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Rejection Risk (rejection + risk)

Distribution by Scientific Domains
Medical Sciences66%

Selected Abstracts

The Impact of False Rejection Risk on Posterior Audit Risk Measurement

INTERNATIONAL JOURNAL OF AUDITING, Issue 1 2001
Anne D. Woodhead
This paper investigates false rejection risk, analysing the a priori relationship between the risk of false rejection and the more common risk of false acceptance, of an account balance by a substantive test. The paper uses probability theory to specify the relationship between these two risks and thus generate a model of posterior audit risk. The paper proceeds to investigate the relationship using the power function of basic statistics. This specifies the relationship between (i) the probability of rejecting the account balance and (ii) the size of the error which the balance contains. We argue that unless there is a discontinuity in the power function around the specified value of material error, then posterior audit risk will be unaffected by the substantive tests undertaken. Posterior risk will then be determined entirely by the assessed inherent and control risks. This conclusion is counter-intuitive to the approach to audit risk adopted by many professional pronouncements and results from the adoption of a mathematically rigorous definition of the risks encountered by the auditor. The primary conclusion is that the discontinuity arises under conditions of careful audit planning. If planning is careful, then false rejection risk contributes very little to posterior risk. In addition, there is very little difference between planned risk and posterior risk. [source]

Allospecific CD154+ T Cells Associate with Rejection Risk After Pediatric Liver Transplantation

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2009
C. Ashokkumar
Antigen-specific T cells, which express CD154 rapidly, but remain untested in alloimmunity, were measured with flow cytometry in 16-h MLR of 58 identically-immunosuppressed children with liver transplantation (LTx), to identify Rejectors (who had experienced biopsy-proven rejection within 60 days posttransplantation). Thirty-one children were sampled once, cross-sectionally. Twenty-seven children were sampled longitudinally, pre-LTx, and at 1,60 and 61,200 days after LTx. Results were correlated with proliferative alloresponses measured by CFSE-dye dilution (n = 23), and CTLA4, a negative T-cell costimulator, which antagonizes CD154-mediated effects (n = 31). In cross-sectional observations, logistic regression and leave-one-out cross-validation identified donor-specific, CD154 + T-cytotoxic (Tc)-memory cells as best associated with rejection outcomes. In the longitudinal cohort, (1) the association between CD154 + Tc-memory cells and rejection outcomes was replicated with sensitivity/specificity 92.3%/84.6% for observations at 1,60 days, and (2) elevated pre-LTx CD154 + Tc-memory cell responses were associated with significantly increased incidence (p = 0.02) and hazard (HR = 7.355) of rejection in survival/proportional hazard analysis. CD154 expression correlated with proliferative alloresponses (r = 0.835, p = 7.1e-07), and inversely with CTLA4 expression of allospecific CD154 + Tc-memory cells (r =,0.706, p = 3.0e-05). Allospecific CD154 + T-helper-memory cells, not CD154 + Tc-memory, were inhibited by increasing Tacrolimus concentrations (p = 0.026). Collectively, allospecific CD154 + T cells provide an estimate of rejection risk in children with LTx. [source]

The Impact of False Rejection Risk on Posterior Audit Risk Measurement

INTERNATIONAL JOURNAL OF AUDITING, Issue 1 2001
Anne D. Woodhead
This paper investigates false rejection risk, analysing the a priori relationship between the risk of false rejection and the more common risk of false acceptance, of an account balance by a substantive test. The paper uses probability theory to specify the relationship between these two risks and thus generate a model of posterior audit risk. The paper proceeds to investigate the relationship using the power function of basic statistics. This specifies the relationship between (i) the probability of rejecting the account balance and (ii) the size of the error which the balance contains. We argue that unless there is a discontinuity in the power function around the specified value of material error, then posterior audit risk will be unaffected by the substantive tests undertaken. Posterior risk will then be determined entirely by the assessed inherent and control risks. This conclusion is counter-intuitive to the approach to audit risk adopted by many professional pronouncements and results from the adoption of a mathematically rigorous definition of the risks encountered by the auditor. The primary conclusion is that the discontinuity arises under conditions of careful audit planning. If planning is careful, then false rejection risk contributes very little to posterior risk. In addition, there is very little difference between planned risk and posterior risk. [source]

Mycophenolate mofetil in combination with reduction of calcineurin inhibitors for chronic renal dysfunction after liver transplantation,

LIVER TRANSPLANTATION, Issue 12 2006
Georges-Philippe Pageaux
The purpose of the study was to introduce mycophenolate mofetil (MMF) in liver transplant recipients with renal dysfunction to decrease calcineurin inhibitor (CNI) dosages without increasing rejection risk. In this prospective, multicenter, randomized study, chronic CNI-related renal dysfunction was defined by an increase in serum creatinine with values >140 ,mol/L and <300 ,mol/L. Patients were randomized in 2 groups. Study group: combination of MMF (2 to 3 g/day) and reduced dose of CNI ,50% of initial dose; control group: no MMF, but with the ability to reduce CNI doses, but not below 75% of initial dose. Fifty-six patients were included, 27 in the study group and 29 in the control group. In the study group, there was a significant decrease in serum creatinine values, from 171.7 ± 24.2 ,mol/L at day 0 to 143.4 ± 19 ,mol/L at month 12 and a significant increase in creatinine clearance, from 42.6 ± 10.9 mL/min to 51.7 ± 13.8 mL/min. No rejection episode was observed in the study group. In the control group, there was no improvement of renal function, assessed by the changes in serum creatinine values, from 175.4 ± 23.4 ,mol/L at day 0 to 181.6 ± 63 ,mol/L at month 12, and in creatinine clearance, from 42.8 ± 12.8 mL/min to 44.8 ± 19.7 mL/min. The differences between the 2 groups were significant: P = 0.001 for serum creatinine, and P = 0.04 for creatinine clearance. In conclusion, the introduction of MMF combined with the reduction of at least 50% of CNI dose allowed the renal function of liver transplant recipients to significantly improve at 1 year, without any rejection episode and without significant secondary effects. Liver Transpl 12:1755,1760, 2006. © 2006 AASLD. [source]

Efficacy, predictors of response, and potential risks associated with antiviral therapy in liver transplant recipients with recurrent hepatitis C,

LIVER TRANSPLANTATION, Issue 7 2006
Marina Berenguer
There are unresolved issues regarding sustained virological response (SVR), tolerance and risk of rejection following antiviral therapy in liver transplantation (LT). The aim of our study was to determine efficacy, rejection risk and factors associated with SVR. HCV-infected LT patients with at least 6 months of follow-up following end-of-therapy (EOT) received combination therapy of ribavirin (Rbvr) + standard (n=31)/pegIFN (n=36) between 1999 and 2004 (95% genotype 1). An EOT and SVR was obtained in 46% and 33%, respectively. Type of antiviral therapy, use of erythropoietin, compliance, and early virologic response (EVR) were predictive of SVR, but only the latter remained in the multivariate analysis. Premature discontinuation, not impacted by the use of erythropoietin or GCSF, occurred in 40% patients. None of the variables predicted rejection (acute n=2, chronic n=4). A SVR occurred in 3/4 patients with chronic rejection. In conclusion, the efficacy of pegIFN-Rbvr is similar to the non-transplant population. An EVR at 3 months is useful to predict lack of response. The type of calcineurin inhibitor and history of prior non-response to IFN before LT do not influence the outcome of therapy. Severe rejection may lead to graft loss, a complication difficult to predict. Liver Transpl 12:1067,1076, 2006. © 2006 AASLD. [source]

Allospecific CD154+ T Cells Associate with Rejection Risk After Pediatric Liver Transplantation

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2009
C. Ashokkumar
Antigen-specific T cells, which express CD154 rapidly, but remain untested in alloimmunity, were measured with flow cytometry in 16-h MLR of 58 identically-immunosuppressed children with liver transplantation (LTx), to identify Rejectors (who had experienced biopsy-proven rejection within 60 days posttransplantation). Thirty-one children were sampled once, cross-sectionally. Twenty-seven children were sampled longitudinally, pre-LTx, and at 1,60 and 61,200 days after LTx. Results were correlated with proliferative alloresponses measured by CFSE-dye dilution (n = 23), and CTLA4, a negative T-cell costimulator, which antagonizes CD154-mediated effects (n = 31). In cross-sectional observations, logistic regression and leave-one-out cross-validation identified donor-specific, CD154 + T-cytotoxic (Tc)-memory cells as best associated with rejection outcomes. In the longitudinal cohort, (1) the association between CD154 + Tc-memory cells and rejection outcomes was replicated with sensitivity/specificity 92.3%/84.6% for observations at 1,60 days, and (2) elevated pre-LTx CD154 + Tc-memory cell responses were associated with significantly increased incidence (p = 0.02) and hazard (HR = 7.355) of rejection in survival/proportional hazard analysis. CD154 expression correlated with proliferative alloresponses (r = 0.835, p = 7.1e-07), and inversely with CTLA4 expression of allospecific CD154 + Tc-memory cells (r =,0.706, p = 3.0e-05). Allospecific CD154 + T-helper-memory cells, not CD154 + Tc-memory, were inhibited by increasing Tacrolimus concentrations (p = 0.026). Collectively, allospecific CD154 + T cells provide an estimate of rejection risk in children with LTx. [source]