Case of 54 Year-Old Patient with Systemic Lupus Erythematosus-Interstitial Lung Disease Managed with Intravenous Immunoglobulin

Introduction: About 15% of patients with interstitial lung disease (ILD) have an underlying systemic rheumatic disease and among them, approximately 2-5% have Systemic Lupus Erythematosus (SLE). Etiology is still unknown but current hypotheses of pathogenesis include inflammatory response to environment pathogens causing influx of inflammatory cells to interstitial and alveolar spaces leading to alveolar epithelial damage. ILD can occur anytime during the course of SLE but on average it develops in patients with disease duration of 10 years and symptoms are non-specific. Usual treatments include systemic steroids, mycophenolate mofetil and cyclophosphamide. Case: This is a case of a 54 year-old female, Filipino with one-month history of productive cough accompanied by episodes of undocumented fever and dyspnea on exertion. Work-ups for COVID-19 including RT-PCR test were done and yielded negative results. Further work-ups were done including highresolution computed tomography (HRCT) of the chest which showed reticular opacities, honeycombing and traction bronchiectasis in both lungs predominantly in lower lobes, pleural thickening and pericardial effusion. Parenchymal findings were consistent with interstitial lung disease. Pulmonary function test showed moderate restrictive ventilator defect with reduced DLCO. ANA and anti-dsDNA results were 1:640 speckled pattern and 41.2 respectively and a score of 13 using EULAR Criteria for SLE. She was given Methylprednisolone 65 mg IV once daily, which she did not tolerate. There was worsening of dyspnea and desaturation, hence she was intubated. Treatment for SLE-ILD was shifted to Intravenous Immunoglobulin (IVIg) 25 g and she was able to receive total of five doses. She was extubated after 11 days and was discharged on the 37th hospital day. Discussion: Diagnosis of SLE-ILD is generally clinical, based on presence of extrapulmonary and serologic evidence of SLE combined with HRCT findings confirming ILD and exclusion of other potential causes. Aside from the usual treatment using systemic steroids, severe cases can be managed using Rituximab while refractory cases are managed with IVIg and plasmapheresis. To date, there are no available practice guidelines for the management of SLE-ILD. The rest of the therapeutic approaches have been extrapolated from those utilized in systemic sclerosis due to the similarity of interstitial involvement. Literatures documenting success of IVIg in management of SLE-ILD are also limited;hence this case was presented to document successful response to IVIg treatment in a patient diagnosed with SLE-ILD.