Peripheral lymphocyte count defines the clinical phenotypes and prognosis in patients with anti‐MDA5‐positive dermatomyositis. (2nd February 2023)

• Record Type: Journal Article
• Authors: Jin, Qiwen; Fu, Lijun; Yang, Hongxia; Chen, Xixia; Lin, Sang; Huang, Zhenguo; Gao, Baoxiang; Tian, Xiaolan; Jiang, Wei; Shu, Xiaoming; Lu, Xin; Wang, Guochun; Peng, Qinglin
• Is Part Of: Journal of internal medicine. Volume 293:Number 4(2023)
• Page Start: 494
• Page End: 507
• Publication Date: 2023-02-02
• Subjects: anti‐MDA5 antibody -- dermatomyositis -- lymphopenia -- phenotype -- prognosis; Internal medicine -- Periodicals; Medicine -- Periodicals; 616
• DOI: 10.1111/joim.13607
• Languages: English
• ISSNs: 0954-6820

Abstract

Abstract: Objective: To explore the role of peripheral lymphocyte count in phenotyping and prognosis prediction in dermatomyositis (DM) patients with anti‐MDA5 antibodies. Methods: In total, 1669 patients with idiopathic inflammatory myopathy (IIM) were retrospectively enrolled. Clinical characteristics and prognosis of patients with anti‐MDA5+ DM were analyzed in association with peripheral lymphocyte counts and clusters determined by unsupervised machine learning. Results: The peripheral lymphocyte count was significantly lower in the anti‐MDA5+ DM group ( N = 421) than in the other IIM serotype groups. The anti‐MDA5+ DM patients were divided into three groups; the severe lymphopenia group had skin ulcers and rapidly progressive interstitial lung disease (RP‐ILD); patients with a normal lymphocyte count had a younger age of onset, more frequent arthritis, and normal serum ferritin levels, whereas mild lymphopenia group showed a moderate increase of serum ferritin and intermediate incidence of RP‐ILD. Survival analysis revealed that the 3‐ and 6‐month mortality rates were significantly higher in the severe lymphopenia group (29.0% and 42.1%, respectively) than in the mild lymphopenia group and normal lymphocyte count group ( p value <0.001). Consistently, unsupervised machine learning identified three similar groups; the arthritis cluster shows the highest lymphocyte counts and best prognosis; the RP‐ILD cluster presents the lowest peripheral lymphocyte, high incidence of RP‐ILD, and poor prognosis; the typical DM rash cluster had a moderate peripheral lymphocyte count and an intermediate prognosis. Conclusions: Lymphopenia is a unique manifestation of anti‐MDA5+ DM. Peripheral lymphocyte count can define clinical phenotypes and predict prognosis in anti‐MDA5+ DM. Abstract :