Serum sCD25 is an indicator for rheumatoid arthritis-associated interstitial lung disease.

Cao S ，Liu X ，Li Y ，Yang Y ，Cai X ，Cong S ，Li Z ，Li Y ，Hong Y ，Su Y ，Li Z ，Luo L ，Sun X ... -  《CLINICAL AND EXPERIMENTAL RHEUMATOLOGY》

Increased circulating Wnt5a protein in patients with rheumatoid arthritis-associated interstitial pneumonia (RA-ILD).

An early diagnosis of interstitial lung disease (ILD) is important for guiding treatments of rheumatoid arthritis (RA)-associated ILD (RA-ILD) in clinical settings. The non-canonical Wnt signaling representative ligand Wnt5a was recently found to involve in idiopathic pulmonary fibrosis (IPF) and pathogenesis of RA. The goal of this study was to examine the clinical relevance of Wnt5a in RA-ILD. In this report, the clinical relevance of plasma Wnt5a protein was evaluated in 40 RA-ILD patients and 41 non-ILD RA cohorts. The results showed an elevated Wnt5a protein in plasmas of RA-ILD patients compared with non-ILD RA patients (p < 0.01), which was positively correlated with the plasma level of rheumatoid factor (RF). Of note, more abundant Wnt5a was also found in patients with usual interstitial pneumonia (UIP) than those with nonspecific interstitial pneumonia (NSIP) and other ILD patterns. More importantly, the disease severity was correlated with the circulating Wnt5a as ascertained by high-resolution computed tomography (HRCT)-UIP scores. The multiple-factor non-conditional logistic regression analysis further revealed that the age, RA duration, smoking and plasma Wnt5a were risk factors with clinical significance for RA-ILD. Interestingly, more Wnt5a-positive patients were identified in RA-ILD smokers relative to RA-ILD never-smokers, and longer smoking duration was strongly correlated with Wnt5a in RA-ILD patients. In consistence, ROC curve also suggested that the Wnt5a was a potential candidate biomarker for identifying patients with RA-UIP. These results demonstrate that the circulating Wnt5a may be a risk factor and potential biomarker for identifying UIP and accessing the severity and progression of ILD in RA patients.

Yu M ，Guo Y ，Zhang P ，Xue J ，Yang J ，Cai Q ，You X ，Ma J ，Yang D ，Jia Y ，Wang Y ，Li F ，Chi S ，Cao M ，Chen J ，Liu X ... -  《-》

Predictive factors of mortality in rheumatoid arthritis-associated interstitial lung disease analysed by modified HRCT classification of idiopathic pulmonary fibrosis according to the 2018 ATS/ERS/JRS/ALAT criteria.

Interstitial lung disease (ILD) is associated with high morbidity and mortality in rheumatoid arthritis (RA). Although usual interstitial pneumonia (UIP) pattern was reported as a poor prognostic factor, in clinical practice, we often cannot classify high-resolution computed tomography (HRCT) patterns specifically as UIP or nonspecific interstitial pneumonia (NSIP). This study of RA-ILD aimed to elucidate prognosis by using our modified HRCT pattern classification according to the latest guideline on idiopathic pulmonary fibrosis (IPF). We analysed the medical records of 96 consecutive patients diagnosed as having RA-ILD. The modified HRCT classifications were defined as definite UIP, probable UIP, indeterminate for UIP (i.e., early UIP or NSIP/UIP), NSIP, organizing pneumonia (OP), NSIP+OP, and unclassifiable. Predictors of prognosis were determined using Cox regression models. Our RA-ILD cohort included definite UIP (21%), probable UIP (20%), indeterminate for UIP (30%) including NSIP/UIP (27%), alternative diagnosis (29%) including NSIP (14%), and other patterns. Interrater agreement for HRCT pattern was good (κ=0.75). Multivariate analysis showed that older age, history of acute exacerbation, and radiological honeycombing were negative prognostic factors of mortality. NSIP/UIP pattern of indeterminate for UIP was the major pattern in RA-ILD. Although classifications of HRCT patterns were not related to survival, the presence of radiological honeycombing could be a useful predictor of poor prognosis, and acute exacerbation of ILD can seriously impact patient survival regardless of the presence of a UIP or indeterminate for UIP pattern. Our modified HRCT classification based on the latest IPF guideline might be useful to assess appropriate strategies of diagnosis in future RA-ILD studies, and radiological honeycombing could better predict poor prognosis rather than HRCT pattern.

Yamakawa H ，Sato S ，Tsumiyama E ，Nishizawa T ，Kawabe R ，Oba T ，Kamikawa T ，Horikoshi M ，Akasaka K ，Amano M ，Kuwano K ，Matsushima H ... -  《-》

Plasma IL-36α and IL-36γ as Potential Biomarkers in Interstitial Lung Disease Associated with Rheumatoid Arthritis: a Pilot Study in the Chinese Population.

Interstitial lung disease (ILD) is a frequent extra-articular manifestation of rheumatoid arthritis (RA) and increases mortality in patients with RA. Early identification of ILD, especially the usual interstitial pneumonia (UIP) pattern with a poor prognosis, is important for guiding treatment of RA-ILD and preventing damage resulting from a delay in diagnosis. Interleukin-36 (IL-36) cytokines are involved in connective tissue diseases. However, IL-36 expression in RA-ILD is unknown. In this study, the clinical relevance of plasma IL-36 cytokines was evaluated in 39 patients with RA-ILD and three other groups (30 healthy controls [HCs], 35 RA patients without ILD, and 27 patients with idiopathic pulmonary fibrosis [IPF]) in the Chinese population. Plasma IL-36α and IL-36γ concentrations were elevated in patients with RA-ILD compared with those in HCs and patients with RA. RA-ILD patients with UIP pattern had higher plasma IL-36γ concentrations than those with RA-ILD without UIP, but these were lower than those in patients with IPF. Receiver operating curve analysis suggested that IL-36α and IL-36γ were potential biomarkers for identifying ILD in patients with RA. Additionally, the optimal cutoff value of IL-36γ for distinguishing RA-ILD with the UIP pattern from RA-ILD without UIP was 555.40 pg/mL and that for distinguishing RA-ILD from IPF was 655.10 pg/mL. No significant difference in plasma IL-36β or IL-36Ra concentrations was found between patients with RA-ILD and the three other groups. We also found that the lungs originating from different types of patients with PF, including RA-ILD and IPF, and those from mice following bleomycin-induced PF were characterized by increased IL-36γ expression. Our findings suggest that using IL-36 cytokines to identify patients with RA for further ILD workups may provide additional diagnostic value to the current clinically available assays. Moreover, IL-36γ may help to identify the presence of the UIP pattern in patients with RA-ILD and to discriminate RA-ILD from IPF.

Zheng W ，Hu X ，Zou M ，Hu N ，Song W ，Wang R ，Liu Y ，Hou Q ，Liu Y ，Chen X ，Cheng Z ... -  《-》

Risk factors for the progression of rheumatoid arthritis-related interstitial lung disease: Clinical features, biomarkers, and treatment options.

The clinical heterogeneity of the progression of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is high, and there is a lack of consensus on the clinical relevance and medical protocols. The purpose of this study is to explore the impact of clinical characteristics, new biomarkers and treatment options on the prognosis of RA-ILD patients and to explore whether these factors can predict the progression and death of these patients. We retrospectively collected case data on RA-ILD patients who visited or were admitted to Changhai Hospital between October 2010 and September 2021. We followed up and finally included 75 patients. The main outcome indicator of disease progression was pulmonary functional impairment, which was assessed by changes of high-resolution computed tomography (HRCT) score or pulmonary function test before and after treatment. The demographics, clinical characteristics, laboratory tests, and treatment plans of RA-ILD patients in the progressive and stable groups were compared and analyzed. Clinically relevant variables were identified, and the incidence of pulmonary dysfunction and adverse events was recorded. Cox regression analysis was used to determine factors related to the progression of ILD. The mean age of RA-ILD onset was 64.0 years (SD 10.3), and 53 (70.7%) patients were female. Thirty-two (42.7%) patients had lung dysfunction, who were classified as the progressive group, and 13 (40.6%) of them died. In univariate analyses, male, smoking, high HRCT scores at baseline, RF-IgA>200 RU/ml, diffusing capacity of the lungs for carbon monoxide (DLCO), and usual interstitial pneumonia (UIP) pattern were significant risk factors for disease progression; while use of Leflunomide (LEF) was associated with better prognosis. The multivariate analysis revealed that RF-IgA>200 RU/ml (hazard ratio [HR] 3.17 [95% confidence interval (CI) 1.29, 7.81], P = 0.012), UIP pattern (HR 3.94 [95% CI 1.68, 9.26], P = 0.002), and male (HR 2.52 [95% CI 1.16, 5.46], P = 0.019) were significantly correlated with unfavorable outcomes in patients with RA-ILD. LEF (HR 0.25 [95% CI 0.10, 0.61], P = 0.002) was related to a better prognosis. However, it might be related to investigating medications changes after baseline. Our data suggests that male, UIP pattern, and increased RF-IgA may be potential predicting factors for poor prognosis of RA-ILD patients. We report a significant association between high titer of RF-IgA at baseline and RA-ILD progression for the first time, which might be a potentially important biomarker for the prognosis of RA-ILD.

Chen N ，Diao CY ，Gao J ，Zhao DB ... -  《-》