Monoclonal immunoglobulin light chains in urine of patients with lymphoma.

Fourteen of 31 patients with non-Hodgkin's lymphoma or chronic lymphocytic leukaemia had a monoclonal immunoglobulin light chain detectable in their urine. These chains are believed to be synthesized by the B lymphoid cells comprising the tumour. Upon comparing the different cases, the occurrence and amount of monoclonal light chain showed no dependence upon the extent of tumour, the presence of leukaemic component, or exposure to cytotoxic therapy. The method of detection involved purifying the urinary light chains by immunosorption, and examining their electrophoretic distributions so as to distinguish between the homogeneous monoclonal chains and their heterogeneous normal analogues.