| Reference notes: |
| 1. Epstein-Barr virus DNA (EBV-DNA) viral load is measured using a quantitative PCR assay (CE-IVD) targeting the EBNA-1 gene in plasma samples. |
| 2. This gene is commonly expressed in nasopharyngeal carcinoma (NPC), prevalent in Hong Kong, Southern China, and Southeast Asia. |
| 3. Studies have shown that cancer-derived plasma EBV DNA levels may be helpful in treatment monitoring for NPC patients after radiotherapy. |
| 4. Plasma EBV DNA testing may be useful for screening for the early asymptomatic detection of NPC. However, since EBV DNA can be detected in other EBV-associated conditions such as infectious mononucleosis, Burkitt lymphoma, chronic active EBV infection, chronic fatigue syndrome, lymphoproliferative disease, T-cell lymphoma, and Hodgkin's disease, consideration of these conditions as well as clinical and family history and risk factors like race, territory, smoking, diet, environmental exposures, etc., are essential for interpreting results. |
| 5. A "weak positive or positive" result indicates EBV DNA was detected. |
| 6. A "negative" test result indicates EBV DNA was not detected. False-negative results may be due to low numbers of virus in the specimen (i.e., below the test's sensitivity). |
| 7. An "indeterminate/invalid" test result may be due to interfering substances such as inhibitors. Suggest repeat testing if clinically indicated. |
| 8. The analytical sensitivity (LOD - cut off ) is 20 copies/mL, and the LOQ is 40 copies/mL. Standards are traceable to WHO 1st International Standard NIBSC 09/260. |
| 9. Studies have shown that EBV DNA assays have sensitivities ranging from ≦ 40% (Stage 1) to about 95% (Stage IV) NPC3. Pathological and imaging examinations are standard follow-ups based on clinical necessity. |
|
| Sources: |
| 1. GeneProof Epstein-Barr Virus (EBV DNA) PCR Kit (CE-IVD) Kit Insert. |
| 2. Liu, W., Chen, G., Gong, X.Eet al.EThe diagnostic value of EBV-DNA and EBV-related antibodies detection for nasopharyngeal carcinoma: a meta-analysis.ECancer Cell IntE21, 164 (2021). |
| 3. Nicholls et al. Negative plasma EBV DNA NPC in an endemic region and its influence on biopsy screening programs. British Journal of Cancer (2019) 121:690-698. |
| 4. https://www.chp.gov.hk/files/pdf/npc_hp_version_hp.pdf |
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| Note: Updated reference notes and methodology 11 Sep 2023. |