Surgery (Austin & Northern Health) - Research Publications
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ItemA novel immune function biomarker identifies patients at risk of clinical events early following liver transplantation(WILEY, 2017-04)Balancing immunosuppression after liver transplant is difficult, with clinical events common. We investigate whether a novel immune biomarker based on a laboratory platform with widespread availability that measures interferon γ (IFNγ) after stimulation with a lyophilized ball containing an adaptive and innate immune stimulant can predict events following transplantation. A total of 75 adult transplant recipients were prospectively monitored in a blinded, observational study; 55/75 (73.3%) patients experienced a total of 89 clinical events. Most events occurred within the first month. Low week 1 results were significantly associated with risk of early infection (area under the receiver operating characteristic curve [AUROC], 0.74; P = 0.008). IFNγ ≤ 1.30 IU/mL (likelihood ratio positive, 1.93; sensitivity, 71.4%; specificity, 63.0%) was associated with the highest risk for infection with minimal rejection risk. Nearly half the cohort (27/60, 45.0%) expressed IFNγ ≤ 1.30 IU/mL. Moreover, an elevated week 1 result was significantly associated with the risk of rejection within the first month after transplant (AUROC, 0.77; P = 0.002), but no episodes of infection. On multivariate logistic regression, IFNγ ≥ 4.49 IU/mL (odds ratio, 4.75) may be an independent predictor of rejection (P = 0.05). In conclusion, low IFNγ suggesting oversuppression is associated with infections, whereas high IFNγ indicating undersuppression is associated with rejection. This assay offers the potential to allow individualization and optimization of immunosuppression that could fundamentally alter the way patients are managed following transplantation. Liver Transplantation 23 487-497 2017 AASLD.
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ItemIncreasing Incidence of Nonalcoholic Steatohepatitis as an Indication for Liver Transplantation in Australia and New Zealand(LIPPINCOTT WILLIAMS & WILKINS, 2019-01)The worldwide increase in obesity and diabetes has led to predictions that nonalcoholic steatohepatitis (NASH) will become the leading indication for orthotopic liver transplantation (OLT). Data supporting this prediction from outside the United States are limited. Thus, we aimed to determine trends in the frequency of NASH among adults listed and undergoing OLT in Australia and New Zealand (ANZ) from 1994 to 2017. Data from the ANZ Liver Transplant Registry were analyzed with patients listed for fulminant liver failure, retransplantation, or multivisceral transplants excluded. Nonparametric trend, Spearman rank correlation, and regression analysis were used to assess trends in etiologies of liver disease over time. Of 5016 patient wait-list registrants, a total of 3470 received an OLT. The percentage of patients with NASH activated for OLT increased significantly from 2.0% in 2003 to 10.9% in 2017 (trend analyses; P < 0.001). In 2017, NASH was the third leading cause of chronic liver disease (CLD) among wait-list registrants behind chronic hepatitis C virus (HCV; 29.5%) and alcohol (16.1%). Similarly, significant increases over time in the percentage of patients undergoing OLT were observed for HCV and NASH (all trend analyses; P < 0.001) but with significant reductions in primary sclerosing cholangitis and cryptogenic cirrhosis (both P < 0.05). By 2017, NASH was the third leading cause of liver disease among patients undergoing OLT (12.4%) and behind chronic HCV (30.2%) and alcohol (18.2%). NASH also became the third most frequent etiology of CLD in patients transplanted (13.8%) with concomitant hepatocellular carcinoma by 2017. In conclusion, NASH is increasing as a primary etiology of liver disease requiring listing and liver transplantation in ANZ.
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ItemEarly viral-specific T-cell testing predicts late cytomegalovirus reactivation following liver transplantation(WILEY, 2018-10)INTRODUCTION: Although antiviral prophylaxis is effective in preventing early cytomegalovirus (CMV) reactivation following liver transplantation (OLT), it predisposes patients to late CMV after prophylaxis has ceased. QuantiFERON-CMV (QFN-CMV, Qiagen, The Netherlands) measures an individual's viral-specific immune response. METHODS: Fifty-nine OLT recipients were prospectively monitored post-OLT in an observational cohort study. QFN-CMV was performed at regular time-points. An absolute QFN-CMV <0.1 IU/mL was considered non-reactive. RESULTS: 50/59 (84.7%) had a reactive QFN-CMV by M6. 38/59 (64.4%) had antiviral prophylaxis or treatment before M6, with 31/38 (81.6%) developing a reactive QFN-CMV by 6 months. Over 90% already had a reactive result as early as 3 months post transplant, 3 patients (5.08%) developed late CMV between 6-12 months (median 251 days)-all had a non-reactive M6 QFN-CMV. And 2/3 experienced CMV disease. Non-reactive M6 QFN-CMV was significantly associated with late CMV (OR = 54.4, PPV = 0.33, NPV = 1.00, P = .003). CONCLUSION: Although only 5% of recipients developed late CMV, 2/3 suffered CMV disease. M6 QFN-CMV has an excellent NPV for late CMV, suggesting patients who exhibit a robust ex vivo immune response at M6 can safely cease CMV monitoring. Furthermore, >90% already express viral-specific immunity as early as 3 months. Conceivably, antiviral prophylaxis could be discontinued early in these patients.
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ItemOutcomes for children after second liver transplantations are similar to those after first transplantations: a binational registry analysis(WILEY, 2020-11)Objective To assess long term graft and patient survival after donor liver retransplantation in children in Australia and New Zealand during 1986–2017; to determine the factors that influence survival. Design Retrospective cohort analysis (registry data). Setting, participants Australia and New Zealand Liver Transplant Registry data for all liver retransplantations in children (under 18 years of age), 1986–2017, in all four paediatric and six adult liver transplantation centres in the two countries. Main outcome measures Graft and patient survival at one, 5, 10 and 15 years. Results 142 liver retransplantations were undertaken in children (59 during 1986–2000, 83 during 2001–2017). Kaplan–Meier survival analysis indicated that survival was significantly greater during 2001–2017 than 1986–2000 (P < 0.001). During 2001–2017, graft survival one year after retransplantation was 84%, at 5 years 75%, at 10 years 70%, and at 15 years 54%; patient survival was 89% at one year, 87% at 5 years, 87% at 10 years, and 71% at 15 years. Median time between transplantations was 0.2 years (IQR, 0.03–1.4 years) during 1986–2000, and 1.8 years (IQR, 0.1–6.8 years) during 2001–2017 (P = 0.002). The proportion of graft failures that involved split grafts was larger during 2001–2017 (35 of 83, 42%) than 1986–2000 (10 of 59, 17%). Graft type, cause of graft failure, and number of transplants did not influence survival following retransplantation. Conclusion Survival for children following retransplantation is excellent. Graft survival is similar for split and whole grafts. Children on the liver waiting list requiring retransplantation should have the same access to donor grafts as children requiring a first transplant.
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ItemExcellent Contemporary Graft Survival for Adult Liver Retransplantation: An Australian and New Zealand Registry Analysis From 1986 to 2017.(Ovid Technologies (Wolters Kluwer Health), 2019-08)BACKGROUND: Liver retransplantation is technically challenging, and historical outcomes are significantly worse than for first transplantations. This study aimed to assess graft and patient survival in all Australian and New Zealand liver transplantation units. METHODS: A retrospective cohort analysis was performed using data from the Australia and New Zealand Liver Transplant Registry. Graft and patient survival were analyzed according to era. Cox regression was used to determine recipient, donor, or intraoperative variables associated with outcomes. RESULTS: Between 1986 and 2017, Australia and New Zealand performed 4514 adult liver transplants, 302 (6.7%) of which were retransplantations (278 with 2, 22 with 3, 2 with 4). The main causes of graft failure were hepatic artery or portal vein thrombosis (29%), disease recurrence (21%), and graft nonfunction (15%). Patients retransplanted after 2000 had a graft survival of 85% at 1 year, 75% at 5 years, and 64% at 10 years. Patient survival was 89%, 81%, and 74%, respectively. This was higher than retransplantations before 2000 (P < 0.001). Univariate analysis found that increased recipient age (P = 0.001), recipient weight (P = 0.019), and donor age (P = 0.011) were associated with decreased graft survival prior to 2000; however, only increased patient weight was significant after 2000 (P = 0.041). Multivariate analysis found only increased recipient weight (P = 0.042) and donor age (P = 0.025) was significant prior to 2000. There was no difference in survival for second and third retransplants or comparing time to retransplant. CONCLUSIONS: Australia and New Zealand have excellent survival following liver retransplantation. These contemporary results should be utilized for transplant waitlist methods.
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ItemEpidemiology and outcomes of acute liver failure in Australia(BAISHIDENG PUBLISHING GROUP INC, 2019-07-27)BACKGROUND: Acute liver failure (ALF) is a life-threatening syndrome with varying aetiologies requiring complex care and multidisciplinary management. Its changing incidence, aetiology and outcomes over the last 16 years in the Australian context remain uncertain. AIM: To describe the changing incidence, aetiology and outcomes of ALF in South Eastern Australia. METHODS: The database of the Victorian Liver Transplant Unit was interrogated to identify all cases of ALF in adults (> 16 years) in adults hospitalised between January 2002 and December 2017. Overall, 169 patients meeting criteria for ALF were identified. Demographics, aetiology of ALF, rates of transplantation and outcomes were collected for all patients. Transplant free survival and overall survival (OS) were assessed based on survival to discharge from hospital. Results were compared to data from a historical cohort from the same unit from 1988-2001. RESULTS: Paracetamol was the most common aetiology of acute liver failure, accounting for 50% of cases, with an increased incidence compared with the historical cohort (P = 0.046). Viral hepatitis and non-paracetamol drug or toxin induced liver injury accounted for 15% and 10% of cases respectively. Transplant free survival (TFS) improved significantly compared to the historical cohort (52% vs 38%, P = 0.032). TFS was highest in paracetamol toxicity with spontaneous recovery in 72% of cases compared to 31% of non-paracetamol ALF (P < 0.001). Fifty-nine patients were waitlisted for emergency liver transplantation. Nine of these died while waiting for an organ to become available. Forty-two patients (25%) underwent emergency liver transplantation with a 1, 3 and 5 year survival of 81%, 78% and 72% respectively. CONCLUSION: Paracetamol toxicity is the most common aetiology of ALF in South-Eastern Australia with a rising incidence over 30 years. TFS has improved, however it remains low in non-paracetamol ALF.
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ItemActivation of the Alternate Renin-Angiotensin System Correlates with the Clinical Status in Human Cirrhosis and Corrects Post Liver Transplantation(MDPI, 2019-04)INTRODUCTION: Recent animal studies have shown that the alternate renin-angiotensin system (RAS) consisting of angiotensin-converting enzyme 2 (ACE2), angiotensin-(1⁻7) (Ang-(1⁻7)) and the Mas receptor is upregulated in cirrhosis and contributes to splanchnic vasodilatation and portal hypertension. To determine the potential relevance of these findings to human liver disease, we evaluated its expression and relationship to the patients' clinical status in subjects with cirrhosis. METHODS: Blood sampling from peripheral and central vascular beds was performed intra-operatively for cirrhotic patients at the time of liver transplantation (LT) or trans-jugular intra-hepatic portosystemic shunt (TIPS) procedures to measure angiotensin II (Ang II) and Ang-(1⁻7) peptide levels and ACE and ACE2 enzyme activity. Relevant clinical and hemodynamic data were recorded pre-operatively for all subjects and peripheral blood sampling was repeated 3 months or later post-operatively. RESULTS: Ang-(1⁻-7) and ACE2 activity were up-regulated more than twofold in cirrhotic subjects both at the time of LT and TIPS and levels returned to comparable levels as control subjects post-transplantation. Ang-(1⁻7) levels correlated positively with the degree of liver disease severity, as measured by the model for an end-stage liver disease (MELD) and also with clinical parameters of pathological vasodilatation including cardiac output (CO). There were strong correlations found between the ACE2:ACE and the Ang-(1⁻7):Ang II ratio highlighting the inter-dependence of the alternate and classical arms of the RAS and thus their potential impact on vascular tone. CONCLUSIONS: In human cirrhosis, the alternate RAS is markedly upregulated and the activation of this system is associated strongly with features of the hyperdynamic circulation in advanced human cirrhosis.