Successful treatment of refractory interstitial lung disease with cyclophosphamide and pirfenidone in a new onset of juvenile SLE: a case report.

Introduction and importance: Systemic lupus erythematosus (SLE) is a systemic immune disease, presented with a broad spectrum of clinical manifestations. The occurrence of interstitial lung disease (ILD) as the initial manifestation of SLE is very rare. Case presentation: The authors present the case of a 6-year-old girl who presented with symptoms of fatigue, fever, oral ulcers, and dry cough with difficulty breathing. On physical examination, the patient had fever and oral ulcers, in addition of acute phase reactant analysis, positive ANA, and double-stranded DNA. Chest computed tomography images showed nonspecific interstitial pneumonia + organizing pneumonia pattern, leading to the diagnosis of onset of SLE with ILD. The patient was treated with steroids and azathioprine for 1 year, and the radiological and immunological resolution was noted. However, the patient continued to cough, have difficulty breathing, and was readmitted to the hospital due to SLE recurrence after 1 year of follow-up. Despite continued corticosteroid therapy and monthly administration of steroids and cyclophosphamide for 6 months, the patient's respiratory symptoms and chest radiography results did not improve significantly. The patient was then prescribed a daily regimen of cyclophosphamide and pirfenidone, which was found to be effective in reducing the steroid dose and achieving remission after 1 year of follow-up. Clinical discussion: Treatment of connective tissue disease-associated ILD is difficult due to a lack of treatment data. Conclusion: This case provided evidence of the efficacy of combination therapy of pirfenidone and cyclophosphamide for refractory connective tissue disease-associated ILD in young children.