CD4+ T lymphocytopenia in children: lack of evidence for a new acquired immunodeficiency syndrome agent.

We investigated children with CD4+ T lymphocytopenia to determine the magnitude and public health impact of this condition and to investigate possible causes. Children < 13 years old with CD4+ T lymphocyte counts below age-adjusted cutoffs (age < 24 months, 1000 cells/microliters; age > or = 24 months, 300 cells/microliters) or < 20% on 2 separate measurements were considered to have CD4+ T lymphocytopenia. We solicited information from clinicians and public health departments on these children and their families and collected blood for immunologic and retroviral testing. We identified 18 children (10 boys; 14 African-Americans) with a median age of 10 months at their first low CD4+ T lymphocyte measurement. Three children had had opportunistic infections and two still had low CD4+ T lymphocyte counts 5 and 7 years later. Of the 11 children born to human immunodeficiency virus (HIV)-infected mothers 7 were asymptomatic. Specimens from all children were negative for HIV and human T lymphotropic virus antibodies and negative for HIV by culture or polymerase chain reaction. Among 12 families interviewed no other HIV-seronegative family or household member had illnesses suggestive of immunosuppression. We conclude that negative retroviral tests and lack of illness among their family members do not support the hypothesis that a retrovirus causes CD4+ T lymphocytopenia among these children.(ABSTRACT TRUNCATED AT 250 WORDS)