FREE LIGHT CHAIN SYNTHESIS BY NEOPLASTIC-CELLS IN CHRONIC LYMPHOCYTIC-LEUKEMIA AND NON-HODGKINS LYMPHOMA

Abstract

Cell populations from 22 [human] cases of B [bone marrow-derived] cell neoplasia reflecting various stages of B lymphocyte maturation were investigated for their ability to synthesize immunoglobulin (Ig) in vitro. All surface Ig positive neoplasms studied synthesized labeled Ig of the same L chain class as that expressed at the cell surface. Immature B cell neoplasms, chronic lymphocytic leukemia (CLL) and CLL-type lymphoma, synthesized only a minor proportion of their total protein as Ig; labeled free L chain was the only detectable secreted Ig product in 13 cases and was in excess in the remaining 4. Labeled H chain was detected in cell lysates in all but 1 case. Follicular center cell lymphomas (neoplasms of more mature B lymphocyte types) synthesized more of their total protein as Ig and showed a more balanced synthesis of H and L chains compared to the other neoplasms studied. The Ig synthesis patterns and free L chain production are discussed in relation to normal B lymphocyte maturation.