Polymethylmethacrylate strengthens antibody response in hemodialysis patients not responding to hepatitis B vaccine: preliminary data.

AIM: Most chronic uremic patients undergoing dialysis show a diminished antibody response to anti-hepatitis B vaccination (anti-HBv) and at this regard high sCD40 serum levels seem to inhibit the immunocompetent response. A simple and feasible technique for removing soluble sCD40 by adsorption is standard bicarbonate dialysis performed by polymethylmethacrylate (PMMA) dialyzers able to remove serum high molecular weight toxins. Aim of the study was to assess whether PMMA dialyzers could enhance the long-term response to anti-HBv in non-responder (NR) ESRD patients.

METHODS: The study involved 5 ESRD patients (mean age 65 years) who had been on maintenance thrice-weekly dialysis for 42.4±15.8 months. They had been previously defined NR to anti-HBv for their low antibody titres (<10 IU/L) despite a previous full course of vaccination using protocols recommended for patients on dialysis. After a period of three months of treatment with PMMA dialyzers, keeping all the parameters of dialysis efficiency (the filter surface of 2.1 m(2), KT/V, dialysis time, QB) unchanged compared to previous treatments, all patients received a new booster dose of Fendrix vaccine (20 µg). Hepatitis B markers were checked at month 1, 3, 12 and 18 after administration of the booster dose and returning to the previous membranes used.

RESULTS: Three of five patients showed a strong antibody response (>1000 IU/L) that lasted effectively over time even after 18 months despite discontinuation of PMMA.

CONCLUSION: In conclusion our preliminary results confirm that PMMA membranes enhance immune response to anti-HBv in NR HD patients.