PROSPECTIVE ANALYSIS OF THE FACTORS INFLUENCING THE ANTIBODY-RESPONSETO HEPATITIS-B VACCINE IN HEMODIALYSIS-PATIENTS

Hepatitis B vaccine is effective in producing protection against hepat itis B virus (HBV) infection in hemodialysis (HD) patients, but the an tibody response is variable. To identify those factors implicated in t he vaccine response, in a prospective study over a 24-month period, we vaccinated 80 seronegative patients on HD (group A) and monitored cli nical, biochemical, and immunologic parameters. The protective immunit y acquired by vaccination was compared with that developed through HBV infection in 22 age-matched HD patients (group B). The anti-HBs antib ody-seronegative patients followed a four-dose vaccination schedule (0 , 1, 2, and 6 months) with 40 mu g DNA-recombinant hepatitis B vaccine . One month after vaccination, 77.5% of the patients had seroconverted , and 72.5% achieved high antibody response, whereas 22.5% were nonres ponders. Patients aged younger than 40 years seroconverted 100%; those aged 40 to 60 years, 75% (P < 0.01); and patients older than 60 years , 74% (P < 0.001). No differences between responders and nonresponders concerning sex, time on HD, HD dose, nutritional status, hemoglobin l evel, HD membrane, iPTH level, calcitriol treatment, or number of tran sfusions during vaccination were found. The presence of other factors, such as recombinant human erythropoietin (rHuEPO) therapy or hepatiti s C virus (HCV) infection, did not significantly influence antibody re sponses to hepatitis-B immunization. A greater frequency of DR3 (53.8% v 25.7%, P < 0.05), DR7 (53.8% v 18.6%, P < 0.01), and DQ2 (76.9% v 4 4.1%, P < 0.05), and a lesser frequency of A2 (7.7% v 37.2%, P < 0.05) were found in nonresponders compared with responders. Eighteen months after vaccination, the analysis showed similar antibody titers but lo wer seroconversion rates in group A as compared with group B. In concl usion, unresponsiveness to hepatitis B vaccine in HD patients was rela ted to factors such as older age, the presence of DR3, DR7, and DQ2, a nd the absence of A2 alleles. Although the seroprotection produced by the vaccine was less than that achieved through natural HBV infection, our protocol of vaccination was sufficiently immunogenic and provided lasting protection. (C) 1997 by the National Kidney Foundation, Inc.