THE RELATIVE PROGNOSTIC VALUE OF PLASMA HIV RNA LEVELS AND CD4 LYMPHOCYTE COUNTS IN ADVANCED HIV-INFECTION

Objective: It has been suggested that the plasma HIV RNA level is a be tter predictor of AIDS and death than the CD4 lymphocyte count. We ass essed whether the prognostic value of plasma virus levels was differen t according to the CD4 count. Design: Prospective cohort study of HIV- infected patients followed for a median of 2.91 years (range, 0.02-4.5 4). Setting: Department of Infectious Diseases at Rigshospitalet, Cope nhagen, Denmark. Participants: A group of 255 HIV-infected individuals with an initial measurement of CD4 lymphocyte count and plasma HIV RN A. Main outcome measure: Survival time. Results: The plasma HIV RNA (m edian 101 410 copies/ml; range (range 200-7 200 000) and the CD4 lymph ocyte count (median 250 cells x 10(6)/l; range 1-1247) were negatively correlated (Pearson r = -0.53; P < 0.00001). Of the 255 patients, 110 died during follow-up. Overall, a higher HIV RNA level was associated with increased risk of death, but the association was smaller in pati ents with lower CD4 lymphocyte counts (test for interaction P < 0.0001 ). In patients with CD4 count below 50 cells x 10(6)/l the association between HIV RNA and risk of death was not statistically significant ( relative hazard per 10-fold higher HIV RNA level was 1.53; P = 0.11; a djusted for age and CD4 count) while that between the CD4 count and ri sk of death was highly significant (relative hazard per 50% towel CD4 count 1.38; P = 0.005; adjusted for age and HIV RNA level). Conclusion s: Patients were relatively lightly treated with antiretroviral drugs both before and during this study. In this situation, it appears that the HIV RNA level has a relatively weak association with risk of death in patients with advanced HIV infection and that the CD4 lymphocyte c ount is probably more useful in assessing prognosis. (C) 1998 Lippinco tt Williams & Wilkins.