Lower Serum Levels of Antibodies against Tetanus Toxin in Patients with Hypothyroidism

Background: A fundamental duty of the immune system is to defend against infectious agents. Significant abnormalities were reported in immune parameters of hypothyroid and hyperthyroid patients. In this study, we aim to assess various quantities of antibodies against the tetanus toxin (anti-TT) in hypothyroid and hyperthyroid patients.  Materials and Methods: Anti-TT levels were measured in serum samples from 50 hypothyroid patients, 50 hyperthyroid patients, and 50 euthyroid individuals, using the ELISA method. Besides, the minimum protective quantity of anti-TT was considered 0.1 IU/mL. Results: Seroprotective rates against tetanus were 100, 80, and 96.0 % in euthyroid, hypothyroid, and hyperthyroid groups with the means of 3.52 ± 0.31, 1.62 ± 0.21, and 4.07 ± 0.32 IU/ml, respectively. Accordingly, hypothyroid patients exhibited lower anti-TT levels and seroprotective rates than the euthyroid group (P < 0.001 and P<0.004, respectively). Besides, in the hypothyroid group, anti-TT quantities and seroprotective rates were lower than those in hyperthyroid individuals (P < 0.001 and P < 0.03, respectively). Conclusions: The findings demonstrated lower immunity and higher susceptibility to tetanus in patients with hypothyroidism. However, more studies are needed to be conducted in this field to provide more data to be considered in health programs.