22332 Tetanus Toxoid IgG Antibody (TTIGS)

Assessment of an antibody response to the tetanus toxoid vaccine, which should be performed at least 3 weeks after immunization

An aid to diagnose immunodeficiency

​This test should not be used to diagnose tetanus infection. The diagnosis of tetanus is by clinical observation. A positive wound culture for the agent of tetanus, Clostridium tetani, may support but does not confirm, the diagnosis. Toxin assays for tetanospasmin may be useful, but are only available in a few laboratories.

The results obtained from this assay are not diagnostic proof of lack of protection against tetanus or the presence/absence of immunodeficiency.

​Tetanus results from contamination of wounds or lacerations with Clostridium tetani spores from the environment. The spores germinate to actively replicating bacterial cells localized within the wound and produce the heat-labile toxin, tetanospasmin. Tetanospasmin attaches to peripheral nerve endings and travels to the central nervous system (CNS) where it blocks inhibitory impulses to motor neurons and leads to severe, spastic muscle contractions, a classic characteristic of tetanus.

The disease is preventable by vaccination with tetanus toxoid (formaldehyde-treated tetanospasmin), which stimulates development of antitetanus toxoid antibodies. In the United States, tetanus toxoid is administered to children as part of the combined diphtheria, tetanus, and acellular pertussis (TDaP) vaccine.

Two to 3 weeks following vaccination, a patient's immunological response may be assessed by measuring the total antitetanus toxoid IgG antibody level in serum. An absence of antibody formation postvaccination may relate to immune deficiency disorders, either congenital or acquired, or iatrogenic due to immunosuppressive drugs.

Vaccinated: POSITIVE (>=0.01 IU/mL)

Unvaccinated: NEGATIVE (<0.01 IU/mL)

​Results greater than or equal to 0.01 suggest a vaccine response.

A tetanus toxoid booster should strongly be considered for patients with anti-tetanus toxoid IgG values between 0.01 and 0.5 IU/mL.

Some cases of tetanus, usually mild, have occasionally been observed in patients who have a measurable serum level of 0.01 to 1.0 IU/mL.