[Value of HIV-1 viral load and CD4 lymphocyte count as determinants of progression to AIDS and survival].

Background: HIV-1 viral load is regarded as a better surrogate marker for progression and death than CD4+ cell counts. Both markers are analysed in a cohort of patients with unknown seroconversion date and advanced HIV infection.

Results: After a median follow up of 763 days, 124 patients developed AIDS and 117 died. Relative risks of progression related to the group that maintained viral load values always 35,000 copies/ml were: 5-fold (95% CI: 1.4-17.0; p 0.05) for patients with any viral load value > 35,000 copies/ml but always 200,000 copies/ml; and 13.6 fold (95% CI: 5.4-34.2; p 0.0001) for patients who could not maintain viral load 200.000 copies/ml. CD4+ counts = 100 x 10(6)/l and viral load = 220,000 copies/ml were the threshold values that best fitted to estimate the probability of survival by a bivariate analysis.

Conclusion: After a median follow up of 763 days, 124 patients developed AIDS and 117 died. Relative risks of progression related to the group that maintained viral load values always 35,000 copies/ml were: 5-fold (95% CI: 1.4-17.0; p 0.05) for patients with any viral load value > 35,000 copies/ml but always 200,000 copies/ml; and 13.6 fold (95% CI: 5.4-34.2; p 0.0001) for patients who could not maintain viral load 200.000 copies/ml. CD4+ counts = 100 x 10(6)/l and viral load = 220,000 copies/ml were the threshold values that best fitted to estimate the probability of survival by a bivariate analysis.