Levels of BAFF in serum in primary biliary cirrhosis and autoimmune diabetes.

Levels of the B-cell activating cytokine BAFF are increased in serum in various autoimmune disease, and particularly Sjögren's syndrome in which there is evident B-lymphocyte proliferation. Studies in two autoimmune disease in which B-cell proliferation is less evident, primary biliary cirrhosis (PBC), and adult-onset Type 1 diabetes, showed serum levels of BAFF to be mostly in the normal range. A single raised level among eight sera tested in one patient studied with autoimmune hepatitis (AH) coincided with a relapse of the disease. Increased levels of BAFF in human sera, indexing a potent antigenic drive on B-cell production and survival in some autoimmune diseases, may mark only particular stages in the evolution of such diseases.