An unusual presentation of infmammatory myopathy in a patient on - PDF document

International Journal of Clinical Rheumatology Case Report An unusual presentation of infmammatory myopathy in a patient on natalizumab treatment for multiple sclerosis: A case report and review of myopathological classifjcation of infmammatory myopathy Beenish Zulfjqar *1 , Jacquelin Abstract: Acquired immune and infmammatory myopathies (IIMs) are traditionally subdivided into Chua 2 , Stacy Weinberg 2 & dermatomyositis, polymyositis, inclusion body myositis (IBM) and necrotizing autoimmune myopathy Sobia Hassan 2 (NAM). Our patient is a 38-year old female who had history of Multiple Sclerosis and was on Natalizumab. 1 Advocate Illinois Masonic Medical Centre, Almost a year later, she presented with acute proximal bilateral upper extremity weakness with elevated USA CPK. She was initially labeled as having ‘viral myositis’. Her subsequent two admissions demonstrated 2 Rush University Medical Center, Chicago, worsening of muscle weakness with dysphagia which was initially unresponsive to high dose of IL, USA steroids. She had an EMG which showed irritative myopathy and a muscle biopsy which showed IMPP. She eventually responded to pulse dose of steroids and IVIG and Natalizumab was held. The temporal *Author for correspondence: relationship between the development of infmammatory myopathy in our patient and subsequent beenish_zulfjqar_ali@yahoo.com improvement in her course after discontinuation of the drug suggests that natalizumab may have played a role in our patient’s disease and warrants further investigation and vigilance. In addition to the case report, we hope to elaborate on the myopathological descriptions increasingly being used to describe the IIMs and to explore the potential link between natalizumab and the onset of IIM in our patient. Keywords: natalizumab myositis • multiple sclerosis • acquired immune and infmammatory myopathies Introduction Case Acquired immune and infmammatory myopathies We present a case of a 38-year-old female with a (IIMs) are traditionally subdivided into medical history signifjcant for Grave’s disease post- dermatomyositis, polymyositis, inclusion body radioablation, hypertension, and anemia. She myositis (IBM) and necrotizing autoimmune also had a history of Multiple Sclerosis diagnosed myopathy (NAM) [1,2]. Tie presence of in 2014 when she fjrst presented with impaired myositis specifjc antibodies and myopathological gait and dysarthria after a sinus infection. Her descriptions help to further delineate these MRI brain fjndings at that time showed several disorders and may help prognostically. We small enhancing lesions in the white matter: left describe an unusual presentation of acute onset cerebellar peduncle, left lateral ventricle, left infmammatory myopathy in a patient who was periventricular white matter, left pons, right on natalizumab treatment for multiple sclerosis and left medial longitudinal fasciculus, and left (MS) and who was initially resistant to high pons. Her course was characterized as relapsing. dose steroids. She was followed by both the She was previously treated with high doses of rheumatology and neuromuscular services steroids and intravenous cyclophosphamide with who characterized her as having an immune improvement. However, in December 2015, myopathy with perimysial pathology (IMPP). In she relapsed and was begun on natalizumab addition to the case report, we hope to elaborate (Tysabri). In September 2016, she began to have on the myopathological descriptions increasingly a headache and neck pain. Work-up including being used to describe the IIMs and to explore MRI of the brain revealed a CSF leak of unknown the potential link between natalizumab and the etiology and she received a blood patch. During onset of IIM in our patient. that time, she also started complaining of Int. J. Clin. Rheumatol. (2018) 13(3), 197-201 ISSN 1758-4272 197

Case Report Z ulfjqar, Chua, Weinberg, et al. persistent bilateral upper extremity pain and and IV methylprednisolone, her swallowing signifjcant arm swelling with proximal muscle and breathing improved. She was sent to weakness. Her exam was notable for 4/5 strength rehabilitation for strength training and recovered in neck fmexor and extensors, 5/5 strength in about 75% of her strength on follow-up. bilateral deltoids, 4/5 in bilateral biceps, 4-/5 Prednisone was tapered and she was started on in bilateral triceps, 5/5 strength in bilateral mycophenolate mofetil as a steroid sparing agent hip fmexor and extensor and quadriceps. Distal for her myositis. extremity power was normal. Her laboratory Discussion work-up revealed CPK of 3500, 106 mg/dl, Adult acquired immune infmammatory AST 126 mg/dl, ALT 53 mg/dl, mildly elevated myopathies are traditionally classifjed using RF; otherwise, ANA, infmammatory markers, the Bohan and Peter criterion which was and complements were normal. EMG fjndings developed in 1975 [3]. Major advances in were suggestive of an irritative myopathy. She knowledge regarding infmammatory myositis was evaluated by rheumatology at that time and have recognized the limitations of such criteria. it was felt that her presentation was more likely Developments of more recent classifjcations to represent a viral myositis than infmammatory have emerged; one of which emphasized myositis given the sudden onset of symptoms clinicoserological profjles, extra muscular organ and also because of the temporal relationship involvement and autoantibodies [4]. Tiese to symptoms suggestive of a viral infection. She newer classifjcations highlight the heterogeneity was discharged home with close follow-up. Her of these myositis syndromes and how this has symptoms persisted and began to include lower implications for prognosis and response to extremity weakness, pain and swelling. She was therapy. However, it does not take into account again admitted to the hospital and had a muscle the pathological fjndings which may also have biopsy that showed infmammatory myopathy with utility for distinguishing between treatable myopathic changes, infmammatory infjltrates, and presently untreatable AIM. For example, a increased labeling of endomysial capillaries patient with rapidly progressive muscle weakness for C5b-9 membrane attack complex but no with mostly necrosis and little infmammation perifascicular atrophy. Her CPK at this time was on biopsy may perform poorly despite steroid 2500. Given worsening symptoms, persistent therapy as opposed to one with infmammation hyperCKemia and biopsy results, she was started but little necrosis or fjbrosis. Familiarity of on prednisone 60 mg/day. Tiree weeks later she myopathological descriptions, then, can provide returned with resolution of swelling; however, insights in to which patients would require her weakness and muscle soreness persisted and more aggressive therapy. Myopathological she had new symptoms of dyspnea and dysphagia. classifjcation includes description of muscle fjber Her proximal upper and lower extremity pathology, immune characteristics, and types strength at this time was 3/5 bilaterally. She was of tissues involved [2]. Currently, 6 patterns of readmitted and started on Methylprednisone acquired IIMs have been identifjed: immune 1 g IV × 3 days and IVIG (2 g/kg in divided myopathies with perimysial pathology (IMPP); doses over two days). Cancer screening including myovasculopathies; immune polymyopathies; ovarian ultrasound, CT chest and abdomen, and immune myopathies with endomysial pathology mammogram were unremarkable. Paraneoplastic (IM-EP); histiocytic infmammatory myopathy; markers were negative. A Myomarker panel was and infmammatory myopathies with vacuoles, sent and was noted to be negative for anti-SRP, aggregates and mitochondrial pathology (IM- anti Jo-1, EJ, OJ, Mi, Ku, MDA5, Anti HMG VAMP) Table 1. Co-A. She was evaluated by the neuromuscular service who reviewed her muscle biopsy and Specifjcally, our patient had myopathy consistent felt that her infmammatory changes were subtle with infmammatory myopathy with perimysial and mostly identifjed in the perimysium region. pathology but with negative myositis antibodies. Tiey labeled her as having an infmammatory IMPP is commonly associated with positive myopathy with perimysial pathology. Due to Anti-Jo1 antibodies. However, autoantibodies her severe and refractory presentation and the can be absent in about 20-40% of patients potential that Natalizumab might have played a in patients with infmammatory myositis [5- role in the development of her myopathy via its 7]. Patients with IMPP and positive anti-Jo-1 immunomodulatory actions, it was discontinued. antibodies can have a constellation of symptoms After she completed her course of IVIG that may include muscle weakness and pain, 198 Int. J. Clin. Rheumatol. (2018) 13(3)