Figure 1.

Serum concentrations of neopterin in dermatomyositis (DM) patients. Serum levels of neopterin were detected in 182 DM patients and 30 healthy controls using the enzyme‐linked immunosorbent assay (ELISA) method (each sample was independently from one individual). (a) Serum levels of neopterin in DM patients were significantly higher than that in healthy controls by using the Mann–Whitney U‐test. (b) Using analysis of variance (anova) comparison, we found that serum neopterin levels significantly differed between individual myositis‐specific autoantibody (MSA) groups (P < 0·001). Multiple comparison showed that serum neopterin levels in the anti‐melanoma differentiation‐associated gene (MDA5) group are significantly higher than those in the anti‐aminoacyl tRNA synthetase (ARS) group (adjusted P < 0·05) and MSA negative group (adjusted P < 0·01). (c) The serum levels of neopterin positively correlated with serum ferritin concentrations by Spearman’s correlation analysis. (d) The serum neopterin concentrations were markedly elevated in patients with rapidly progressive interstitial lung disease (RP‐ILD) compared to those with non‐RP‐ILD or with no ILD. (e–g) Serum neopterin concentration correlated inversely with pulmonary function impairment parameters by Spearman’s correlation analysis. (h) No difference was found in serum neopterin concentrations between cancer associated myositis (CAM) and non‐CAM patients using the Mann–Whitney U‐test. (i) Patients with disease duration of less than 3 months had significantly higher serum neopterin levels compared to patients whose disease durations were 3–12 months and those whose disease duration longer than 12 months. The displayed P‐values marked by asterisk * have been adjusted by Bonferroni correction and are from one‐way analysis of variance (anova) tests of logarithmically transformed data. HC = healthy control; FEV₁ = forced expiratory volume in 1 s; FVC = forced VC; DLco = diffusing capacity of carbon monoxide; n.s. = not significant.