SAT0206 MINOR SALIVARY GLAND BIOPSY AND SEROLOGICAL PROFILE IN PRIMARY SJÖGREN’S SYNDROME: A SINGLE TERTIARY REFERRAL CENTER EXPERIENCE
Authors: C. M. Gamboa-Alonso, M. J. Garza Martínez, B. R. Vázquez Fuentes, G. Figueroa-Parra, D. Vega-Morales, J. C. Riegatorres, J. D. Ángulo, D. Á. Galarza-Delgado
Journal: Annals of the Rheumatic Diseases (2020)

Background: Minor salivary gland biopsy (MSGB) portrays an important role as part of the diagnostic criteria of primary Sjögren’s syndrome (pSS) in the ACR/EULAR 2016 classification. Autoantibodies anti-Ro/SSA and anti-La/SSB embody part of these criteria. Patients with negative serology have been classified as pSS using MSGB outcomes in up to 40% of cases. Objectives: Compare MSGB and serological characteristics between pSS positive biopsy versus pSS negative biopsy and sicca groups. Methods: 174 subjects with sicca symptoms and MSGB biopsy were studied. Patients who fulfilled the ACR/EULAR 2016 criteria were classified as pSS. Serological profile: Rheumatoid factor (RF) (IgA, IgG and IgM), Anti La/SSB and Anti-Ro/SSA, available in 148 and 161 patients respectively, as well as histopathological characteristics of MSGB were recollected (Table 2). Table 1. Comparison between serological and histopathological characteristics in pSS and sicca groups Groups Positive biopsy n=95 Negative biopsy n=47 Sicca n=32 p 1 p 2 Age (years) mean, (SD) 54.59 (11.69) 50.17 (12.35) 49.18 (12.74) 0.42 (0.43-0.45) 0.78 Female, n (%) 92 (96.8) 46 (97.87) 32 (100) 0.779 0.58 Serological profile Rheumatoid factor IgA (%) 26 (27.4) 12 (25.5) 4 (12.5) 0.35 (0.47-0.49) 0.23 IgM (%) 47 (49.5) 25 (53.19) 7 (21.9) 0.34 (0.41-0.43) 0.015 IgG (%) 13 (13.7) 7 (14.8) 1 (3.1) 0.35 (0.45-0.47) 0.25 Positivity Anti-Ro/SSA, n (%) 47 (52.8) 12 (30) 2 (6.3) 0.015 (0.013-0.018) &lt;0.05 Positivity Anti-La/SSB, n (%) 17 (19.77) 3 (9.09) 0(0) 0.003 (0.002-0.004) 0.019 1 p of the comparison between pSS positive biopsy group vs pSS negative biopsy group 2 p of the comparison of the 3 groups Anti-Ro/SSA: available in pSS biopsy positive group n=89, pSS negative biopsy group n=40 Anti-La/SSB: available in pSS biopsy positive group n=86, pSS negative biopsy group n=33 Table 2. Histopathologic characteristics and comparison in pSS and sicca groups. Characteristics Positive biopsy n=95 Negative biopsy n=47 Sicca n=32 p 1 p 2 Lobules, n (SD) 12.45 (7.24) 15.2 (9.95) 11.84 (9.84) 0.19 (0.13 0.15) 0.43 Foci, n (SD) 3.23 (3.16) 0(0) 0(0) &lt;0.05 &lt;0.05 Atrophy, n (%) 27 (28.4) 9 (9.5) 7 (21.9) 0.007 0.57 Adipose infiltration, n (%) 22 (23.2) 12 (12.6) 6 (18.8) 0.12 NA Ductal dilatation, n (%) 22 (23.2) 8 (8.4) 6(18.8) 0.05 0.73 1 p of the comparison between pSS positive biopsy group vs pSS negative biopsy group 2 p of the comparison of the 3 groups Comparison between subgroups according to biopsy status was performed. Differences between serology and MSGB were reported using Chi square, a p&lt;0.05 was considered statistically significant Results: 95(54.59%) pSS patients with positive biopsy, 47 (27. 02%) pSS with a negative biopsy and 32 (18.39%) sicca patients were included. A positive serology profile (RF, Anti-Ro/SSA, Anti-La/SSB) was found more frequently in the pSS positive biopsy cohort when compared to the pSS negative biopsy and sicca groups (Table 1). Histopathological characteristics of MSGB are described in Table 2. Sicca group had more alterations when compared to pSS negative biopsy group. Conclusion: Histopathological alterations in MSGB (atrophy, adipose infiltration and ductal dilatation) can act as confounding data at biopsy interpretation since they were found in close prevalence in the pSS positive biopsy group and sicca group and should be carefully taken into account at diagnosis. A positive serologic profile was associated with more histopathological alterations in the positive biopsy group. References: [1]Wicheta S, Van der Groen T, Faquin W, August M. Minor Salivary Gland Biopsy—An Important Contributor to the Diagnosis of Sjögren Syndrome. Journal of Oral and Maxillofacial Surgery. 2017;75(12):2573-2578. Disclosure of Interests: None declared