Serum Protein Analysis

Although the monoclonal immunoglobulins are generally assumed not to be true antibodies antibody activity has nevertheless been found in several cases (Potter, 1971). In particular, antistreptolysin-O activity has been found in monoclonal immunoglobulins somewhat surprisingly often. Sauvezie et al. (1974) mention 17 cases of such antibodies out of a total of 57 monoclonal Ig with antibody activity reported up to 1974. Other antibody activities comprise rheumatoid factors (Waldenstrom et al., 1964; Klein et al., 1968), anti-DNA (Riesen and Morell, 1972), antithyroglobulin and antismooth muscle (Wager et al., 1971), antilipoproteins (Beaumont, 1969), and several others. Monoclonal antibodies have also been found or elicited in animals (Osterland et al., 1966; Potter, 1971; van den Berg et al., 1976). In most instances the activity of such antibodies, which may belong to any Ig class, has no demonstrable connection with the disease in which they are occurring or with any previous illness. In some cases, however, such a connection has been suggestedfor example, by Sauvezie et al. (1974) and by Seligmann et al. (1968, 1973). Most of the monoclonal antibodies appear in cases ofmultiple myeloma or Waldenstrom's macroglobulinaemia or in the less well-defined group of 'benign' monoclonal gammapathies (Waldenstrom, 1964). Monoclonal antibodies against human erythrocyte components (cold agglutinins) appear either without known