Diagnostic evaluation and classification criteria in Sjögren's Syndrome

Our objective is to carry out a clinical study of the performance of the preliminary European classification criteria for Sjögren Syndrome and that of the criteria proposed by the American European Consensus Group.

Eighty-eight patients who had undergone a biopsy of the salivary gland on suspicion that they were suffering from Sjögren Syndrome were studied by two independent rheumatologists. Two pathologists independently revised the biopsies without knowing the diagnosis. With all of this information, the clinicians established, or did not establish, a diagnosis of primary Sjögren Syndrome or secondary Sjögren Syndrome. Finally, it was analysed whether or not the patients met the American European Consensus Group classification criteria and the preliminary European criteria for primary Sjögren Syndrome and secondary Sjögren Syndrome, and their sensitivity and specificity with respect to the clinical diagnosis were determined.

Clinicians estimated that 35 cases (39.8%) had primary Sjögren Syndrome (kappa 0.718) and 17 cases (19.3%) had secondary Sjögren Syndrome (kappa 0.761). The specificity and sensitivity of American European Consensus Group criteria, with regard to the clinical diagnosis, for primary Sjögren Syndrome were 97.2% and 48.6%, respectively. For secondary Sjögren Syndrome, the specificity was 97.2% and the sensitivity 64.7%. The preliminary European criteria for primary Sjögren Syndrome demonstrated a lesser specificity (75%), but a higher sensitivity (65.7%). In secondary Sjögren Syndrome the specificity reached 97.2% with sensitivity at 70.6%.

These results underline the difficulty in applying the Sjögren Syndrome classification criteria from the American European Consensus Group and the preliminary European criteria, in the diagnosis of individual patients.