[O21] MARGINAL ZONE B CELLS ARE DEPLETED IN HIV-1 INFECTION AND ARE NOT RESTORED BY ANTIRETROVIRAL THERAPY

12th Annual Conference of the British HIV Association

29 March–1 April 2006, Brighton, UK

MARGINAL ZONE B CELLS ARE DEPLETED IN HIV-1 INFECTION AND ARE NOT RESTORED BY ANTIRETROVIRAL THERAPY

HIV Med 2006 Mar 29-Apr 1 (Suppl 1);12:6 (abstract no. O21)

Melanie Hart¹, Alan Steel², Sally Clark², Jamie Whitehorn³, Donald C Henderson¹, Robert Wilson⁴, Frances Gotch², Graham Moyle³, Brian Gazzard² and Peter Kelleher²
¹ Hammersmith Hospitals NHS Trust, London, ² Department of Immunology, Imperial College, London, ³ Chelsea and Westminster NHS Trust, London, ⁴Royal Brompton and Harefield NHS Trust, London, UK

AIMS: Invasive pneumococcal disease is an important cause of morbidity and mortality in HIV-1 infection. High affinity IgM anti-pneumococcal antibodies secreted by marginal zone B (MZB) cells play an important role in host immunity against invasive pneumococcal infection. The aim of this study was to determine the concentration of MZB cells and pneumococcal antibodies in drug-naïve and antiretroviral-treated (ART) HIV-1 patients.

METHODS: B-cell subsets were determined using a whole blood-flow cytometric method and pneumococcal serology was evaluated by standard ELISA technology in 15 healthy controls (HC), 25 drug-naïve and 30 ART HIV-1 patients.

RESULTS: The percentage of MZB cells was significantly reduced in drug-naïve and ART patients compared with healthy controls (HC). Drug-naïve HIV-1infected patients with a CD4 cell count >350 cells/µl had a significant increase in MZB cell percentage compared with patients who have more advanced disease. There was no difference between the percentage of germinal centre memory B-cells between the HIV patient groups and HC. Serum levels of pneumococcal IgM levels were significantly depressed in both HIV-1 patient groups compared with HC.

CONCLUSIONS: Our data suggest a possible reason for the increased risk of invasive pneumococcal disease in HIV-1 infection. Further functional studies of immune responses to pneumococcal immunisation are in progress and will be reported.

2006-03-29
O21

Copyright © 2006 - British HIV Association (BHIVA) Reproduction of this abstract (other than one copy for personal reference) must be cleared through the BHIVA Organising Secretariat 1 Mountview Court, 310 Friern Barnet Lane, London N20 0LD