NAVIGATING DIAGNOSIS AND TREATMENT OF RAPIDLY PROGRESSING SERONEGATIVE MYOSITIS INDUCED INTERSTITIAL LUNG DISEASE

Document Type

Conference Proceeding

Publication Date

6-27-2024

Publication Title

J Gen Intern Med

Keywords

3 hydroxy 3 methylglutaryl coenzyme A, azathioprine, copper, creatine kinase, folic acid, ganglioside, mycophenolate mofetil, mycophenolic acid, myelin associated glycoprotein, parietal cell antibody, SARS-CoV-2 vaccine, selenium, tacrolimus, thyrotropin, acute hypoxemic respiratory failure, adult, adverse drug reaction, autoimmune necrotizing myopathy, bronchiolitis obliterans organizing pneumonia, case report, cell infiltration, chronic inflammatory demyelinating polyneuropathy, clinical article, computer assisted tomography, conference abstract, diagnosis, differential diagnosis, drug dose, drug therapy, electromyogram, electromyography, gastroesophageal reflux, ground glass opacity, human, hyperlipidemia, hypoxia, immunosuppressive treatment, interstitial lung disease, lung embolism, lung fibrosis, male, muscle biopsy, muscle weakness, myopathy, myositis, respiratory failure, side effect, tachycardia, therapy

Abstract

CASE: A 76 year old male with PMH of CAD, hyperlipidemia, GERD, and type II DM developed acute hypoxic respiratory failure and muscle weakness 2 weeks after receiving COVID-19 vaccination. 4 weeks later, the patient presented at an outside hospital for worsening acute hypoxic respiratory failure. Initial work up showed suspicion for cryptogenic organizing pneumonia or pulmonary fibrosis with no evidence of infection or autoimmune disease. CT scan showed ground glass opacities eliciting transfer to quaternary care center. Upon consultation with the interstitial lung disease (ILD) team patient was placed on steroid burst taper. Development of intermittent tachycardia and progressive hypoxia evoked workup for pulmonary embolism. CT significant for worsening diffuse lung disease. Patient experienced proximal muscle weakness which prompted subsequent autoimmune neurologic workup. MSAs yielded negative results. EMG findings showed proximal myopathy concerning chronic inflammatory demyelinating polyneuropathy. Lab work showed CPK, TSH/T4, Ca, folate, PTH, zinc, intrinsic factor, ANA, copper, gastric parietal cell antibody, HMG CoA within normal limits. Serum was positive for selenium 171, but negative for myelin associated glycoprotein antibody and ganglioside. Statin was discontinued and muscle biopsy was collected with myositis panel. Patient started on IVIG but was forced to stop due to O2 falling to the 60s and transfer to MICU. Five days later the patient received 5 IVIG infusions, unfortunately the patient passed due to worsening lung condition. The original muscle biopsy revealed randomly distributed necrotic muscle fibers without mononuclear cell infiltrates confirming inflammatory myopathy. IMPACT/DISCUSSION: Rapidly progressive myositis associated ILD is correlated with worse survival, meaning early recognition and treatment plays a vital role in illness management. ILD can present prior to symptoms of myositis, therefore as other causes of ILD are ruled out myositis should be kept in the differential diagnosis and investigated early in disease progression. Negative serological testing warrants further workup and muscle biopsy since it is more common for patients with immune mediated necrotizing myopathy (IMNM) to present in this manner. Seronegative patients form a distinct subgroup with unique features within IMNM, showing higher rates of extramuscular disease activity. Treatment guidelines for rapidly progressive myositis are currently limited, especially rapidly progressive subtype. High dose steroids combined with azathioprine or mycophenolate, and tacrolimus is recommended for initial treatment. Finally, evidence for use of IVIG is limited but shows promising results in treatment resistant cases when implemented early, unlike our case. CONCLUSION: 1) Myositis can present with extra muscular involvement with lung comprising the most common organ 2) Prompt multimodal immunosuppressive therapy is the treatment for myositis associated rapidly progressive ILD.

Volume

39

First Page

S340

Find It @ Sladen

Share

COinS