Vanishing Lung

Abstract

SESSION TITLE: Fellow Case Report Slide: Pulmonary Disorders SESSION TYPE: Affiliate Case Report Slide PRESENTED ON: Tuesday, October 25, 2016 at 04:30 PM - 05:30 PM INTRODUCTION: Shrinking lung syndrome (SLS) is a rare complication of systemic lupus erythematosus (SLE) with only 77 cases reported in a review published in 2009 (1). CASE PRESENTATION: A 38 year-old woman with SLE complicated by inflammatory arthropathy and proteinuria managed with mycophenolate mofetil (MMF) and hydroxychloroquine was referred to our care with history of shortness of breath associated with pleuritic chest pain for 6 months. These symptoms started after her MMF was tapered down from 4,000 mg per day to 2,000 mg per day and her prednisone tapered off. Pulmonary function testing was mostly consistent with a severe restrictive process but radiographic evaluation with plain films and chest CT did not show evidence of interstitial or pleural pathology. Supine forced vital capacity decreased by 30% from upright values and MEP was diminished, implicating diaphragmatic dysfunction as an etiology. Prednisone was restarted at 40 mg per day with the patient reporting substantial improvement in her exertional limitations 6 weeks later. DISCUSSION: Various pathological mechanisms for SLS have been proposed, including diaphragmatic weakness with abnormal diaphragmatic pressures, intercostal muscle involvement, and phrenic nerve involvement (2, 3), though the precise cause is contested. We have implicated diaphragmatic dysfunction in our patient’s case in light of significant FVC drop in the supine position. Corticosteroids are the mainstay of treatment and there are also reports addressing benefit of inhaled beta agonists and theophylline (2, 3). Interestingly, our patient did demonstrate objective improvement with inhaled beta-agonists with subjective improvement after steroids were begun. CONCLUSIONS: We present a case of SLS, demonstrating evidence of diaphragmatic dysfunction with a significant improvement with inhaled beta agonists and subjective improvement with escalation in immunosuppresive therapy - all of these features inconsistently described in prior case reports and series. With its rarity, SLS is poorly characterized with subsequent heterogeneity in proposed etiology, treatment and prognosis. Reference #1: Calderaro DC et.al Presentation and prognosis of shrinking lung syndrome in systemic lupus erythematosus: report of four cases. Rheumatol Int.2012 May;32(5):1391-6 Reference #2: Carmier D et.al. Respiratory involvement in systemic lupus erythematosus. Rev Mal Respir. 2010 Oct;27(8):e66-78. Reference #3: Warrington KJ et.al. The shrinking lungs syndrome in systemic lupus erythematosus. Mayo Clin Proc. 2000 May;75(5):467-72. DISCLOSURE: The following authors have nothing to disclose: Venkata Ravi Kumar Angirekula, Yasir Tarabichi No Product/Research Disclosure Information