Effects of relief of biliary obstruction on mononuclear phagocyte system function and cell mediated immunity.

Obstructive jaundice causes depression of immune system function but it is unclear at present how rapidly immune function recovers after relief of biliary obstruction. To address this issue, we studied 218 Sprague-Dawley rats with common bile duct obstruction. Mononuclear phagocyte function, cell mediated immune function, portal-systemic shunt fraction, liver function tests, and liver histology were evaluated in normal (sham) rats, obstructed rats, and at weekly intervals after relief of biliary obstruction. Hepatic uptake of radiolabelled bacteria was 82 per cent in sham rats and 66 per cent in rats 21 days after CBD obstruction (P less than 0.05). Phagocytic activity returned to normal within 7 days after choledochoduodenostomy. Cell mediated immunity, measured by skin graft rejection, was significantly prolonged in the obstructed group (P less than 0.05) but had returned to normal 7 days after biliary diversion. Return of hepatocellular function, as measured by liver function tests, paralleled recovery of immune function. This study demonstrates prompt recovery of the immune system after internal biliary drainage for obstructive jaundice. This finding is in contrast to previous studies that demonstrated persistent immune suppression months after biliary diversion. These data may have implications concerning the usefulness of internal biliary drainage before surgery in patients with obstructive jaundice.