In vitro study of immunologic changes in long-term cytapheresis donors.

Several in vitro measurements of immune function were examined retrospectively in a population of active long-term cytapheresis donors (group I; n = 50) and the results were compared to age- and sex-matched controls (group II; n = 50) who had donated only whole blood. In group I, significantly different mean absolute lymphocyte counts (P = .0025), total T-cells (P = .0026) and T-helper cells (P less than .0001), and helper-to-suppressor ratios (P = .0279) were present. No differences were noted between the two groups for peripheral blood mean B-cell count, T-suppressor numbers, lymphocyte responsiveness to mitogens or alloantigen, and serum immunoglobulin level. The reduced mean absolute lymphocyte count in group I was due to the reduction in T-helper cell numbers and accounted for the imbalance in the helper-to-suppressor ratio. These disturbances are currently unexplained and, while no clinical consequences have so far become evident, there is a need to continuously monitor the immunologic status of cytapheresis donors. It is also important to determine whether reversal of the defects occurs and, if so, over what time interval.

Blood donors with antibody to the human immunodeficiency virus--the Natal experience.

The major incursion of human immunodeficiency virus type I (HIV-1) infection into the South African heterosexual population has been by southerly migration of the heterosexual HIV-1 epidemic from central Africa. Much important information can be obtained from blood donor seroprevalence data and cohort studies of those individuals infected during the early stages of the epidemic in South Africa. By the end of April 1989, over half a million blood donors in Natal had been screened and the presence of antibody to HIV-1 confirmed in more than 200. The majority of these anti-HIV-1 positive donors are young and single (many of them still at school), although a substantial proportion already have children of their own and a recent history of sexually transmitted disease is common. The Natal Blood Transfusion Service experience indicates that the heterosexual HIV-1 epidemic in Natal is essentially no different from the earlier stages of heterosexual epidemics elsewhere in Africa. There is still time for effective programmes to have a major impact on progression of the epidemic in South Africa, particularly if these programmes are directed at the young population in educational institutions.

The clinical and lymphocyte status of HIV antibody-positive black blood donors.

Forty-seven HIV antibody-positive black blood donors presented for assessment and counselling at King Edward VIII Hospital, Durban. Thirteen were found to have generalised lymph node enlargement and 1 had a tuberculous pulmonary infiltrate. Significant reduction in helper T-cell numbers and in the helper-suppressor ratios was noted. Counselling appeared to produce disturbingly few positive effects.