Age-Adjusted CD4⁺ Lymphocyte Parameters in Healthy Children at Risk for Infection with the Human Immunodeficiency Virus

Values for CD4⁺ lymphocytes are reported to vary by age. We evaluated an ethnically diverse population of healthy children at risk for human immunodeficiency virus infection to establish normal ranges for age-adjusted CD4⁺ lymphocyte parameters. We identified a threshold of ∼30% CD4⁺ lymphocytes which corresponded to a 5th percentile for all ages. It is important that no significant differences in absolute CD4⁺ lymphocyte counts on the basis of ethnic group were found.