Avaliação estereológica da glândula salivar menor em pacientes com suspeita de Síndrome de Sjögren

Abstract

Sjögren's syndrome (SS) is a chronic inflammatory disease that affects the epithelial tissue of exocrine secretion glands, characterized by immunological changes as the infiltration of salivary and lacrimal glands by CD4 + T lymphocytes and B lymphocytes and the presence of autoantibodies against nuclear antigens. Genetic, hormonal and environmental factors are also important in its pathogenesis. In its diagnosis are used different criteria approved by the American College of Rheumotology (ACR) and the European Call Against Rheumatism (EULAR) which include semi-quantitative histological examination of samples of minor salivary glands sublabial processed in paraffin and stained with hematoxylin-eosin (foci scores; 50 lymphocytes/4 mm2). From the experimental point of view, this method is susceptible to bias, since it is based on an extremely limited area of tissue to be analyzed and has the potential to result in lower precision and accuracy. In an attempt to minimize such bias this proposal aims to standardize quantitative morphometric measurements in minor salivary gland biopsies (GSM) in SS suspected patients using stereological tools free of systematic bias, therefore, to ensuring precision and accuracy in morphometry. Such tools allow the detection of minimal morphological changes that would otherwise be overlooked by semi-quantitative assessment of routine. To this end, 10 biopsies of female patients suspected of having SS were histologically processed and embedded in acrylic resin hydroxyethyl methacrylate (Technovit 7100, Heraues-Kulzer, Germany). The blocks containing the biopsy fragments were randomly oriented to allow obtaining isotropic sections (Orientator). Serial sections (6-13/biopsy) were stained with eosin hematoxylin and Harrys. Fields of view chosen in a uniform, systematic and random way were photographed and analyzed quantitatively using appropriate software (IMOD 4.5/Stereology). Based on the criteria for the diagnosis of SS by the ACR, patients were divided into Group Non-SS (N = 4; 0-1 satisfied criterion) and SS group (N = 6; 2-3 criteria met). In evaluating the density of the components of GSMs (t-test), there was a significant increase in the proportion of lymphocytes in the SS group (p = 0.033). The other components showed no significant changes. The number of lymphocytes (p=0.025) and lymphoplasmacytic infiltrates (p = 0.038) were increased in the SS group, but no significant change was observed in the number of plasma cells and the volume of GSMs between groups. The CE of GSM Cavaliere volume remained below 5%. The number of evaluated sections influences the precision and accuracy of the results. There is no correlation between pathological score and stereological evaluation of lymphocytic infiltrates. The SS group was characterized by the presence of positive values for the Anti-SSA antibodies/Anti- SSB, high focal score and reduced dry score. We conclude that quantitative analysis of GSM by stereology provides detailed information that can implement and complement the laboratory and clinical findings in the diagnosis of Sjögren's syndrome.