Anti-Ro (SSA)/La (SSB) antibodies and Sjögren's syndrome.

Antibodies to Ro (SSA) and La (SSB) cellular ribonucleoprotein complexes are found in the circulation of patients with Sjögren's syndrome (SS), mainly in those with the primary form of the syndrome. Their presence is associated with long disease duration, earlier disease onset, parotid gland enlargement, systemic manifestations and also with hypergammaglobulinemia, rheumatoid factors and monoclonal type II cryoglobulins. While anti-Ro (SSA) antibodies are not specific for SS, anti-La (SSB) antibodies seem to be specific. Studies of HLA class II molecules in Ss patients with and without these antibodies have shown that their production is under genetic control. Finally, there is no conclusive evidence relating pathogenetically these autoantibodies to tissue destruction in SS.