Serum protein polymorphisms in patients with primary Sjögren's syndrome.

The distribution of 4 serum proteins, the protease inhibitor alpha-1-antitrypsin, haptoglobin, transferrin and group-specific component or vitamin D-binding protein, were examined in 26 patients with primary Sjögren's syndrome and 208 healthy donor controls. No significant associations were found between any of the 4 systems and susceptibility to primary Sjögren's syndrome.