Decreased Serum and Tissue Levels of Isthmin‐1 in Patients With Idiopathic Granulomatous Mastitis: A Case–Control Study

OpenAlex · İngilizce

Background: Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory breast disorder with unclear etiology. Isthmin-1 (ISM1), a secreted protein with anti-inflammatory properties, has not been previously studied in IGM. Objective: This study aimed to compare serum and tissue ISM1 levels between IGM patients and healthy controls, and to assess its diagnostic potential. Methods: This case-control study included 30 women with histopathologically confirmed IGM and 30 age-matched controls undergoing breast reduction surgery. Serum and tissue ISM1 levels were measured using ELISA. Receiver operating characteristic (ROC) analysis assessed the diagnostic performance of serum ISM1. Results: < 0.001). ROC analysis demonstrated moderate diagnostic accuracy (area under the curve [AUC]: 0.768, 95% CI: 0.651-0.885; optimal cutoff: 676.13 pg/mL; sensitivity: 66.7%; specificity: 83.7%). Standard inflammatory markers showed no significant differences between groups. Conclusions: Reduced ISM1 levels in IGM patients suggest potential involvement in disease pathogenesis. While serum ISM1 shows promise as a supportive biomarker, larger studies, including other inflammatory breast conditions, are needed to confirm specificity and clinical utility.