Schistosomiasis-Associated Pulmonary Arterial Hypertension

Schistosomiasis is the third most common endemic disease and has been considered the most common cause of pulmonary arterial hypertension (PAH) in the world. Around 6 % of people with chronic schistosomiasis in endemic areas are affected. Schistosomiasis-associated pulmonary arterial hypertension (Sch-PAH) is classified by the World Health Organization as group 1 pulmonary arterial hypertension because it has clinical, pathological, and hemodynamic characteristic that are similar to idiopathic pulmonary arterial hypertension. Sch-PAH is a severe disease that affects mainly middle-aged women. Symptoms and signs of right-heart insufficiency may be present, such as dyspnea, syncope, and peripheral edema. It has been demonstrated that Sch-PAH has a more benign clinical course and a better survival than idiopathic pulmonary hypertension. There are few reports of any beneficial effect from specific therapy directed toward group 1 PAH in this population of patients. The mechanisms responsible for the development of pulmonary hypertension in patients with schistosomiasis are unknown. There is growing evidence that vessel obstruction and granulomatous reaction to pulmonary embolization of eggs is not the sole mechanism that causes the disease. Further studies are needed to better elucidate the pathogenesis of Sch-PAH and to develop targeted therapies for this devastating disease.