Meteorin-like(IL-41), is a novel cytokine that is thought to be immunoregulatory and is highly expressed in psoriatic skin. We investigated IL-41 protein expression in synovial tissue in RA(Rheumatoid Arthritis), PsA(Psoriatic Arthritis) and OA(Osteoarthritis) patients and evaluated IL-41 production from healthy enthesis samples, as the enthesis represent the primary inflammatory site in PsA. IL-41 was measured in synovial fluid from PsA, RA and OA patients. Synovial biopsies were stained for IL-41 by immunohistochemistry. IL-41 was highly expressed in the synovial fluid and synovial tissue of PsA patients (median = 7722 pg/ml) when compared to OA patients (median = 5044 pg/ml). We found that entheseal stromal cells were the dominant producer of IL-41 from the enthesis. Moreover, stromal derived IL-41, could be further induced by IL-17A/F and TNF. In conclusion, IL-41 is expressed in PsA synovium and is present and inducible at the enthesis. Its functional effect in psoriatic inflammation remains to be fully elucidated.

中文翻译：

---

新型细胞因子Metrnl / IL-41在银屑病关节炎滑膜中升高，可从包膜和滑膜成纤维细胞中诱导。

Meteorin-like（IL-41）是一种新型的细胞因子，被认为具有免疫调节作用，并在牛皮癣皮肤中高度表达。我们调查了RA（类风湿关节炎），PsA（银屑病关节炎）和OA（骨关节炎）患者滑膜组织中IL-41蛋白的表达，并评估了健康标本样品中IL-41的产生，因为该标本代表了PsA中的主要炎症部位。在来自PsA，RA和OA患者的滑液中测量了IL-41。通过免疫组织化学对滑膜活检组织进行IL-41染色。与OA患者（中位数= 5044 pg / ml）相比，IL-41在PsA患者的滑液和滑膜组织中高表达（中位数= 7722 pg / ml）。我们发现，粘膜基质细胞是IL-41的主要生产者。而且，基质衍生的IL-41可被IL-17A / F和TNF进一步诱导。总之，IL-41在PsA滑膜中表达，并在其表达时被诱导。其在银屑病炎症中的功能作用仍有待充分阐明。