AB0332 IS MINOR SALIVARY GLAND HISTOLOGY A GOOD BIOMARKER SCORE TO PREDICT THE EXTRAGLANDULAR INVOLVEMENT IN PATIENTS WITH PRIMARY SJOGREN’S SYNDROME?
Authors: A. Martins, R. Ferreira, S. Pimenta, L. Costa
Journal: Annals of the Rheumatic Diseases (2021)

Background: The minor salivary gland biopsy (MSGB) is considered the “ gold standard ” for the diagnosis of primary Sjögren’s syndrome (pSS). The histological hallmark is focal lymphocytic infiltration with the presence of 50 or more lymphocytes per 4 mm 2 (focus score ≥ 1). Several studies have documented the association between focus score (FS) and extraglandular involvement, suggesting that FS could be used as a histological index of disease severity and a prognostic tool. Objectives: To investigate the association between the FS and clinical, haematological and serological findings in a cohort of patients with pSS. Methods: We performed a retrospective analysis of patients with pSS who fulfilled the ACR/EULAR 2016 classification criteria that were submitted to a minor salivary gland biopsy (MSGB). Demographic data, disease duration, extraglandular involvement and histopathologic data were collected and analyzed. The severity of histologic changes was graded according to the Chisholm and Mason scoring system and the FS was determined. Fisher’s exact test/Chi-square test and Mann-Whitney U test were used to compare the patients with and without positive biopsy (FS &lt;1 versus FS ≥ 1). Futhermore, to investigate the association between the quantitative value of focus score in groups with and without each extraglandular manifestations the authors used the Mann-Whitney U test. P-value &lt; 0.05 was considered statistically significant. Results: A total of 59 pSS patients were included. Regarding the histopathologic pattern, 40 of 59 patients had a FS ≥ 1, while 19 patients had a FS &lt;1. Although described as having FS ≥ 1, the pathologists failed to report the absolute value in 11 of 40 (27,5%) patients. Germinal center-like structures were found in 1 (1,7%) patient. The demographic and clinical features in pSS patients with FS &lt;1 and with FS ≥ 1 are presented in table 1. Anti-SSA was strongly associated with FS &lt;1 (p &lt;0,001). No significant difference in demographic and clinical features were found between the two groups. Table 1. Demographic and clinical features in pSS patients with FS &lt;1 and with FS ≥ 1 (* Fisher’s exact/Chi-square test; † T-test; ‡ Mann-Whitney U test). FS &lt;1 (n=19 ) FS ≥ 1 (n=48 ) p-value Gender (female), n (%) 17 (89,5) 34 (85,0) 0,639 * Current age (years) (mean ± SD) 60,11+-13,39 54,78 (+-13,48) 0.16 † Disease duration (years) (median, P25-P75) 3 (2-7) 4 (3-5) 0,507 ‡ Extraglandular involvement Arthralgias/Arthritis, n (%) 6 (31,7) 22 (55,0) 0,092 * Myositis, n (%) 0 (0) 1 (2,5) - Pulmonary involvement, n (%) 3 (15,8) 5 (12,5) 0,704 * PNS involvement, n (%) 0 (0) 1 (2,5) - CNS involvement, n (%) 0 (0) 1 (2,5) - Cutaneous involvement, n (%) 1 (5,3) 1 (2,5) 0,544 * Lymphoma, n (%) 0 (0) 2 (5,6) - Haematological and serological characteristics Leukocytopenia, n (%) Hypergammaglobulinaemia, n (%) 10 (52,6) 16 (40,0) 0,361 * RF positivity, n (%) 5 (26,3) 10 (25,6) 1 * ANA positivity, n (%) 18 (94,7) 34 (85,0) 0,411* Anti-SSA positivity, n (%) 19 (100) 21 (52,5) &lt; 0,001 * Anti-SSB positivity, n (%) 7 (36,8) 12 (32,5) 0,742 * ESSDAI score (median, P25-P75) 2 (0-8) 2 (0-7,25) 0,816 ‡ When comparing the quantitative value of FS in groups with and without each extraglandular manifestation, the authors found that patients with articular involvement had a significant higher FS value than patients without articular manifestations (p=0.037). No other significant association was found. Conclusion: Regarding the clinical manifestations, we didn’t find a significant difference between patients with a FS &lt; 1 and those with a FS ≥ 1. Anti-SSA was strongly associated with a FS &lt;1, which corroborates the importance of anti-SSA for the pSS diagnosis in patients with a negative biopsy. We found that a higher FS value was associated with articular involvement. However, this study has limitations such as a small sample and a low incidence of extraglandular manifestations. In conclusion, more studies are needed to clarify the associations found in the literature. Disclosure of Interests: None declared