A primary disturbance in immunoglobulin synthesis.

Biclonal gammopathy, a gammopathy in which the serum contains two distinct monoclonal immunoglobulins.

Monoclonal gammopathy, any one of a group of disorders due to proliferation of a single clone of lymphoid or plasma cells (visible on electrophoresis as a single peak) and characterised by the presence of monoclonal immunoglobulin in serum or urine.

Polyclonal gammopathy, a gammopathy in which there is a heterogeneous increase in immunoglobulins involving more than one cell line; may be caused by any of a variety of inflammatory, infectious, or neoplastic disorders.

(05 Mar 2000)