Ab0687 chronic sclerosing sialadenitis, is it a sjögren’s syndrome or not?

Background The Sjögren’s syndrome (SS) is a chronic autoimmune disease. The classification criteria of SS have been evolved through the decades. Recent in 2016, American college of rheumatology (ACR)–European Alliance of Associations for Rheumatology (EULAR) classification requires at least one positive finding in either the labial salivary gland biopsy or anti-Ro (SSA) serology for the confirmation of SS. Chronic sclerosing sialadenitis (CSS) is unusual, underrecognized condition that affects the salivary gland, reported by H. Kutter at first. [1] Though the CSS already has been eliminated from the diagnostic criteria of SS, there is controversy in the meaning of CSS in SS. And that makes it difficult to determine whether the patient who suffers from sicca symptom is SS or not. Objectives Investigating the clinical meaning of CSS in association with SS by comparing the clinical and laboratory findings, we provide the extent of understanding CSS, the rare pathologic condition of salivary gland. Methods This study is a single center retrospective study, including patients confirmed as CSS via biopsy in Seoul St. Mary’s Hospital from 2000 to 2022. (1) Patients with history of head and neck radiation, (2) graft-versus-host disease (GVHD), (3) IgG4-RD, (4) positive biopsy result in IgG4 immunohistochemistry (IHC) staining, and (4) insufficient pathologic result to distinguish IgG4-RD from CSS were excluded. 21 of 27 CSS patients were eligible to our analysis. 4 of positivity with IgG4 in IHC staining positivity, 1 of GVHD, and 1 of prior head and neck radiation were excluded. We assessed 239 patients from 341 of the Korean Initiative of primary SS (KISS) prospective cohort study as SS control group, eligible to 2016 classification. Results In CSS group, only 1 of 21 was diagnosed as SS. Table 1 summarizes the result. ‘CSS as SS’ consisted of CSS patients meeting 2016 criteria, assuming that the CSS could be a part of SS pathology. Table 1. The clinical characteristics of chronic sclerosing sialadenitis. CSS (n=21) SS (n=239) N p CSS as SS (n=15) N p Female sex 19 (90.5%) 237 (99.2%) 260 0.034 15 (100.0%) 254 1.000 Age at diagnosis 50.6 ± 12.2 61.9 ± 9.5 260 <0.001 64.1 ± 6.8 254 <0.001 BMI (kg/m 2 ) 22.1 ± 3.7 22.2 ± 2.9 260 0.843 21.6 ± 3.2 254 0.873 Sicca symptom Dry eye 15 (71.4%) 223 (93.3%) 260 0.004 11 (73.3%) 254 0.022 Dry mouth 18 (85.7%) 227 (95.0 %) 260 0.110 13 (86.7%) 254 0.196 Diagnostic items for SS Salivary gland biopsy 0 (0.0%) 215 (90.0%) 260 <0.001 - Anti-Ro (SSA) Ab 2 (10.0%) 185 (84.1%) 240 <0.001 1 (6.7%) 235 <0.001 Schirmer test 1 (14.3%) 169 (72.2%) 241 0.003 1 (25.0%) 238 0.072 Ocular staining score 0 (0.0%) 64 (43.2%) 155 0.042 0 (0.0%) 152 0.139 Unstimulated salivary flow test 15 (78.9%) 78 (82.1%) 114 0.750 15 (100.0%) 110 0.121 Unstimulated salivary flow rate (ml/min) 0.08 ± 0.10 0.10 ± 0.19 107 0.856 0.035 ± 0.033 103 0.311 EGM 0.4 ± 0.7 1.1 ± 1.0 260 0.001 0.4± 0.7 254 0.006 ESSDAI 1.0 ± 2.5 3.1 ± 3.7 259 <0.001 1.3 ± 2.8 254 0.005 ESSPRI 4.8 ± 1.6 5.4 ± 1.8 206 0.131 4.6 ± 1.7 200 0.004 ANA Titer 9 (45.0%) 220 ± 560 165 (89.2%) 610 ± 670 205 204 <0.001 <0.001 8 (53.3%) 280 ± 640 200 199 0.001 <0.001 Anti-La (SSB) Ab 1 (8.3%) 112 (51.1%) 231 0.010 0 (0.0%) 228 0.003 Rheumatoid factor Titer 4 (22.2%) 12.0 ± 18.7 125 (65.8%) 98.9 ± 206.2 208 208 0.001 <0.001 4 (28.6%) 14.8 ± 20.4 204 204 0.012 0.001 Anti-CCP Ab 0.2 ± 0.3 23.2 ± 82.4 200 <0.001 0.1 ± 0.3 199 <0.001 Stimulated salivary flow rate (ml/min) 0.65 ± 0.57 0.54 ± 1.15 103 <0.001 0.50 ± 0.41 99 0.006 Abbreviations: BMI, body mass index; Ab, antibody; EGM, extraglandular manifestations; ESSDAI, EULAR Sjögren’s syndrome disease activity index; ESSPRI. EULAR Sjogren’s syndrome patient reported index. Conclusion The CSS were once inculeded in pathologic category of SS. However, it is a distinct phenotype separated from SS in such aspects of the (1) age of onset, (2) proportion of occular manifestation, (3) autoimmune profiles, and (4) stimulated salivary flow rate. Thus, physicians should also consider the possibility of CSS in old age patient with xerostomia. References [1]Küttner H. “Über entzündliche Tumoren der Submaxillar-Speicheldrüse.” Beitr Klin Chir, 15 (1896): 815-828 Acknowledgements: NIL. Disclosure of Interests None Declared.