Gammopathies

Abstract

Hypergammaglobulinemia results from a pathologically increased production of γ globulins, that can be either mono- or polyclonal. Monoclonal gammopathy is always the consequence of a clonal B lymphocyte/plasma cell expansion with homogeneous monoclonal (M) immunoglobulin production. Diseases associated with this type of clonal proliferation are also referred to as plasma cell dyscrasia or dysproteinemias. In contrast, polyclonal gammopathy consists of a multitude of immunoglobulins produced by various stimulated B lymphocytes. It can occur in the context of lupus erythematosus, rheumatoid arthritis, sarcoidosis, Sjögren's syndrome, or chronic infections such as hepatitis B or C or acrodermatitis chronica atrophicans, as a result of repeated stimulation by an antigen. The clinical manifestations of polyclonal gammopathies are heterogeneous.