Interpretive Handbook

Test 83262 :
Diphtheria Toxoid IgG Antibody Assay, Serum

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

In the United States, diphtheria toxoid is administered to children as part of the combined diphtheria-pertussis-tetanus vaccine. Anti-diphtheria toxoid antibodies form in response to vaccination using diphtheria toxoid protein.


This immunoassay, which uses the same protein (toxoid) that is used in the vaccine, provides a measurement of specific IgG antibodies produced in response to vaccination.

Useful For Suggests clinical disorders or settings where the test may be helpful

Determining a patient's immunological response to diphtheria toxoid vaccination


As an aid in the evaluation of immunodeficiency

Interpretation Provides information to assist in interpretation of the test results

Results greater than or equal to 0.10 IU/mL suggest a vaccine response.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This assay does not provide diagnostic proof of lack of protection/protection against diphtheria, or the presence or absence of immunodeficiency. Results must be confirmed by clinical findings and other serological tests.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

The minimum level of protective antibody in the normal population is between 0.01 and 0.1 IU/mL. The majority of vaccinated individuals should demonstrate protective levels of antibody >0.1 IU/mL.

Clinical References Provides recommendations for further in-depth reading of a clinical nature

1. Booy R, Aitken SJ, Taylor S, et al: Immunogenicity of combined diphtheria, tetanus, and pertussis vaccine given at 2, 3, and 4 months versus 3, 5, and 9 months of age. Lancet 1992;339(8792):507-510

2. Maple PA, Efstratiou A, George RC, et al: Diphtheria immunity in UK blood donors. Lancet 1995;345(8955):963-965

3. WHO meeting report: The Control of Diphtheria in Europe. WHO ref:EUR/ICP/EPI/024 1990