Doença de Sjögren: intervenção nutricional e expressão de marcadores teciduais e salivares

Abstract

Sjögren's Disease (SD) is an autoimmune dysfunction characterized by dry mouth and eyes, resulting from lymphocytic infiltration and subsequent destruction and dysfunction of the exocrine salivary and lacrimal glands. The diagnosis and management of the disease are challenging, requiring multidisciplinary approaches and the investigation of new markers. The aim of this study was to explore two approaches: 1) A literature review to investigate the effects of nutritional interventions on dry mouth and eye outcomes in individuals with SD; 2) Investigation of tissue markers, such as sialic acid-binding immunoglobulin-like lectins (siglecs), with emphasis on siglec-5, and salivary markers, including siglec-5, Interleukin 6 (IL-6), and Interleukin 8 (IL-8). Siglecs are binding proteins found on immune system cells and, along with cytokines IL-6 and IL-8, regulate the inflammatory response, potentially playing a crucial role in the development and progression of SD. The methodology adopted consisted of: 1) A literature review in four databases on nutritional interventions and dry symptoms. Two researchers performed data extraction, the quality of the studies was analyzed, and the data were analyzed descriptively. 2) A cross-sectional study with individuals under investigation for SD at the Hospital das Clínicas of UFMG and the School of Dentistry of the Federal University of Minas Gerais (UFMG). The diagnosis of SD followed the clinical, microscopic, and laboratory parameters defined by the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) of 2016. Individuals whose diagnosis was inconsistent with SD were classified as non-Sjögren sicca and included as the comparison group. Tissue collection from the minor salivary glands was performed for immunohistochemical analysis of siglec-5. Saliva was used for the evaluation of siglec5/siglec-14, IL-6, and IL-8 by the Enzyme-linked Immunosorbent Assay (ELISA) method. The systematic review resulted in 18 articles, nine in humans and nine in animal models. The dietary interventions varied, addressing the use of supplements, vitamins, medicinal herbs, and modified diets. The main outcomes evaluated were salivary flow (unstimulated and stimulated), salivary gland inflammation, and ocular dryness, measured by the Schirmer test. The results indicated that caloric restriction, gluten-free diets, low-fat diets, and supplements such as resveratrol, triptolide, and polysaccharides derived from Lycium barbarum led to improvements in salivation and reduced inflammation in animal models of SD. In human studies, the results were more varied, with improvements in salivation observed after the use of vitamins, herbal supplements, gluten-free diets, liquid diets, and diets based on whole foods and plantbased foods. In the cross-sectional study, there was a significant increase in salivary concentration and tissue expression of siglec-5 among patients with SD, compared to the "non-Sjögren sicca" group. However, there was no difference in the concentration of IL-6 and IL-8 markers. Together, the results emphasize the need for further studies on nutritional approaches in the management of SD, as well as highlighting the role of siglec-5 as a potential salivary and tissue biomarker for the diagnosis and monitoring of the disease.