Lactoferrin and lysozyme in the intrahepatic bile duct of normal livers and hepatolithiasis. An immunohistochemical study.

Lactoferrin and lysozyme have bactericidal activities and are responsible for mucosal defense against local bacterial infections. To assess the local defense mechanisms in the intrahepatic biliary tree, we studied the distribution of lactoferrin and lysozyme immunohistochemically in 14 normal autopsy livers and in 29 surgically resected and two autopsy livers of hepatolithiasis. In the latter, bacterial infection was constantly found. Lactoferrin and lysozyme were detected in low doses and in specific areas in the intramural and extramural glands of certain normal livers. In contrast, in hepatolithiasis, the incidence of lactoferrin- and lysozyme-positive cases significantly increased both in the intramural glands (94% and 77% of 31 cases, respectively) and in the extramural glands (72% and 48% of 29 cases, respectively) (p less than 0.01) in the stone-containing bile ducts. These glands proliferated considerably in the stone-containing bile ducts and were stained more widely and intensely than in normal livers. These data suggest that these proliferated peribiliary glands in the stone-containing bile ducts produce and secrete significant amounts of lactoferrin and lysozyme. Increased production and secretion of lactoferrin and lysozyme suggests activated local defense mechanisms against bacterial infection in the stone-containing bile ducts, and may be beneficial for inhibition of the growth of calculi and prevention of the suppurative inflammation.