[Long-term evaluation of immune response to hepatitis B vaccine in 136 patients undergoing hemodialysis].

Unlabelled: Hemodialysis (HD) patients have an impaired response to hepatitis B(HB) vaccines, and the persistence of immunity, the efficacy of revaccination and the periodicity of post-vaccination testing are not well defined. We present the experience during 13 years in an outpatient dialysis center of 136 HD patients who completed a HB vaccination program consisting in 3 doses of 40 microg intramuscular recombinant B vaccine (Engerix-B). In all patients anti-HBs titers were determined annually and in 31 patients every 6 months. Nonresponders patients and responders patients that lost their antibodies(< 10 UI/ml) received annually a booster double dose of vaccine. Seventy-four patients(54.4%) developed immunity and the remaining 62 patients were considered nonresponders. When compared both groups, gender and the etiology of chronic kidney disease did not differ between the two groups; nevertheless, nonresponders patients were significantly older than responders. After 1 year of follow-up, 32% of responders had no detectable anti-HBs levels, and only 18% of patients remained immunoreactive 6 years afer vaccination. The peak anti-HBs titer immediately after completion of the vaccination schedule was found to be a major predictor of maintaining immunity: 75% of patients with anti-HBs titers greater than 1000 IU/ml remained immunoreactive 3 years after vaccination compared to 47% of patients with titers between 100-999 IU/ml(p=0.08) and 34% of patients with titers between 11-99 IU/ml(p=0.02). The administration of additional doses of vaccine were effective in 24% of the nonresponders patients, and 69% of them remained seropositive at the end of the 1-year follow up. Repeated booster doses of vaccine in nonresponders patients to the first booster dose afforded seroconversion in 19.6% of the patients. Performing post-vaccination testing every six months it would have allowed to give booster doses of vaccine in 16% of responder patients before the annual period.

Conclusion: This current study demonstrates that a HB vaccination schedule with a regular serological follow-up and repeated booster doses , affords an acceptable seroprotection in HD patients.