Quantification of Epstein-Barr virus DNA load, interleukin-6, interleukin-10, transforming growth factor-β1 and stem cell factor in plasma of patients with nasopharyngeal carcinoma

A total of 78 untreated NPC patients were enrolled in this study. Of these, 51 were followed-up after treatment. The remaining patients had irregular or were lost to follow-up. Plasma EBV DNA was quantified using real-time quantitative PCR. The levels of plasma interleukins and growth factors were quantified using ELISA.A significant decrease in EBV DNA load was detected in plasma of untreated NPC patients (1669 ± 637 copies/mL; n = 51) following treatment (57 ± 37 copies/mL, p < 0.05); n = 51). Plasma EBV DNA load was shown to be a good prognosticator for disease progression and clinical outcome in five of the follow-up patients. A significant difference in IL-6 levels was noted between the untreated patients (164 ± 37 pg/mL; n = 51) and following treatment (58 ± 16 pg/mL, p < 0.05; n = 51). Positive correlations between EBV DNA load and IL-10 (r(49) = 0.535, p < 0.01), between IL6 and IL-10 (r(49) = 0.474, p < 0.01) and between TGF and SCF (r(49) = 0.464, p < 0.01) were observed in patients following treatment. None of the parameters tested including IgA-VCA were associated with tumour stages.We conclude that among the parameters investigated, EBV DNA load and IL-6 levels were promising markers for the presence of NPC and for the assessment of treatment outcome.Nasopharyngeal carcinoma (NPC) is rarely reported in the West but occurs in high frequencies in Southern China, Hong Kong, Taiwan, Singapore and Malaysia [1,2]. In Malaysia for the year 2003, NPC was the second major cause of cancer mortality among males and ranked twelfth among females. The frequencies NPC in males and females were, respectively, 8.8% and 2.5% of the total cases of cancers reported. NPC is an epithelial neoplasm arising from the fossa of Rosenmuller situated at the post-nasal space [3]. NPC is classified into three histological types with the WHO Type II being more prevalent in Asia and is strongly associated with Epstein-Barr virus (EBV) [4]. EBV has been implicated as an important aetiol