Delayed Hypersensitivity in Chronic Lymphocytic Leukemia 1

leukemia (Cll) were studied in relation to the expression of delayed hypersensitivity reactions. Patients with more advanced disease were separated, only with regard to such reactions, From patients with less ab-normal clinical and laboratory characteristics of Cll through the use of sophisticated methods of statistical evaluation. Impairment of delayed hypersensitivity as measured by skin reactivity to 2,4-dinitrochlorobenzene and microbial antigens was uncommon though lymphocyte transFormation in vitro with phytohemagglutinin M and streptolysin 0 was quite low. Indirect evidence For both an increased number of circulating immune reactive and nonreactive cells in CLl was suggested From these studies.-J Nat Cancer Inst 42: 973-980, 1969. CIRCULATING ANTIBODY production is often impaired in patients with chronic lymphocytic leukemia (CLL) (1-3), but the ability to develop delayed hypersensitivity is less clearly defined