|Year : 2019 | Volume
| Issue : 2 | Page : 98-100
V Arun Raja1, J Harikrishna1, M Ganesh1, C Rahul1, A Praveen1, S Aparna Reddy2, Alladi Mohan1
1 Department of Medicine, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
2 Department of Rheumatology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
|Date of Web Publication||11-Nov-2019|
Professor and Head, Department of Medicine, Sri Venkateswara Institute of Medical Sciences, Tirupati - 517 507, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
We report the case of a 39-year-old female who presented with breathlessness on exertion, cough, myalgias for the past 6 months and fever for 1 month. Chest X-ray revealed bilateral multilobar consolidation. High-resolution computed tomography (HRCT) of the chest revealed bilateral interstitial thickening, traction bronchiectasis and consolidation in the posterior segment of the left upper lobe. Laboratory investigations showed mild normocytic, normochromic anaemia (haemoglobin 10.4 g/dL), thrombocytosis (platelet count 6.03 lakhs/mm3), peripheral blood eosinophilia (11%) and raised erythrocyte sedimentation rate (100 mm at the end of the first hour). Serum creatine kinase (178 IU/L) was normal. Anti-nuclear antibody (ANA) tested positive and ANA profile revealed anti-Jo-1 antibodies. She was diagnosed to have anti-synthetase syndrome based on the above clinical features and positive autoantibodies. The present case highlights the importance of obtaining HRCT chest and ANA profile in confirming the diagnosis in patients with clinically suspected inflammatory muscle diseases and associated interstitial lung diseases. This case also brings to light the uncommon occurrence of anti-synthetase syndrome among idiopathic inflammatory muscle diseases.
Keywords: Anti Jo-1 antibodies, anti-synthetase syndrome, Idiopathic inflammatory muscle diseases
|How to cite this article:|
Raja V A, Harikrishna J, Ganesh M, Rahul C, Praveen A, Reddy S A, Mohan A. Anti-synthetase syndrome. J Clin Sci Res 2019;8:98-100
|How to cite this URL:|
Raja V A, Harikrishna J, Ganesh M, Rahul C, Praveen A, Reddy S A, Mohan A. Anti-synthetase syndrome. J Clin Sci Res [serial online] 2019 [cited 2020 Jun 2];8:98-100. Available from: http://www.jcsr.co.in/text.asp?2019/8/2/98/270746
| Introduction|| |
Anti-synthetase syndrome is a constellation of clinical findings seen in up to 30% of patients with dermatomyositis (DM) or polymyositis (PM). These findings include relatively acute disease onset, constitutional symptoms (e.g., fever and weight loss), myositis, the Raynaud's phenomenon, mechanic's hands, arthritis that is generally non-erosive and interstitial lung disease (ILD). Affected patients have antibodies to aminoacyl-transfer ribonucleic acid (tRNA) synthetase enzymes. Anti-Jo-1 antibodies are the most frequently observed myositis-specific autoantibody. Anti-Jo-1 antibodies are seen in about 20% of patients with idiopathic inflammatory myopathy. Here, we report a case of a 39-year-old female patient who presented with breathlessness and fever in whom anti-synthetase syndrome was diagnosed.
| Case Report|| |
A 39-year-old lady presented to the emergency room with chief complaints of breathlessness on exertion, cough, myalgias for the past 6 months and fever for 1 month. She was in her usual state of health 6 months back when she developed her breathlessness on exertion, which was gradual in onset and then progressively worsened over the past in 1 month. There was no history of wheezing, paroxysmal nocturnal dyspnoea or orthopnoea. She gave a history of cough with scanty expectoration for the past 6 months. There was a history of fever for the past 1 month, low grade, intermittent and not associated with chills and rigors; there was no skin rash. There was also a history of anorexia and loss of weight over the past 6 months.
In the past, she used to have episodes of cough and breathlessness since the age of 15 years. There was no seasonal variation. She had consulted doctors at her place of domicile and was using inhalers when she was symptomatic. Otherwise, she had been previously healthy with no co-morbid conditions and had no known allergies. She was a hostel warden. There was no history of exposure to moulds. She had no exposure to animals, and there was no history of recent travel. She was a non-smoker and did not consume alcohol; there was no history of exposure to firewood smoke.
On general physical examination, she was febrile (temperature of 101°F), pulse 120/min and respirations 34 breaths/min. Her blood pressure was 120/70 mmHg in the right arm in supine position. Oxygen saturation (SpO2) measured by pulse oximetry, while she was breathing room air, was 89%. She had pallor, no icterus, no cyanosis, no clubbing, no pedal oedema and no lymphadenopathy. She was malnourished (body mass index: 17.8 kg/m2). Respiratory system examination revealed bilateral crepitations in infra-mammary, infra-axillary, infra-scapular areas. Rest of the physical examination was unremarkable. Chest radiograph revealed bilateral multilobar consolidation [Figure 1]. Electrocardiogram showed normal sinus rhythm. Other laboratory investigations showed mild normocytic, normochromic anaemia (haemoglobin: 10.4 g/dL), thrombocytosis (platelet count: 6.03 lakhs/mm3), peripheral blood eosinophilia (11%) and raised erythrocyte sedimentation rate (100 mm at the end of the 1st h). Serum creatine kinase (178 IU/L) was normal. High-resolution computed tomography (HRCT) of the chest revealed bilateral interstitial thickening, traction bronchiectasis, ground- glass opacities, and consolidation in the anterior basal segment of left lower lobe [Figure 2]. With a working diagnosis of ILD with left upper lobe pneumonia, the patient was initiated on intravenous piperacillin-tazobactam (4.5 g thrice daily) and azithromycin (500 mg once daily). Sputum Gram stain showed pus cells. Sputum bacterial culture grew Klebsiella species sensitive to piperacillin-tazobactam. Sputum smear tested negative for acid-fast bacilli (AFB) (twice). Sputum Xpert Mycobacterium tuberculosis/rifampin tested negative. Sputum cytology was negative for malignant cells and fungal elements. Anti-nuclear antibody (ANA) tested positive and ANA profile revealed anti-Jo-1 antibodies.
|Figure 1: Chest radiograph (postero-anterior view) showing non-homogeneous opacity in bilateral lungs|
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|Figure 2: High-resolution computed tomography chest showing bilateral interstitial thickening, traction bronchiectasis, ground-glass opacification and consolidation in the anterior basal segment of left lower lobe|
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She was diagnosed to have anti-synthetase syndrome based on the above clinical features and positive autoantibodies. She was started on intravenous methylprednisolone (1 g daily) for 3 days, and then, oral prednisolone was started. Later her breathlessness worsened, hypoxaemia deteriorated. She required tracheal intubation and assisted mechanical ventilation. She was also started on intravenous immunoglobulin (400 mg/kg/day) for next five days. Subsequently, on the 12th day of hospital stay, the patient's attenders got her discharged at request for seeking further care at another centre of choice and has been lost to follow-up.
| Discussion|| |
Anti-synthetase syndrome is generally considered present in patients with an anti-synthetase antibody plus two of the following features: ILD, inflammatory myopathy and inflammatory polyarthritis. Anti-Jo-1 antibodies are directed against histidyl–tRNA synthetase, one of a group of enzymes that catalyse the attachment of specific amino acids to their cognate tRNAs during the process of protein synthesis. Patients with other types of autoantibodies (e.g., anti-PM-Scl or anti-U1 ribonucleoprotein antibodies) can also present with these types of features. However, patients with anti-synthetase antibodies generally have more prominent or severe myositis and ILD. Anti-Jo-1 and other anti-synthetase antibodies, such as anti-PL-12, have been observed in some patients with ILD who lack evidence of myositis. Patients with either DM or PM (classically those with the anti-synthetase syndrome) may have 'mechanic's hands', which present with hyperkeratotic, fissured skin on the palmar and lateral aspects of the fingers. Sometimes, these changes result in irregular, dirty-appearing horizontal lines that resemble those of a manual labourer. The majority of patients with DM or PM who develop ILD have a clinical and histopathologic pattern of non-specific interstitial pneumonia or organising pneumonia (OP). Less commonly, patients with DM or PM will develop other patterns of ILD, such as usual interstitial pneumonia, acute interstitial pneumonia or lymphoid interstitial pneumonia. Systemic glucocorticoids are the mainstay of treatment of ILD in patients with PM or DM, regardless of whether the predominant feature of the patient's illness is pneumonitis or myositis. High-dose intravenous glucocorticoids (e.g., methylprednisolone 1 g daily for 3 days) may be used at the start of therapy in addition to a second immunosuppressive agent for patients with impending respiratory failure due to rapidly progressive interstitial pneumonitis.
In our patient, ANA tested positive and ANA profile revealed anti-Jo-1 antibodies. HRCT of the chest revealed bilateral interstitial thickening, few centrilobular nodules, traction bronchiectasis and consolidation in the posterior segment of the left upper lobe, suggestive of OP type of ILD. In one study at an academic medical centre, inflammatory myositis, often with the anti-synthetase syndrome, was present in 94% of 81 patients with anti-Jo-1 antibodies in whom testing had been performed for suspected autoimmune disease. DM or PM was present in 88%, and an undifferentiated connective tissue disease or overlap syndrome was present in 12% of patients, several of whom had systemic sclerosis. Other findings in the patients positive for Jo-1 included ILD (69%), arthritis (57%), Raynaud's phenomenon (53%), mechanic's hands (17%) and sclerodactyly (12%). In our case, skin manifestations, the Raynaud's phenomenon and sclerodactyly were absent. The presence of anti-Jo-1 antibody along with inflammatory myopathy and ILD helped us in diagnosing this rare case of anti-synthetase syndrome.
Our experience with this case suggests that ANA profile and HRCT chest must be included in the routine workup of any adult presenting with chronic cough, breathlessness on exertion and myalgias. The present case also highlights the point that not all patients with anti-synthetase antibodies or even those classified as having the anti-synthetase syndrome have all manifestations of this syndrome.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]