Objective: To measure diurnal variation in the CD4 cell count and T-cell reactivity of drug users.
Design: A prospective epidemiological study among HIV-infected and non-infected drug users attending the Municipal Health Service of Amsterdam, The Netherlands.
Patients: Eleven HIV-infected and seven non-infected drug users.
Main outcome measures: CD4 cell counts and T-cell reactivity three times a day. T-cell subsets and T-cell reactivity were determined from blinded samples within 2 hours.
Results: The number of CD4 cells increased by 130 x 10(6)/l (P < 0.05) in HIV-infected intravenous drug users over 8 hours. Following stimulation with anti-CD3 monoclonal antibodies, the T-cell reactivity of HIV-infected drug users rose from 118 to 221 c.p.m. (P < 0.01) over 8 hours. CD4 cell counts of the total study population increased by 37% and T-cell reactivity by 93%. The increase in the number of CD4 cells was more marked among active drug users than among drug users who had not used drugs recently.
Conclusion: Variation in the CD4 cell count and in T-cell reactivity is large among drug users.