Chronic renal failure is associated with humoral immune alterations characterized by a diminished vaccine response notably against hepatitis B virus (HBV). Defects in cellular contact between immunological cells have been hypothesized to explain this observation but the precise mechanism leading to this "immunocompromised" status is not clear. The soluble form of CD40 (sCD40) is dramatically increased in the serum of uremic patients, particularly in the hemodialyzed patients. This molecule acts like an inhibitor of the CD40/CD154 contact, which is pivotal in the establishment of a proper humoral immune response. It has been shown that the most elevated sCD40 levels are associated with a lack of response to HBV vaccination in the hemodialyzed patients. The majority of the hemodialysis membranes, including high flux polysulfone membranes are unable to clear sCD40 from the sera. However, we found that the high flux polymethylmetacrylate (PMMA) membrane (BK-F Toray Medical Company, Japan) allows for sCD40 clearing.
The aim of this study is to assess the effect of dialysis on PMMA membrane on the improvement of humoral immune response through the efficiency of HBV vaccination in hemodialysed patients who were non responders to one ore more previous vaccination and its link to sCD40 clearing.
