Monoclonal immunoglobulins in the serum of patients with primary Sjögren's syndrome.

Monoclonal immunoglobulins (M Igl) were detected in the serum of 10 of 20 patients with primary Sjögren's syndrome (prim. SS), by using high resolution electrophoretic technique combined with immunofixation. The finding of three free lambda chains and two IgG lambda suggests that the lambda-expressing B-clones are involved in this process, but the class distribution is different from one series to another, and from one country to another. The prim. SS patients with multiogran disease have the higher incidence of M Igl.