SSB (ANTIBODY)

Autoantibodies targeting Sjogren syndrome (SS)A (Ro), SSB (La), ribonucleoprotein (RNP), and Smith (Sm) proteins, collectively known as extractable nuclear antigens (ENA), play a crucial role in the landscape of systemic rheumatic diseases. Hypro Diagnostics recognizes the significance of these autoantibodies in the diagnostic journey of patients with connective tissue diseases. SSA or Ro, characterized by 52 kDa and 60 kDa protein antigens along with cytoplasmic RNA species, exhibits significant associations with diverse connective tissue diseases. Notably, it is prevalent in Sjogren syndrome (up to 90% of cases), systemic lupus erythematosus (SLE) (40%-60% of cases), and rheumatoid arthritis. SSA antibodies demonstrate notable links with childhood SLE, neonatal SLE, and congenital heart block in infants born to mothers with SLE. Furthermore, they are implicated in extraglandular inflammation features in SLE patients, including vasculitis, purpura, cytopenias, and adenopathy. In contrast, SSB or La, consisting of a 48-kDa protein combined with RNA species, is predominantly found in patients with Sjogren syndrome or SLE, occurring in approximately 60% and 15% of cases, respectively. Remarkably, SSB antibodies are infrequent in the absence of SSA antibodies. This nuanced understanding of the associations between these autoantibodies and various connective tissue diseases contributes to diagnostic insights and underscores their clinical significance in autoimmune contexts. For Hypro Diagnostics, recognizing and elucidating these specific autoantibodies is paramount, providing valuable information for clinicians in their diagnostic and prognostic assessments, thereby aiding in the tailored management of patients with these complex autoimmune conditions.