Prognostic value of single measurements of beta-2-microglobulin, immunoglobulin A in HIV disease after controlling for CD4 lymphocyte counts and plasma HIV RNA levels

The interrelationships between the CD4 lymphocyte count, plasma viral load [human immunodeficiency virus (HIV) RNA], beta-2-microglobulin (β₂-M) and immunoglobulin A (IgA) and the mortality risk was explored in 234 HIV-infected individuals (median CD4 count 230 cells/mm³, range 1-1,247). Product-moment correlation analysis was used to study the association between β₂-M, IgA and HIV RNA. A proportional hazards Cox model was used to estimate the relative hazard (RH) of death. Both β₂-M (r = 0.49, p < 0.0001) and IgA (r = 0.42, p < 0.0001) were positively correlated with HIV RNA. High β₂-M levels were associated with an increased risk of death in both univariate Cox analysis and after adjustment for HIV RNA, CD4 lymphocyte count and age [RH = 1.16 per 100 nmol/l higher β₂-M, 95% confidence interval (CI) 1.05-1.27]. Raised IgA levels were associated with shorter survival in individuals with a CD4 count above 50 cells/mm³ in univariate analysis as well as after adjusting for age and CD4 lymphocyte count (RH = 1.19 per 10 μmol/l higher IgA, 95% CI 1.01-1.39). However, this association was no longer significant after further adjusting for HIV RNA. In conclusion, β₂-M levels provided additional prognostic information for survival to the information obtained by CD4 count and HIV RNA levels, whereas serum IgA only was a weak prognostic marker in this fairly progressed cohort.