A CASE OF SHRINKING LUNG SYNDROME ASSOCIATED WITH SYSTEMIC LUPUS ERYTHEMATOSUS AND SJÖGREN SYNDROME

Abstract

TOPIC: Diffuse Lung Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Shrinking lung syndrome (SLS) is a rare disease that presents with progressive dyspnea, pleuritic chest pain, and restrictive lung disease. Most commonly seen with systemic lupus erythematosus (SLE), but also seen in other rheumatologic conditions such as Sjogren's syndrome, scleroderma, and rheumatoid arthritis. We present a case of a 28-year-old female with shrinking lung syndrome in the setting of SLE and Sjogren's Syndrome. CASE PRESENTATION: A 28-year-old female with an 18-year history of SLE with +ANA > 1:2560, +Smith, + SS-A/SS-B, and +dsDNA >379, presented with six months of dyspnea on exertion. Her other medical history included moderate mitral valve regurgitation, Sjogren's syndrome, depression, and hypothyroidism. Her SLE was managed with prednisone 7.5 mg daily, hydroxychloroquine, and mycophenolate, with a SELENA-SLEDAI score of 18, indicating high disease activity. Evaluation of her dyspnea included a high-resolution chest CT showing pleural thickening with normal lung parenchyma and an echocardiogram with evidence of moderate mitral valve regurgitation with normal ejection fraction. Pulmonary function testing revealed severe restrictive disease with TLC 1.6 L (39% of predicted), DLCO 6.23 ml/min/mmHg (24%), FEV1 0.91 L (32%) and FVC 1.13 L (34%). Right heart catheterization (RHC) was notable for PCWP 19, mPAP 28, PVR 160.75 dynes, CO 5.65 L/min concerning for pulmonary hypertension. DISCUSSION: Shrinking lung syndrome is a rare condition with a reported incidence in patients with SLE of 0.26% to 1.1%, with a female predominance up to 94% in some case series. First described by Hoffbrand and Beck in 1965, SLS commonly presents with pleuritic chest pain, dyspnea, diaphragmatic elevation, and restrictive lung disease. The diagnosis of SLS requires evidence of reduced lung volumes and DLCO in the setting of normal lung parenchyma. The pathogenesis and pathophysiology are still unknown and may be a result of phrenic nerve paralysis, alveolar microatelectasis, and hyaline membrane formation, or pleural thickening and adhesions. Most cases respond to high-dose steroids and/or immunosuppression with stabilization or improvement in lung function in the majority of patients. One case series showed a 95% clinical improvement in patients treated with steroids and/or immunosuppressants; however partial chronic restriction remained. CONCLUSIONS: This patient demonstrated severe restrictive disease with normal lung parenchyma. Although the reduced DLCO seen in our patient's pulmonary function testing could be seen with pulmonary hypertension, the severe restriction with normal parenchyma is consistent with a diagnosis of shrinking lung syndrome. She is currently undergoing treatment for her lupus with prednisone and immunosuppressants. REFERENCE #1: Carmier D, Diot E, Diot P. Shrinking lung syndrome: recognition, pathophysiology and therapeutic strategy. Expert Rev Respir Med 2011;5(1):33-9. REFERENCE #2: Duron L, Cohen-Aubart F, Diot, E, et al. Shrinking lung syndrome associated with systemic lupus erythematosus: a multicenter collaborative study of 15 new cases and a review of the 155 cases in the literature focusing on treatment response and long-term outcomes. Autoimmun Rev 2016;15(10):994-1000. REFERENCE #3: Deeb M, Tselios K, Gladman DD, et al. Shrinking lung syndrome in systemic lupus erythematosus: a single-centre experience. Lupus 2018;27(3):365-371. DISCLOSURES: Consultant relationship with Boehringer Ingelheim Please note: 12 months Added 04/20/2021 by Ryan Boente, source=Web Response, value=Consulting fee No relevant relationships by Matthew Glick, source=Web Response