14th International AIDS Conference Barcelona, Spain - July 7-12, 2002

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. A10079)

derlund J, Andersson J, Maseruka H, Ait-Khalid M, Goh LE, Broliden K
Karolinska Institutet/Huddinge University hospital, Stockholm, Sweden

BACKGROUND: In the present study we have characterized the IgA response retrospectively in sera of patients with primary HIV-1 infection (PHI) taken at the onset (day 1) of HAART (Combivir/Abacavir/Amprenavir), and subsequently at weeks 24, 42 and 72 of treatment.

METHODS: The study cohort consisted of 10 PHI patients from QUEST Trial (Goh LE et al, HIV Clin Trials. 2001 Sep-Oct;2(5):438-44). Baseline viraemia was 5.17 log c/mL for rapid responders (n=4) and 5.58 log c/mL for slow responders (n=6) to HAART - rapid response being defined as viremia clearance ≤ 50 copies/ml by week 12. IgA purified from serum, was quantified and its neutralizing capacity measured against HIV-1 (SF2) and HIV-1 primary isolates (pi), X4 and R5.

RESULTS: HIV-1 neutralization was obtained with purified IgA at day 1 in some of the patients against SF2 and R5 pi, whereas none of the IgA samples neutralized the X4 pi. In most patients the neutralizing capacity at day 1 was retained at weeks 24, 42 and 72 after initiation of HAART. Neutralization of the X4 pi was not detected at these later time points either. Neutralization with unpurified serum was seen at day 1 only in one patient and only against the R5 pi. However, at later time points, unpurified sera from a few patients showed neutralizing capacity against SF2 as well as the R5 and X4 pi.

CONCLUSION: Thus, this report confirms previous studies of PHI patients in which neutralizing antibodies cannot be readily detected against pi. However by purifying the IgA fraction, the present study has shown neutralization also in PHI patients.

020707
A10079

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