Upadacitinib therapy in refractory inflammatory myositis: a case series of 10 patients.

OBJECTIVES: To evaluate the effectiveness and safety of upadacitinib in treatment-refractory inflammatory myositis. METHODS: Patients with refractory inflammatory myositis treated with upadacitinib from a single urban centre in Vancouver, British Columbia, Canada, were included from September 2020 to June 2023. The medical records of these patients were retrospectively reviewed. RESULTS: 10 total patients were identified for review, including 5 classic dermatomyositis (DM), 3 amyopathic DM (ADM) and 2 antisynthetase syndrome. The patients failed an average of four immunosuppressants before initiation of upadacitinib. Three had prior Janus kinase inhibitor therapy with tofacitinib. In the classic DM and ADM aggregate group, upadacitinib offered clinically and statistically significant cutaneous improvement. Lack of active muscle disease at baseline precluded analysis of the effect of upadacitinib on muscle weakness. Nine patients remained on upadacitinib at the end of the study period. One patient discontinued upadacitinib due to severe facial acne. CONCLUSION: Upadacitinib appears to be effective in targeting cutaneous manifestations of refractory inflammatory DM. Further research is still needed to validate its efficacy on a broader population scale.

Involvement of YKL-40-positive macrophages commonly identified in polymyositis and dermatomyositis in the pathogenesis of myositis: a retrospective study.

YKL-40 is implicated in inflammation and tissue repair, but no reports have investigated its involvement in myositis in polymyositis (PM) and dermatomyositis (DM). Therefore, we aimed to investigate the relationship between YKL-40 and PM/DM. We retrospectively enrolled 35 patients diagnosed with PM/DM along with 26 healthy controls (HCs). Both PM and DM were diagnosed according to Bohan and Peter's criteria. Serum YKL-40 levels were measured, age-corrected to YKL-40 percentile values, and compared to HCs. Patients with myositis without interstitial lung disease were also enrolled and compared to HCs. Immunofluorescence staining was performed to identify YKL-40-positive inflammatory cells in muscle biopsy samples from two patients each with PM and DM. Age-corrected serum YKL-40 levels were significantly higher in patients with PM/DM compared to HCs with and without lung disease; however, these levels decreased significantly after treatment. Immunohistochemical analysis showed infiltration of YKL-40-positive inflammatory cells into the intramuscular sheath and perimuscular membrane. Immunofluorescence staining showed CD68 expression in YKL-40-positive inflammatory cells, suggesting that these cells were macrophages. To the best of our knowledge, this is the first study to demonstrate that YKL-40-positive macrophages are present in PM and DM, indicating that YKL-40 may be involved in PM/DM.

Clinicopathological features of graft versus host disease-associated myositis.

BACKGROUND AND OBJECTIVE: Chronic graft versus host disease (GVHD)-associated myositis targeting skeletal muscle is a relatively rare but potentially debilitating complication following allogeneic hematopoietic stem cell transplantation (HSCT). We reviewed the clinicopathological features of GVHD-associated myositis among patients receiving allogeneic HSCT to elucidate the cellular pathogenesis. METHODS: We retrospectively reviewed clinical data and muscle biopsy results from 17 consecutive patients diagnosed with GVHD-associated myositis at our institution between 1995 and 2019. Immunostaining findings of GVHD-associated myositis were compared to those of patients with anti-tRNA-synthetase antibody-associated myopathy (ASM) (n = 13) and dermatomyositis (DM) (n = 12). RESULTS: The majority of patients with GVHD-associated myositis showed subacute or chronic progression of mild to moderate limb weakness together with elevated serum creatine kinase. These patients also exhibited mild C-reactive protein elevation but were negative for myositis-related autoantibodies. Programmed death-1 (PD-1)-positive cells were observed in muscle interstitium adjacent to myofibers expressing human leukocyte antigen (HLA)-DR. The interstitium was also HLA-DR-positive, similar to biopsy samples from ASM patients but not DM patients. The proportions of HLA-DR-positive muscle fibers and PD-1-positive interstitial cells were significantly higher in GVHD and ASM samples than DM samples. The PD-1-positive cells were mostly CD-8-positive lymphocytes. DISCUSSION: GVHD-associated myositis is characterized by HLA-DR-positive myofibers and infiltration of PD-1-positive lymphocytes. These features distinguish GVHD-associated myositis from DM but not from ASM.

Polymyositis following varicella and mumps infection in adults: report of two cases.

Idiopathic immune myopathies (IIMs) are autoimmune diseases caused by immune-mediated muscle damage. The etiology remains unclear. Epidemiological and experimental studies, both in animals and humans, hint at viruses as major environmental factors able to trigger aberrant immune responses through many different mechanisms. However, only a few cases of either dermatomyositis or polymyositis following a specific viral infection have been reported in the literature. The objective of this study is to describe the clinical features and the treatment strategy of 2 cases of polymyositis developing shortly after chickenpox and mumps, respectively, and to review the existing literature on the topic. The clinical records of the 2 patients suspected to have developed inflammatory myositis following a viral infection were reviewed. Their clinical history, main laboratory findings, and treatment outcome are presented here. Moreover, a literature search was performed in the PubMed and MEDLINE databases to identify reports describing the association between viral infections and IIMs in patients aged ≥18. The 2 patients reported here developed polymyositis shortly after chickenpox and mumps, respectively, suggesting a causal role for viruses in triggering autoimmunity. Only a few reports published between 1990 and 2020 were found in the literature, possibly linking infections to myositis development. Intravenous immunoglobulin and rituximab were effective for the treatment of viral-triggered polymyositis.

New-onset Immune-mediated Necrotizing Myopathy and Trigeminal Neuropathy after SARS-CoV-2 mRNA Vaccination in a Patient with Rheumatoid Arthritis and Sjögren's Syndrome.

We present the case of a 42-year-old woman with rheumatoid arthritis and Sjögren's syndrome treated with adalimumab who developed immune-mediated necrotizing myopathy (IMNM) and trigeminal neuropathy after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccination. Trigeminal neuralgia and elevated serum creatine kinase levels emerged 12 days post-vaccination, followed by myalgia in the femoral muscles. IMNM was histologically diagnosed. The pathogenesis may involve molecular mimicry between the SARS-CoV-2 spike glycoprotein and autologous tissues triggered by vaccination. This case emphasizes the association between SARS-CoV-2 vaccination, tumor necrosis factor inhibitor, IMNM, and trigeminal neuropathy, as well as the importance of monitoring immune-mediated adverse events following SARS-CoV-2 vaccination in patients with autoimmune disease.

Response to: myositis after SARS-CoV-2 vaccination occurs more frequently than assumed and is probably causally related.

We thank Finsterer et al. for the attention paid to our publication; we recognize the validity of the points mentioned in their letter to the editor and will try to answer the observations made.

Myositis after SARS-CoV-2 vaccination occurs more frequently than assumed and is probably causally related.

We read with interest the article by Camargo-Coronel et al. reporting on a systematic review of patients with idiopathic, inflammatory myopathy developing after anti-SARS-CoV-2 vaccinations.

Myositis developing after Covid-19 mRNA vaccine: Case Report.

Vaccine-related side effects are common. Usually, pain, edema, redness and tenderness may be seen at the injection site. Symptoms such as fever, fatigue, myalgia may occur. The coronavirus 2019 disease (Covid-19) has affected many people around the world. Although the vaccines that have been used play an active role in the fight against the pandemic, adverse events still continue to be reported. We present a 21-year-old patient who was diagnosed as having myositis after receiving covid vaccine with complaints of pain in her left arm two days after the 2nd dose of BNT162b2 mRNA Covid-19 vaccine, followed by inability to stand up from sitting and squatting and difficulty in going up and down stairs. Keywords: vaccine, myositis, creatine kinase, IVIG.

Murine models of idiopathic inflammatory myopathy.

Idiopathic inflammatory myopathies (IIMs) are characterized by inflammation of muscles and other organs. Several myositis-specific autoantibodies (MSAs) have been identified in IIMs and were found to be associated with distinct clinical features. Although MSAs are valuable for the diagnosis of IIMs, the pathogenic roles of these antibodies remain unknown. To investigate the pathogenesis of IIMs, several animal models of experimental myositis have been established. Classical murine models of autoimmune myositis, experimental autoimmune myositis, and C protein-induced myositis are established by immunization with muscle-specific antigens, myosin, and skeletal C protein, respectively. Furthermore, a murine model of experimental myositis was generated by immunization with a murine recombinant histidyl-tRNA synthetase, Jo-1, in which muscle and lung inflammation reflecting anti-synthetase syndrome are induced depending on acquired immunity. Recently, the transfer of human IgGs from patients with immune-mediated necrotizing myopathy, comprising anti-signal recognition particles and anti-3-hydroxy-3-methylglutaryl coenzyme A reductase antibodies, was found to induce complement-mediated myositis in recipient mice. CD8+ T cell-mediated myositis can be established depending on autoimmunity against transcriptional intermediary factor 1γ (TIF1γ), an autoantigen for MSAs induced by recombinant human TIF1γ immunization. These new murine models reflecting MSA-related IIMs are useful tools for accurately understanding the pathological mechanisms underlying IIMs.

Benign acute childhood myositis following human Influenza B virus infection - A case series.

Influenza virus primarily affects ciliated cells of respiratory epithelium. Humans do not have innate immunity for these viruses and are vulnerable to get attacked. Benign acute childhood myositis usually occurs at the early convalescent phase of a influenza viral illness when fever, cough, myalgia, nasal discharge are the initial presentation.

Systemic Sclerosis with Inflammatory Myositis: A Case Report.

The overlap of systemic sclerosis and inflammatory myositis is a rare disorder which results in immune system activation and production of autoantibodies. We present a case of a 28-year-old female with complaints of generalized weakness, multiple joint pain, facial puffiness, and blackish discolouration of skin over the last 4 months. Blood investigations demonstrated autoantibodies positive for overlap syndrome. She was managed with hydroxychloroquine, mycophenolate mofetil and steroids. This case report highlights the importance of early diagnosis and treatment of this rare entity for better patient outcomes. Keywords: antibodies; case reports; inflammation; systemic sclerosis.

Miositis viral aguda en un paciente pediátrico con Covid-19: a propósito de un caso / Acute viral myositis in a pediatric patient with Covid-19: about a case

Se presenta el reporte de un caso de miositis aguda en un niño de 4 años de edad con COVID-19. El paciente manifestó fiebre y dolor en ambas pantorrillas. Con sospecha de miositis se realizó análisis de CPK, encontrando valores de 4460 UI/L. Asimismo se realizó hisopado nasofaríngeo para SARS-CoV 2, confirmando la infección. El paciente recibió hiperhidratación, presentando resolución de su cuadro clínico en menos de 5 días

This case report describes a 4 year old child with COVID-19. He presented with fever and pain in both calves. Under the suspicion of myositis a CPK analysis was performed, which showed CPK: 4460 UI/L. Nasopharyngeal RT - PCR was also performed, which was positive. As a treatment, the patient received hyperhydration, achieving full recovery after five days

Environmental Risks for Inflammatory Myopathies.

This is an up-to-date review on external environmental factors for adult-onset idiopathic inflammatory myopathies (IIMs). Environmental factors with suggestive evidence including ultraviolet radiation, smoking, infectious agents (viruses in particular), pollutants, medications (ie, statin) and vitamin D deficiency are discussed. We also discuss the potential implications of environmental factors in IIM development, identify current challenges, and provide insight into future investigations.

Inflammatory myopathy following coronavirus disease 2019 vaccination: A systematic review.

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].

Peripherally Inserted Central Catheter-Related Infectious Myositis: A Case Report.

BACKGROUND Peripherally inserted central catheters (PICCs) are commonly used by clinicians in daily practice as a safe and reliable alternative to central venous catheters. While there are advantages to the use of PICCs, such as a low insertion-related complication rate and cost-effectiveness, using PICCs may expose patients to life-threatening severe complications such as a central line-associated bloodstream infection and deep venous thrombosis (DVT). There have been no reports of infectious myositis associated with PICC insertion. CASE REPORT We report a case of infectious myositis related to PICC insertion complicated by brachial DVT in a 43-year-old immunocompromised patient with myelodysplastic syndrome. Despite the administration of broad-spectrum antibiotics, the patient's condition did not improve. He developed septic shock and required emergency excision of the infected and necrotic muscles. Although the pathogen responsible for the infection was unknown, infectious myositis and myonecrosis were observed intraoperatively. Furthermore, histopathological examination revealed evidence of infectious myositis in the biceps brachii and brachial muscles. The septic shock resolved with treatment and the patient survived with residual elbow joint dysfunction. CONCLUSIONS We present a case of infectious myositis related to PICC insertion. We believe that urgent resection of infected and necrotic tissues, rather than broad-spectrum antimicrobial therapy alone, was essential to save the patient's life.

Dengue infection triggered immune mediated necrotizing myopathy in children: a case report and literature review.

BACKGROUND: Immune-mediated necrotizing myopathy (IMNM) is a subgroup of idiopathic inflammatory myopathies manifesting with progressive weakness, elevated serum creatine kinase (CK) levels, and necrotizing myopathic features on muscle biopsy. There is a paucity of data on the clinical presentation of IMNM in children. We report a paediatric patient who developed anti-3-hydroxy-3-methylglutaryl-CoA reductase (anti-HMGCR)-positive necrotizing myopathy after recent dengue infection. CASE PRESENTATION: A previously healthy 9-year-old boy presented with acute proximal muscle weakness after recovery from dengue infection. Five days after the fever subsided, he could not stand from a squatting position. He denied having skin rash, arthritis, or other systemic features. He had marked elevation of CK level of 30,833 mg/dL and was put on steroid therapy. The patient initially responded to oral prednisolone, however the weakness persisted and muscle enzymes increased as steroids were decreased. He was then referred to our hospital for further assessment. Subsequent investigation revealed anti-HMGCR positivity along with specific histopathological findings consistent with IMNM. The patient was treated with six cycles of intravenous immunoglobulin (IVIG) monthly, then followed by a gradual taper of prednisolone and oral methotrexate weekly with complete recovery in motor power. CONCLUSIONS: Our report presents a child with clinical manifestations of IMNM which can be categorized as acute onset of muscle weakness following dengue infection. Two key points supporting a diagnosis in this case are clinical response after immunosuppressive therapy and absence of rashes found in juvenile dermatomyositis.

A rare case of paraneoplastic myositis associated with neuroendocrine carcinoma of the pancreas.

Pancreatic cancer is only rarely associated with myopathy. We present a case of a 69-year-old male with recently diagnosed pancreatic cancer, who presented himself with a paraneoplastic myositis of both legs. MRI and EMG contributed to this diagnosis. Treatment was started with high dose corticosteroids followed by urgent laparoscopic pancreaticoduodenectomy. Postoperatively there was a rapid normalisation of the creatinine kinase levels with gradual increase of the muscle strength. The anatomopathology of the biopsy specimen showed a large cell neuroendocrine carcinoma. Paraneoplastic myositis associated with pancreatic cancer may be treated successfully with cancer specific treatment.