Background: This study aimed to describe the clinical characteristics and analyze the poor prognostic factors in patients with anti-MDA5 dermatomyositis. Methods: A total of 126 adults with anti-MDA5 dermatomyositis were enrolled in this retrospective study. Information on survival time, cause of death, and baseline characteristics was collected. Patients were divided into two groups: a survival group and a non-survival group. Items with clinical significance that showed significant differences between the two groups were screened by Kaplan–Meier and Cox regression analyses to identify the predictors of poor survival. Results: Thirty-two patients were included in the non-survival group, most of whom died from respiratory failure, with pulmonary infection accounting for half. Epstein–Barr virus infection was relatively common in both groups. Aspartate transaminase, lactate dehydrogenase, and ferritin levels; erythrocyte sedimentation rate; and anti-Ro52 antibody levels were significantly higher, while the lymphocyte count was lower in the non-survival group compared with the survival group. Notably, patients in the non-survival group were more likely to present with rapidly progressive interstitial lung disease than those in the survival group. Kaplan–Meier and Cox multivariate regression analyses revealed that the prevalence of rapidly progressive interstitial lung disease, levels of anti-Ro52 antibody, and age > 57 years were important prognostic factors independent of multiple clinical parameters. Conclusions: Rapidly progressive interstitial lung disease, anti-Ro52 antibody levels, and age > 57 years are possible predictors of mortality risk in patients with anti-MDA5 dermatomyositis.

Objective: Interleukin (IL)-37 is a natural suppressor of inflammation. Macrophages play an important role in acute gout flare by dominating the inflammation and spontaneous relief. We have reported that IL-37 could limit runaway inflammation in gout. Here we focus on whether IL-37 inhibits gouty inflammation by altering macrophage functions, and how it does so. Methods: Macrophage functions were evaluated in terms of phagocytosis, pyroptosis, polarization and metabolism. Phagocytosis and polarization of macrophages were detected by side scattering and double-labelling induced nitrogen monoxide synthase (iNOS)/arginase-1 (Arg-1) using flow cytometry, respectively. Transcription of pyroptosis-related molecules was detected by qPCR. Metabolomics was performed by liquid chromatograph mass spectrometer. Human IL-37 knock-in mice and a model with point mutation (S9A) at mouse Gsk3b locus were created by CRISPR/Cas-mediated genome engineering. MSU was injected into the paws and peritoneal cavity to model acute gout. Vernier calliper was used to measure the thickness of the paws. The mice paws and human synovium tissues or tophi were collected for pathological staining. Peritoneal fluid of mice was used to enrich macrophages to detect polarization. Results: IL-37 promoted non-inflammatory phagocytic activity of macrophages by enhancing phagocytosis of MSU, reducing transcription of pyroptosis-related proteins and release of inflammatory cytokines, protecting mitochondrial function, and mediating metabolic reprogramming in MSU-treated THP-1 cells. These multifaceted roles of IL-37 were partly depended on the mediation of glycogen synthase kinase-3β (GSK-3β). Conclusions: Our study revealed that IL-37 could shape macrophages into a ‘silent’ non-inflammatory phagocytic fashion. IL-37 may become a potentially valuable treatment option for patients of chronic gout, especially for those with tophi.

Background: Previous studies have indicated that the programmed death molecule 1 (PD-1) signaling pathway may play a key role in rheumatoid arthritis (RA). However, the pathogenesis of rheumatoid arthritis-related interstitial lung disease (RA-ILD) is not clear. We examined the serum levels of soluble PD-1 in patients with RA and its relationship with RA-ILD. Methods: Blood samples were obtained from 87 patients with RA (58 with ILD and 29 without ILD) and 45 healthy controls. Serum sPD-1 was measured by Enzyme-Linked Immunosorbent Assay. The pulmonary interstitial disease score was completed by a pulmonary physician and a radiologist through chest high-resolution computed tomography. Patients with RA-ILD were tested for lung function [e.g., forced vital capacity (FVC%), diffusing capacity of lungs for carbon monoxide (DLCO%)]. Associations between ILD and various markers, including sPD-1 and confounding factors, were investigated by logistic regression analysis. Diagnostic values of sPD-1 for the presence of ILD were investigated using receiver operating characteristic curve analysis. Results: Serum sPD-1 levels were higher in RA patients with ILD than in RA patients without ILD and healthy controls (185.1 ± 109.0 pg/ml vs. 119.1 ± 77.5 pg/ml vs. 52.1 ± 21.7 pg/ml, P < 0.05). Serum sPD-1 levels were positively correlated with RF titer (P = 0.02, r = 0.249), anti-cyclic citrullinated peptide antibody status (P = 0.02, r = 0.243), and serum IgG levels (P < 0.001, r = 0.368), negatively associated with FVC% (P = 0.02, r = − 0.344), forced expiratory volume (FEV1%) (P = 0.01, r = − 0.354), total lung capacity (TLC%) (P = 0.046, r = − 0.302), and was independently associated with the presence of ILD in RA patients by multivariate logistic regression analysis. The sensitivity and specificity of sPD-1 levels for the detection of ILD in RA patients were 58.6% and 75.9%, respectively. The area under the curve was 0.689. Conclusion: Serum sPD-1 levels were increased in RA patients with ILD. Increased sPD-1 may be a valuable biomarker to predict the presence of ILD in patients with RA.