Clinical manifestations correlated to the prevalence of autoantibodies in a large (n=321) cohort of patients with primary Sjögren's syndrome: a comparison of patients initially diagnosed according to the Copenhagen classification criteria with the American-European consensus criteria.

In this study we imposed the recently described American-European consensus criteria for primary Sjögren's syndrome (pSS) on a large cohort of patients originally classified according to the Copenhagen set of criteria. Of the 321 patients fulfilling the Copenhagen criteria, 205 conformed to the Consensus criteria. When comparing clinical manifestations and laboratory findings between the two groups defined by different standards we found only small variations. Thus, the consequence of using the Consensus criteria in daily clinical practice will lead to the exclusion of a considerable proportion of patients with classical features of pSS. The main reason for this discrepancy is probably the absolute requirement of a positive test for anti-Ro/La or a characteristic lymphocytic infiltration in the labial gland biopsy. The sensitivity and specificity of testing for autoantibodies to Ro-52, Ro-60, and La were calculated for each set of criteria. Antibodies to La but not to Ro-52 or Ro-60 were strongly correlated to internal organ (kidney, lung, liver) dysfunction in pSS (OR 6; 95% CI 3-12), p<0.0001. Although presence of ANA was slightly more prevalent among patients with internal organ involvement it did not reach statistical significance. The fine speckled ANA pattern was most often found followed by the homogeneous and centromere pattern. Individual ANA patterns did not correlate with any particular organ manifestation.