Antibodies against nuclear proteins occur in a number of autoimmune diseases.
Ro/SSA - Sjogren's syndrome, systemic lupus erythmatosus
La/SS - Sjogren's syndrome, systemic lupus erythmatosus
Sm - systemic lupus erythmatosus (low sensitivity, buy very high specificity)
RNP - systemic lupus erythmatosus, mixed connective tissue disease
centromere - CREST
anti-Scl 70 - systemic sclerosis (scleroderma)
anti-Jo1