Cytogenetic studies of stimulated lymphocytes in hairy cell leukemia

Using a sister chromatid differentiation (SCD) technique, cell cycle analysis in lymphocytes from two patients with hairy cell leukemia (HCL) revealed it to be similar to cell cycle progression of normal lymphocytes stimulated with lipopolysaccharide W from Escherichia coli 0.55:B5 (LPS). It appears that LPS can readily stimulate the leukemic cells of HCL into mitosis. In the two cases of B cell HCL studied, one (case 1) was revealed to have an abnormal clone with a missing chromosome #22 that was related to the production of lambda-chains.