To identify potential risk factors and prognostic factors of Pneumocystis jirovecii pneumonia (PJP) infection in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (anti-MDA5+ DM) patients, and to evaluate the diagnostic performance of metagenomic next-generation sequencing (mNGS). Anti-MDA5+ DM patients who underwent mNGS or real-time PCR for PJP detection were recruited. The potential risk factors for PJP occurrence and death were analyzed via Logistic regression and Cox proportional hazards regression, respectively. The diagnostic efficacy of mNGS was compared with the conventional methods. 91 patients were enrolled and 44 were assigned to PJP+ group. The PJP detection rate was 48.4%. PJP often occurred in the first 3 months (68.2%) of the disease; this period also showed the highest mortality rate (20.5%). Fever and increased lactate dehydrogenase (LDH) were independent risk factors for PJP occurrence, while trimethoprim-sulfamethoxazole (TMP/SMZ) prophylaxis was an independent protective factor (all p< 0.05). Older age and increased LDH were predictors for mortality in patients with anti-MDA5+ DM and PJP (all p< 0.05). In addition, we found that mNGS had a sensitivity of 100.0% and specificity of 90.0% in diagnosing PJP, with the highest area under the curve of 0.95 (p< 0.001). PJP has high prevalence and mortality in anti-MDA5+ DM. It is crucial for clinicians to identify high-risk patients and promptly institute TMP/SMZ to prevent PJP. mNGS is the preferred approach for pathogen detection in anti-MDA5+ DM when PJP is suspected.

Background: Anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody-positive dermatomyositis (DM) has low survival rate, whereas macrophage activation syndrome (MAS) is a severe and life-threatening syndrome associated with autoimmune diseases. Their coexistence is very rare. This study aimed to describe the prevalence, clinical characteristics, and outcomes of anti-MDA5 antibodies-positive DM patients complicated with MAS. Methods: In this retrospective study, we enrolled DM patients with anti-MDA5 antibodies, who were hospitalized between 2016 and 2020 and included patients diagnosed with MAS. Results: We identified four (2%) DM patients with anti-MDA5 antibodies. They were females with interstitial lung disease (ILD). The level of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and ferritin were significantly higher in the MAS group than those without MAS ( p < 0.05). Patients with MAS were significantly more likely to develop a dysphagia ( p = 0.012). Literature review revealed eight similar cases. Together with the present study, we identified 12 patients complicated with ILD. The median age of disease onset was 52 years with a male to female ratio of 1:6. The median duration between DM onset and MAS diagnosis was 3 months. The mortality of MAS in anti-MDA5 antibody-positive DM was 50%. Patients who died were older than those who survived (56.7 years versus 35.5 years; p = 0.015). Conclusions: MAS was rare in anti-MDA5 antibody-positive DM. The higher the level of AST, LDH, and ferritin, the greater the risk of MAS. They were associated with high mortality rates, particularly in older patients.

Introduction: Reports of unexpected side effects have accompanied the vaccination of larger proportions of the population against coronavirus disease 2019 (COVID-19), including a few cases of inflammatory myopathy (IM). In a bid to improve understanding of the clinical course of vaccine complications, a systematic review of reported cases of IM following COVID-19 vaccination has been conducted.Methods: The PRISMA guideline 2020 was followed. Two independent investigators systematically searched PubMed and Embase to identify relevant studies published up to July 2022, using the following keywords: COVID-19 Vaccine, inflammatory myositis. The Joanna Briggs Institute critical appraisal tools were used for the risk of bias.Results: A total of 24 articles presenting clinical features of 37 patients with IM following COVID-19 vaccine were identified. Female patients composed 59.5% of cases and 82.4% had been vaccinated with BNT162b2 or ChAdOx1. Onset of symptoms occurred within 2 weeks of the first or second vaccine dose in 29 (85.3%) patients and included muscular weakness in 54.1% and skin rash in 71.4% of patients. Myositis specific autoantibodies (MSAs) and myositis associated autoantibodies (MAAs) were reported in 28 patients. Specific clinical subtypes of myositis, reported in 27 patients, included 22 (81.5%) cases of dermatomyositis (DM) and 3 (11.1%) cases of immune-mediated necrotizing myopathy (IMNM). Following treatment, 32 (86.5%) patients showed improvement on follow-up.Conclusion: COVID-19 vaccine may induce various clinical myositis subtypes and related antibodies. Muscular weakness was the most common presenting symptom. Clinicians should be aware of this unexpected adverse event following COVID-19 vaccination and arrange for appropriate management.Systematic review registration: INPLASY https://inplasy.com/inplasy-2022-9-0084/ [INPLASY202290084].

To evaluate the efficacy and safety of Janus kinase inhibitors (JAKi) in the treatment of refractory anti-synthetase syndrome (ASS) in real-world clinical settings. The medical records of all refractory ASS patients who were treated with JAKi from October 2020 to June 2023 were retrospectively reviewed. Twenty patients were included, and all (100 %) patients had interstitial lung disease (ILD). After treatment with JAKi, 14 (70 %) of the refractory ASS patients showed significant improvement in clinical manifestations, including arthritis (56.3 % vs. 6.3 %, p = 0.002), rash (77.8 % vs. 27.8 %, p = 0.012), shortness of breath (55.6 % vs. 16.7 %, p = 0.039), cough (61.1 % vs. 11.1 %, p = 0.012). Improvement was noted for myalgia (50 % vs. 11.1 %, p = 0.016) and muscular weakness (61.1 % vs. 11.1 %, p = 0.012), while creatine kinase (CK) levels, which were abnormally elevated in five patients prior treatment, were significantly lowered (1096 ± 1042.98 IU/L vs. 199.2 ± 144.66 IU/L, p = 0.043). A decrease in levels of inflammatory markers, including erythrocyte sedimentation rate (ESR) (p = 0.001) and C-reactive protein (CRP) (p = 0.023) was observed in the patients. In ASS-ILD, the CT score reduced (188.75 ± 69.67 vs. 156.35 ± 74.62, p = 0.001). Furthermore, the glucocorticoid dose significantly reduced (21.42 ± 13.26 mg vs. 11.32 ± 8.59 mg; p = 0.001). JAKi were effective in most refractory ASS patients as evidenced by improved skin rash, myositis, and ILD. However, larger prospective controlled studies are required to evaluate its efficacy.