William D. Hardy

Infection with Human T-Cell Leukemia Virus Type I in Patients with Leukemia

Among 211 adults with leukemia who received multiple transfusions, 6 were found to be seropositive for human T-cell leukemia virus Type I (HTLV-I). Before the positive serum specimens were obtained, these patients received a mean of 14 units of red cells and 78 units of platelets. Seroconversion could be documented in three patients. None of the 6 patients seropositive for HTLV-I had a T-cell leukemia, other illnesses attributable to HTLV-I infection, or risk factors for HTLV-I infection other than transfusion: none were seropositive for human immunodeficiency virus. Patients with leukemia who receive multiple transfusions appear to be at risk for HTLV-I infection.

Antitumor activity of protein a administered intravenously to pet cats with leukemia or lymphosarcoma

Extracorporeal immunoadsorption with protein A (SpA) containing Staphylococcus aureus Cowan I (SAC) has previously been shown to induce an antitumor and antiviral response in some feline leukemia virus (FeLV)‐infected, lymphosarcoma (LSA) cats. However, the mechanism by which this response is induced is unknown. Since it is possible that SpA dissociates from the SAC column during treatment, and that intravenous infusion of SpA could be a more efficacious form of treatment than extracorporeal immunoadsorption therapy, 6 normal cats and 15 FeLV‐infected pet cats with naturally occurring leukemia or LSA were infused with SpA. No toxic effects resulting from SpA infusion were observed in the normal cats. Antitumor effects were observed in one of the eight cats with LSA and in three of the six cats with leukemia, but there were no antiviral responses. The antitumor responses were objective regressions; however, all tumors recurred. These results demonstrate that infusion of SpA into FeLV‐infected LSA or leukemic cats can result in an antitumor but apparently not in an antiviral response.

Plasma-mediated leukemia cell destruction: concentration and purification of the antileukemia factor.

Summary Selective destruction of leu-kemic cells has been observed in AKR mice following infusion of normal serum, plasma, or whole blood. Heparinized plasma has significantly greater antileukemia activity than serum, and the active factor can be concentrated and purified by heparin precipitation or adsorption onto a calcium phosphate gel.