Serology and histology in Sjögren's syndrome diagnosis: a retrospective accuracy study.

Introduction: Sjögren's syndrome (SS) presents complex diagnostic challenges due to its multi-organ involvement, often leading to misdiagnosis, which can result in unnecessary treatments, elevated healthcare costs, and significant impacts on patient quality of life. Accurate diagnosis is therefore critical, utilising ACR/EULAR criteria that include both labial minor salivary gland (LMSG) biopsy and anti-SSA antibodies.

Methods: This retrospective study analysed medical records of 87 adults suspected of primary SS, who underwent both anti-SSA serology and LMSG biopsy. We evaluated the diagnostic accuracy of these tests under existing ACR/EULAR criteria and a newly proposed 'modified ACR/EULAR criteria - ClinDx'. Statistical analysis included Pearson's chi-square test for the association between test results and disease status and receiver operating characteristic (ROC) curves to assess the sensitivity and specificity of the diagnostic models.

Results: Utilising ACR/EULAR criteria, 40 patients were diagnosed with SS, while 47 were categorised as non-diseased. The ClinDx criteria application resulted in 32 SS diagnoses and 55 non-diseased classifications, highlighting discrepancies in patients with low anti-SSA titers (< 200 MFU). Statistical analysis confirmed a significant association (p < 0.001) between test results and disease status, indicating the robustness of the modified criteria in enhancing diagnostic accuracy.

Conclusions: This study underscores the utility of integrating serological tests and histological biopsies in diagnosing SS. While anti-SSA antibodies provide a good preliminary screening tool, the specificity of LMSG biopsies is indispensable. Refining both serological and histological assessments per ClinDx criteria can improve diagnostic accuracy, aiding in better management of SS and reducing healthcare burdens.