title: Individual probability for onset of full-blown disease in patients infected with human immunodeficiency virus type 1.
abstract: Increased concentrations of neopterin, a marker for cell-mediated immune activation, and decreased numbers of CD4+ T cells, are predictors for progression of disease after infection with human immunodeficiency virus type 1. Previous studies have demonstrated different rates of onset of full-blown acquired immunodeficiency syndrome (AIDS) for groups of patients, defined by laboratory marker values, who were initially symptom-free. By re-analysis of one such study, we demonstrate how for an individual patient, the individual marker values, together with a prior risk estimate, can be converted into current or accumulated post-test probability of onset of AIDS at a certain time. We used a statistical technique suggested by Albert et al. (Clin Chem 1984;30:69-76), which allows incorporation of fixed and time-dependent covariates. Besides allowing individual projections, the method shows that the predictive abilities of CD4+ T cell numbers and of neopterin concentrations do not vary greatly with regard to time of observation; both laboratory markers independently modulate the underlying prior probability of AIDS onset, which is significantly increased with the passage of time.
authors.affiliation: Institute of Medical Chemistry and Biochemistry, Innsbruck, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Reibnegger
authors.forename: T J
authors.initials: TJ
authors.lastname: Spira
authors.forename: D
authors.initials: D
authors.lastname: Fuchs
authors.forename: G
authors.initials: G
authors.lastname: Werner-Felmayer
authors.forename: M P
authors.initials: MP
authors.lastname: Dierich
authors.forename: H
authors.initials: H
authors.lastname: Wachter
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology*; D001708:Biopterins / Q000031:analogs & derivatives* / Q000652:urine; D015704:CD4 Antigens / Q000276:immunology; D006679:HIV Seropositivity / Q000276:immunology*; D006716:Homosexuality; D006801:Humans; D008297:Male; D008954:Models, Biological; D019798:Neopterin; D011237:Predictive Value of Tests; D011336:Probability; D012044:Regression Analysis; D012307:Risk Factors; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors
chemical_list: D015704:CD4 Antigens; D001708:Biopterins; D019798:Neopterin