Eosinophilia in patients infected with human immunodeficiency virus.

Patients infected with human immunodeficiency virus (HIV) frequently are said to have eosinophilia. To evaluate this assumption, the differential blood cell counts of 855 HIV-infected patients were examined over 4 years. All differential cell lines in the HIV-infected population were less than those in a noninfected control group, but the difference was much less pronounced for eosinophils than for the other blood cell components. For HIV-infected patients, the eosinophil count increased and the other blood cell components decreased as the CD4 cell count decreased. The increase in eosinophils was the result of eosinophilia in a subgroup of patients and a preservation of that cell line for the other patients. No etiologic agent was associated with eosinophilia; hence, HIV infection itself may induce proliferation of eosinophils while other cell components are declining.