Interferon Gamma Targeted Therapy: Is It Justified in Primary Sjogren's Syndrome?

Background: The pathomechanism of primary Sjogren syndrome (pSS) is multifactorial. Many cytokines take part in this process, including interferon. The study aimed to quantify certain cytokines involved in the pathomechanism of primary Sjogren syndrome (IL2, IL5, IL6, IL10, IL13, TNF alpha, IFN gamma) and determine their common clinical correlation. On this basis, we discuss the potential use of anti-cytokine drugs in pSS therapy. Methods: The study group consisted of adult patients with a confirmed diagnosis of pSS. Results: The most frequently detected cytokines were IFN gamma (82% of patients), TNF alpha (70%), IL6 (50%), and IL2 (42.5%). In all patients, except for one patient, IFN gamma was found in the presence of other specific cytokines. There was no difference in clinical symptoms, age, and laboratory test results between the group of patients with IL-6 + TNF alpha + IFN gamma positive cytokine, and the group of patients in whom they were not detected. There was no correlation between the presence of IL5, IL13, IL2, IL6, IL10, TNF alpha and musculoskeletal symptoms, skin lesions, glandular domains, pulmonary neurological, lymphadenopathy, biological and hematological domains in ESSDAI (p > 0.05). Conclusions: IFN gamma most likely plays a central role in the pathomechanism of the disease. We have not noticed a clinical correlation between the three most common cytokines (IL6, IFN gamma and TNF alpha), preliminary research results open up the possibility of searching for new treatments for pSS. The lower percentage of patients with detectable levels of TNF alpha and IL6 may explain the ineffectiveness of drugs targeting cytokines in clinical trials to date.