ABSTRACT
While practising in Hong Kong in 1930, Digby drew attention to a condition which was subsequently known as recurrent pyogenic cholangitis by reporting on eight cases of ‘common duct stones of liver origin’.1 The term recurrent pyogenic cholangitis or RFC was used by Cook et al. in 1954 when they reported their experience with the condition in a series of 90 patients.2 The synonyms associated with this condition include Asiatic cholangiohepatitis, oriental cholangiohepatitis, Hong Kong Disease,3 Chinese biliary obstruction syndrome4 and primary cholangitis.5 This condition is commonly seen in Chinese living in Canton and Hong Kong but is not restricted to the Chinese in the Orient since it also occurs in Chinese immigrants in Malaysia, Singapore, North America and Australia.6-8 RPC is also common in Japanese in Japan and Taiwanese in Taiwan. Although rare, RPC has also been reported to afflict occidentals.9,10
Pathogenesis
In RFC the gallstones found within the biliary system are calcium bilirubinate stones or pigmented calcium stones. Calcium bilirubinate stones are prevalent in Asia and are very rare in Europe and the United States. In addition to the presence of these friable concretions of various shapes and sizes within the biliary tree, the bile is often muddy in consistency and contains numerous fine particles of calcium bilirubinate. Biochemical analysis of these stones revealed a bilirubin content of 40.2-57.1% and a cholesterol content of 2.9-25.6%. This differs greatly from cholesterol stones, which are common in Europe and the United States, which contain >96% of cholesterol in pure cholesterol stone, and >71.3% in mixed cholesterol stone but the bilirubin content is only 0.025.0%.11 The peculiarity of the formation of calcium bilirubinate stones in RPC has been ascribed to the high incidence of bile being infected with Escherichia coli (E. coli). In man, the major portion of bilirubin is excreted in bile as bilirubin glucuronide. In the presence of (3-glucuronidase, bilirubin glucuronide is hydrolysed into free bilirubin and glucuronic acid. Normally, calcium is secreted into bile and when it combines with the carboxyl radical of free bilirubin, insoluble calcium bilirubinate is formed. Normal bile is free of β-glucuronidase activity, whereas bile infected with E. coli has intense βglucuronidase activity. Bile calcium content increases in the presence of biliary tract inflammation and this coupled with the increased hydrolysis of bilirubin glucuronide by the β-glucuronidase from E. coli gives rise to the multiple stones formation classically
seen in RPC.11 There are two types of pigmented stones, black and brown. The infected type seen in RFC is the brown pigment stone.
