Infectious mononucleosis: diagnosis
Last reviewed: 23.04.2024
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Diagnosis of infectious mononucleosis is based on a complex of leading clinical symptoms (fever, lymphadenopathy, enlargement of the liver and spleen, changes in peripheral blood).
In addition to examining the blood picture, the diagnosis is based on the detection of heterophilic antibodies and specific antibodies to the Epstein-Bar virus.
Heterogeneous antibodies. Modified hetero-hemagglutination reactions are used: the Paul-Bunnell reaction (the reaction of agglutination of lamb erythrocytes) is currently not recommended because of low specificity. The Hoff-Bauer reaction is the agglutination of the serum of the patient with formalized horse erythrocytes (4% suspension), the reaction is carried out on the glass, the results are taken into account after 2 minutes; possible application for express diagnostics. The titres of heterophilic antibodies peak at the 4-5th week from the onset of the disease, then decrease and may persist for 6-12 months. However, this reaction can also give false positive and false negative results.
More specific and sensitive diagnosis of infectious mononucleosis, based on the definition of antigen markers of Epstein-Bar virus antigens (NERF, ELISA). Which can determine the form of infection.
Diagnostic value of antibodies to the Epstein-Barr virus
Antibodies | ||||
Form of infection |
IgM to the capsid antigen |
Igl to the capsid antigen |
To the nuclear antigen, the sum |
To early antigens, the amount |
Not infected |
- |
- |
- |
- |
Acute stage of primary infection |
- |
- + - | - |
- + |
Infection transferred up to 6 months ago |
- |
- + - |
- |
- + |
Infection transferred more than 1 year ago |
- |
+ - |
- |
- |
Chronic infection, reactivation | - | ----- | - | - + |
Malignant neoplasms. Connected with EWB | - |
----- |
- |
- ++ |
Antibodies (IgM) to the capsid antigen in infectious mononucleosis are detected from the end of the incubation period, they are defined no more than 2-3 months. Igl to the capsid antigen appear in the acute period of infection and persist for life. Antibodies to early antigens (IgM) appear at the height of the disease in 70-80% of patients and rapidly disappear, and antibodies to Igl persist for a long time. An increase in antibody titer to early antigens is characteristic for the reactivation of EBV infection and for tumors caused by this virus. Antibodies against nuclear antigen appear 6 months after infection and persist in low titers for life.
An additional confirmation of EBV infection can serve as a test for detecting the DNA of a virus in the blood or saliva by PCR. Its use is effective for the detection of EBV infection in newborns, when the detection of serological markers is ineffective due to the formed immune system, as well as in complex and doubtful cases in the diagnosis of Epstein-Bar virus in adults.
Indications for consultation of other specialists
All patients diagnosed with infectious mononucleosis and suspected of it should be examined for HIV infection in the acute period of the disease, at 1, 3 and 6 months in the period of convalescence.
With the preservation of hematologic changes, consultation and examination is shown in the hematologist, with the appearance of pain in the abdomen - consultation of the surgeon and ultrasound of the abdominal cavity organs.
When neurologic symptoms appear, consultation of a neurologist is necessary.
Indications for hospitalization
Patients are hospitalized for clinical reasons. The main indications for hospitalization and treatment of a patient in a hospital are: prolonged high fever, jaundice, complications, complicated diagnosis of infectious mononucleosis.
Differential diagnosis of infectious mononucleosis
Differential diagnosis of infectious mononucleosis is accompanied by febrile illnesses that occur with lymphadenopathy and hepatolenal syndrome; flowing with the syndrome of acute tonsillitis and flowing with the presence of atypical mononuclears in the blood.