PROTEIN LAYER ON HEMODIALYSIS MEMBRANES - A NEW IMMUNOHISTOCHEMISTRY TECHNIQUE

In order to investigate the nature of the protein layer deposited on h emodialysis membranes we developed a direct immunohistochemical techni que using fluoresceinated antibodies to plasma proteins. Fifteen patie nts on regular dialytic treatment were dialyzed with CU, HE, PAN, PS a nd PMIMA and the dialyzers analyzed at the end of a standard dialytic session. Snap frozen sections of hollow fiber devices were treated wit h flourescein-isothiocyanate conjugated antibodies for IgG, IgA, IgM, C3c, fibrinogen, factor VIII, factor XIIIa-s, antithrombin III, fibrin ogen degradation products (PDF) and plasminogen. Protein deposits were evaulated by a quantitative criteria, which evaluates the intensity o f fluorescence and the area of the capillary wall occupied by this flu orescence by using an image analysis software. The coagulation cascade is activated by all membranes and similar deposits of these proteins were revealed, whereas important differences in C3c deposition were fo und.