Diagnostic Use
Positive results in neonatal specimens (<6 months of age) must be interpreted with caution due to passive transfer of maternal IgG.
Pre- and post vaccination samples should be run simultaneously.
Results may be used to aid a diagnosis of immunodeficiency.
Results from this assay are not diagnostic proof of lack protection / protection against H. Influenzae infection or the presence or absence of immunodeficiency.
Haemophilus influenzae (Hib) is an encapsulated Gram negative bacterium which can cause a range of conditions including meningitis, septicaemia, cellulites, epiglottis, pneumonia and septic arthritis. Hib infections are common in children under five years of age where it is the major cause of bacterial meningitis. A protective level of 0.15mg/L is generally accepted, however, as responses are age related, paediatric protective levels may vary from this concentration. This assay will be used as an aid to identify individuals with suspected immunodeficiency. Results of this assay are correlated with vaccine responses to diphtheria toxoid, HBsAg and tetanus toxoid to determine the probable type of immunodeficiency.
Interpretation
Assay measuring range: 9.00-0.11 mg/L
Interpretation provided with result.
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.
A protective level of 0.15 mg/L is generally accepted, but in our setting, the assay is used to determine if patients can mount an immune response when challenged with the vaccine.
Reference Intervals
Not applicable for this assay. The use of this assay is to determine if antibody is present in a pre-vaccine blood specimen and if low or absent, does the level increase under an antigen challenge (post-vaccine specimen).
Test Method
ELISA - automated
DS2 robotic processing
Limitations / Interference
Grossly haemolysed and/or high lipaemic serum specimens.
Uncertainty of Measurement
16%