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Featured researches published by ng M. Ma.


Liver Transplantation | 2004

Sirolimus-based immunosuppression for liver transplantation in the presence of extended criteria for hepatocellular carcinoma.

Norman M. Kneteman; José Oberholzer; Mohammed Al Saghier; Glenda Meeberg; Maurice Blitz; Mang M. Ma; Winnie Wong; Klaus S. Gutfreund; Andrew L. Mason; Larry Jewell; A. M. James Shapiro; Vincent G. Bain; David L. Bigam

An increasing number of patients with hepatocellular carcinoma (HCC) are undergoing evaluation for listing for liver transplantation. Criteria for selection require ongoing review for suitability. A consecutive series of 40 patients with HCC within the standard Milan criteria (single tumors n = 19 <5 cm, or up to 3 tumors <3 cm) and beyond (Extended Criteria; single tumors n = 21 <7.5 cm, multiple tumors <5 cm) underwent liver transplant with a sirolimus‐based immunosuppressive protocol designed to minimize exposure to calcineurin inhibitors and steroids. At 44.3 ± 19.3 months (mean ± standard deviation) follow‐up, 1‐ and 4‐year survivals (Kaplan‐Meier) are 94.1 ± 5.7% and 87.4 ± 9.3%, in the Milan group, respectively, and 90.5 ± 6.4% and 82.9 ± 9.3% in the Extended Criteria group, respectively. Five patients died during follow‐up, only 1 from recurrent HCC. Five tumor recurrences have occurred at median 17 (mean 22 ± 17) months posttransplant, 1 in the Milan group and 4 in the Extended Criteria group. Median survival in the patients with recurrent tumor is 42 months (mean 45 ± 25), and the median postrecurrence survival is 15.5 months (mean 23 ± 16). The rate of patients who were alive and free of tumor at 1 and 4 years is 94.1 ± 5.7% and 81.1 ± 9.9%, respectively, in the Milan group and is 90.5 ± 6.4% and 76.8 ± 10.5%, respectively, in the Extended Criteria group. Five patients had sirolimus discontinued for toxicity, while 24 of 35 surviving patients have sirolimus monotherapy immunosuppression. In conclusion, the Milan criteria for liver transplantation in the presence of HCC can be carefully extended without compromising outcomes. This sirolimus based immunosuppression protocol appears to have beneficial effects on tumor recurrence and survival with an acceptable rate of rejection and toxicity. (Liver Transpl 2004;10:1301–1311.)


Liver Transplantation | 2012

Severe muscle depletion in patients on the liver transplant wait list: Its prevalence and independent prognostic value

Puneeta Tandon; Michael Ney; Ivana Irwin; Mang M. Ma; Leah Gramlich; Vincent G. Bain; Nina Esfandiari; Vickie E. Baracos; Aldo J. Montano-Loza; Robert P. Myers

As detected by cross‐sectional imaging, severe muscle depletion, which is termed sarcopenia, holds promise for prognostication in patients with cirrhosis. Our aims were to describe the prevalence and predictors of sarcopenia in patients with cirrhosis listed for liver transplantation (LT) and to determine its independent prognostic significance for the prediction of waiting‐list mortality. Adults listed for LT who underwent abdominal computed tomography/magnetic resonance imaging within 6 weeks of activation were retrospectively identified. The exclusions were hepatocellular carcinoma, acute liver failure, prior LT, and listing for multivisceral transplantation or living related LT. Sixty percent of the 142 eligible patients were male, the median age was 53 years, and the median Model for End‐Stage Liver Disease (MELD) score at listing was 15. Forty‐one percent were sarcopenic; sarcopenia was more prevalent in males versus females (54% versus 21%, P < 0.001) and increased with the Child‐Pugh class (10% for class A, 34% for class B, and 54% for class C, P = 0.007). Male sex, the dry‐weight body mass index (BMI), and Child‐Pugh class C cirrhosis (but not the MELD score) were independent predictors of sarcopenia. Sarcopenia was an independent predictor of mortality (hazard ratio = 2.36, 95% confidence interval = 1.23‐4.53) after adjustments for age and MELD scores. In conclusion, sarcopenia is associated with increased waiting‐list mortality and is poorly predicted by subjective nutritional assessment tools such as BMI and subjective global assessment. If this is validated in larger studies, the objective assessment of sarcopenia holds promise for prognostication in this patient population. Liver Transpl 18:1209–1216, 2012.


Transplantation | 2007

De novo sirolimus-based immunosuppression after liver transplantation for hepatocellular carcinoma: Long-term outcomes and side effects

Christian Toso; Glenda Meeberg; David L. Bigam; José Oberholzer; A. M. James Shapiro; Klaus S. Gutfreund; Mang M. Ma; Andrew L. Mason; Winnie Wong; Vincent G. Bain; Norman M. Kneteman

Background. We report long-term outcomes and side effects after transplantation for hepatocellular carcinoma (HCC) using de novo, sirolimus-based immunosuppression (IS). Methods. A total of 70 patients with HCC (mean age: 54.4±7 years, female/male: 12/58) were transplanted and included in the study. Immunosuppression included de novo sirolimus, low-dose calcineurin inhibitor for 6 to 12 months, with short-course (3 months) or no steroids. Results. After 49 months-median follow-up, eight patients have experienced an HCC recurrence, 2 of 34 when Milan criteria were respected (6%) and 6 of 36 when beyond Milan criteria (17%). One- and 4-year tumor-free survivals were 85 and 73%, when Milan criteria were respected and 82% and 75% when they were not, respectively. (P=0.9). After recurrence, mean survival was 23±28 months. Half (35 of 70) of the patients experienced a rejection. Incisional hernia (24 of 70, 34%), wound infection (12 of 70, 17%), anemia (39 of 70, 56%), leucopenia (39 of 70, 56%), high triglyceride (43 of 70, 61%), and cholesterol (28 of 70, 40%) levels and mouth ulcers (20 of 70, 29%) were among the most frequent complications. No hepatic artery thrombosis was observed. Conclusions. These data suggest that de novo sirolimus-based immunosuppression is associated with satisfactory outcomes after transplantation, even in selected patients beyond Milan criteria. The protocol has proven safe, with an acceptable side-effect profile. This study supports the conduct of larger randomized trials investigating sirolimus after transplantation for HCC.


Transplantation | 1996

Efficacy of lamivudine in chronic hepatitis B patients with active viral replication and decompensated cirrhosis undergoing liver transplantation.

Vincent G. Bain; Norman M. Kneteman; Mang M. Ma; Klaus S. Gutfreund; Shapiro Ja; Fischer K; Graham Tipples; Lee H; Jewell Ld; Tyrrell Dl

Liver transplantation for endstage hepatitis B virus (HBV) infection has been associated with survival inferior to that of liver transplantation in other chronic liver diseases due to HBV reinfection of the graft. Lamivudine is a new nucleoside analog with potent antiviral effects against hepatitis B. Our aim was to test its efficacy when used pre- and posttransplantation in HBV-DNA positive patients with endstage liver disease. Patients received oral lamivudine 100 mg daily both pretransplant and posttransplant. Viral serology, serum and tissue HBV-DNA and liver histology were assessed sequentially. Five consecutive patients with endstage hepatitis B were entered into the trial. Serum HBV-DNA was cleared pretransplant in all patients. Three of four transplanted patients cleared HBeAg and HBsAg postoperatively, whereas all four became negative for serum HBV-DNA (dot-blot and PCR). Liver biopsies were negative for HBV-DNA by PCR in 3 of 4 cases. Lymphocytes were negative for HBV-DNA by PCR in all cases. With follow-up of 3, 14, 16, and 26 months, two patients have normal liver enzymes and normal liver histology and two have developed recurrent hepatitis B. No significant side effects were seen. This pilot study shows that lamivudine can effectively inhibit hepatitis B virus in cirrhotic patients pretransplant and posttransplant. A lamivudine resistant mutant developed in two patients. Transplant recipients with actively replicating HBV related cirrhosis may achieve a good outcome after liver transplantation using lamivudine, but viral resistance is likely to be a significant problem.


Liver International | 2005

Transplant immunosuppressive agents in non‐transplant chronic autoimmune hepatitis: the Canadian association for the study of liver (CASL) experience with mycophenolate mofetil and tacrolimus

Nazira Chatur; Alnoor Ramji; Vincent G. Bain; Mang M. Ma; Paul Marotta; Cameron N. Ghent; Leslie B. Lilly; E. Jenny Heathcote; Marc Deschenes; Samuel S. Lee; Urs P. Steinbrecher; Eric M. Yoshida

Background: Conventional treatment of autoimmune hepatitis consists of either prednisone alone or in combination with azathioprine. Ten to 20% of patients do not respond to or are intolerant of this treatment. Novel drug treatments include immunosuppressive drugs such as tacrolimus (TAC), mycophenolate mofetil (MMF), methotrexate and cyclosporine. We describe a multi‐centre Canadian experience with MMF and TAC.


Journal of Hepatology | 2000

Genotypic succession of mutations of the hepatitis B virus polymerase associated with lamivudine resistance

Klaus S. Gutfreund; Mark Williams; Rajan George; Vincent G. Bain; Mang M. Ma; Eric M. Yoshida; Jean-Pierre Villeneuve; Karl P. Fischer; David L.J. Tyrrell

BACKGROUND/AIMSnHepatitis B mutant strains of virus emerging during treatment with the nucleoside analog lamivudine are being increasingly recognized. In the majority of lamivudine-resistant isolates the mutations have been reported to occur within the YMDD motif of the viral polymerase, either as a single mutation M552I or as M552V concomitant with L528M. We analyzed the time course and genetic succession pattern during the emergence of lamivudine resistance.nnnMETHODSnSeven patients with breakthrough viremia in the setting of chronic hepatitis (n=5) or recurrent HBV after liver transplantation (n=2) were investigated. Pre- and post-breakthrough serum samples were evaluated by single- or second-round PCR amplification and sequencing analysis.nnnRESULTSnGenotypic succession of the virus populations was observed to occur from M552I to M552I/L528M (n=2) and from L528M to M552V/L528M (n=1). The double mutations M552I/L528M (n=4) or M552V/L528M (n=2) were found in six out of seven patients, and represented the stable virus populations throughout the follow-up period. Breakthrough viremia was not associated with the single L528M mutation. The mean duration of uninterrupted treatment with lamivudine until breakthrough was 422 days (range 182-642) and was longer in the setting of chronic hepatitis B than in recurrent hepatitis B after liver transplantation. HBV DNA levels after breakthrough were lower than pretreatment levels in the majority of patients with chronic hepatitis but higher after liver transplantation.nnnCONCLUSIONnOur observations show that the virus populations conferring resistance to lamivudine can evolve from single to double mutations at amino acid 552 and 528 of the HBV polymerase, and that M552I/ L528M or M552V/L528M seem to be the predominant mutations arising during long-term antiviral therapy with lamivudine.


The American Journal of Gastroenterology | 2009

A shorter duration of pre-transplant abstinence predicts problem drinking after liver transplantation.

Puneeta Tandon; Karen J. Goodman; Mang M. Ma; Winnie Wong; Andrew L. Mason; Glenda Meeberg; Donna Bergsten; Michelle Carbonneau; Vincent G. Bain

OBJECTIVES:Liver transplantation for alcoholic liver disease (ALD) can be complicated by abusive or “problem” drinking (PD) after transplant. There are limited data for evaluating the effect of pre-transplant abstinence on post-transplant PD. Few existing studies have included a substantial number of patients with co-existing causes of hepatic dysfunction, and the effect of PD on survival in recent European studies has been controversial. We hypothesized that a longer duration of pre-transplant abstinence would lead to less PD after transplantation. Accordingly, the objectives of this study are to analyze a North American cohort of patients with ALD with or without a secondary diagnosis of liver disease to estimate (i) the incidence of PD and its predictors, as well as (ii) the effect of PD on patient survival.METHODS:We conducted a retrospective review of all patients transplanted for ALD surviving for more than 3 months after transplant. PD was defined as either any drinking (AD) to the point of intoxication or drinking above the toxic threshold (>20u2009g/day in women and >40u2009g/day in men) on at least two separate occasions. We used Coxs proportional hazards regression to estimate risk ratios and Kaplan–Meier curves with log-rank analysis to compare survival.RESULTS:Of 213 eligible transplant patients, 42 were excluded. Of the 171 remaining patients, 78% were male; mean age was 52 years. Overall 53% of patients had co-existing causes of liver dysfunction. The mean follow-up was 64.8 months. The median pre-transplant abstinence was 19 months. In all patients, the risk of AD was 24% and PD 13%. Pre-transplant abstinence duration was the only independent predictor of PD after transplant. For every 1-month increment in pre-transplant abstinence, there was a 5% decrease in the adjusted relapse rate. There was no survival difference noted between problem drinkers and non-drinkers.CONCLUSIONS:The risk of PD decreased with increasing pre-transplant abstinence. Our data support pre-transplant abstinence as an important predictor of post-transplant recidivism; however, the optimal period of abstinence remains unclear. Patients with <18 months of abstinence may benefit from more intensive follow-up and rehabilitation after transplant.


Canadian Journal of Gastroenterology & Hepatology | 2010

The natural history of inflammatory bowel disease and primary sclerosing cholangitis after liver transplantation – a single-centre experience

Karli Moncrief; Anamaria Savu; Mang M. Ma; Vince Bain; Winnie Wong; Puneeta Tandon

OBJECTIVEnTo describe the natural history of primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) after liver transplant, the predictors of PSC and IBD recurrence, and the interaction of these disease processes.nnnMETHODSnData regarding patients who received liver transplants for PSC at the University of Alberta Hospital (Edmonton, Alberta) from 1989 to 2006 were retrospectively reviewed. Recurrent PSC (rPSC) was defined by the Mayo Clinic criteria. Cox proportional hazards modelling and Kaplan-Meier statistics were used.nnnRESULTSnFifty-nine patients were studied, with a median follow-up of 68 months. A total of 71.2% of patients were diagnosed with IBD pretransplant. Clinical IBD severity post-transplant compared with severity pretransplant was unchanged in 67%, worse in 26.5% and improved in 6.1% of patients. Twenty-five per cent of patients developed rPSC posttransplant. The occurrence of at least one episode of acute cellular rejection (hazard ratio 5.7; 95% CI 1.3 to 25.8) and cytomegalovirus mismatch (hazard ratio 4.2; 95% CI 1.1 to 15.4) were found to be significant predictors of rPSC. Although not statistically significant, there was no rPSC in patients without pre- or post-transplant IBD, and in only one patient with a colectomy. Actuarial patient survival rates at one, five and 10 years posttransplant were 97%, 86% and 79%, respectively. Although a significant proportion of patients experienced worsening IBD post-transplantation, the presence or severity of IBD did not influence rPSC or patient survival.nnnCONCLUSIONnAcute cellular rejection and cytomegalovirus mismatch were both identified as independent predictors of rPSC. The impact of steroids and the ideal immunosuppressive regimen for the control of both IBD and PSC post-transplant requires further examination in prospective studies.


Liver International | 2009

Effects of probiotic therapy on portal pressure in patients with cirrhosis: a pilot study

Puneeta Tandon; Karli Moncrief; Karen Madsen; Marie C. Arrieta; Richard J. Owen; Vince Bain; Winnie Wong; Mang M. Ma

Background: Recent literature has supported the role of bacterial translocation as a mediator of splanchnic vasodilatation and portal hypertension. The objective of this study was to determine whether the probiotic VSL#3 would reduce portal pressure in patients with cirrhosis.


Liver International | 2009

The effect of 1 month of therapy with midodrine, octreotide-LAR and albumin in refractory ascites: a pilot study

Puneeta Tandon; Ross T. Tsuyuki; Lesley G. Mitchell; Michael Hoskinson; Mang M. Ma; Winnie Wong; Andrew L. Mason; Klaus S. Gutfreund; Vincent G. Bain

Background: The pathogenesis of refractory ascites (RA) is linked to splanchnic vasodilation. We hypothesized that a combination of midodrine, octreotide long‐acting release (LAR) and albumin would result in increased natriuresis, better control of ascites and an improvement in renal function in patients with RA±Type 2 hepatorenal syndrome.

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Eric M. Yoshida

University of British Columbia

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