Protein analyses in myelomatosis

The criteria for the admission of patients to the Medical Research Council's (MRC) myeloma trials are the finding of abnormal plasma cells in bone marrow films or sections and in addition either of characteristic skeletal lesions demonstrated radio-logically or of characteristic protein changes in the serum or urine. Ninety per cent of the patients in the first myeloma trial satisfied all three criteria (Medical Research Council, 1971). Before the introduction of alkylating agents in the treatment of myelomatosis the median survival of patients with this disease was 17 months after the onset of symptoms and seven months after the start of treatment (Farhangi and Osserman, 1973). The survival of patients is now much longer and this is due partly to the introduction of alkylating agents such as melphalan and cyclophosphamide and partly to improved techniques of biochemical monitoring of the tumour. The subject of this article is the monitoring of immunocytomas by biochemical analyses. The Detection of Paraproteins Plasma cells in the marrow and lymphoid tissue normally make complete immunoglobulins. The two heavy polypeptide chains are synthesized on large polyribosomes in about two and a half minutes, and the two light polypeptide chains are synthesized on smaller polyribosomes in about one minute (Askonas and Williamson, 1967). The four poly-peptide chains are then assembled and carbohydrate is added in the Golgi apparatus. The production of heavy and light chains is well balanced, there being normally a very small excess of light chains syn-thesized. About 2 to 3 mg of polyclonal free light chain is excreted into the urine per day. Differing chemical properties of the heavy chains allow immunoglobulins to be divided into distinc