Increase in Leu 2+ Leu 7+ lymphocytes in HIV 1-seropositive patients with hemophilia repeatedly treated with clotting factor concentrates.

The fact that patients with hemophilia treated with clotting factor and HIV 1-seronegative subjects with congenital anemias given repeated blood transfusions both have decreased ratios of T4/T8 lymphocytes and diminished NK cell activity indicates that these immunological abnormalities can be due to repeated exposure to blood and blood products, and are not necessarily indicative of HIV 1 infection. To search for an immunological change specific for HIV 1 infection we tested 36 hemophiliacs (22 HIV 1-seropositive, 14 HIV 1-seronegative), and 27 normal subjects for peripheral blood lymphocytes which coexpress Leu 2, a marker associated with suppressor/cytotoxic cells, and Leu 7, an NK cell marker. Compared to normal subjects, seropositive hemophiliacs showed a 2.5-fold increase in Leu 2+ Leu 7+ cells. No increase in this population was seen in the seronegative hemophiliacs. An increase in the percentage of Leu 2+ Leu 7+ cells is therefore an immunological alteration associated with HIV 1 infection but not blood product exposure per se.