Bile immunoglobulins and blockage of biliary endoprosthesis: an immunohistochemical study

Background Endoscopie biliary stenting for pancreaticobiliary malignancy is often limited by recurrent stent occlusion as a result of bacterial biofilm formation and sludge deposition. Bile immunoglobulins are thought to be important in combating biliary sepsis. Objectives To investigate whether bile immunoglobulins are involved in the pathogenesis of stent blockage. Design Immunohistochemical technique was used to study the distribution of bile immunoglobulins, bacteria and sludge in blocked biliary stents. Methods Patients with malignant obstructive jaundice were palliated by endoscopie insertion of a 10-FG polyethylene stent into the biliary tract. Blocked stents were retrieved from those who presented with recurrent jaundice and fever. The stents were cross-sectionally cut into slices and fixed in formalin. Immunoglobulins were demonstrated by the peroxidase-anti-peroxidase staining procedure using rabbit anti-serum. Results The central bulk of the stent deposits appeared as an amorphous, structureless material. IgA was found as a rim of dark brown discoloration at the periphery. IgG showed similar distribution and intensity to that of IgA whereas little IgM was detected. Clumps of bacteria were mixed with the immunoglobulin deposits. Conclusions Bile immunoglobulins may facilitate bacterial adhesion, clumping, and hence biofilm formation on the stent surface.