BACKGROUND: Nasopharyngeal carcinoma (NPC) is prevalent in Southeast Asia. Over the last decade, plasma Epstein-Barr virus (EBV) DNA has been developed as a tumor marker for NPC. In this study, the authors investigated whether plasma EBV DNA analysis is useful for NPC surveillance. METHODS: In total, 1318 volunteers ages 40 to 60 years were prospectively recruited. Plasma EBV DNA and serology for viral capsid antigen immunoglobulin A (IgA) were measured. Participants who had detectable plasma EBV DNA or positive IgA serology underwent nasal endoscopic examination and a follow-up plasma EBV DNA analysis in approximately 2 weeks. All participants were followed for 2 years to record the development of NPC. RESULTS: Three individuals with NPC were identified at enrolment. All of them were positive for EBV DNA and remained positive in follow-up analysis. Only 1 of those patients was positive for EBV serology. In 1 patient who had NPC with a small tumor confined to the mucosa, the tumor was not detectable on endoscopic examination. Because of a 2-fold increase in plasma EBV DNA on the follow-up analysis, that patient underwent magnetic resonance imaging, which revealed the tumor. Among the participants who did not have NPC but had initially positive plasma EBV DNA results, approximately 66% had negative EBV DNA results after a median of 2 weeks. CONCLUSIONS: Plasma EBV DNA analysis proved useful for detecting early NPC in individuals without a clinical suspicion of NPC. Repeating the test in those who had initially positive results differentiated those with NPC from those who had false-positive results.

No abstract

BackgroundCirculating bacterial DNA fragment is related to systemic inflammatory state in peritoneal dialysis (PD) patients. We hypothesize that plasma bacterial DNA level predicts cardiovascular events in new PD patients.MethodsWe measured plasma bacterial DNA level in 191 new PD patients, who were then followed for at least a year for the development of cardiovascular event, hospitalization, and patient survival.ResultsThe average age was 59.3 ± 11.8 years; plasma bacterial DNA level 34.9 ± 1.5 cycles; average follow up 23.2 ± 9.7 months. At 24 months, the event-free survival was 86.1%, 69.8%, 55.4% and 30.8% for plasma bacterial DNA level quartiles I, II, III and IV, respectively (p < 0.0001). After adjusting for confounders, plasma bacterial DNA level, baseline residual renal function and malnutrition-inflammation score were independent predictors of composite cardiovascular end-point; each doubling in plasma bacterial DNA level confers a 26.9% (95% confidence interval, 13.0 – 42.5%) excess in risk. Plasma bacterial DNA also correlated with the number of hospital admission (r = -0.379, p < 0.0001) and duration of hospitalization for cardiovascular reasons (r = -0.386, p < 0.0001). Plasma bacterial DNA level did not correlate with baseline arterial pulse wave velocity (PWV), but with the change in carotid-radial PWV in one year (r = -0.238, p = 0.005).ConclusionsCirculating bacterial DNA fragment level is a strong predictor of cardiovascular event, need of hospitalization, as well as the progressive change in arterial stiffness in new PD patients.