Early intervention guidelines in HIV infection require knowledge of CD4+ lymphocyte count; however, CD4+ determinations require special laboratory procedures and may not be readily available in all situations. Using data from 207 HIV-seropositive homosexual men without AIDS, we evaluated the association of difference clinical conditions or serologic tests with CD4+ count. Men with conditions including seborrheic dermatitis, hairy leukoplakia, oral candidiasis and chronic diarrhea, and men with beta2-microglobulin levels greater than or equal to 4.0 mg/l had significantly lower CD4+ counts. However, the probability that a subject with such parameters had less than 200 x 10(6)/l CD4+ cells was limited (25-63%). Although the probability that a subject with such parameters had less than 500 x 10(6)/l CD4+ cells was better (76-88%), the probability that a person without these parameters had greater than or equal to 500 x 10(6)/l CD4+ cells was only 45-50%. Clinical and serologic parameters may provide important prognostic information, but cannot be used to reliably determine the level of CD4+ cells.