Immune markers and viral load after HIV-1 seroconversion as predictors of disease progression in a cohort of haemophilic men.

OBJECTIVE

To assess the prognostic value of HIV RNA levels measured shortly after HIV seroconversion and whether markers of immune response (CD4+ and CD8+ T-cell counts, IgA and IgG) measured at the same time, continue to provide prognostic information once the HIV RNA level is known.

DESIGN AND METHODS

HIV RNA levels were measured approximately 2.5 years after seroconversion in 97 haemophilic men followed for up to 17 years. Levels of CD4+ and CD8+ T cells, IgA and IgG were measured within 1 year of the HIV RNA level. The relationships between these markers and progression to AIDS and death were studied using Kaplan-Meier plots and proportional hazards regression models.

RESULTS

High HIV RNA levels were associated with faster progression to AIDS and shorter survival in univariate Cox regression models. High IgA and IgG levels were also associated with faster disease progression. In multivariate models, high HIV RNA levels remained independently associated with faster disease progression [relative hazard (RH), 1.86; P = 0.01 for AIDS; RH, 1.66; P = 0.05 for death). However, high IgA and IgG levels provided strong independent prognostic information for AIDS and death (IgA: RH, 1.38; P = 0.006 for AIDS; RH, 1.33; P = 0.07 for death; IgG: RH, 1.10; P = 0.02 for AIDS; RH, 1.12; P = 0.01 for death).

CONCLUSIONS

Our results confirm the importance of the HIV RNA level in assessing the long-term prognosis in individuals infected with HIV. However, our results suggest that immune activation markers, rather than merely reflecting high HIV RNA levels are important in assessing prognosis in their own right. These findings may improve our understanding of HIV pathogenesis and may aid clinical management of patients.