title: Accelerated changes (inflection points) in levels of serum immune activation markers and CD4+ and CD8+ T cells prior to AIDS onset.
abstract: The trajectories of change in CD4+ and CD8+ lymphocytes and serum neopterin and beta2-microglobulin (beta2M) levels were determined in 158 HIV-seropositive individuals during 5.5 years before a clinical AIDS diagnosis. Each patient was evaluated separately using a two-piece regression model with seven possible change points to identify any adverse change (inflection point) in the slopes of each immunologic marker of HIV infection. Two categories of subjects were distinguished for each marker--those with statistically significant inflection points and those who demonstrated a steady progression of changes to AIDS. Fifty-nine percent had an inflection point for CD4+ T cells. The frequency of inflection points for CD8+ was 49%, for serum neopterin -48% and for beta2M -38%. Inflection points were found over a 4-year span. Three distinctive categories of inflection points were observed on the basis of their independent occurrence: one was in CD4+ T cells, another in CD8+ T cells, and a third in the serum markers of immune activation. The inflection point for CD4+ usually occurred prior to those for CD8+ T cells (p=.0002). The HIV-positive persons with inflection points were diagnosed with AIDS when immunologic parameters were significantly more abnormal than in those with steady progression (p < .0003). Thus, these two groups differed in the course of immune changes and in the levels of immune abnormalities associated with the occurrence of clinical AIDS.
authors.affiliation: Center for Interdisciplinary Research in Immunology and Disease, Department of Medicine, University of California--Los Angeles School of Medicine, 90095-1747, USA.
authors.forename: P
authors.initials: P
authors.lastname: Nishanian
authors.forename: J M
authors.initials: JM
authors.lastname: Taylor
authors.forename: B
authors.initials: B
authors.lastname: Manna
authors.forename: N
authors.initials: N
authors.lastname: Aziz
authors.forename: S
authors.initials: S
authors.lastname: Grosser
authors.forename: J V
authors.initials: JV
authors.lastname: Giorgi
authors.forename: R
authors.initials: R
authors.lastname: Detels
authors.forename: J L
authors.initials: JL
authors.lastname: Fahey
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000175:diagnosis* / Q000276:immunology; D000328:Adult; D015415:Biomarkers; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D015331:Cohort Studies; D018450:Disease Progression; D006679:HIV Seropositivity / Q000276:immunology*; D006801:Humans; D008137:Longitudinal Studies; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D019798:Neopterin / Q000097:blood*; D012189:Retrospective Studies; D013997:Time Factors; D001613:beta 2-Microglobulin / Q000032:analysis*
chemical_list: D015415:Biomarkers; D001613:beta 2-Microglobulin; D019798:Neopterin