Immunohistochemical demonstration of lysozyme in pseudopyloric glands in chronic cholecystitis

Gallbladders of 12 cases with chronic cholecystitis showing pseudopyloric glands (PPG) and of 18 cases with acute cholecystitis or chronic cholecystitis but without PPG were examined by the peroxidase - antiperoxidase (PAP) method using rabbit antibody against human lysozyme (LM). LM-immunoreactivity was detected in the cytoplasm of PPG and, to a lesser extent, in the pits of epithelial crypts that gave rise to PPG. No LM was found in normal gallbladders; in cases of cholecystitis without PPG, LM-immunoreactivity was restricted to infiltrating inflammatory cells. The presence of LM in PPG suggests that PPG represent functional metaplastic areas, involved in the non-specific defence mechanisms through participation of LM.