An Immunohistochemical Technique for the Study of Plasma Proteins Adsorbed on Dialysis Membranes

A protein layer coats the dialysis membrane on the first contact with blood: the nature of this layer may influence the following biological, immunological and clinical events such as intrinsic coagulation system and complement cascade activation (1). The nature of adsorbed protein on dialysis filters has been studied by the use of SDS-PAGE following various desorption procedures. Unfortunately results seem not easily reproducible among different studies: protein-surface interaction depends upon membrane chemical structure and varies among in vitro experiments and in clinical use. In order to better characterize the nature of the protein layer we have developed a new immunohistochemical method with the fluorescent antibody technique already used for the kidney biopsy. Biocompatibility of four different dialysis membranes was evaluated comparing protein cake deposition, plasma anaphilatoxin generation an platelet degranulation as B-TG release.