral treatment reverses these changes in an African population is uncertain.


METHODS
A cross-sectional study was performed. We recruited HIV-uninfected and HIV-infected Malawian adults both on and off antiretroviral therapy attending the Queen Elizabeth Central hospital in Malawi. Using flow cytometry, we enumerated B cells and characterized memory B cells and compared these measurements by the different recruitment groups.


RESULTS
Overall 64 participants were recruited - 20 HIV uninfected (HIV-), 30 HIV infected ART naïve (HIV+N) and 14 HIV-infected ART treated (HIV+T). ART treatment had been taken for a median of 33 months (Range 12-60 months). Compared to HIV- the HIV+N adults had low absolute number of naïve resting B cells (111 vs. 180 cells/μl p = 0.008); reduced memory B cells (27 vs. 51 cells/μl p = 0.0008). The HIV+T adults had B-cell numbers similar to HIV- except for memory B cells that remained significantly lower (30 vs. 51 cells/μl p = 0.02). In the HIV+N group we did not find an association between CD4 count and B cell numbers.


CONCLUSIONS
HIV infected Malawian adults have abnormal B-cell numbers. Individuals treated with ART show a return to normal in B-cell numbers but a persistent deficit in the memory subset is noted. This has important implications for long term susceptibility to co-infections and should be evaluated further in a larger cohort study.
Longwe
Herbert
H
1Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
Gordon
Stephen
S
Malamba
Rose
R
French
Neil
N
D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D001402:B-Lymphocytes / Q000276:immunology*; D003430:Cross-Sectional Studies; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory; D018655:Lymphocyte Count; D008295:Malawi; D008297:Male; D008875:Middle Aged
D019380:Anti-HIV Agents