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Dive into the research topics where John Chi-Hang Yuen is active.

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Featured researches published by John Chi-Hang Yuen.


Journal of Hepatology | 2008

Independent risk factors and predictive score for the development of hepatocellular carcinoma in chronic hepatitis B

Man-Fung Yuen; Yasuhito Tanaka; Daniel Tik-Pui Fong; James Fung; Danny Ka-Ho Wong; John Chi-Hang Yuen; David But; Annie On-On Chan; Benjamin Chun-Yu Wong; Masashi Mizokami; Ching-Lung Lai

BACKGROUND/AIMS To determine whether gender, age, hepatitis B virus genotype, core promoter and precore mutations, HBeAg/ anti-HBe status, HBV DNA, ALT levels and cirrhosis on presentation were independent risk factors and derive a novel risk score for the development of HCC. METHODS CHB patients (820) were followed up (mean duration 76.8 months) for the occurrence of HCC. RESULTS The 5- and 10-year prevalence of HCC were 4.4% and 6.3%, respectively. Cox regression analysis showed that male gender (p = 0.025, RR 2.98), increasing age (p < 0.001, RR 1.07), higher HBV DNA levels (p = 0.02, RR 1.28), core promoter mutations (p = 0.007, RR 3.66), and presence of cirrhosis (p < 0.001, RR 7.31) were independent risks for the development of HCC. A risk score was derived and validated with sensitivity > 84% and specificity > 76% to predict the 5- and 10- year risks for the development of HCC. The AUC for the 5- and 10-year prediction were 0.88 and 0.89, respectively. CONCLUSIONS The risk score, based on age, gender, HBV DNA levels, core promoter mutations and cirrhosis, can estimate the chance of development of HCC in 5 and 10 years after presentation. It can be used to identify high-risk CHB patients for treatment and screening of HCC.


Gut | 2005

Prognostic determinants for chronic hepatitis B in Asians: therapeutic implications.

M.-F. Yuen; He-Jun Yuan; Danny Ka-Ho Wong; John Chi-Hang Yuen; Wm Wong; Aoo Chan; B. C. Y. Wong; Kc Lai; Ching-Lung Lai

Background: Identifying risk factors for the development of complications of chronic hepatitis B (CHB) is important for setting up treatment criteria. Aim: To determine risk factors for the development of complications in Asian CHB patients. Patients and methods: A total of 3233 Chinese CHB patients (mean follow up 46.8 months) were monitored for liver biochemistry, viral serology, hepatitis B virus (HBV) DNA levels, acute exacerbation, hepatitis B e antigen (HBeAg) seroconversion, and development of cirrhotic complications and hepatocellular carcinoma. Results: Median age for HBeAg seroconversion and development of complications was 35 years and 57.2 years, respectively. Patients with alanine aminotransferase (ALT) levels of 0.5–1 times the upper limit of normal (ULN) and 1–2× ULN had an increased risk for the development of complications compared with patients with ALT levels <0.5× ULN (p<0.0001 for both). HBeAg/antibody to hepatitis B e antigen status, and number of episodes, duration, and peak ALT levels of acute exacerbations were not associated with an increased risk of complications. In patients with complications, 43.6% had HBV DNA levels less than 1.42×105 copies/ml. Male sex, stigmata of chronic liver disease, old age, low albumin, and high α fetoprotein levels on presentation were independently associated with increased cumulative risk of complications. Male sex, presence of hepatitis symptoms, old age, low albumin level, and presence of complications on presentation were independently associated with shorter survival. Conclusion: Prolonged low level viraemia causing insidious and continual liver damage, as reflected by ALT levels of 0.5–2× ULN, is the most likely pathway for the development of complications in Asian CHB patients.


Gastroenterology | 2008

HBsAg Seroclearance in Chronic Hepatitis B in Asian Patients: Replicative Level and Risk of Hepatocellular Carcinoma

Man-Fung Yuen; Danny Ka-Ho Wong; James Fung; Philip P.C. Ip; David But; Ivan Fan-Ngai Hung; Kevin Lau; John Chi-Hang Yuen; Ching-Lung Lai

BACKGROUND & AIMS Our aims were to study the virologic, histologic, and clinical outcome in chronic hepatitis B (CHB) patients with hepatitis B surface antigen (HBsAg) seroclearance. METHODS We determined the age of HBsAg seroclearance that is associated with a lower risk for hepatocellular carcinoma (HCC) in 298 CHB patients (median follow-up, 108 months). The following virologic and histologic features were also determined: liver stiffness (n = 229), liver histology, serum HBV DNA levels over time (n = 265), intrahepatic HBV DNA with covalently closed circular DNA (cccDNA) levels, and messenger RNA (mRNA) expression. RESULTS The median age of HBsAg seroclearance was 49.6 years. Seven (2.4%) patients developed HCC. Cumulative risk for HCC was higher in patients with HBsAg seroclearance at ages >or=50 years compared with those with HBsAg seroclearance at ages <50 (P = .004) years. Of these 2 groups of patients, 29.5% and 7.9%, respectively, had significant fibrosis by liver stiffness measurement (P = .001), and 15.4% of patients had mild histologic fibrosis. Intrahepatic total HBV DNA and cccDNA were detected in 100% and 79.3% of patients, respectively. All patients had undetectable surface and precore/pregenomic RNA transcripts. One (9.1%) patient had X mRNA expression. Serum HBV DNA were detectable in 13.4%, 6.1%, and 3.7% of patients within 1 year and 5-10 and >10 years after HBsAg seroclearance, respectively, and 82.1% patients had persistently normal alanine aminotransferase levels. CONCLUSIONS HBV persisted at low replicative and transcriptional levels after HBsAg seroclearance. HBsAg seroclearance at age <50 years was associated with a lower risk for the development of HCC.


Gut | 2007

Risk for hepatocellular carcinoma with respect to hepatitis B virus genotypes B/C, specific mutations of enhancer II/core promoter/precore regions and HBV DNA levels

Man-Fung Yuen; Yasuhito Tanaka; Noboru Shinkai; Ronnie Tung-Ping Poon; David But; Daniel Tik-Pui Fong; James Fung; Danny Ka-Ho Wong; John Chi-Hang Yuen; Masashi Mizokami; Ching-Lung Lai

Background/aim: To examine the risks for hepatocellular carcinoma (HCC) with respect to hepatitis B virus (HBV) genotypes, specific viral mutations (MT), serum HBV DNA levels, and cirrhosis. Methods: HBV genotypes, 1653/1753/core promoter (CP)/precore MT and HBV DNA levels were determined in 248 HBV patients with HCC and 248 HBV controls. Results: Genotype C, CP-MT, T1653, HBV DNA levels ⩾4 log10 copies/ml and cirrhosis had a higher risk for HCC compared to patients with genotype B (p = 0.001, OR 1.9), CP wild-type (WT) (p<0.001, OR 4.1), C1653 (p = 0.028, OR 2.4), HBV DNA <4 log10 copies/ml (p = 0.003, OR 2.1) and without cirrhosis (p<0.001, OR 4.0) respectively. Multivariate analysis showed that CP-MT, T1653, HBV DNA ⩾4 log10 copies/ml and cirrhosis were independent factors for HCC (all p<0.05). A receiver operating characteristics curve showed no cut-off HBV DNA level associated with minimal chance of HCC. Patients with CP-MT and cirrhosis had a 22.2-fold increased risk of HCC compared to patients with CP-WT and without cirrhosis. Patients with CP-MT and HBV DNA levels ⩾4 log10 copies/ml had a 7.2-fold increased risk of HCC compared to patients with CP-WT and HBV DNA levels <4 log10 copies/ml. Patients with CP-MT and T1653 had a 9.9-fold increased risk of HCC compared to patients with wild-type for both regions. Conclusions: CP-MT, T1653, HBV DNA levels ⩾4 log10 copies/ml and cirrhosis are independent factors for development of HCC. The risks increased substantially in patients having these factors in combination.


Hepatology | 2007

Hepatitis B virus DNA levels at week 4 of lamivudine treatment predict the 5‐year ideal response

Man-Fung Yuen; Daniel Tik-Pui Fong; Danny Ka-Ho Wong; John Chi-Hang Yuen; James Fung; Ching-Lung Lai

The best time and hepatitis B virus (HBV) DNA level during an early lamivudine treatment period for predicting the long‐term outcome are unknown. We aimed to determine the optimal time and HBV DNA level during an early treatment period for the prediction of the response after a 5‐year lamivudine treatment. The HBV DNA levels at the baseline, at weeks 2, 4, 8, 12, 16, 24, and 32, and at yearly intervals until year 5 were measured in 74 hepatitis B e antigen (HBeAg)–positive chronic HBV patients receiving lamivudine treatment. Seventeen patients achieved an ideal response [HBV DNA level < 2000 copies/mL (400 IU/mL), HBeAg seroconversion, normal alanine aminotransferase levels, and absence of tyrosine‐methionine‐aspartate‐aspartate (YMDD) mutations] at year 5. Receiver operating characteristic curves showed good predictions as early as week 4. The areas under the curve for weeks 4 and 16 were 0.89 and 0.94, respectively. Predictive indices revealed 4 and 3.6 log copies/mL (2000 and 800 IU/mL, respectively) to be the best cutoff HBV DNA levels for these 2 times, respectively. All patients with HBV DNA levels lower than these respective cutoff levels at the 2 times achieved an ideal response at year 5. Patients with HBV DNA levels above these cutoff values had 83.8% and 87.7% chances of not achieving an ideal response at year 5, respectively. Conclusion: The measurement of the HBV DNA levels at week 4 of lamivudine treatment should be performed in all patients to predict the long‐term outcome. The treatment can be continued for those with HBV DNA levels of less than 4 log copies/mL (2000 IU/mL). The addition of or switch to alternative antiviral agents should be considered for patients who fail to achieve this early target. (HEPATOLOGY 2007.)


Oncogene | 2004

PIN1 overexpression and β-catenin gene mutations are distinct oncogenic events in human hepatocellular carcinoma

Roberta Pang; John Chi-Hang Yuen; Man-Fung Yuen; Ching-Lung Lai; Terence K.W. Lee; Kwan Man; Ronnie Tung-Ping Poon; Sheung Tat Fan; Chun M Wong; Irene Oi-Lin Ng; Yok-Lam Kwong; Eric Tse

The peptidyl-proplyl-isomerase, PIN1, upregulates β-catenin by inhibiting its interaction with APC. β-catenin accumulation occurs in about 70% of hepatocellular carcinoma (HCC), of which only 20% are due to β-catenin mutations. The role of PIN1 in β-catenin upregulation in HCC was investigated. PIN1 was shown to be overexpressed in more than 50% of HCC. All cases with PIN1 overexpression also showed β-catenin accumulation, with 68% of cases showing concomitant β-catenin and cyclin D1 accumulation. PIN1 was shown to contribute to β-catenin and cyclin D1 overexpression directly by in vitro cell-line transfection experiments. Finally, we showed that PIN1 overexpression and β-catenin gene mutations appeared to be mutually exclusive events, leading to β-catenin accumulation in HCC. These results showed that PIN1 overexpression leading to β-catenin accumulation might be a critical event in hepatocarcinogenesis, and that PIN1 is a potential target for therapeutic intervention in HCC.


Annals of Surgical Oncology | 2004

Radiofrequency ablation for subcapsular hepatocellular carcinoma.

Rtp Poon; Ktp Ng; C. M. Lam; John Chi-Hang Yuen; St Fan

AbstractBackground: Limited data from recent studies suggested an increased risk of bleeding complications, needle-track seeding, and local recurrence after radiofrequency ablation (RFA) of subcapsular hepatocellular carcinoma (HCC). Methods: Between May 2001 and October 2002, 80 patients underwent RFA of 104 HCC nodules. Forty-eight patients had subcapsular HCC (group I), whereas the other 32 patients did not have subcapsular HCC (group II). RFA was performed via celiotomy, laparoscopy, or a percutaneous approach. Subcapsular HCCs were ablated by indirect puncture through nontumorous liver, and the needle track was thermocoagulated. Results: There were no significant differences between groups in treatment morbidity (14.6% vs. 15.6%; P = .898), mortality (2.1% vs. 0%; P = 1.000), complete ablation rate after a single session (89.4% vs. 96.9%; P = .392), local recurrence rate (4.3% vs. 12.5%; P = .216), recurrence-free survival (1 year: 60.9% vs. 49.2%; P = .258), or overall survival (1 year: 88.3% vs. 79.4%; P = .441). After a median follow-up of 13 months, no needle-track seeding or intraperitoneal metastasis was observed. Conclusions: This study shows that the results of RFA for subcapsular HCCs are comparable to those of RFA for nonsubcapsular HCCs. Subcapsular HCC should not be considered a contraindication for RFA treatment.Background: Limited data from recent studies suggested an increased risk of bleeding complications, needle-track seeding, and local recurrence after radiofrequency ablation (RFA) of subcapsular hepatocellular carcinoma (HCC). Methods: Between May 2001 and October 2002, 80 patients underwent RFA of 104 HCC nodules. Forty-eight patients had subcapsular HCC (group I), whereas the other 32 patients did not have subcapsular HCC (group II). RFA was performed via celiotomy, laparoscopy, or a percutaneous approach. Subcapsular HCCs were ablated by indirect puncture through nontumorous liver, and the needle track was thermocoagulated. Results: There were no significant differences between groups in treatment morbidity (14.6% vs. 15.6%; P = .898), mortality (2.1% vs. 0%; P = 1.000), complete ablation rate after a single session (89.4% vs. 96.9%; P = .392), local recurrence rate (4.3% vs. 12.5%; P = .216), recurrence-free survival (1 year: 60.9% vs. 49.2%; P = .258), or overall survival (1 year: 88.3% vs. 79.4%; P = .441). After a median follow-up of 13 months, no needle-track seeding or intraperitoneal metastasis was observed. Conclusions: This study shows that the results of RFA for subcapsular HCCs are comparable to those of RFA for nonsubcapsular HCCs. Subcapsular HCC should not be considered a contraindication for RFA treatment.


Liver International | 2008

Correlation of liver biochemistry with liver stiffness in chronic hepatitis B and development of a predictive model for liver fibrosis

James Fung; Ching-Lung Lai; Daniel Tik-Pui Fong; John Chi-Hang Yuen; Danny Ka-Ho Wong; Man-Fung Yuen

Aim: To correlate liver stiffness with demographical factors and routine liver biochemistry and to assess the predictive value of these as potential markers of fibrosis.


Hepatology | 2012

A large case‐control study on the predictability of hepatitis B surface antigen levels three years before hepatitis B surface antigen seroclearance

Wai-Kay Seto; Danny Ka-Ho Wong; James Fung; Ivan Fan-Ngai Hung; Daniel Tik-Pui Fong; John Chi-Hang Yuen; Teresa Tong; Ching-Lung Lai; Man-Fung Yuen

The kinetics of hepatitis B surface antigen (HBsAg) levels preceding spontaneous HBsAg seroclearance has not been fully investigated. The kinetics of HBsAg and hepatitis B virus (HBV) DNA of 203 treatment‐naïve, hepatitis B e antigen (HBeAg)‐negative patients with spontaneous HBsAg seroclearance were compared with 203 age‐ and sex‐matched HBeAg‐negative controls. Serum samples at 3 years, 2 years, 1 year, and 6 months before HBsAg seroclearance and at the time of HBsAg loss were tested. Median HBsAg levels at these respective time points before HBsAg seroclearance were 23.5, 3.51, 0.524, and 0.146 IU/mL. For all time points, patients with HBsAg seroclearance had significantly lower median HBsAg and HBV DNA levels, compared to those of the controls (all P < 0.001). Median HBsAg and HBV DNA levels declined significantly until HBsAg seroclearance (P < 0.001). Although median HBsAg levels also decreased significantly with time (P = 0.006) in controls, median HBV DNA levels remained similar (P = 0.414). Serum HBsAg levels, followed by HBsAg log reduction, were the best predictors of HBsAg seroclearance, with an area under the receiving operator characteristic (AUROC) of 0.833 (95% confidence interval [CI]: 0.792‐0.873) and 0.803 (95% CI: 0.755–0.849), respectively. The optimal cut‐off HBsAg level and HBsAg reduction to predict HBsAg seroclearance were <200 IU/mL (sensitivity, 84.2%; specificity, 73.4%) and 0.5 log IU/mL/year (sensitivity, 62.8%; specificity, 88.7%), respectively. For patients with HBsAg levels ≥200 IU/mL, an annual 0.5‐log reduction was highly predictive of subsequent HBsAg seroclearance (AUROC, 0.867; 95% CI: 0.778‐0.956). Conclusion: To conclude, serum HBsAg <200 IU/mL and 0.5‐log reduction in HBsAg were predictive of HBsAg seroclearance within 3 years of follow‐up. These parameters may serve as good indicators for the consideration of treatment duration and cessation for chronic hepatitis B. (HEPATOLOGY 2012;56:812–819)


Journal of Hepatology | 2003

Clinical outcome and virologic profiles of severe hepatitis B exacerbation due to YMDD mutations

Man-Fung Yuen; Takanobu Kato; Masashi Mizokami; Annie On-On Chan; John Chi-Hang Yuen; He-Jun Yuan; Danny Ka-Ho Wong; Siu-Man Sum; Irene Oi-Lin Ng; Sheung Tat Fan; Ching-Lung Lai

BACKGROUND/AIMS To study the outcome and the virologic profiles of severe hepatitis exacerbations due to YMDD mutants in lamivudine-treated patients. METHODS Eighteen lamivudine-treated patients with severe hepatitis exacerbations due to YMDD mutants were recruited. Laboratory and clinical parameters were monitored. Viral genotypes and YMDD mutations were determined. RESULTS None of the 18 patients had YMDD wild-type during exacerbations. Three (17%) and 15 (83%) patients had genotypes B and C, respectively. Elevated bilirubin levels and prolonged prothrombin time were found in 11 (61%) and six patients (33%) respectively. Three patients (17%) had adverse outcome with the development of ascites and/or encephalopathy. One of these patients required liver transplantation and one died. Both patients had evidence of cirrhosis before treatment and hepatitis B e antigen (HBeAg) seroreversion from anti-HBe positivity. The remaining 16 patients (89%) have no evidence of pre-existing cirrhosis. Thirty seven percent of patients had normal alanine aminotransferase levels at the last follow-up. The median HBV DNA level at the last follow-up was significantly lower than the pre-treatment level (P=0.009). CONCLUSIONS Though the majority of patients with severe hepatitis exacerbations due to YMDD mutants had uneventful course, early liver transplantation should be considered in patients with pre-existing cirrhosis and HBeAg seroreversion.

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James Fung

University of Hong Kong

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Wai-Kay Seto

University of Hong Kong

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M.-F. Yuen

University of Hong Kong

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Cl Lai

University of Hong Kong

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Jyy Fung

University of Hong Kong

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