Immunity to tetanus in major beta thalassemia patients

PURPOSE Patients with beta thalassemia major are at increased risk for bacterial infections specially splenectomized patients. The aim of this study was to determine the anti-tetanus antibody concentration among patients with beta thalassemia major. MATERIALS AND METHODS The anti-tetanus antibody concentration was investigated in 224 patients with thalassemia major and 224 healthy subjects matched for age and gender. Tetanus antibody and ferritin serum level were determined by enzyme-linked immunosorbent assay method using commercial kits. Subjects who had antibody level ≥ 0.1 IU/mL was defined as complete protection, 0.01 to < 0.1 IU/mL as partial protection and < 0.01 IU/mL as no protection. For the analysis, we used SPSS version 11.5 software. A two-sided p-value less 0.05 was considered statistically significant. RESULTS In patients with beta thalassemia major, antibody level against tetanus was inversely dependent about 29.3% to serum ferritin level. Thus, when serum ferritin increased 1 ng/mL, serum antibody against tetanus decreased 0.002 IU/mL. Mean anti-tetanus (IgG) antibody titers was lower in thalassemia patients compared to healthy subjects (1.53 ± 1.71 vs. 2.02 ± 2.05, p = 0.007) that was no significantly associated to age and gender in both study groups. All of participants had serum antibody level 0.01 IU/mL or greater. The complete protective level of anti-tetanus antibody was lower in thalassemia subjects in compare to healthy persons (71% vs. 87.9%, p < 0.001). CONCLUSION Patients with thalassemia had lower anti-tetanus antibody level than healthy subjects. Thus the vaccine recommendation seems essential for patients with beta thalassemia major.