Sjogren Syndrome Antigen A2 (SSA2)

The cDNA that encodes the 60-kD Ro/SSA autoantigen recognized by autoantibodies in certain lupus erythematosus and Sjogren syndrome sera was cloned and sequenced by Deutscher et al. and confirmed with minor differences by Ben-Chetrit et al..Ro autoantigens are of clinical significance because antibodies directed against them are found in most patients with primary Sjogren syndrome, subacute cutaneous lupus erythematosus, neonatal lupus erythematosus, ANA-negative lupus erythematosus, and systemic lupus erythematosus-like disease secondary to homozygous C2 or C4 complement deficiency. Ro antibody is a frequent cause of congenital heart block. Alspaugh and Tan described 3 types of precipitating antibodies in the serum of Sjogren patients; they designated the 3 types as SS-A, SS-B, and SS-C.