Background
Recurrent pyogenic cholangitis (RPC) is characterized by a recurrent syndrome of bacterial cholangitis that occurs in association with intrahepatic pigment stones and intrahepatic biliary obstruction. It was first described in 1930 and has been called by different names, including Hong Kong disease, primary hepatolithiasis, Oriental cholangitis, Oriental cholangiohepatitis (OCH), and Oriental infestational cholangitis. All aspects of the disease are still not completely understood.
Pathophysiology
Recurrent episodes of cholangitis develop in the absence of extrahepatic biliary obstruction (EHBO) as a result of pyogenic bile duct infection. Predominantly coliform-type bacteria are seeded into the biliary system, and, as a consequence, a cascade of stone formation and recurrent cholangitis is initiated. The bile ducts of patients with cholangiohepatitis are thought to be increasingly susceptible to bacterial seeding as a result of helminthic infections or as a consequence of malnutrition.
Malnutrition results in a relative deficiency of enzymes, such as beta-glucuronidase inhibitor glucaro-1,4-lactone, that inhibit deconjugation of conjugated bilirubin. The relatively unopposed deconjugation favors breakdown of conjugated bilirubin to its unconjugated form, which then complexes with calcium to form calcium bilirubinate. Calcium bilirubinate acts as the nidus for the formation of brown pigmented stones. Pigment stone formation then leads to recurrent biliary obstruction with the characteristic consequence of suppurative cholangitis. This theory of nutrition associated deficiency of beta-glucuronide has been called into question as definite differences in enzyme levels between patients with gallstones and control subjects are difficult to demonstrate.
Infection in the biliary system from Ascaris lumbricoides or from trematodes, such as Clonorchis sinensis and Opisthorchis viverrini, often results in significant epithelial damage. The causal role of these infestations is, however, not proved beyond doubt. Clinical and experimental data suggest that coliforms may then result in portal bacteremia by bacterial translocation as a result of this epithelial damage. Repeated portal bacteremia, in turn, results in the cascade of events characterized by biliary stasis, obstruction, and stone formation, which consequently result as recurrent pyogenic cholangitis (RPC).
However, it is more likely that infection and malnutrition act in concert to give rise to RPC.
Etiology
The underlying mechanism of recurrent pyogenic cholangitis (RPC) is unclear. Most experts believe that RPC is initiated by helminthic infection of the bile ducts and/or sludge/stone formation from deficient glucuronidation as a consequence of profound malnutrition. The initial insult(s) to the bile ducts precipitates a cycle of biliary stone formation and infection that results in recurrent episodes of pyogenic cholangitis.
Epidemiology
United States data
Recurrent pyogenic cholangitis (RPC) is rare. It often is observed in immigrants from Southeast Asia or from other regions of the world where trematode infections are endemic. Patients who have RPC develop it over time; hence, there does not appear to be a risk of developing RPC for visitors to endemic areas.
International data
The worldwide prevalence of RPC is unclear largely because of the paucity of disease statistics in many parts of the world where this disease is endemic. RPC is prevalent in Hong Kong, East Asia, and South East Asia on the rim of the South China Sea. It is a disease of rural populations and of poverty. A case in Turkey was successfully treated with surgery. [1]
Although the arrival of Asian immigrants in the United Kingdom, Australia, Europe, and the United States has resulted in more cases reported in nonendemic areas, the overall incidence in East Asia has been in decline over the last 20 years. Population surveys confirm this trend. The decline in incidence has been credited to the improved economic situation and living standards with the associated westernization of diet.
Prognosis
The prognosis is variable and is directly related to the presence or absence of comorbidities, the presence or absence of liver dysfunction, and the presence or absence of malignancy. In general, the prognosis of patients with recurrent pyogenic cholangitis (RPC) is not well documented; however, death occurs in approximately 15-20% of patients over 5-6 years.
Morbidity/mortality
Morbidity is related to recurrent biliary infection and may manifest as pancreatobiliary abnormalities, such as pancreatitis, biliary fistulae, hepatic abscesses, and suppurative cholangitis. Consequences of systemic infections and remote foci of infections account for distant or nonpancreatobiliary morbidity.
Complications
The complications of RPC are protean; acutely, patients may experience systemic sepsis with all of the potential complications of single and multisystem organ failure and hemostatic dysfunction. Over time, patients may develop secondary biliary cirrhosis (SBC) with portal hypertension and liver parenchymal insufficiency. Cholangiocarcinoma is an increasingly well-recognized long-term complication of cholangiohepatitis and is observed in up to 5% of affected patients. [2]
