Risk factors for positive minor salivary gland biopsy findings in Sjögren's syndrome and dry mouth patients

Objective. To investigate risk factors for positive minor salivary gland biopsy results in Sjögren's syndrome (SS) and dry mouth patients. Methods. A total of 289 patients with dry mouth symptoms were evaluated. Potential risk factors for positive minor salivary gland biopsy results (> 1 focus of lymphocytes) were studied in 2 phases. In phase 1, predictor variable candidates were identified for the test study (phase 2). Odds ratios were calculated for predictor variables. Results. IgG, IgA, keratoconjunctivitis sicca, and sex, identified as the best predictor variables from phase 1 data, were included in a logistic regression model using phase 2 data. Only IgG demonstrated association with biopsy results (X² = 20.4, P = 0.0001). An elevated IgG level (> 1,482 mg/dl) had a high specificity (97% and 97%), high positive predictive value (PPV) (97% and 97%), but poor sensitivity (40% and 45%) in predicting positive biopsy results and SS, respectively. Conclusion. Elevated serum IgG levels best predicted a positive biopsy result and SS with high PPV and specificities.