Evaluation of histopathological results of minor salivary gland biopsies in patients with the diagnosis of Sjögren’s syndrome

Abstract

Objectives: This study aims to evaluate which of the histomorphological criteria defined in labial salivary gland biopsy are more valuable in diagnosing Sjögren’s syndrome (SS) and to examine its correlation with clinical and laboratory findings. Patients and methods: Between January 2005 and January 2019, a total of 927 patients (104 males, 823 females; mean age: 51 years; range, 19 to 85 years) who underwent minor salivary gland biopsies with the suspicion of SS were retrospectively analyzed. The American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) 2016 classification criteria were used for the classification of SS. We evaluated salivary gland biopsies histomorphologically for the presence and number of lymphocytic focus, as well as chronicity findings (acinar atrophy, ductal dilatation, fibrosis), the presence of lymphocytic infiltration, distribution, localization, ectopic germinal center, and mast cell count. The presence of accompanying diseases, clinical and laboratory findings including age, sex, the presence of dry eye and mouth, and autoantibodies for discriminating SS were noted. Histomorphologically, salivary gland biopsy which fulfilled the adequacy criteria for glandular tissue were compared with the other criteria used to diagnose SS. Results: Strong chronicity and diffuse lymphocytic infiltration were significantly higher in the SS group compared to the non-SS group (p<0.001). Lymphocytic focus score >1 was significantly higher in the SS group compared to the non-SS group (p<0.001). Strong chronicity, acinar atrophy, and ductal dilatation were significantly higher in the SS group compared to the non-SS group (p<0.001). Conclusion: More than one lymphocytic focus is the most valuable finding in diagnosing SS. However, it should be kept in mind that, in cases of SS, ductal dilatation, acinar atrophy, and chronicity may be present without lymphocytic infiltration.

Advances in cellular and molecular pathways of salivary gland damage in Sjögren’s syndrome

“…During the early and middle stages of the disease, there is an increase in foci infiltrated by immune cells, particularly B lymphocytes, around the ductal cells, leading to the formation of lymphoid tissue germinal centers (GC) within the SG and subsequent autoantibody production. Chronic inflammatory stimulation and injury result in a marked decline in follicular and ductal cells populations, which are gradually replaced by fibrous and adipose tissue ( 30 , 31 ). Electron microscopy has revealed degeneration and atrophy of SGECs, fatty infiltration within the cytoplasm, and swelling of intracellular organelles—pathological alterations that significantly diminish the secretory function of the SG ( 32 ).…”

Outline of Salivary Gland Pathogenesis of Sjögren’s Syndrome and Current Therapeutic Approaches

“…Salivary gland lesions in SS patients are characterized by dense periductal cellular infiltration and the loss of acini [ 18 ] ( Figure 1 (B1,B2)). In microscopic examinations of the salivary glands of SS patients, a periductal lymphocytic infiltrate of 50 or more cells per 4 mm 2 of tissue is counted as one focus, which is a histological marker of diagnostic criterion in SS [ 19 , 20 ]. When SS progresses, the number of foci with periductal cellular infiltration increases, and the percentage of B cells in the focus gradually increases.…”

“…In addition, structures similar to the GCs of lymphoid tissue, eGCs, are formed in the salivary glands and autoantibodies are produced in these lymphoid structures ( Figure 1 C). Following reductions in acinar cells and ductal cells, the space is often replaced by fibrous and adipose tissues [ 20 , 21 , 22 ]. When striated ductal cells are lost, terminal excretory ducts with a larger diameter will become dominant in the histology of inflamed salivary glands.…”