Human B Lymphocytes Show Greater Susceptibility to H2O2 Toxicity Than T Lymphocytes Journal of Immunology, Vol. 132, No. 5, May 1994 C.M. Farber, L.F. Liebes, D.N. Kanganis, and R. Silber Abstract: Lymphocytes from patients with chronic lymphocytic leukemia (CLL) and from normal subjects were incubated with a glucose-glucose oxidase hydrogen peroxide (H2O2) generating system to study the effect of oxidant stress on these cells. Within 4 hr, 90% of normal but only 21% of CLL lymphocytes remained viable. When normal and CLL preparations enriched in B or T cells were exposed to H2O2, B lymphocytes from both groups were highly susceptible to oxidative damage while T lymphocytes were relatively resistant. The H2O2 scavenger catalase prevented the cytotoxicity. The present work identifies the human B lymphocyte as a cell that should be a suitable target for selective killing by H2O2 generating systems.