The relationship between idiopatic granulomatous mastitis and II-37

Idiopathic granulomatous mastitis (IGM) is a non-infectious inflammatory disorder of the breast characterized by non-caseous granulomas. It is a chronic granulomatous inflammatory disease frequently seen in young fertile women, the cause of which has not been clearly understood. Immunosuppressive agents and surgical interventions are used in the treatment. LL-37 is a cathelicidin-derived antimicrobial peptide with immunomodulatory properties that are effective in innate immunity. In addition, IL-36, galectin 3, TLR3 are effective in autoimmunity with proinflammatory properties. With this study, it was aimed to investigate possible changes in the levels of LL-37, IL-36, galectin 3 and TLR3 in IGM. 36 female patients with biopsy-confirmed IGM and 37 healthy controls were included in the study. The serum samples of the subjects LL-37, IL 36, galectin 3 and TLR3 levels were studied using the Elisa method. LL-37 and galectin 3 levels in the tissue were analysed. 16 IGM patients whose paraffin blocks were eligible for re-study and 10 patients who underwent mammoplasty due to cosmetic reasons for the control group were included in the study for tissue examinations. Immunoreactivity in stainings were based on the prevalence (0.1: <25%, 0.4: 26-50%, 0.6: 51-75%, 0.9: 76-100%) and severity (0: no, +0.5: very little, +1: little, +2: medium, +3: severe) and histoscore was created (histoscores = prevalence × severity). The data were evaluated using appropriate statistical analysis and p<0.05 was considered statistically significant. When the patient and control groups included in the study were compared, there was no significant difference in mean age. In serum samples, LL-37, IL-36, galectin 3 and TLR3 levels were statistically significantly lower in the IGM group compared to the control group (p<0.001 for each). In biopsy samples, LL-37 level was found to be significantly lower in IGM group compared to the control group (p<0.001). However, no statistically significant difference was detected in tissue galectin 3 levels between the both groups. In our study, the decreased levels of LL-37, IL-36, galectin 3 and TLR3 were found in serum samples from patients with IGM disease whose etiology was not clearly understood. In addition, it was showed that in patients with IGM, LL-37 levels were decreased at the tissue level. These results suggest that LL-37 a cathelicidin may affect the pathogenesis of IGM. Key words: Idiopathic granulomatous mastitis, LL-37, interleukine-36, galectin 3