Isospora cholangiopathy: case study with histologic characterization and molecular confirmation.

Isospora belli is an intracellular protozoan parasite that causes diarrhea worldwide and is endemic in the tropics. In the United States, it is an uncommon cause of traveler's diarrhea and a relatively rare opportunistic pathogen among the immunocompromised, particularly AIDS patients. Isospora infects the small intestine, where both sexual and asexual replication occur, and oocysts are shed in the stool. Isosporiasis of the gallbladder has also been described in AIDS patients. We report a case of diffuse biliary isosporiasis in a West African man who presented with acute illness and was found to have dilated bile ducts. He had no history of hepatobiliary disease; his HIV status was unknown. Endoscopic retrograde cholangiopancreatography demonstrated markedly abnormal intrahepatic and extrahepatic bile ducts, with radiologic findings reminiscent of primary sclerosing cholangitis. However, common bile duct biopsies revealed Isospora belli, which was confirmed by both electron microscopy and polymerase chain reaction-based molecular analysis.

Phylogeny of Coccomyxa (Myxosporea: Myxidiidae) spp. with the description of a new species from Bathygobius cyclopterus (Gobiidae) in the northern Red Sea.

Two species of Coccomyxa Léger et Hesse, 1907, one of the least studied myxosporean genera, are reported from shallow coastal waters in the Gulf of Eilat, Red Sea, Israel. A new species, Coccomyxajirilomi sp. n. is described from the spotted frillgoby Bathygobius cyclopterus (Valenciennes) (Gobiidae). It forms polysporous plasmodia that invade the liver and form packed clusters inside the bile ductules. Plasmodia also occur in the bile ducts and gall bladder of the host, attached to the epithelial lining or free floating in the bile. Infected hepatic bile ductules packed with plasmodia were partially occluded, with evidence of cholestasis, periductular fibrosis and pericholangitis. The mature spore is ellipsoid, has smooth valves and contains a single polar capsule with the polar filament arranged in 4-5 oblique coils. Spore dimensions are 9.0-11.3 x 5.0-7.0 microm. A second species, Coccomyxa sp., with smaller 7.6-9.6 x 4.2-5.2 microm and more delicate spores, was found in the gall bladder of the rippled rockskipper, Istiblennius edentulus (Forster et Schneider) (Blenniidae). The small subunit (SSU) rDNA sequence analysis of both Coccomyxa species suggests that they are closely related to members of the genera Myxidium, Zschokkella and Auerbachia, whose members infect the gall bladder of marine fish.

Gall bladder and extrahepatic bile duct changes in Opisthorchis viverrini-infected hamsters.

Opisthorchis viverrini infection is associated with several hepatobiliary diseases, but few reports have described extrahepatic lesions in opisthorchiasis. We therefore sequentially investigated histological changes of the gall bladder and extrahepatic bile duct in hamsters infected with 25 (group 1), 50 (group 2) and 100 (group 3) metacercariae for up to 180 days. Acute inflammatory reactions, including congestion, neutrophil and eosinophil infiltration, occurred in the gall bladder as early as day 7 of groups 2 and 3 and on day 14 in group 1; the extrahepatic bile ducts exhibited the changes on day 3 post-infection (p.i.). Mononuclear cell infiltration, mucus hypersecretion and fibrosis were gradually observed thereafter. Active inflammation reached a plateau at approximately 60 days in all infected groups. The well-established chronic histological changes of the gall bladder and extrahepatic bile duct were fibrosis and mononuclear cell infiltration with lymphoid aggregation and, additionally, ductal dilatation for the latter. Overall, the pathological changes in the extrahepatic bile duct were more severe than those in the gall bladder for the same dose and period of infection. The results demonstrate that pathological changes in the gall bladder and extrahepatic bile duct do occur in O. viverrini infection and may be extrapolated to human infection.

MR cholangiography in massive hepatobiliary ascariasis. A case report.

The ultrasonographic and MR cholangiographic findings in a patient with massive hepatobiliary ascariasis are described.

Localisation of parasite antigens and inflammatory responses in experimental opisthorchiasis.

The time course localisation of parasite antigens and related host pathology were studied in hamsters infected with 100 metacercariae of Opisthorchis viverrini for up to 6 months. Parasite antigens, as detected by immunofluorescence and/or immunoperoxidase-staining, were first observed in the flukes and the biliary epithelium of the intrahepatic and extrahepatic bile ducts as early as day 3 p.i. Antigens increased as the parasite matured, both in tissues in direct contact with the flukes and those surrounding the infection. Opisthorchis antigens were also observed in the first order bile ducts (small bile ducts) of the liver, which are not normally inhabited by flukes. In addition, they were found in damaged liver cells, Kupffer cells, macrophages, and within epithelioid and giant cells in the egg granuloma. The presence of the antigens was associated with heavy inflammatory cell infiltration, particularly with mononuclear cells. The results strongly support the role of fluke-associated antigens and local parasite-specific immune responses in the pathogenesis of opisthorchiasis.

Ultrasound appearances of intra- and extrahepatic biliary ascariasis.

BACKGROUND: To determine the range of ultrasonographic (US) appearances of Ascaris lumbricoides roundworms in the biliary system, their distribution in the intra- and extrahepatic parts of the system, and associated features. METHODS: All cases of biliary ascariasis during a 10-year period were reviewed. There were 42 cases in which diagnosis was based on established US criteria, and 2 cases diagnosed surgically in which US had been negative. These 44 cases occurred in 36 patients. RESULTS: In the US-diagnosed cases, worms were present in intrahepatic ducts in 32 cases, in the main duct in 37, and in the gallbladder in eight. In six cases, the liver was lifted off the main portal vein by a bundle of worms obliterating the lumen of the main bile duct. Worms packing and dilating intrahepatic ducts produced pseudotumorous appearances in the liver in four cases and bundlelike appearances in three. Worms were also seen in the pancreatic duct in two cases. Stones in intrahepatic ducts were present in 12 patients. CONCLUSION: Biliary ascariasis should be searched for inside and outside the liver. The appearances of bundles and boluses are different from those of single worms. Intra- and extrahepatic biliary stones may be present.

Biliary complications of Fasciola hepatica: the role of endoscopic retrograde cholangiography in management.

The parasite Fasciola hepatica resides in the biliary tree but rarely causes significant clinical sequelae. In this report, we review our experience with four patients in whom F. hepatica infection resulted in biliary complications, especially severe biliary colic and jaundice. The diagnosis was achieved with endoscopic retrograde cholangiography which demonstrated the worms in the extrahepatic bile ducts. Endoscopic sphincterotomy was performed uneventfully in all patients allowing balloon extraction of the parasites and resolution of their symptoms.