IDENTIFICATION OF MONOCLONAL IMMUNOGLOBULINS AND QUANTITATIVE IMMUNOGLOBULIN ABNORMALITIES IN HAIRY-CELL LEUKEMIA AND CHRONIC LYMPHOCYTIC-LEUKEMIA

Serum and urine samples from 161 cases of hairy cell leukemia (HCL) an d 50 cases of chronic lymphocytic leukemia (CLL) were analyzed for mon oclonal immunoglobulin (Mlg) by using a combination of high-resolution protein electrophoresis, immunoelectrophoresis, and immunofixation. Q uantitative immunoglobulin analysis also was performed on all serum sa mples. Monoclonal immunoglobulin, usually of low intensity, was identi fied in serum or urine in 26 (16.1%) cases of HCL compared with 27 (54 %) cases of CLL. Forty-eight (29.8%) cases of HCL had an increase in o ne or more immunoglobulins; increases in IgG were the most frequent. I n CLL, 48 (96.0%) cases had a decrease in one or more immunoglobulins, with decreases in IgG, IgA, and IgM in 76%, 68%, and 56% of the cases , respectively. The: correlation between serum or urine monoclonal imm unoglobulin light chain and the surface membrane light chain was 88% i n CLL. compared with 47.4% in I-ICL. These findings confirm previous o bservations of frequent polyclonal hyper-gamma-globulinemia in HCL, hy po-gamma-globulinemia in CLL, and weak monoclonal immunoglobulins in b oth disorders. The contrasting immunoglobulin abnormalities in HCL and CLL indicate distinctive biologic differences in these chronic B-cell leukemias.