We prospectively randomized 27 granulocytopenic patients who experienced a total of 30 episodes of gram-negative septicemia. The control group received an appropriate antibiotic regimen alone, whereas the "transfusion" group received infusions of granulocytes in addition to the antibiotics. Five of 14 controls survived, and 12 of 16 in the transfusion group survived, and 12 of 16 in the transfusion group survived (P less than 0.04). An important factor in the outcome of treatment was the recovery of bone-marrow function (return of peripheral granulocyte count greater than or equal to 1000 per microliter). Eighty-three per cent (five of six) of the control group and all (four of four) of the transfusion group with recovery of granulocyte levels survived the episode of sepsis. In contrast, none of the eight control patients, as compared to 67 per cent (eight of 12) of the transfusion group, survived persistent granulocytopenia (P less than 0.005). Granulocyte transfusions appear to complement appropriate antibiotic treatment of gram-negative-septicemia due to granulocytopenia.

No abstract

The cellular events leading to proliferation of cultured human lymphocytes after in vitro stimulation with phytomitogens or allogeneic cells are poorly understood. Little is known on the nature of the proliferating lymphocytes, or whether interactions between different cell types are required for blastogenic transformation of the eventually responding lymphocytes. Investigating these questions, attention has to focus primarily on monocytes, and the different lymphocyte subpopulations.The role of the monocyte (or the monocyte-derived maerophage [1,2], respectively) in antigen-induced lymphocyte activation continues to be of great interest. Lymphocyte response to many antigens requires the presence of monocytes. Removal of glassadherent cells abolishes the in vitro antibody formation by mouse spleen cells against sheep erythrocytes (3) and antigen-induced transformation of human lymphocytes (4); addition of macrophages restores the lymphocyte reactivity (5, 6). Macrophagelymphocyte interaction is also required for lymphocyte activation by allogeneic histoincompatible lymphocytes in vitro, the mixed leukocyte culture (MLC) 1 (7-11). In contrast, lymphocyte activation by plant mitogens such as phytohemagglutinin (PHA), concanavalin A (Con A), or pokeweed mitogen (PWM) is widely attributed to direct interaction of the soluble mitogen with lymphocyte membrane receptors (12-15). Opinions about the role of monocytes in the mitogen-induced lymphocyte proliferation are controversial: reports that phagocytic cells inhibit the lymphocyte response to PHA (16) conflict with others that removal of phagocytic cells decreases lymphocyte activation by this mitogen (17, 18). Alter and Bach described potentiation of PHA-induced lymphocyte proliferation by monocytes (11), whereas Oppenheim and co-workers (4) observed this effect only at suboptimal doses of PHA.Lymphocytes can be separated into thymus-dependent (T) and thymus-independent (B) cells on the basis of ontogeny, function, and cell surface differentiation markers. Relatively small fractions of B or T cells from immunized animals will respond to the sensitizing antigens (19,20), whereas a large fraction of the lymphocyte inoculum will be stimulated in vitro by phytomitogens (21,22). Therefore, the lymphocyte response to phytomitogens is generally considered to be nonspecific, 1 Abbreviations used in this paper: Con A, concanavalin A; HBSS, Hanks' balanced salt solution; MLC, mixed leukocyte culture; N-SRBC, neuraminidase-pretreated sheep erythrocytes; PHA, phytohemagglutinin; PWM, pokeweed mitogen.

Four patients with acute leukemia developed toxoplasmosis following leukocyte transfusions from donors with chronic myelogenous leukemia. Serologic data, obtained from the donors retrospectively, revealed elevated antitoxoplasma antibody titers, suggesting that the transfused leukocytes were the source of the organism in the recipients.