Upregulation of Interleukin 21 and Interleukin 21 Receptor in Patients with Dermatomyositis and Polymyositis.

Tao LIU; Ying HOU; Ting-Jun DAI; Chuan-Zhu YAN

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Upregulation of Interleukin 21 and Interleukin 21 Receptor in Patients with Dermatomyositis and Polymyositis.

Author: Tao LIU ¹ ; Ying HOU ² ; Ting-Jun DAI ² ; Chuan-Zhu YAN ³ ;
Author Information

1. Research Institute of Neuromuscular and Neurodegenerative Diseases, Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong 250012; Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China.
2. Research Institute of Neuromuscular and Neurodegenerative Diseases, Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
3. Research Institute of Neuromuscular and Neurodegenerative Diseases, Department of Neurology, Qilu Hospital, Shandong University
Publication Type:Journal Article
From: Chinese Medical Journal 2017;130(17):2101-2106
CountryChina
Language:English
Abstract:
BACKGROUNDThe immunopathologic mechanism underlying dermatomyositis (DM) and polymyositis (PM) remains poorly understood. Many cytokines play a pathogenic role in DM and PM. Interleukin 21 (IL-21) has a pleiotropic effect on inflammation regulation. This study aimed to detect the serum IL-21 level and investigate the expression of IL-21 and IL-21 receptor (IL-21R) in muscle tissues of patients with DM and PM.
METHODSBiopsied muscle samples were obtained from 11 patients with DM, 12 with PM, and six controls; mRNA levels of IL-21 and IL-21R were analyzed by real-time quantitative reverse transcription-polymerase chain reaction; and immunohistochemical staining was used to evaluate the protein expression of IL-21 and IL-21R. Serum samples were obtained from 36 patients with DM, 19 with PM, and 20 healthy controls. The serum IL-21 level was detected by enzyme-linked immunosorbent assay.
RESULTSThe expression of IL-21 was upregulated in patients with DM and PM. The IL-21 mRNA level was significantly increased in muscle tissues of patients with DM and PM (DM vs. control, P= 0.001; PM vs. control, P= 0.001), whereas IL-21R mRNA level in patients with DM/PM was not statistically different from that of healthy controls. Immunohistochemical staining showed both IL-21 and IL-21R were significantly expressed in the inflammatory cells in muscle tissues of patients with DM and PM. The serum IL-21 level was also significantly higher in patients with DM/PM than in controls (DM vs. control, 49.12 [45.28, 60.07] pg/ml vs. 42.54 [38.69, 48.85] pg/ml, P= 0.001; PM vs. control, 50.77 [44.19, 60.62] pg/ml vs. 42.54 [38.69, 48.85] pg/ml, P= 0.005).
CONCLUSIONSIL-21 expression is upregulated in patients with DM and PM in both muscle tissue and serum. In addition, IL-21R protein is highly expressed in affected muscle tissues of patients with DM and PM. IL-21 may play a pathogenic role through IL-21R in patients with DM and PM.