RESUMO
OBJECTIVE: To study the impact of chronic schistosomiasis on the protective immunity induced by vaccine against hepatitis B virus. METHODS: 24 patients with chronic or advanced schistosomiasis (experimental group) and 26 healthy volunteers (control group) all without hepatitis B virus infection were selected for the study. Sera of the subjects in the two groups were collected before inoculation and on the 35th day after inoculation with yeast-derived recombinant hepatitis B vaccine. The level of anti-Hbs, IL-2 and TNF-alpha in sera was examined by ELISA respectively. RESULTS: Anti-Hbs in both groups were negative before inoculation, with an average absorbance (A value) of 0.134 and 0.150 respectively. After inoculation, positive rate of anti-Hbs was 17% (4/24, average A value 0.145 ) in experimental group and 92% (24/26, average A value was 1.210) in control group. The vaccine against hepatitis B induced significantly higher level of anti-Hbs in healthy volunteers compared with that in schistosomiasis patients (P < 0.01). The level of IL-2 and TNF-alpha increased in both groups after inoculation without significant difference compared with the level before inoculation. CONCLUSION: The results suggest that the protective immunity of patients with chronic schistosomiasis is deficient to the stimulation of hepatitis B virus and it may involve in a higher incidence of hepatitis B among schistosomiasis patients.
