Primary Sjögren’s syndrome (pSS) is a connective tissue disease characterized by a wide spectrum of clinical features, extending from a benign glandular disease to an aggressive systemic disorder and/or lymphoma. The pathogenesis of Sjögren’s syndrome (SS) is not completely understood, but it is assumed that pathogenesis of SS is multifactorial. The studies based on the animal models of SS provided significant insight in SS disease pathogenesis and management. The aim of this review is to summarize current studies on animal models with primary SS-like symptoms and discuss the impact of these studies on better understanding pathogenesis and management of Sjögren’s syndrome. Databases PubMed, Web of Science, Scopus and Cochrane library were searched for summarizing studies on animal models in SS. Available data demonstrate that animal models are highly important for our understanding of SS disease.

Background and Objectives: Patients with Sjögren’s disease (SjD) do not experience any improvement in gastroesophageal reflux disease (GERD) symptoms after SjD treatment, and in some patients, reflux even worsens. It is important to note that GERD manifests itself through typical and atypical symptoms, the latter of which may include eye damage, as evidenced by a growing body of research. When SjD patients were prescribed medication to treat GERD, their condition improved at the same time. Therefore, we aim to investigate whether there is a link between ocular dryness and gastroesophageal reflux disease (GERD) in patients with Sjögren’s disease (SjD). Materials and Methods: Our study included 27 patients with SjD according to the 2016 American College of Rheumatology and the European League Against Rheumatism (ACR/EULAR) Sjögren’s syndrome Classification Criteria, and 28 patients with non-autoimmune sicca syndrome due to GERD (nonautoimmSicca). Results: The study involved 55 participants, 48 (87.3%) women and 7 (12.7%) men. The median age was 54 years (IQR 49–64). A total of 41 subjects (74.5%) had GERD, and 20 subjects (36.4%) tested positive for Helicobacter pylori: 13 (48.1%) and 1 (3.7%) in the SjD group, and 28 (100.0%) and 19 (67.9%) in the nonautoimmSicca group, respectively. A significant difference in asymmetric tear secretion (p < 0.001) was found between the nonautoimmSicca and SjD patients, with values of 5 (3–10) mm/5 min and 1 (0–2) mm/5 min, respectively. A low correlation was detected between sialometry results and tear secretion asymmetry (r = 0.48, p < 0.001). An increase of 1 mm/5 min in the tear secretion asymmetry between the eyes was associated with a 2.04-fold increase in the odds ratio for having GERD (95% CI 1.25–3.32, p = 0.004), and was associated with a 1.9-fold increase in the odds ratio for having GERD (95% CI 1.04–3.49, p = 0.038) in patients with SjD. The presence of Helicobacter pylori is associated with asymmetric tear secretion [95% CI 1.22 (1.05–1.41, p = 0.010)]. Conclusions: Asymmetric tear secretion between the eyes is associated with the odds of having GERD. Patients with non-autoimmune sicca syndrome due to GERD have significantly greater asymmetry in tear secretion compared to those diagnosed with Sjögren’s disease.