T-LYMPHOCYTE SUBSETS IN ACUTE ILLNESS

Objectives: To determine the range of T-lymphocyte subsets (CD4, CD8, and CD4/CD8 ratios) in acutely ill, hospitalized patients and to deter mine whether these concentrations correlate with illness severity, sur vival rate, or immunodepression. Design: Cross-sectional study, compar ing Acute Physiology and Chronic Health Evaluation II (APACHE II) scor es and the calculated, disease-specific, predicted mortality rate with T-lymphocyte subsets. Setting: Urban county hospital intensive care u nit (ICU), serving as the designated trauma center. Patients: One hund red two consecutively admitted ICU patients (72 medical and 30 surgica l). Interventions: None. Measurements and Main Results: Patient clinic al data, APACHE IP scores, and their associated predicted mortality ra te were recorded, Blinded human immunodeficiency virus (HIV) and lymph ocyte testing was performed on samples from all patients on ICU admiss ion, Despite only three (2.9%) of 102 patients testing positive for HI V antibodies, 41% (42/102) of patients had CD4 concentrations of <400 cells/mu L, and 29% (29/102) had CD4 concentrations of <300 cells/mu L . Mean CD8 concentrations were even lower, compared with normal labora tory values, resulting in a slight increase in CD4/CD8 ratios, althoug h 16% (16/102) of patients had a CD4/CD8 ratio of <1. CD4 counts were linearly related to total lymphocyte concentrations (Pearson correlati on coefficient = 0.948), but no relationship was found between total l ymphocyte or lymphocyte subset counts and APACHE II score, predicted m ortality rate, or survival rate. Conclusions: Acute illness alone, in the absence of HIV infection, can be associated with profound decrease s of T-lymphocyte populations, This problem is unpredictable and does not correlate with severity of illness, predicted mortality rate, or a ctual mortality rate, No conclusions regarding HIV serostatus or survi val can be made based on single measurements of T-cell concentrations in acutely ill hospitalized patients.