Pulmonary Venoocclusive Disease In A Patient With Chronic Myeloid Leukemia After Hematopoietic Stem Cell Transplantation

SESSION TITLE: Global Case Report Posters SESSION TYPE: Global Case Reports PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pulmonary veno-occlusive disease (PVOD) is a rare complication after hematopoietic stem cell transplantation (HSCT). The overall understanding on this condition is very limited. CASE PRESENTATION: A 58 year-old man had chronic myeloid leukemia on Imatinib(2011-13), Dasatinib(2013-14) and Nilotinib(since 2014) and failed to achieve molecular remission. He undertook one-HLA antigen mismatched sibling HSCT in late 2015, with the Fludarabine and Busulfan as conditioning. However, he had primary graft failure and required rescue from a second one-HLA mismatched sibling HSCT, using Fludarabine and anti-thymocyte globulin conditioning,with which he engrafted.There was no evidence of acute graft versus host disease. He presented with progressive dyspnea three months later. Chest radiograph showed pulmonary edema. Electrocardiogram revealed right heart strain pattern. CT thorax found dilated pulmonary trunk and pulmonary congestion. Lung function showed preserved lung volumes with reduced diffusing capacity(50%). Echocardiogram found normal chamber sizes and function, and RVSP 70mmHg. On right heart catheterization,mean pulmonary arterial pressure (mPAP) was 37mmHg(normal<20mmHg),mean pulmonary capillary wedge pressure 4mmHg (normal 2-14mmHg), cardiac index 2.89 L/min/m2,pulmonary vascular resistance 7.67 WU(normal<3WU). Nitric oxide test was positive. His blood pressure was borderline for calcium channel blocker. He was treated with Frusemide and Sildenafil with symptomatic improvement.However,three months after discharged, he was re-admitted for influenza A infection, severe hypoxemia,right heart decompensation with renal and liver derangement.He did not respond to maximal medical therapies and was deemed not a lung transplant candidate due to the recent history of hematological malignancy. He succumbed. DISCUSSION: The mortality of PVOD approaches 100% mortality in two years. The available literature on this rare condition is limited to case reports/series. Endothelial injury plays a major role in the progression of this disorder. Cytotoxic agents or irradiation in the conditioning regime may induce endothelial injury,inflammation and activate a pro-thrombotic environment in the microvasculature. Histological confirmation is needed in less definitive scenarios. Many cases had the diagnosis established after post-mortem examination.No medical treatment has been convincingly shown to be effective in this condition. In the present case report, the possible risk factors for PVOD could be the need of undertaking conditioning cytotoxic therapies and HSCT for twice. Imatinib and Dasatinib have been reported to be associated with lung vascular toxicity and pulmonary hypertension. The respiratory virus infection could further exaggerate systemic inflammatory response and pulmonary venous occlusion. CONCLUSIONS: PVOD is a rare complication of HSCT, that warrants early recognition and treatment, albeit the prognosis is poor. Reference #1: M C Bunte, M M Patnaik, M R Pritzker, L J Burns. Pulmonary veno-occlusive disease following hematopoietic stem cell transplantation: a rare model of endothelial dysfunction. Bone Marrow Transplantation volume 41, P677–686(2008) Reference #2: Makiko Yomota, Tatsuru Okamura, Yusuke Ohkuma, Yukio Hosomi, Hirotoshi Horio, Kazuteri Ohashi, Tsunekazu Hishima. Pulmonary veno-occlusive disease after hematopoietic stem cell transplantation. European Respiratory Journal 2015 46: PA813 Reference #3: Dandoy CE, Hirsch R, Chima R, Davies SM, Jodele S. Pulmonary hypertension after hematopoietic stem cell transplantation. Biol Blood Marrow Transplant. 2013 Nov;19(11):1546-56. DISCLOSURES: No relevant relationships by Thomas Chan, source=Web Response No relevant relationships by Ka-yan Chiang, source=Web Response No relevant relationships by Mary Ip, source=Web Response No relevant relationships by Albert LIE, source=Web Response No relevant relationships by Mei Sze Lui, source=Web Response No relevant relationships by Ming Yen Ng, source=Web Response No relevant relationships by Joycelyn Sim, source=Web Response No relevant relationships by Chor Cheung TAM, source=Web Response