Reference Range

Nonreactive

A negative result doesn't completely rule out mono in the first week. Further Epstein-Barr virus specific antibody tests may be needed if suspicion remains high.

False negative results have been reported. Some of these may represent cases of infectious mononucleosis (IM) which persistently remain sero-negative for the IM heterophil antibody. However, some false negative results have been shown to be due to a delayed IM heterophil antibody response.

Patients with exceptionally high levels of the serum sickness heterophil antibody may test falsely positive for the IM heterophil. These patients are generally found in counrties where horse serum is used prophylactically.

The IM heterophil has been associated with several diseases other than IM. These include leukemia, Burkitt's lymphoma, pancreatic carcinoma, viral hepatitis, CMV infections, and others.