Accuracy of Labial Salivary Gland Biopsy in Suspected Cases of Sjogren’s Syndrome

Introduction: Sjögren's syndrome (SS) is a chronic autoimmune disorder primarily characterized by dysfunction of the exocrine glands, leading to dryness of the eyes and mouth (sicca symptoms). Labial salivary gland biopsy (LSGB) is a key diagnostic tool used to confirm SS through histopathological analysis. LSGB evaluates lymphocytic infiltration in the salivary glands, a hallmark of SS. Despite its utility, discrepancies between LSGB results and other diagnostic methods, like serology and clinical examination, persist. Given the potential for false negatives, especially in early-stage or mild diseases, LSGB is often used alongside other diagnostic tools. Assessing its diagnostic accuracy and correlation with clinical, demographic, and serological factors is critical for improving diagnostic precision in SS. Objectives: This study aims to evaluate the diagnostic accuracy of LSGB in suspected SS cases, focusing on its correlation with clinical diagnoses, serological markers, and demographic factors. It also investigates whether LSGB can serve as a standalone diagnostic tool or should be integrated with other methods to enhance accuracy. Methods: This retrospective study evaluated 166 patients who underwent LSGB for suspected SS. Results were classified as "suggestive" or "not suggestive" of SS based on the histopathological evidence of lymphocytic infiltration. The relationship between LSGB outcomes and various demographics, serological markers, and the presence of other autoimmune diseases was examined. Statistical analyses assessed the significance of these associations. Categorical data were presented by frequency with percentage, and continuous data by mean with standard deviation (SD). Analyses were conducted using the Statistical Package for the Social Sciences (SPSS) version 27.0, with a P-value < 0.05 considered statistically significant. Results: Among the 166 patients, 55 (33.1%) had LSGB results suggestive of SS, while 111 (66.9%) had non-suggestive findings. A significant association was found between antinuclear antibody (ANA) positivity and suggestive LSGB results (P = 0.003), indicating that ANA-positive patients were more likely to show histopathological evidence of SS. No significant associations were found with other serological markers, except for a near-significant trend with anti-Ro (anti-Ro/SSA antibodies) (P = 0.062). Age did not significantly influence biopsy outcomes (P = 0.580). The presence of other autoimmune diseases was significantly associated with suggestive LSGB findings (P = 0.034). Conclusion: LSGB remains a valuable diagnostic tool for SS, especially when serological and clinical findings are inconclusive. The study confirmed significant associations between ANA positivity and suggestive LSGB results, as well as the influence of other autoimmune diseases on histopathological outcomes. While Schirmer's test may detect ocular dryness, its correlation with LSGB findings was limited. LSGB should not be used as a standalone diagnostic measure but integrated with other tools, including serology and imaging, to improve accuracy. Future research should explore combining LSGB with salivary gland ultrasonography (SGUS) to enhance the detection of SS, particularly in early-stage or seronegative patients.