EBV is a virus of the herpesvirus family and was the first human tumor virus to be identified. The virus is transmitted mainly through human saliva, and its infection period is early, peaking at about 3 to 5 years of age. In developing countries, more than 80% of children aged 3 to 5 years are seropositive for EBV. Most infections in young children are asymptomatic or cause mild upper whistle symptoms. Some studies show that more than 90% of the population has been infected with EBV.
EBV is associated with the development of nasopharyngeal carcinoma and lymphoma. The detection of EBV-related markers can help in the early diagnosis of nasopharyngeal carcinoma.
The lysis of EBV in nasopharyngeal carcinoma cells and the release of its components appear in the plasma and serum of patients or cause an immune response in the body resulting in a significant increase in its antibody concentration. EBV-related markers differ significantly between patients with and without nasopharyngeal carcinoma, and their concentrations are significantly higher in patients with progressive nasopharyngeal carcinoma than in those without progression. DNA testing had a significantly higher positive rate than in patients without recurrence. It is generally believed that EBV-associated antibodies or DNA in plasma or serum of NPC patients can be used as a tumor marker for nasopharyngeal carcinoma, which not only helps in the diagnosis of nasopharyngeal carcinoma, but also reflects the disease process and prognosis.
The detection of the concentrations of EBV coat antigen – VCA, early antigen – EA, and nuclear antigen – EBNA are all beneficial in guiding the diagnosis, treatment and prognosis of nasopharyngeal carcinoma. Currently, it is believed that the detection of VCA-IgA antibody is helpful in screening patients with early-stage nasopharyngeal carcinoma, and its sensitivity is high, with a 94% positive rate of serum VCA-IgA in nasopharyngeal carcinoma patients; while EA-IgA antibody is more specific than VCA-IgA in the diagnosis of nasopharyngeal carcinoma. The titer of EB frozen antibody changes with the change of disease, and increases if the cancer progresses, recurs or metastasizes.
Therefore, in patients with chronic nasal congestion, tinnitus, blood in the ears, headache or with neck masses, testing for EBV-related markers can help clarify the cause and differential diagnosis when looking for the cause. In patients with nasopharyngeal carcinoma, testing for tumor markers can help reflect the course of the disease and prognosis. It should be noted that positive EBV markers, especially weakly positive ones, do not necessarily indicate nasopharyngeal carcinoma, and infectious diseases must be excluded and evaluated in conjunction with dynamic changes.
It is important to note that patients with negative EBV markers do not necessarily rule out nasopharyngeal carcinoma because some patients with nasopharyngeal carcinoma (e.g., some highly differentiated nasopharyngeal carcinomas, adenocarcinomas, etc.) may show negative EBV markers and must be evaluated in conjunction with imaging and pathology to rule out nasopharyngeal carcinoma.