Investigation of the relationships between miRNA 146, miRNA 21 parameters and apoptosis in psoriatic arthritis patients

Objective: Psoriatic arthritis is a chronic inflammatory autoimmune disease in which Rheumatoid factor (RF) is usually negative and the disease is characterized by articular destruction and bone resorption that could accompany psoriasis. Our purpose is to investigate the levels of M30 which is a marker in serum for apoptosis in this disease and M65 which is a marker of total cellular death; and microRNA 146a (miR146a), microRNA 21 (miR21) and interleukin 17A (IL-17A) which are thought to be related to the pathogenesis of the disease. Patient and Methods: 51 patients with diagnosis of PsA and 36 healthy controls were included in the study. Sociodemographic characteristics and history of the patients were collected. Serum levels of IL-17A, M30 and M65 parameters were measured with ELISA method. RNA isolation was performed first for determination of microRNA 146a and microRNA 21 levels in serum. Afterwards, complementer DNA (cDNA) was synthesized from these RNAs and amplification of selected microRNAs was obtained from determined primer by Real-time PCR. For evaluation of the results, student-t test was used for evaluating differences of parametric tests between the two groups and chi-square test was used for analysis of categorical data. Results: IL-17A level was found to be significantly higher in patient group compared to the control group (p=0.002). No statistically significant difference was present in relation to M30 (p=0.424); however, M65 parameter was significantly higher in the patient group (p=0.003). miR146a was observed to be expressed in both patient and control groups, no significant difference was present between the groups (p=0.590). miR21 expression was observed to be very low in patient and control groups. Therefore, no statistical evaluation was performed. Conclusions: In conclusion of our study, it had been thought that IL-17A is effective in PsA pathogenesis however, miR146a and miR21 have no roles in pathogenesis. In addition, both types of cellular death were observed in these patients, however, necrosis was more prominent than apoptosis.