Evaluation of a short term effect of praziquantel treatment in opisthorchiasis-induced hepatobiliary inflammation by urinary 8-oxodG.

Inflammation of the hepatobiliary system in chronic opisthorchiasis is associated with an elevated level of urinary 8-oxo-7,8 dihydro-2'deoxyguanosine (8-oxodG) during active as well as past exposure to Opisthorchis viverrini infection. In this study, we evaluated the short-term effect of praziquantel treatment on hepatobiliary disease (HBD) using urinary 8-oxodG as an inflammatory marker in a cohort of residents in endemic areas of opisthorchiasis in Khon Kaen, Thailand. The HBD status in terms of periductal fibrosis (PDF) was determined by abdominal ultrasonography and O. viverrini infection was monitored at baseline and 2-4 weeks after curative treatment by praziquantel. Analysis of O. viverrini-infected participants who were PDF-ve revealed that there was a significant reduction of urinary 8-oxodG after treatment compared with the baseline levels (p <  0.001). By contrast, in PDF+ve individuals, the levels of urinary 8-oxodG were similar between baseline and those post-treatment. Although confirmation by using a larger sample size is needed, the positive association between HBD and urinary 8-oxodG level after worm clearance suggests that chronic hepatobiliary inflammation is neither affected nor interrupted by short-term praziquantel treatment. Individuals with persistent PDF at pre- and post-treatment who have a high risk of cholangiocarcinoma, could be identified within 2-4 weeks after parasite removal by drug treatment. Thus, urinary 8-oxodG is a useful biomarker for predicting persistent PDF in individuals with a recent drug treatment history who require further clinical investigation, management and treatment.