Mononucleosis Test, Qualitative With Reflex to Titer on Positives* (006536)

Detect heterophil antibodies related to infectious mononucleosis.

Rare patients may have positive heterophil agglutinins after a negative initial test. Ten percent of cases of true EBV mononucleosis may have negative heterophil agglutinins. These may be diagnosed with EBV specific tests.

A positive test in the presence of consistent clinical and/or hematologic findings confirms the diagnosis of infectious mononucleosis. Approximately 10% of mononucleosis syndromes are heterophil-negative. In some of these, antibody to specific Epstein-Barr viral antigen can be demonstrated. Others may be due to CMV, HSV, or toxoplasmosis. Although this classic test has excellent specificity, false-positive tests can occur and may lead to diagnostic confusion.