High incidence of monoclonal proteins in the serum and urine of chronic lymphocytic leukemia patients

Abstract

Chronic lymphocytic leukemia (CLL) is generally considered a nonsecretory B cell immunoproliferative disorder. Conventional electrophoretic and immunoelectrophoretic methods have revealed serum monoclonal proteins in less than 10% of these patients. However, there is increasing experimental evidence from in vitro studies demonstrating that CLL cells may secrete immunoglobulins, particularly free light chains. We examined the serum and urine of 36 consecutive CLL patients for monoclonal proteins using sensitive immunochemical methods (high resolution agarose gel electrophoresis combined with immunofixation). The results obtained were correlated with the Rai stage, quantitative immunoglobulin levels, and lymphocyte membrane immunoglobulin phenotype of the leukemic cells. Twenty-three monoclonal proteins were identified in the serum or urine of 22 patients, an incidence of 61%. Six patients had serum monoclonal proteins, seven had only urinary monoclonal proteins, and nine had monoclonal proteins in serum and urine. In every instance the monoclonal protein was the same light chain type as expressed on the leukemic cells. Our findings suggest that the monoclonal proteins observed in the serum or urine of CLL patients are secretory products of the tumor cells and that their discovery is a function of the sensitivity of the method used for their detection.

Surface immunoglobulin on B lymphocytes as a potential target for specific peptide ligands in chronic lymphocytic leukaemia

“…A similar approach may be used with CLL where the presence of paraproteins in the blood is not unusual (Hansen et al, 1994). Indirect proof, such as coinciding light and heavy chain phenotype, have suggested a common clonal origin of the paraprotein and B-CLL surface immunoglobulin (Deegan et al, 1984). Specific peptide binders to clonal immunoglobulin would support this connection.…”

Monoclonal Gammopathy in Chronic Lymphocytic Leukemia: A Case Report and Review of its Literature

“…[1] The incidence of monoclonal proteins in patients with CLL ranges between 60% and 80%. [2,3] IgG kappa is the most common abnormality detected in CLL followed by IgG lambda, IgM kappa, IgM lambda, and IgA lambda in the order of frequency. [4] Free light chains are also commonly detected abnormalities in CLL.…”

A Case of Monoclonal Gammopathy in Extranodal Marginal Zone B-cell Lymphoma of the Small Intestine

“…Approximately 50% of patients with lymphoplasmacytic lymphoma have elevated serum Ig levels. Paraproteinemias are often noted in patients with CLL and are less common in patients with diffuse large B-cell lymphoma [ 12 ]. The presence of monoclonal gammopathy has been reported in up to 50% of patients with splenic MZL, and it has been reported in 36% of those with ENMZL [ 7 , 13 ].…”