Anti-V3 loop spectrotype in HIV-infected individuals during zidovudine therapy

In order to investigate the role played by zidovudine (ZDV) as immune modulator, particularly on B-cell response, the anti-V₃ loop spectrotype in 115 sera from 26 HIV-infected individuals was evaluated, prior to and during treatment with ZDV, by isoelectric focusing and reverse blotting (IEF-RB), a technique useful for indirectly measuring the activity and the number of B-cell clones. All 18 patients showing seroreactivity by IEFRB displayed a clear oligoclonal banding pattern, with no change in the spectrotype (i.e. new bands), in sequential analysis over the course of therapy. Only minor changes in band intensity were found, without any correlation with ZDV treatment or CD4⁺ cell count. In addition, among the sera reactive in spectrotypic analysis, the percentage of those with p24 antigen positivity was significantly lower than those with no detectable p24 antigen (19.8% vs 80.2%, respectively, p = <0.0001, Fisher's exact test). In conclusion, it could not be demonstrated by IEFRB that there was any effect of ZDV on the activity and the number of anti-V₃ specific B-cell clones. This data is in line with previous studies showing the constancy of anti-gp120 antibody spectrotype over the long course of the disease.