The Autoimmune Profiles in the Etiopathogenesis of Granulomatous Lobular Mastitis

OBJECTIVES: Granulomatous lobular mastitis (GLM) is a chronic breast inflammation with low remission and high recurrence. This study aimed to investigate GLM patients' autoimmune profiles and their correlation with GLM etiopathogenesis. METHODS: T cells, regulatory T cells and CD4/CD8 ratio) and cytokines (IL-1β, IL-6, IL-8, IL-10, IL-12 and TNF-α) tests. Immunohistochemical staining (10 GLM, 10 FA normal tissues) detected IL-1β, IL-6, CD86 and CD206, and immunofluorescence (3 GLM, 3 FA normal tissues) evaluated CD86 and CD206 expression. Multivariate analysis was done using logistic regression. RESULTS: GLM featured granulomas with non-caseation necrosis and inflammatory cell infiltration. GLM patients showed higher C3 (P < 0.001), C4 (P < 0.001), IgE (P < 0.05), IgA (P < 0.05), IL-6 (P < 0.001), and IL-8 levels (P < 0.05). M1 (CD86) and M2 (CD206) macrophage markers were significantly higher in GLM than controls in both immunohistochemical and immunofluorescent staining (P < 0.05). The multivariate logistic regression analysis revealed that reproductive history (OR = 7.011, P < 0.01) and C3 expression level (OR = 5565.570, P < 0.001) were independent factors of GLM. CONCLUSIONS: The results highlighted the crucial role of elevated M1 and M2 macrophages in GLM inflammation. GLM was associated with reproductive history, C3, C4, IgE, IgA, IL-6, and IL-8, with reproductive history and C3 as independent risks.