Delayed-type hypersensitivity, in vitro T-cell responsiveness and risk of active coccidioidomycosis among HIV-infected patients living in the coccidioidal endemic area.
The prognostic importance of specific and general tests of immune function were examined among a cohort of 170 subjects infected with human immunodeficiency virus type-1 (HIV), living in an area endemic for the fungal infection coccidioidomycosis. Using the proportional hazards model and multivariate analysis, lack of expression of coccidioidal delayed-type hypersensitivity (DTH) was found to be dependent on anergy in response to the non-coccidioidal antigens mumps, Trichophyton and Candida (relative hazard 4.2, 95% CI 1.8-9.8, P=0.001). Among subjects with CD4 lymphocyte counts >/=250 microl-1 on entry into the study, the in vitro lymphocyte transformation (LT) response to the coccidioidal antigen toluene spherule lysate was 4967+/-1652 (mean counts per minute (c.p.m.)+/-SEM) in subjects with coccidioidal DTH compared with 136+/-222 in those with negative DTH (P<0.001). However, amongst those whose CD4 count was <250 microl-1, LT responses were low and there was no significant difference based on coccidioidal DTH (P=0.965). Using the proportional hazards model and multivariate analysis, only a CD4 count <250 microl-1 was prognostically associated with the development of either active coccidioidomycosis or AIDS. These data indicate that immunodeficiency, particularly a CD4 lymphocyte count <250 microl-1, is the most important factor in the lack of expression of specific immunity to coccidioidomycosis and in the development of active coccidioidomycosis among HIV-infected individuals living in the coccidioidal endemic area.
Ampel
N M
NM
Medical and Research Services of the Tucson Veterans Affairs Medical Center, Department of Medicine of the University of Arizona College of Medicine 85723, USA. nampel@u.arizona.edu
D001130:Arizona / Q000453:epidemiology; D018791:CD4 Lymphocyte Count; D003045:Coccidioides / Q000276:immunology; D003047:Coccidioidomycosis / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005500:Follow-Up Studies; D015658:HIV Infections / Q000150:complications* / Q000276:immunology; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D008213:Lymphocyte Activation; D012307:Risk Factors; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*