title: Is there a general tendency for CD4 lymphocyte decline to speed up during human immunodeficiency virus infection? Evidence from the Italian Seroconversion Study.
abstract: It has been suggested that the rate of CD4 cell decline accelerates in parallel with decreasing numbers of cells; however, the statistical literature suggests the opposite. CD4 cells were counted about every 6 months in a cohort of 1264 human immunodeficiency virus-infected subjects (the Italian Seroconversion Study cohort). Kaplan-Meier analysis was used to estimate the time for CD4 cells to decline by 100 cells/mm3, conditional on reaching predefined levels. In addition, CD4 cell counts were modeled as a function of time since seroconversion in individuals with > or = 5 counts. Kaplan-Meier survival times for a 100 cell/mm3 decrease in CD4 cells increased as lower counts were reached (log rank test, P < .001). The shape of the overall fitted curve of the CD4 cell counts does not suggest an increasing rate of decline. Data from the Italian Seroconversion Study cohort do not show a general tendency for accelerating CD4 cell decline in association with lower counts.
authors.affiliation: Department of Primary Care and Population Sciences, Royal Free Hospital, London, United Kingdom.
authors.forename: A C
authors.initials: AC
authors.lastname: Lepri
authors.forename: C A
authors.initials: CA
authors.lastname: Sabin
authors.forename: P
authors.initials: P
authors.lastname: Pezzotti
authors.forename: P D
authors.initials: PD
authors.lastname: England
authors.forename: A N
authors.initials: AN
authors.lastname: Phillips
authors.forename: G
authors.initials: G
authors.lastname: Rezza
mesh_terms: D018791:CD4 Lymphocyte Count; D015658:HIV Infections / Q000276:immunology*; D006801:Humans