Case Report Of Myositis Research Articles

E018 COVID-19 vaccine-induced myositis

Abstract Background/Aims Through the COVID pandemic there have emerged reports of autoimmunity or new rheumatic diseases presenting in patients after they had COVID-19. This is thought to be caused by cross-reactivity of the COVID-19 spike protein to human antigens. Given the use of mRNA COVID-19 vaccinations which express the spike protein we might expect to see presentation of new rheumatic diseases following their use. We discuss a case where this appears to have occurred. Methods Our patient is a 24-year-old male with mixed phenotype acute leukaemia who had been treated with allogenic stem cell transplant and was currently in remission. He presented with fevers, palpitations, myalgia and bilateral arm and leg swelling. Symptoms began the day after receiving the first dose of an mRNA COVID-19 vaccination (Pfizer/BioNTech.) There were no other symptoms or recent change in medications. Physical examination revealed tender oedema in his forearms, biceps and thighs bilaterally with sparring of the hands. He had reduced power with shoulder (MRC 3/5), elbow (4), wrist (4+) and hip (4) movements. Observations revealed tachycardia and fevers up to 40C. Results Laboratory studies showed markedly elevated C-reactive protein (202), creatinine kinase (6697) and troponin (593) whilst investigations for infection were negative. An autoimmune panel was positive for anti-PM-SCL-75-Ab. An electrocardiogram showed sinus tachycardia. Echocardiogram was normal. Bilateral upper limb dopplers revealed no deep vein thrombus. An MRI of his thighs showed diffuse symmetrical oedema within the muscles, in keeping with an inflammatory myositis. A quadricep muscle biopsy showed evidence of MHC class 1 up-regulation, suggesting an inflammatory process. In addition, there were numerous macrophages evident in the endomysium. While this can be seen in graft-versus-host disease (GVHD), they would usually be found in the perimysium. After discussion between haematology, rheumatology and neurology, this was felt to be a case of vaccine induced myositis and myocarditis. Autoimmune myositis was thought to be less likely due to the relative sparing of the hands and the absence of Raynaud’s phenomenon. 1 gram of intravenous methylprednisolone was then given for 3 days. The patient had a marked response with defervescence, improving laboratory markers, improved myalgia and decreased limb swelling. The patient was stepped down to a reducing regime of prednisolone and discharged. Due to relapse whilst weaning he has started on mycophenalate mofetil and rituximab and now continues to improve. Conclusion There are case reports of myositis following COVID-19 vaccination but our patient’s case is complicated by the differential diagnosis of GVHD and concurrent myocarditis. Ongoing work is needed to clarify the exact link between vaccination and the presentation of a new inflammatory myositis, but it is important to recognise and start treatment early in order to preserve muscle bulk and ensure recovery. Disclosure L. Thompson: None. T. Nadin: None. J. Meiring: None. S. Thomas: None. R. Kumari: None. S. Carter: None. M. Akil: None. A. Alfred: None. N. Morley: None.

P60 A case of autoimmune inflammatory myositis in a patient with SLC29A3 spectrum disorder

Introduction/BackgroundThe SLC29A3 gene encodes the equilibrative nucleoside transporter hENT3. SLC29A3 spectrum disorder, an autosomal recessive disorder caused by mutations in this gene, is a rare multisystem disorder resulting in cutaneous manifestations (hyperpigmented, hypertrichotic and indurated patches of skin) and a variety of systemic features, with variable phenotypic expression. Along this spectrum are H syndrome and pigmented hypertrichotic dermatosis with insulin-dependent diabetes (PHID) syndrome. The majority of cases reported in the literature have been in patients of Arab descent. We report a case of a patient with SLC29A3 mutation who later developed features of autoimmune disease and myositis.Description/MethodAn 11-year-old girl with an established diagnosis of SLC29A3 mutation, dysosteosclerosis, camptodactyly and type 1 diabetes mellitus presented with a three-week history of intermittent fever, myalgia, muscle weakness and cervical lymphadenopathy. She had a non-specific rash over her eyelids, interphalangeal joints of both hands, torso and limbs. Her movements were restricted due to myalgia. She had no evidence of arthritis. Her creatine kinase was elevated (>1400 units/litre) and MRI of her thighs revealed evidence of myositis not akin to Juvenile Dermatomyositis distribution. An extensive investigation screen showed no evidence of infections. The bone marrow was hypocellular but there was no evidence of malignancy or histiocytosis. An autoinflammatory disease was suspected and the patient was treated with three pulses of IV methylprednisolone, to which she initially responded well but soon relapsed. Anakinra was trialled but this failed as the patient’s daily fevers persisted and her muscle weakness continued to worsen. Methotrexate was commenced and did not result in the desired reduction in prednisolone dose, so the patient was started on 4-weekly infliximab infusions. Following commencement of infliximab, the patient’s fever and rash resolved; her energy levels and muscle power improved and her muscle enzymes began to normalise. Repeat MRI showed her myositis was in remission. Infliximab was stopped after 13 doses due to side effects at the end of the infusions (tachycardia, hypertension and pyrexia). In addition, it was found that she had developed antibodies against infliximab and measured serum drug levels were low. Methotrexate was eventually stopped. The patient is now off all rheumatological treatment (as of February 2019) and she has not had reactivation of any of her symptoms.Discussion/ResultsThe patient we report had insulin-dependent diabetes mellitus, dysosteosclerosis and camptodactyly, three systemic features associated with SLC29A3 mutation. She presented concomitantly with signs of autoinflammatory disease and myositis. While up to 25% of patients with SLC29A3 mutation develop autoinflammatory features, to our knowledge, this is the first reported case of myositis in a patient with this mutation. Both the inflammatory features and myositis resolved following treatment with infliximab infusions. A number of case reports have described successful treatment of inflammation in SLC29A3 mutation with IL-6 inhibitors such as tocilizumab. The complete remission demonstrated in this case following infliximab infusions points to TNF-α inhibition as another potential therapeutic target. It is also interesting to note that our patient is now off all rheumatological treatment, which contrasts with other case reports in the literature where the patients have typically required maintenance immunomodulation therapy to remain asymptomatic. This case may therefore represent a new clinical subtype of SLC29A3 mutation with an autoimmune inflammatory myositis, rather than autoinflammatory as initially suspected, that carries a better prognosis. Further case reports of myositis in SLC29A3 mutation would help to build a clearer picture of its clinical presentation, prognosis and response to biologic therapies.Key learning points/Conclusion1. SLC29A3 spectrum disorder is a rare multisystem disorder that has only recently been recognised. By presenting this case report we hope to increase awareness of this condition and network with other clinicians who have encountered inflammatory disease associated with SLC29A3 mutation, either in their clinical practice or research.2. Up to a quarter of patients with SLC29A3 mutation present with autoinflammatory disease.3. We report on the first case of autoimmune inflammatory myositis in a patient with SLC29A3 mutation, to our knowledge.4. Our patient demonstrated complete remission of her inflammatory disease following treatment with infliximab, which may represent a new clinical subtype of SLC29A3 mutation with an autoimmune, rather than autoinflammatory, myositis that carries a better prognosis.

P14 A case of myositis in patient with atypical bacterial pneumonia

Case report - IntroductionBacterial community-acquired atypical pneumonia is sometimes complicated by myositis or by renal parenchymal disease. They can present with myositis and present with muscle weakness, pain or swelling, and elevated muscle enzymes. We present the case of a patient with lower limb weakness and raised creatinine kinase with atypical pneumonia caused by Legionella pneumophila.Case report - Case descriptionA 76-year-old Caucasian man, who was previously fit and independent and walked 3 miles every day presented with a 1-week history of progressive leg weakness, and inability to mobilize. He had a fall and was on the floor for 2 hours. He had a background history of hypercholesterolemia and was on atorvastatin for 15 years. On his vital observation, he was found tachypnoeic, tachycardic, and hypoxic. He had a right upper lobe crackle but he didn’t have respiratory symptoms. His muscle power in his leg was 3/5 with carpet burns on knees and elbow. Initial investigation showed raised inflammatory marker CRP 412mg/L, AKI stage 1, and CK 43400 IU/L. His CXR showed dense right upper lobe consolidation. Legionella urinary antigen was positive. Myositis myoblot, ANA, ANCA negative. COVID-19 swab negative.Treated with IV antibiotic, supplemental oxygen, and IV fluid. Transferred to ITU due to worsening of hypoxia and kidney function. Interestingly, the CK level had improved significantly within 48 hours along with clinical improvement in his symptoms. There was no role of steroid or immunosuppressant due to his significant clinical improvement. On day 7 he was off oxygen, kidney function improved, had physiotherapy, and transferred to ward and on day 10 he was ambulant and discharged home.Case report - DiscussionTo date, very few case reports of myositis in a patient with atypical pneumonia have been reported. The mechanism underlying acute myositis in atypical pneumonia is still unknown. The present analysis points out that the organism underlying atypical bacterial pneumonia may occasionally invade the muscle tissue thereby inducing both myositis and secondary kidney damage.Case report - Key learning pointsWe should be aware of this rare complication of atypical pneumonia and the resolution of symptoms that occur with the treatment of pneumonia. This would avoid unnecessary investigation and use of steroid.