SESSION TITLE: Autoimmune Diseases Gone Wild: Rare Cases of Pulmonary ManifestationsSESSION TYPE: Rapid Fire Case ReportsPRESENTED ON: 10/18/2022 01:35 pm - 02:35 pmINTRODUCTION: Shrinking Lung Syndrome (SLS) is an uncommon pulmonary manifestation of systemic autoimmune diseases, most seen in Systemic Lupus Erythematosus (SLE). It is seen in 0.5% to 1.5% of all SLE patients and is six times more prevalent in females.CASE PRESENTATION: A 65-year-old female with a 7-year history of SLE was evaluated for a 6-month history of worsening dyspnea recently associated with orthopnea. She had two episodes of SLE flares in the last 12 months, responded to treatment with steroids. Her active medications included hydroxychloroquine 400mg/d and prednisone 5mg daily. She was a non-smoker with no occupational exposure to lung irritants. Her oxygen saturation was normal. Her history and clinical exam were negative for the neuromuscular disorder, cervical trauma, kyphosis, or scoliosis, chest auscultation was significant for reduced breath sounds at lung bases. ESR and CRP was elevated to 75mm/hr (2-15mm/hr) and 63mg/L (0.0-4.9mg/L). Echocardiogram revealed ejection fraction of 55 to 60% with normal left ventricular thickness and estimated pulmonary artery pressure, without pericardial effusion. Chest x-ray revealed low lung volumes with bilateral basal atelectasis which was not seen in previous imaging 2 years ago (Figure1). Pulmonary function tests revealed low lung volumes with restrictive ventilatory defect with severe diffusion limitation (FEV1: 44%, FVC:43%, FEV/FVC: 76%, TLC: 55%, DLCO [Hb]: 46%). Evaluation with HRCT was negative for interstitial fibrosis (Figure 2). Further evaluation with supine spirometry showed 15% reduction in FVC when compared to sitting spirometry with reduced maximal inspiratory pressure pointing towards diaphragmatic dysfunction (Figure 3).DISCUSSION: Diagnosis of SLS was made in her case based on progressive dyspnea, orthopnea with low lung volumes on imaging and restrictive ventilatory with diaphragmatic dysfunction on spirometry in the clinical context of systemic autoimmune diseases, after ruling out other possibilities for dyspnea including interstitial fibrosis and pulmonary hypertension. Her dose of prednisone was increased to 1mg/kg/day and scheduled for follow-up.CONCLUSIONS: SLS is a diagnosis of exclusion. Insidious onset of dyspnea, orthopnea or pleuritic chest pain associated with lung volume reduction on imaging without parenchymal fibrosis and restrictive ventilatory defect with diffusion limitation on pulmonary function tests in the setting of systemic autoimmune diseases should alert the clinicians to the possibility of SLS. Its pathogenesis remains unclear. The possible explanations are diaphragmatic weakness due to immune-mediated diaphragmatic dysfunction or chronic pleural inflammation impairing deep inspiration causing low lung volumes. There are no evidence-based guidelines in terms of management, but treatment almost invariably involves the use of steroids. In refractory cases, rituximab has emerged as a promising option.Reference #1: Smyth H, Flood R, Kane D, Donnelly S, Mullan RH. Shrinking lung syndrome and systemic lupus erythematosus: a case series and literature review. QJM. 2018 Dec 1;111(12):839-843. doi: 10.1093/qjmed/hcx204. PMID: 29088421.Reference #2: Duron L, Cohen-Aubart F, Diot E, Borie R, Abad S, Richez C, Banse C, Vittecoq O, Saadoun D, Haroche J, Amoura Z. 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 Oct;15(10):994-1000. doi: 10.1016/j.autrev.2016.07.021. Epub 2016 Jul 29. PMID: 27481038.Reference #3: Karim MY, Miranda LC, Tench CM, Gordon PA, D'cruz DP, Khamashta MA, Hughes GR. Presentation and prognosis of the shrinking lung syndrome in systemic lupus erythematosus. Semin Arthritis Rheum. 2002 Apr;31(5):289-98. doi: 10.1053/sarh.2002.32555. PMID: 11965593DISCLOSURES: No relevant relationships by Yaron GoldmanNo relevant relationships by Amos LalNo relevant relationships by Gayatri NarayanNo relevant relationships by Chidambaram Ramasamy SESSION TITLE: Autoimmune Diseases Gone Wild: Rare Cases of Pulmonary Manifestations SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/18/2022 01:35 pm - 02:35 pm INTRODUCTION: Shrinking Lung Syndrome (SLS) is an uncommon pulmonary manifestation of systemic autoimmune diseases, most seen in Systemic Lupus Erythematosus (SLE). It is seen in 0.5% to 1.5% of all SLE patients and is six times more prevalent in females. CASE PRESENTATION: A 65-year-old female with a 7-year history of SLE was evaluated for a 6-month history of worsening dyspnea recently associated with orthopnea. She had two episodes of SLE flares in the last 12 months, responded to treatment with steroids. Her active medications included hydroxychloroquine 400mg/d and prednisone 5mg daily. She was a non-smoker with no occupational exposure to lung irritants. Her oxygen saturation was normal. Her history and clinical exam were negative for the neuromuscular disorder, cervical trauma, kyphosis, or scoliosis, chest auscultation was significant for reduced breath sounds at lung bases. ESR and CRP was elevated to 75mm/hr (2-15mm/hr) and 63mg/L (0.0-4.9mg/L). Echocardiogram revealed ejection fraction of 55 to 60% with normal left ventricular thickness and estimated pulmonary artery pressure, without pericardial effusion. Chest x-ray revealed low lung volumes with bilateral basal atelectasis which was not seen in previous imaging 2 years ago (Figure1). Pulmonary function tests revealed low lung volumes with restrictive ventilatory defect with severe diffusion limitation (FEV1: 44%, FVC:43%, FEV/FVC: 76%, TLC: 55%, DLCO [Hb]: 46%). Evaluation with HRCT was negative for interstitial fibrosis (Figure 2). Further evaluation with supine spirometry showed 15% reduction in FVC when compared to sitting spirometry with reduced maximal inspiratory pressure pointing towards diaphragmatic dysfunction (Figure 3). DISCUSSION: Diagnosis of SLS was made in her case based on progressive dyspnea, orthopnea with low lung volumes on imaging and restrictive ventilatory with diaphragmatic dysfunction on spirometry in the clinical context of systemic autoimmune diseases, after ruling out other possibilities for dyspnea including interstitial fibrosis and pulmonary hypertension. Her dose of prednisone was increased to 1mg/kg/day and scheduled for follow-up. CONCLUSIONS: SLS is a diagnosis of exclusion. Insidious onset of dyspnea, orthopnea or pleuritic chest pain associated with lung volume reduction on imaging without parenchymal fibrosis and restrictive ventilatory defect with diffusion limitation on pulmonary function tests in the setting of systemic autoimmune diseases should alert the clinicians to the possibility of SLS. Its pathogenesis remains unclear. The possible explanations are diaphragmatic weakness due to immune-mediated diaphragmatic dysfunction or chronic pleural inflammation impairing deep inspiration causing low lung volumes. There are no evidence-based guidelines in terms of management, but treatment almost invariably involves the use of steroids. In refractory cases, rituximab has emerged as a promising option. Reference #1: Smyth H, Flood R, Kane D, Donnelly S, Mullan RH. Shrinking lung syndrome and systemic lupus erythematosus: a case series and literature review. QJM. 2018 Dec 1;111(12):839-843. doi: 10.1093/qjmed/hcx204. PMID: 29088421. Reference #2: Duron L, Cohen-Aubart F, Diot E, Borie R, Abad S, Richez C, Banse C, Vittecoq O, Saadoun D, Haroche J, Amoura Z. 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 Oct;15(10):994-1000. doi: 10.1016/j.autrev.2016.07.021. Epub 2016 Jul 29. PMID: 27481038. Reference #3: Karim MY, Miranda LC, Tench CM, Gordon PA, D'cruz DP, Khamashta MA, Hughes GR. Presentation and prognosis of the shrinking lung syndrome in systemic lupus erythematosus. Semin Arthritis Rheum. 2002 Apr;31(5):289-98. doi: 10.1053/sarh.2002.32555. PMID: 11965593 DISCLOSURES: No relevant relationships by Yaron Goldman No relevant relationships by Amos Lal No relevant relationships by Gayatri Narayan No relevant relationships by Chidambaram Ramasamy