AN UNCOMMON PRESENTATION OF ANTISYNTHETASE SYNDROME-RELATED INTERSTITIAL LUNG DISEASE IN A YOUNG INDIAN MALE

Abstract

SESSION TITLE: Systemic Diseases with Deceptive Pulmonary ManifestationsSESSION TYPE: Rapid Fire Case ReportsPRESENTED ON: 10/18/2022 12:25 pm - 01:25 pmINTRODUCTION: Idiopathic inflammatory myopathies (IIM) are a group of acquired progressive skeletal muscle inflammatory diseases [1]. IIM has an incidence of 6-10/million, an average age of diagnosis at 50 years, and a female predominance [2]. 50-75% will have interstitial lung disease (ILD). We present a patient with Antisynthetase (AS) syndrome, a subtype of IIM with associated ILD.CASE PRESENTATION: A 32-year-old Indian male presented with two months of worsening fevers, myalgias, cough, and an unintentional weight loss. Prior to admission, he had been treated with oral antibiotics for suspected community-acquired bacterial pneumonia. Despite treatment, his symptoms worsened, which prompted his presentation to the emergency department. Physical examination revealed normal vitals and bibasilar lung crackles with no pitting edema, perioral cyanosis, or clubbing of digits. Labs revealed a leukocytosis of 13,110/mL, an elevated erythrocyte sedimentation rate of 92 mm/hr, and a C-reactive protein of 6.81 mg/dL. His brain natriuretic peptide, respiratory pathogen panel, and urine antigen for Legionella and Streptococcus were negative. A Computed tomography scan of the chest revealed mediastinal lymphadenopathy and bilateral lower lobe predominant interstitial and patchy ground-glass opacities [Figure 1]. A bronchoscopy with mediastinal sampling revealed mixed lymphocytes and histiocytes. He subsequently underwent a surgical lung biopsy, which revealed uniform interstitial fibrosis with mixed interstitial chronic inflammation. After noting palmar hyperkeratosis (mechanic's hands), evaluation for IIM was initiated. He was noted to have a creatine kinase of >1000 U/L and positive Ro-52 and anti-EJ antibodies. The patient was diagnosed with AS syndrome-related ILD and started on prednisone and mycophenolate mofetil with improvement. Unfortunately, six months after diagnosis, the patient was admitted with a severe ILD exacerbation and passed away from refractory hypoxemic respiratory failure.DISCUSSION: AS syndrome is defined by the presence of myositis-specific antibodies (MSA), ILD, fever, arthralgia, and mechanic's hands [1]. Only 50% of IIM patients have a detectable MSA [3]. Anti-Jo-1, the most common MSA, is found in 75% of AS syndrome cases. Anti-EJ antibodies account for < 2% of AS syndrome [2]. The presence of MSA in those with IIM may portend ILD development [3]. Treatment for AS syndrome consists of systemic corticosteroids and steroid-sparing agents [1]. Among patients with IIM, those who had MSA had a 21% mortality rate, while those without MSA antibodies had a 7% mortality rate [3].CONCLUSIONS: AS syndrome is a rare manifestation of IIM with an associated ILD that providers should be aware of as it has characteristic clinical findings and requires antibody-specific diagnostic evaluation.Reference #1: Love LA, Leff RL, Fraser DD, Targoff IN, Dalakas M, Plotz PH, et al. A new approach to the classification of idiopathic inflammatory myopathy: myositis-specific autoantibodies define useful homogeneous patient groups. Medicine (Baltimore). 1991; 70(6):360–74. [PubMed: 1659647]Reference #2: Solomon, Joshua, Jeffrey J. Swigris, and Kevin K. Brown. "Myositis-related interstitial lung disease and antisynthetase syndrome.” Jornal brasileiro de pneumologia 37.1 (2011): 100-109.Reference #3: Douglas WW, Tazelaar HD, Hartman TE, Hartman RP, Decker PA, Schroeder DR, et al. Polymyositis-dermatomyositis-associated interstitial lung disease. Am J Respir Crit Care Med. 2001; 164(7):1182–5. [PubMed: 11673206]DISCLOSURES: No relevant relationships by Preet PatelNo relevant relationships by Shaili PatelNo relevant relationships by Tarang PatelNo relevant relationships by SACHIN PATIL SESSION TITLE: Systemic Diseases with Deceptive Pulmonary Manifestations SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/18/2022 12:25 pm - 01:25 pm INTRODUCTION: Idiopathic inflammatory myopathies (IIM) are a group of acquired progressive skeletal muscle inflammatory diseases [1]. IIM has an incidence of 6-10/million, an average age of diagnosis at 50 years, and a female predominance [2]. 50-75% will have interstitial lung disease (ILD). We present a patient with Antisynthetase (AS) syndrome, a subtype of IIM with associated ILD. CASE PRESENTATION: A 32-year-old Indian male presented with two months of worsening fevers, myalgias, cough, and an unintentional weight loss. Prior to admission, he had been treated with oral antibiotics for suspected community-acquired bacterial pneumonia. Despite treatment, his symptoms worsened, which prompted his presentation to the emergency department. Physical examination revealed normal vitals and bibasilar lung crackles with no pitting edema, perioral cyanosis, or clubbing of digits. Labs revealed a leukocytosis of 13,110/mL, an elevated erythrocyte sedimentation rate of 92 mm/hr, and a C-reactive protein of 6.81 mg/dL. His brain natriuretic peptide, respiratory pathogen panel, and urine antigen for Legionella and Streptococcus were negative. A Computed tomography scan of the chest revealed mediastinal lymphadenopathy and bilateral lower lobe predominant interstitial and patchy ground-glass opacities [Figure 1]. A bronchoscopy with mediastinal sampling revealed mixed lymphocytes and histiocytes. He subsequently underwent a surgical lung biopsy, which revealed uniform interstitial fibrosis with mixed interstitial chronic inflammation. After noting palmar hyperkeratosis (mechanic's hands), evaluation for IIM was initiated. He was noted to have a creatine kinase of >1000 U/L and positive Ro-52 and anti-EJ antibodies. The patient was diagnosed with AS syndrome-related ILD and started on prednisone and mycophenolate mofetil with improvement. Unfortunately, six months after diagnosis, the patient was admitted with a severe ILD exacerbation and passed away from refractory hypoxemic respiratory failure. DISCUSSION: AS syndrome is defined by the presence of myositis-specific antibodies (MSA), ILD, fever, arthralgia, and mechanic's hands [1]. Only 50% of IIM patients have a detectable MSA [3]. Anti-Jo-1, the most common MSA, is found in 75% of AS syndrome cases. Anti-EJ antibodies account for < 2% of AS syndrome [2]. The presence of MSA in those with IIM may portend ILD development [3]. Treatment for AS syndrome consists of systemic corticosteroids and steroid-sparing agents [1]. Among patients with IIM, those who had MSA had a 21% mortality rate, while those without MSA antibodies had a 7% mortality rate [3]. CONCLUSIONS: AS syndrome is a rare manifestation of IIM with an associated ILD that providers should be aware of as it has characteristic clinical findings and requires antibody-specific diagnostic evaluation. Reference #1: Love LA, Leff RL, Fraser DD, Targoff IN, Dalakas M, Plotz PH, et al. A new approach to the classification of idiopathic inflammatory myopathy: myositis-specific autoantibodies define useful homogeneous patient groups. Medicine (Baltimore). 1991; 70(6):360–74. [PubMed: 1659647] Reference #2: Solomon, Joshua, Jeffrey J. Swigris, and Kevin K. Brown. "Myositis-related interstitial lung disease and antisynthetase syndrome.” Jornal brasileiro de pneumologia 37.1 (2011): 100-109. Reference #3: Douglas WW, Tazelaar HD, Hartman TE, Hartman RP, Decker PA, Schroeder DR, et al. Polymyositis-dermatomyositis-associated interstitial lung disease. Am J Respir Crit Care Med. 2001; 164(7):1182–5. [PubMed: 11673206] DISCLOSURES: No relevant relationships by Preet Patel No relevant relationships by Shaili Patel No relevant relationships by Tarang Patel No relevant relationships by SACHIN PATIL