Clinical, histopathological, and immunohistochemical characteristics of patients with sicca syndrome with a focus score ≥ 1 in the minor salivary gland biopsy

Introduction: Sjögren’s syndrome is a systemic autoimmune disease. The usefulness of immunohistochemistry in minor salivary gland biopsies has been described to be helpful in indirectly characterizing the lymphocyte phenotype in difficult diagnosis cases.

Objective: To describe sociodemographic, clinical, serological, histopathological, and immunohistochemical variables in patients with sicca syndrome and a minor salivary gland biopsy focus score greater than or equal to one.

Materials and methods: We conducted an observational, retrospective study that included patients under study for potential sicca syndrome whose minor salivary gland biopsy was available and had obtained a focus score greater than or equal to one. Immunohistochemistry was performed on the minor salivary gland biopsy with chromogen red staining for CD8 T lymphocytes and brown staining for CD4 T lymphocytes. Expression ratio of CD20:CD3 and CD4:CD8 markers was determined with the MoticEasyScan Pro 6™ (MOTIC) device and the QuPath™ software. Qualitative variables were analyzed using the chi-square or Fisher’s exact test, and quantitative variables were analyzed according to their assumption of normality.

Results: Twenty-eight patients were analyzed: 16 patients had Sjögren’s syndrome, and 8 of them had polyautoimmunity. An association was found between atrophy in the minor salivary gland biopsy and development of polyautoimmunity (OR = 11.1; 95% CI: 1.12-112; p value = 0.033). The CD20:CD3 and CD4:CD8 ratios were normal, with no statistically significant differences between patients with and without Sjögren’s syndrome. In the subgroup of patients with Sjögren’s syndrome, CD4 T lymphocytes were predominant, with 15 cases out of 16 with CD4:CD8 ratios equal to or greater than 2:1.

Conclusions: Glandular atrophy was associated with the development of polyautoimmunity and a predominance of CD4 T lymphocytes in patients with Sjögren’s syndrome. This finding highlights the potential value of immunohistochemistry of minor salivary gland biopsies in this group.