Insights on the Pathophysiology of the Progression to Decompensated Hepato-Splenic Schistosomiasis

Abstract

Hepato-splenic schistosomiasis is the most important etiology of non-cirrhotic portal hypertension. It represents a particular type of chronic liver disease, which presents unique characteristics that differentiate it from those found in cirrhosis. The relative preservation of liver parenchyma despite portal fibrosis was thought to yield a more benign course of hepato-splenic schistosomiasis in terms of synthetic dysfunction and late decompensations. However, a wide range of immunologic and vascular modifications is responsible for an otherwise progressive liver disease resulting in decompensated condition frequently undistinguished from hepatic cirrhosis. A predominant Th2 immune response type, in which a fibrogenic profile of cytokines and interleukins such as IL-13, provides an immune-inflammatory background that favors fibrosis and its progression. Intra-hepatic vascular changes with portal vein branch derangement and abnormal vascular proliferation also contribute to continued disarray of the liver architecture resulting in decompensated disease frequently undistinguished from hepatic cirrhosis. This article will review immunologic and pathophysiological aspects of hepato-splenic schistosomiasis that might explain disease progression and severity.