Tests:Infectious Mononucleosis, Plasma

Overview
Department	Haematology
Test Code	IM
Synonyms	Monospot   Paul Bunnell   Glandular fever   IM
Base Lab Availability	Monday - Sunday, testing routinely available out of hours
Hawera Lab Availability	Monday - Friday 8 am - 5pm
Turnaround Time	1-5 hrs
Stability – Add test	24 hrs at room temp, 3 days at 4 degrees Celsius.
Specimen Requirements
Specimen	Plasma
Specimen Transportation
Preferred	6mL Plain Red-Top
Acceptable	4mL EDTA Purple-Top , or Li-Hep Green-Top
Unacceptable
Paediatric Requirements	0.5 mL Plain Red-Top, 500 μL EDTA Microtainer , or 600 μL Li-Hep Microtainer
Aliquot Requirements
Sample
Preferred Volume
Minimum Volume
Aliquot Transportation
Clinical Information
Reference Intervals	Positive test suggests the diagnosis of glandular fever in the context of appropriate symptoms and blood film changes such as reactive lymphocytosis.
Test Method	Clearview IM rapid immunoassay kit for detection of EBV IgM Heterophile Antibody.
Advanced Notice
Patient Preparation
Comments
This test screens for the presence of heterophile antibodies.  EBV serology is the preferred test in cases of suspected infectious mononucleosis due to the inferior sensitivity of the monospot test.   The monospot test will not be performed on children <6yrs due to the poor sensitivity in this age group.   Any sample with a negative monospot test result will be referred for EBV serology.     Limitations of the monospot test:   During the first week of disease 30-40% of patients will produce a false negative result. Suggest repeat EBV serology if symptoms persist.   50% of children <6 years of age and 10-20% of adults will not produce heterophile IM antibodies.     False positive results may be seen in cases of CMV, malaria, toxoplasmosis and some autoimmune diseases.