Molecular diagnosis of Epstein-Barr virus-related diseases

Epstein-Barr virus (EBV) is the causative agent of Infectious mononucleosis , and it may also be found in a wide variety of benign and malignant lesion s including oral hairy leukoplakia, inflammatory pseudotumor, Hodgkin's dis ease, non-Hodgkin's lymphoma, nasopharyngeal carcinoma, and gastric carcino ma. Molecular testing is increasingly Important in the diagnosis and monito ring of patients affected by these diseases. In biopsy tissues, molecular d etection of EBV-encoded RNA transcripts by in situ hybridization remains th e gold standard for proving that a histopathological lesion is EBV-related, EBV-encoded RNA hybridization and EBV LMP1 immunostains are used routinely to detect latent EBV in tissues affected try posttransplant lymphoprolifer ative disorder (PTLD) or in enlarged nodes from patients with infectious mo nonucleosis. Traditional serology is the best test for evaluating acute ver sus remote infection in healthy individuals. High serological titers serve as a tumor marker for some EBV-related malignancies, but titers are not a d ependable tumor marker in Immunocompromised hosts. EBV viral load testing b y quantitative DNA amplification of blood samples Is a promising new labora tory test that has proven useful for early diagnosis and monitoring patient s with PTLD, Recent studies suggest a role for EBV viral load testing in na sopharyngeal carcinoma, Hodgkin's disease, and AIDS patients with brain lym phoma. Further research is needed to define more fully the clinical utility of viral load tests In the full spectrum of EBV-associated diseases. Gene expression profiling Is on the horizon as a means to improve subclassificat ion of EBV-related diseases and to predict response to therapy.