Schistosoma mansoni: exacerbation of inflammatory granulomatous response in mice chronically infected and submitted to reinfection

Mem. Inst. Oswaldo Cruz

2004

Advanced schistosomiasis produces in man one of the most characteristic gross picture presentation of hepatic pathology. On the cut surface of the liver this lesion appears as whitish fibrous plaques replacing portal spaces on a background of normal looking hepatic parenchyma (Fig. 1C, D). Exactly one century ago, Symmers (1904) classically described this picture after performing autopsies in Egypt. It represents the anatomical counterpart of the clinical condition known as hepatosplenic schistosomiasis. A cursory gross and microscopic examination of the lesion will reveal important clues about its pathogenesis. It can then be noted that the lesion resulted from the deposition of numerous schistosome eggs along the periportal tissues, which provoked chronic granulomatous inflammation with consequent fibrous expansion of the portal spaces and intrahepatic portal vein obstruction. The parenchyma usually maintains its normal architecture, in a good correlation with the preservation of the normal hepatic function, as usually exhibited by the patients. The presence of numerous eggs points to the pathogenetic importance of worm load. Thus, schistosomal hepatopathy seems a good example of a straightforward condition, with a simple, characteristic, and understandable pathology.Although these main lines mentioned above are correct, they say little about the complexities that this unique type of chronic hepatopathy discloses when more closely and properly investigated. A closer view of its physiopathology will reveal several points of interests that are usually overlooked, but that are important for the understanding of the disease in patients and so are worth discussing here. Schistosomal hepatopathy represents a special type of a chronic liver disease. Its pathology contains unique features, one of the most important refers to its vascular changes, which differs from those found in cirrhosis, and are key factors for the understanding of the fundamental pathogenesis and the clinical potential for evolution presented by hepatosplenic schistosomiasis.

Section: Pathogenesismentioning

confidence: 98%

Schistosomal hepatopathy

Mem. Inst. Oswaldo Cruz

2004

“…Transmission control in an isolated endemic area of the state of Bahia, Brazil, was followed by amelioration of clinical manifestations and by suppression of hepatosplenic disease development 4 . Experimentally, periovular granulomas are larger 5 and periportal fibrosis more frequent in mice subjected to repeated schistosomal infections 14 . In cases of intestinal helminthiasis the severity of the clinical repercussions is usually directly related to worm load.…”

Section: Discussionmentioning

confidence: 99%

Capillaria hepatica-induced hepatic fibrosis in rats: paradoxical effect of repeated infections

Oliveira¹,

Souza

Rev. Soc. Bras. Med. Trop.

2004

“…Alguns dados da patologia experimental aparentemente apoiam esta tese, pois o desenvolvimento da chamada fibrose pipestem no chimpanzé só foi obtida com infecções múltiplas 16 . Há também um dado experimental indicativo de que os granulomas nos camundongos reinfectados são maiores do que naqueles com infecção única 9 .…”

unclassified

Reinfecções e desenvolvimento da fibrose periportal esquistossomótica no modelo murino

Santos¹,

Souza

Rev. Soc. Bras. Med. Trop.

2000

Experimental pipestem fibrosis of the liver developed more frequently (69.2%) in mice submitted to repeated infections with Schistosoma mansoni, than with single infection (11.1%). The counting of eggs in the liver revealed no significant differences between the two experimental groups. Although the reason why multiple infections favor the development of pipestem fibrosis has not been elucidated, the data obtained represent an experimental support to clinico-epidemiological claims that repeated infections play a role in pathogenesis of hepatosplenic schistosomiasis