Journal of Hepatology 1998; 28: 426–432 Copyright C European Association for the Study of the Liver 1998 Printed in Denmark ¡ All rights reserved Munksgaard ¡ Copenhagen Journal of Hepatology ISSN 0168-8278 Bile duct bacterial isolates in primary sclerosing cholangitis: a study of explanted livers Rolf Olsson, Einar Björnsson, Lars Bäckman, Styrbjörn Friman, Krister Höckerstedt, Bertil Kaijser and Mikael Olausson Gastroenterology Unit, Department of Medicine, Transplantation Unit, Department of Surgery, and Department of Clinical Bacteriology, Sahlgrenska University Hospital, Sahlgrenska, Göteborg, Sweden Background/Aims: The pathogenesis of the inflam- matory lesion in primary sclerosing cholangitis is un- known. The clinical picture is characterized by i.a. episodes of fever, the cause of which also remains speculative. Previous studies of bacterial isolates in the liver or bile ducts in primary sclerosing cholangitis have had the shortcoming of possible contamination associated with the sampling. The aim of this study was to investigate whether bile and bile duct tissue, obtained under sterile conditions in connection with liver transplantation, contain bacteria. Methods: We studied bile from bile duct walls and bile collected from the explanted livers of 36 patients with primary sclerosing cholangitis and 14 patients with primary biliary cirrhosis. Results: Positive cultures were obtained from 21 of 36 primary sclerosing cholangitis patients, but from none of the primary biliary cirrhosis patients. The number of bacterial strains was inversely related to the time after the last endoscopic retrograde cholangiography. P  sclerosing cholangitis (PSC) is a disease of unknown etiology, usually occurring in associ- ation with ulcerative colitis (1,2). There is no doubt that genetic factors play a role in the development of PSC (3). The presence of T-cell infiltrates in the portal area, the occurrence of autoantibodies, and the in- crease in activated autoreactive T-lymphocytes indicate that immune mechanisms are involved in the disease process (4–6). There is little evidence in the literature that bacteria cause PSC. Cultivation of portal venous blood or liver biopsies from patients with inflamma- Received 18 June; revised 29 September; accepted 1 October 1997 Correspondence: Rolf Olsson, Gastroenterology Unit, Sahlgrenska University Hospital, Sahlgrenska, S-413 45 Göteborg, Sweden. Tel: 46 31 601830. Fax: 46 31 822152. 426 Treatment with antibiotics or intraductal stent, or the occurrence of fever before liver transplantation did not seem to influence the culture results, whereas anti- biotic treatment in connection with endoscopic retro- grade cholangiography may possibly have reduced the number of isolates in the cultures. Alpha-haemolytic Streptococci were retrieved as late as 4 years after the last endoscopic retrograde cholangiography. Retrospective analysis of liver laboratory tests after endoscopic retrograde cholangiography did not indi- cate a deleterious effect of the investigation. Conclusions: The data suggest that antibiotics should be given routinely in connection with endoscopic retro- grade cholangiography. They also raise the question of a possible role of alpha-haemolytic Streptococci in the progression of primary sclerosing cholangitis. Key words: Bile samples; Cholangiography; Liver transplantation; Microbiology; Primary sclerosing cholangitis. tory bowel disease (IBD) have yielded a wide range of organisms not felt to play an etiopathogenetic role in the liver damage frequently seen in IBD (7–11). How- ever, it is not possible to deduce whether any of the patients studied had PSC. The course of PSC is characterized by episodes of pain, pruritus and fever, the last being the most incapa- citating symptom (12). The cause of the fever in PSC remains speculative. Arguments against a bacterial pathogenesis are the facts that blood cultures are al- most always negative and that the attacks are almost always self-limited. On the other hand, leukocyte dif- ferential counts display an increase in neutrophils, sug- gesting a bacterial etiology. In the present paper we report the results of bac- terial cultures of bile duct walls and bile aspirated from