[An evaluation of combination antibiotic therapy in infections with hematological disorders. Hyogo Cooperative Study Group of Infectious Diseases Complicating Hematological Disorders].

A clinical study was undertaken to determine the effects of combination antibiotic therapy in 104 patients with infections associated with hematological disorders. All patients were treated with sulbactam/cefoperazone (SBT/CPZ) plus an aminoglycoside as an empiric therapy for fever. The overall efficacy rate of the therapy was 63.5%. Efficacy rates were 61.2% and 71.9% when initial neutrophil counts were less than 500/mm3 and over 500/mm3, respectively. No significant difference was found between the cases in which initially used antibiotics were continued (efficacy rate 62.5%) and those in which antibiotics were switched during the course of therapy (65.6%). Antibiotic therapy with SBT/CPZ plus an aminoglycoside provides adequate antibiotic coverage against infections associated with hematological disorders. This combination was highly effective even in the neutropenic periods of febrile patients.

Restriction fragment length polymorphism of bcr in Japanese patients with hematological malignancies.

We surveyed DNAs from patients with various hematological malignancies by Southern blot hybridization to analyze bcr rearrangements, and detected a new restriction fragment length polymorphism (RFLP) of the breakpoint cluster region at a BamHI site in three patients. By using a 1.2-kb HindIII-BglII 3' bcr probe, unusual BamHI restriction enzyme fragments (1.9 kb and 1.4 kb) were detected from the DNAs of three patients with hematological malignancies. DNAs from cultured fibroblasts derived from the skin of a patient, as well as from peripheral leukocytes of the father of a patient and the mother of another patient, showed identical 1.9- and 1.4-kb additional bands, besides a 3.3-kb germline band, establishing that polymorphism, rather than gene arrangement, was responsible for these additional restriction enzyme fragments. However, RFLP was not detected in the DNAs of 40 normal unrelated individuals.

Expression of interleukin-2 receptor on T cell chronic lymphocytic leukemia cells and their response to interleukin-2.

We analyzed peripheral blood leukemic cells from six patients with T cell chronic lymphocytic leukemia (T-CLL) with monoclonal antibodies including the anti-Tac antibody, which recognizes the receptor for interleukin 2 (IL 2). The patients were divided into two groups according to the reactivity of the monoclonal antibodies. Leukemic cells from three patients with T-CLL reacted with OKT3 and T4 but not T8, whereas those from the remaining three patients reacted with OKT3 and T8 but not T4. IL 2 receptor, which is expressed on activated T cells but not on resting T cells, was preferentially expressed on T4+ T-CLL cells. The IL 2 receptor on T4+ T-CLL cells was indistinguishable from that on normal activated T cells with respect to molecular weight and downregulation by the anti-Tac antibody. Moreover, fresh T4+ T-CLL cells, but not T8+ T-CLL cells, proliferated in response to exogenous IL 2 without prior activation, and this proliferation was inhibited by the anti-Tac antibody. These results suggest that malignant growth of T4+ T-CLL cells can be regulated by IL 2 not only in vitro but also in vivo.