Background Sarcoidosis is Th1-mediated chronic granulomatous disease characterized by non-caseating granulomas formation. Interleukin-23 (IL-23) is a protein encoded by the IL-23 gene in humans and is produced by dendritic cells and macrophages. IL-23 and IL-12 share a common p40 subunit and are important proinflammatory cytokines.

Objectives This study aim to determine the serum IL-23 level as well as serum IL-6, IL-12, IL-17 levels in patients with sarcoidosis, and to determine a possible correlation with clinical and laboratory findings of the disease.

Methods Forty-four biopsy proven sarcoidosis patients followed at a single center and 41 healthy volunteers were included in the study. Demographic, clinical, laboratory and radiological data of all patients were recorded. Serum samples from all the patients and the control group were taken and IL-6, IL-12, IL-17, IL-23 were measured by ELISA method.

Results Among 44sarcoidosis patients 13 (29.5%) were male and 31 (70.5%) were female. Average patient age was 47.4 years, mean disease duration was 3.2year. Twenty-one (47.7%) patients had erythema nodosum, three (6.8%) had uveitis, 40 (90.9%) had arthralgia, 23 (52.3%) had ankle arthritis, 15 (34.1%) had enthesitis. Laboratory evaluation showed increased serum ACE level in 24 (54.5%) patients, increased serum calcium level in 11 (25%) patients, increased serum D3 level in 5 (11.4%) patients, increased ESR and CRP levels in 22 (50%) and 23 (52.3%) patients, respectively. Compared with the control group higher serum IL-23 level were found in patients with sarcoidosis (p=0.01). Serum IL-23 were associated with ankle arthritis (p=0.02). Serum IL-6, IL-12 and IL-17 levels were similar in sarcoidosis patients and control group (p=0.128, p=0.212, p=0.521 respectively).

Conclusions In our study we found increased serum IL-23 in patients with sarcoidosis, while serum IL-6, IL-12 and IL-17 were detected as normal. Despite our results are somewhat contradictory to other studies in literature, sarcoidosis still should be discussed if is Th1/Th17 disease or not? Multicenter studies are needed in this regard.

Disclosure of Interest None declared