Paired sera should be obtained wherever possible:
(a) acute sample - as early as possible in the illness, and
(b) convalescent sample 2 - 3 weeks after onset.
Assay measuring range: 3.00-0.004 IU/mL
Interpretation provided with result.
Uncertainty of measurement: 16%
Positive results in neonatal specimens (< 6 months of age) must be interpreted with caution due to passive transfer of maternal IgG
Results may be used to aid a diagnosis of immunodeficiency.
Results from this assay are not diagnostic proof of lack protection / protection against diphtheria or the presence or absence of immunodeficiency.
Anti-diphtheria toxoid antibodies are raised in response to vaccination with diphtheria toxoid protein. This assay is intended for the in-vitro measurement of specific IgG antibodies against diphtheria toxoid present in serum in order to determine protective status pre and post vaccination. Protective levels are cited as between 0.01-0.1 IU/mL, with the higher level being the most desirable. In our setting, the assay is used in conjunction with vaccine challenge results from Hib, HBsAg and tetanus toxoid to assist in the determination of the probable type of immunodeficiency.
References
Binding Site insert for Diphtheria Toxoid IgG EIA kit.
For further information contact the laboratory (09) 307 4949 ext 22000 or:
Associate Professor Rohan Ameratunga , Immunopathologist: Locator 93-5724
Or the LabPLUS Immunology Team