The relative osmotic resistance of chronic lymphocytic leukemia lymphocytes.

By DAVID \V. \\ESTRING AND SUZANNE B. BnrrrlN T lIE HEMOLYTIC RESPONSE of erythrocytes to hypotonic stress is well known. Complex enzyme systems are required by the cell to maintam membrane integrity during exposure to hypotonic solutions. When certain of these enzymes are defective, erythrocyte osmotic fragility may be altered.3 On the other hand, the response of leukocytes to osmotic stress has received very little attention. The activities of many leukocyte enzymes have been studied, however, and several deficiencies have been demonstrated in leukemic lymphocytes.4’7’8 It seems possible, therefore, that an altered leukocyte osmotic fragility might be one result of these metabolic dysfunctions. Using recently developed technics for obtaining pure cell populations,9 the experiments described below indicate significant differences in response to osmotic stress between lymphocytes from normal subjects and patients with chronic lymphocytic leukemia ( CLL).