Calculation and use of an HIV-1 disease progression score

Objective: The pathogenesis of human disease is often multifactorial. For f atal diseases, it is common to combine survival information in relation to different aspects of pathogenesis. Here we explored a scoring system for HI V disease markers that combines measures of immunodeficiency (CD4 cell coun t), plasma viral burden, and immune activation (CD38 expression on CD8 T ce lls) Design: Observational data from 252 HIV-infected individuals from the Multi center AIDS Cohort Study (MACS) was used for model development. Methods: A statistical model was used to develop a system that related mark er values to the outcomes of clinical AIDS or death. Results: Mathematical formulae were derived to calculate AIDS and death pro gression scores. These scores give the number of days at which there is a 5 0% probability that a person may develop AIDS or die. Graphs were construct ed that can be used to determine the probability that a person will be AIDS -free or alive for times between 6 months and 4 years. The model was valid when tested on data from 240 additional people from the MACS cohort. Conclusions: These formulae and graphs are a convenient way for individuals and their physicians to apply existing MACS cohort data to HIV disease mar kers in order to estimate probabilities of progression to AIDS or death. Fu rther investigation is needed to determine whether modifications of the for mulae are required to predict outcome accurately in those patients on highl y active antiretroviral therapy or in other demographic groups. (C) 2000 Li ppincott Williams & Wilkins.