Anti-SAE Autoantibody-Positive Japanese Patient with Juvenile Dermatomyositis complicated with Interstitial Lung Disease - A Case Report
Background Clinical phenotypes and outcomes in juvenile dermatomyositis (JDM) have been defined by various myositis-specific autoantibodies (MSAs). One of the recently described MSAs associated with DM is targeted against the small ubiquitin-like modifier 1 activating enzyme (SAE). We report an anti-SAE autoantibody-positive JDM patient complicated with interstitial lung disease (ILD).
Case presentation: An 8-year-8-month-old Japanese girl presented with bilateral eyelid edema and facial erythema. At 8 years 4 months, she had dry cough and a papule with erythema on the dorsal side of the bilateral phalangeal joints. Her facial erythema gradually worsened and did not improve with topical steroids. At the first visit to our department at 8 years 8 months of age, she had a typical heliotrope rash and Gottron’s papules, with no fever or weight loss, and a chest computed tomography scan showed ground-grass opacity under visceral pleura. There was no clinical evidence of myositis, muscle weakness, myalgia, or muscle magnetic resonance imaging (MRI) findings. She had mild dry cough, without any signs of respiratory distress. Laboratory tests showed no elevated inflammatory markers. She had a normal serum creatine kinase level with a slightly elevated aldolase level, and serum anti-SAE autoantibody was detected by immunoprecipitation—western blotting. She was diagnosed with juvenile amyopathic DM complicated by ILD and received two courses of methylprednisolone pulse therapy followed by oral corticosteroid and cyclosporin A. We gradually reduced the corticosteroid dose as her skin rash tended to improve after treatment initiation. There was no progression of muscle symptoms, dysphagia, or disease flare during an 18-month follow-up period.
Conclusions: We report a patient with anti-SAE autoantibody-positive JDM complicated by interstitial pneumonia. This patient had no progression of muscle symptoms and dysphagia during an 18-month follow-up period, which differs from previous reports in adult patients with MSAs. There have been no previous reports of pediatric patients with SAE presenting with ILD. However, ILD seen in this case was not rapidly progressive and did not require cytotoxic agents. To prevent overtreatment, appropriate treatment choices are required considering the type of ILD.
Figure 1
Posted 29 Sep, 2020
On 13 Nov, 2020
Received 11 Oct, 2020
Received 09 Oct, 2020
Received 06 Oct, 2020
On 29 Sep, 2020
On 29 Sep, 2020
Received 29 Sep, 2020
On 28 Sep, 2020
Received 28 Sep, 2020
On 26 Sep, 2020
On 25 Sep, 2020
Invitations sent on 24 Sep, 2020
On 22 Sep, 2020
On 21 Sep, 2020
On 21 Sep, 2020
On 21 Sep, 2020
Anti-SAE Autoantibody-Positive Japanese Patient with Juvenile Dermatomyositis complicated with Interstitial Lung Disease - A Case Report
Posted 29 Sep, 2020
On 13 Nov, 2020
Received 11 Oct, 2020
Received 09 Oct, 2020
Received 06 Oct, 2020
On 29 Sep, 2020
On 29 Sep, 2020
Received 29 Sep, 2020
On 28 Sep, 2020
Received 28 Sep, 2020
On 26 Sep, 2020
On 25 Sep, 2020
Invitations sent on 24 Sep, 2020
On 22 Sep, 2020
On 21 Sep, 2020
On 21 Sep, 2020
On 21 Sep, 2020
Background Clinical phenotypes and outcomes in juvenile dermatomyositis (JDM) have been defined by various myositis-specific autoantibodies (MSAs). One of the recently described MSAs associated with DM is targeted against the small ubiquitin-like modifier 1 activating enzyme (SAE). We report an anti-SAE autoantibody-positive JDM patient complicated with interstitial lung disease (ILD).
Case presentation: An 8-year-8-month-old Japanese girl presented with bilateral eyelid edema and facial erythema. At 8 years 4 months, she had dry cough and a papule with erythema on the dorsal side of the bilateral phalangeal joints. Her facial erythema gradually worsened and did not improve with topical steroids. At the first visit to our department at 8 years 8 months of age, she had a typical heliotrope rash and Gottron’s papules, with no fever or weight loss, and a chest computed tomography scan showed ground-grass opacity under visceral pleura. There was no clinical evidence of myositis, muscle weakness, myalgia, or muscle magnetic resonance imaging (MRI) findings. She had mild dry cough, without any signs of respiratory distress. Laboratory tests showed no elevated inflammatory markers. She had a normal serum creatine kinase level with a slightly elevated aldolase level, and serum anti-SAE autoantibody was detected by immunoprecipitation—western blotting. She was diagnosed with juvenile amyopathic DM complicated by ILD and received two courses of methylprednisolone pulse therapy followed by oral corticosteroid and cyclosporin A. We gradually reduced the corticosteroid dose as her skin rash tended to improve after treatment initiation. There was no progression of muscle symptoms, dysphagia, or disease flare during an 18-month follow-up period.
Conclusions: We report a patient with anti-SAE autoantibody-positive JDM complicated by interstitial pneumonia. This patient had no progression of muscle symptoms and dysphagia during an 18-month follow-up period, which differs from previous reports in adult patients with MSAs. There have been no previous reports of pediatric patients with SAE presenting with ILD. However, ILD seen in this case was not rapidly progressive and did not require cytotoxic agents. To prevent overtreatment, appropriate treatment choices are required considering the type of ILD.
Figure 1