Recombinant hepatitis B vaccination in renal failure patients.

Abstract

Hepatitis B (HB) in haemodialysis patients results in morbidity and mortality, through chronicity, which leads to cirrhosis and liver carcinoma, even after renal transplantation. Hepatitis B vaccination is protective against HB virus infection. Suppressed immunity in renal failure leads to low HB vaccination success rates. Uremia, inadequate dialysis, use of low biocompatibility dialysis material, hyperparathyroidism, anemia, iron overload and malnutrition are all factors contributing to depressed immunity. Renal failure, associated with chronic inflammation, leads to impaired monokine production which results in decreased immunity. This impairment could result from defective HLA-DR B7-2 expression on monocytes. Hepatitis B vaccination non-responders express increased levels of HLA class II alleles (T-cell immune response modulators) DRB1 01 (DR1) and DRB1 15 (DR15). Various methods have been used to enhance the immune response to HB vaccination such as recombinant adjuvants, thymopentine, IL-2, levamisole and GM-CSF: they have produced variable results. Better dialysis biocompatibility and adequacy have also been conducted to overcome this low immune response. Response to conventional intramuscular HB vaccination is considered an index of adequate dialysis and low inflammatory state, both associated with better cardiovascular outcome and survival. HB vaccination reinforcement techniques evolved from an initial intramuscular double/multiple-dosing regimen to more frequent intradermal smaller dose injection. This newer regimen achieves a higher and almost complete seroconversion rate, although frequent boosters shots are necessary to maintain protective levels. Experience with pre-S1/S2, third generation, vaccines is limited and they have not been proven to be more effective than intradermally administered S antigens. Recombinant HB vaccines, intradermally administered, have been shown to elicit an immune response in all renal failure patients. Additionally the use of recombinant erythropoietin treatment to correct anemia contributes to this success.