Cellular composition of the minor salivary gland inflammatory infiltrates as an additional diagnostic criterion for primary Sjogren’s syndrome

Primary Sjogren’s syndrome (pSS) is one of the most frequent among the connective tissue diseases. Histological examination of the minor salivary gland (MSG) is important diagnostic method. The currently established histological criteria for pSS do not have absolute sensitivity and specificity, which makes the search for additional morphological hallmark relevant.

Aim – to study of the qualitative and quantitative composition of cellular populations inflammatory infiltrates in MSG pSS patient with the assessment of additional diagnostic criteria for disease based on the data obtained.

Subjects and methods. The study included 55 patients with a diagnosis of pSS according to the criteria of ACR/ EULAR 2016. The control group consisted of 18 healthy volunteers. A MSG biopsy was performed all subjects for histological and immunohistochemical studies with a quantitative assessment of CD3+, CD4+, CD8+, CD20+, CD21+, CD68+, CD138+ cells. Statistical data analysis was performed using the Statistica 10.0 for Windows (StatSoft Inc., USA). For comparison of quantitative traits, the Mann – Whitney U-test was used. To determine the diagnostic threshold of the number of a ROC analysis was performed. An operating characteristic curve was plotted. The area under the curve (AUC), diagnostic specificity, diagnostic sensitivity, diagnostic accuracy, likelihood ratio of the positive and negative results of the test were calculated. The construction of classification models, including the number of different cell types, was carried out using linear discriminant analysis.

Results and discussion. The number of CD3+, CD4+, CD8+, CD20+, CD138+ cells in 4 mm2 (area of section) was significantly higher in the pSS group. The largest AUC were observed for the quantitative evaluation of CD3+ cells – 0.88 [95% confidence interval (CI): 0.80–0.96] and CD8+ cells – 0.87 [95% CI: 0.79–0.95], which at the specified diagnostic thresholds corresponded to the sensitivity of 70.9% [95% CI: 57.86–81.23] and 65.45% [95% CI: 52.25–76.64], specificity of 94.4% [95% CI: 74.24–99.72] and 100% [95% CI: 82.41–100], respectively. The CD21+ follicular dendritic cells were detected only in MSG of pSS group. AUC for quantitative assessment of these cells was 0.65 [95% CI: 0.52–0.78], sensitivity 29.1% [95% CI: 18.77–42.14] and specificity 100% [95% CI: 82.41–100]. Using the method of discriminant analysis, we designed classification models that included various combinations of the studied markers. The highest AUC among all possible combinations was observed for the decimal logarithms of the number of CD3+ and CD68+ cells – 0.92 [95% CI: 0.85–0.98], which for a given diagnostic threshold corresponded sensitivity – 81.82% [95% CI: 69.67–89.81], specificity – 94.4% [95% CI: 74.24–99.72].

1. Nasonov EL (ed.). Rheumatology. Russian clinical guidelines. Moscow:GEOTAR-Media;2017:464 (In Russ.).

2. Qin B, Wang J, Yang Z, Yang M, Ma N, Huang F, et al. Epidemiology of primary Sjögren’s syndrome: A systematic review and meta-analysis. Ann Rheum Dis. 2015;74:1983-1989. doi: 10.1136/annrheumdis-2014-205375

3. Shiboski CH, Shiboski SC, Seror R, Criswell LA, Labetoulle M, Lietman TM, et al. 2016 American College of Rheumatology/ European League Against Rheumatism classification criteria for primary Sjögren’s syndrome: A consensus and data-driven methodology involving three international patient cohorts. Arthritis Rheumatol. 2017;69:35-45. doi: 10.1002/art.39859

4. Guellec D, Cornec D, Jousse-Joulin S, Marhadour T, Marcorelles P, Pers JO, et al. Diagnostic value of labial minor salivary gland biopsy for Sjögren’s syndrome: A systematic review. Autoimmun Rev. 2013;12:416-420. doi: 10.1016/j.autrev.2012.08.001

5. Bodeutsch C, de Wilde PC, Kater L, van Houwelingen JC, van den Hoogen FH, Kruize AA, et al. Quantitative immunohistologic criteria are superior to the lymphocytic focus score criterion for the diagnosis of Sjögren’s syndrome. Arthritis Rheum. 1992;35:1075-1087. doi: 10.1002/art.1780350913

6. van Woerkom JM, Kruize AA, Barendregt PJ, Kater L, Hené R, Bootsma H, et al. Clinical significance of quantitative immunohistology in labial salivary glands for diagnosing Sjogren’s syndrome. Rheumatology (Oxford). 2006;45:470-477. doi: 10.1093/rheumatology/kei191

7. Fisher BA, Jonsson R, Daniels T, Bombardieri M, Brown RM, Morgan P, et al. Standardisation of labial salivary gland histopathology in clinical trials in primary Sjogren’s syndrome. Ann Rheum Dis. 2017;76:1161-1168. doi: 10.1136/annrheumdis-2016-210448

8. Navazesh M, Kumar SKS. Measuring salivary flow. Dent Assist J. 2008;139:35S-40S. doi: 10.14219/jada.archive.2008.0353

9. Teppo H, Revonta M. A follow-up study of minimally invasive lip biopsy in the diagnosis of Sjögren’s syndrome. Clin Rheumatol. 2007;26:1099-1103. doi: 10.1007/s10067-006-0457-1

10. Quartuccio L, Baldini C, Bartoloni E, Priori R, Carubbi F, Corazza L, et al. Anti-SSA/SSB-negative Sjögren’s syndrome shows a lower prevalence of lymphoproliferative manifestations, and a lower risk of lymphoma evolution. Autoimmun Rev. 2015;14:1019-1022. doi: 10.1016/j.autrev.2015.07.002

11. Christodoulou MI, Kapsogeorgou EK, Moutsopoulos HM. Characteristics of the minor salivary gland infiltrates in Sjögren’s syndrome. J Autoimmun. 2010;34:400–407. doi: 10.1016/j.jaut.2009.10.004

12. Jonsson MV, Skarstein K. Follicular dendritic cells confirm lymphoid organization in the minor salivary glands of primary Sjögren’s syndrome. J Oral Pathol Med. 2008;37:515-521. doi: 10.1111/j.1600-0714.2008.00674.x

13. Braun M, Melchers I, Peter HH, Illges H. Human B and T lymphocytes have similar amounts of CD21 mRNA, but differ in surface expression of the CD21 glycoprotein. Int Immunol. 1998;10(8):1197-1202.

14. Daridon C, Pers JO, Devauchelle V, Martins-Carvalho C, Hutin P, Pennec YL, et al. Identification of transitional type II B cells in the salivary glands of patients with Sjögren’s syndrome. Arthritis Rheum. 2006;54:2280-2288. doi: 10.1002/art.21936

15. Le Pottier L, Devauchelle V, Fautrel A, Daridon C, Saraux A, Youinou P, et al. Ectopic germinal centers are rare in Sjogren’s syndrome salivary glands and do not exclude autoreactive B cells. J Immunol. 2009;182:3540-3547. doi: 10.4049/jimmunol.0803588

16. Ushio A, Arakaki R, Yamada A, Saito M, Tsunematsu T, Kudo Y, et al. Crucial roles of macrophages in the pathogenesis of autoimmune disease. World J Immunol. 2017;7(1):1-8. doi: 10.5411/wji.v7.i1.1

17. Ushio A, Arakaki R, Otsuka K, Yamada A, Tsunematsu T, Kudo Y, et al. CCL22-producing resident macrophages enhance T cell response in Sjögren’s syndrome. Front Immunol. 2018;9:2594. doi: 10.3389/fimmu.2018.02594