Whiteside S, et al. - In this study involving patients undergoing chemotherapy for acute leukemia, researchers investigated if allergen-specific IgE (A-IgE) levels in atopic individuals (serum A-IgE ≥0.35 kU_A/L) decrease into the nonatopic range (< 0.35 kU_A/L) after chemotherapy. They also measured B cell counts before and after chemotherapy in a subset of these patients. A total of 105 patients were included, of whom 36 were atopic. The observed median A-IgE level before chemotherapy and after chemotherapy in these patients was 1.6 kU_A/L and 0.6 kU_A/L, respectively. Post-chemotherapy evaluation revealed decreased A-IgE levels but markedly less than B cell counts. Therefore, at least some A-IgE plasma cells appeared to survive chemotherapy.