INTRODUCTION: Pulmonary hypertension is a serious and potentially devastating disease of the pulmonary vasculature with diverse etiologies and pathogenesis. Schistosomiasis is a rare cause.
CASE PRESENTATION: A 50-year old male presented with a one year history of increasing abdominal girth and progressive shortness of breath. He reported a productive cough with occasional hemoptysis. His past history was significant for schistosomiasis in 1969 while in Yemen, for which he received treatment. He had moved to the United States approximately ten years prior to his presentation. His physical exam revealed room air oxygen saturation of 85%, jugular venous distension, loud P2, holosystolic murmur at apex and right parasternal heave. He had ascites and bilateral pitting edema of his extremities. Laboratory work revealed a normal complete blood count, basic metabolic panel and coagulation profile. Liver function showed only mild elevation in alkaline phosphatase. Hepatitis serologies and alpha fetoprotein were negative. Urine analysis was unremarkable and negative for red blood cells. Electrocardiograph revealed right ventricular hypertrophy and chest radiograph showed moderate cardiomegaly with prominent pulmonary arteries. Inspection bronchoscopy for evaluation of hemoptysis was unrevealing. His pulmonary function test, ventilation-perfusion scan and serologies for collagen vascular diseases were negative. A fast-ELISA test for schistosomiasis was non-reactive, stool studies and rectal biopsy were negative for parasites. Abdominal ultrasound showed periportal fibrosis. Echocardiogram showed a dilated right atrium and ventricle, severe tricuspid valve regurgitation with normal left ventricular systolic function. Cardiac catheterization confirmed severe pulmonary hypertension with mean pulmonary artery pressure of 66 mmHg, pulmonary vascular resistance 21 WU and cardiac index 2.1 L/min/m2 without pulmonary vascular reactivity to adenosine. Patient was started on home oxygen, aldactone, digoxin, lasix and oral pulmonary vasodilator therapy with endothelin receptor blocker,Bosentan.
DISCUSSIONS: Schistosomiasis is the third leading endemic parasitic disease in the world. Infesting more than 300 million individuals, these blood flukes live in the perivisceral veins. The eggs are shed in the urine and feces of infected individuals and the fresh water snail acts as an intermediate host. Pulmonary lesions are attributed to 3 species: S. haematobium, S. mansoni and S. japonicum. Acutely, transient chest radiographic abnormalities and nonspecific influenza-like symptoms can occur, including cough. Limited data suggests that cardiopulmonary schistosomiasis is seen most often in S. mansoni infections. In less than 5% of cases the eggs migrate through the pulmonary vessel wall and trigger a granulomatous response in the pulmonary vasculature. The end result of cumulative injuries to the pulmonary vasculature is the development of obliterative arteritis leading to fibrosis, pulmonary hypertension and subsequently cor-pulmonale. Diagnosis of cardiopulmonary schistosomiasis depends on the detection of viable schistosomal ova in stool , urine or rectal biopsy and serolgies along with evidence of characteristic hepatic fibrosis and pulmonary hypertension. Although treatment with praziquantel can effectively eradicate schistosomal infections with minimal toxicity, cardiopulmonary manifestations are not likely to be reversible given the chronic fibrotic tissue changes that are present. Our patient presented with right heart failure secondary to severe pulmonary arterial hypertension. With his history of residence in an endemic region, prior history of schistosomiasis and pathognomonic liver ultrasound findings with periportal fibrosis, chronic pulmonary schistosomiasis was diagnosed. In the absence of evidence for active infection specific treatment with praziquantel was not initiated. On treatment for heart failure and oral pulmonary vasodilator therapy, he demonstrated complete resolution of facial puffiness, ascites and pedal edema within a few days and a significant improvement in his exercise tolerance from a six minute walk distance of 335 meters to 550 meters over the next year.
CONCLUSION: To our knowledge, this is the first case report demonstrating the effectiveness of bosentan in treating a case of severe pulmonary hypertension secondary to schistosomiasis.
DISCLOSURE: Naricha Chirakalwasan, None.