Occurrence Of Acute Cellular Rejection Research Articles

Study of Risk Factors Associated With Recurrent Primary Sclerosing Cholangitis After Liver Transplantation in Shiraz >From 2011 to 2021.

Primary sclerosing cholangitis is an autoimmune illness affecting the intrahepatic and/or extrahepatic bile ducts that has a varying clinical history and no clear therapy. Recurrence of primary sclerosing cholangitis after transplantation can cause recurring liver failure, decreased survival, and the necessity for retransplant. Here, we explored the incidence of recurrence while also identifying the risk factors of primary sclerosing cholangitis. In this retrospective cohort study, we collected demographic and clinical data from patients with a history of primary sclerosing cholangitis after liver transplant between 2011 and 2021. With SPSS software, we compared results in 2 groups of patients (with and without recurrent sclerosing biliary cholangitis) in terms of demographic and clinical variables. The study included 408 patients. Lower donor age and the occurrence of acute cellularrejection were shown to be key risk factors for recurrence of primary sclerosing cholangitis. Acute cellularrejection showed the best likelihood of predicting primary sclerosing cholangitis recurrence. As the number of acute cellular rejection episodes increased, so did the chance of primary sclerosing cholangitis. Death rate of patients with recurrence of primary sclerosing cholangitis was 40.8% (n = 20 patients) compared with 18.9% (n = 68 patients) in those without recurrence (significant at P < .001). The recurrence of primary sclerosing cholangitis had a detrimental effect on survival after liver transplant. Modifiable risk variables have the potentialto affecttherapies on care and prevention of primary sclerosing cholangitis recurrence. Donor age and acute cellular rejection were risk factors for decreased survival and higher primary sclerosing cholangitis recurrence. The use of mycophenolate (Cellcept) increased recurrence, but tacrolimus reduced mortality.

Diagnostic performance of electronic nose technology in chronic lung allograft dysfunction.

There is a need for reliable biomarkers for the diagnosis of chronic lung allograft dysfunction (CLAD). In this light, we investigated the diagnostic value of exhaled breath analysis using an electronic nose (eNose) for CLAD, CLAD phenotype, and CLAD stage in lung transplant recipients (LTR). We performed eNose measurements in LTR with and without CLAD, visiting the outpatient clinic. Through supervised machine learning, the diagnostic value of eNose for CLAD was assessed in a random training and validation set. Next, we investigated the diagnostic value of the eNose measurements combined with known risk factors for CLAD. Model performance was evaluated using ROC-analysis. We included 152 LTR (median age 60 years, 49% females), of whom 38 with CLAD. eNose-based classification of patients with and without CLAD provided an AUC of 0.86 in the training set, and 0.82 in the validation set. After adding established risk factors for CLAD (age, gender, type of transplantation, time after transplantation and prior occurrence of acute cellular rejection) to a model with the eNose data, the discriminative ability of the model improved to an AUC of 0.94 (p=0.02) in the training set and 0.94 (p=0.04) in the validation set. Discrimination between BOS and RAS was good (AUC 0.95). Discriminative ability for other phenotypes (AUCs ranging 0.50-0.92) or CLAD stages (AUC 0.56) was limited. Exhaled breath analysis using eNose is a promising novel biomarker for enabling diagnosis and phenotyping CLAD. eNose technology could be a valuable addition to the diagnostic armamentarium for suspected graft failure in LTR.

Cardiac Allograft Rejection Induces Changes in Nucleocytoplasmic Transport: RANGAP1 as a Potential Non-Invasive Biomarker.

The non-invasive diagnosis of acute cellular rejection (ACR) is a major challenge. We performed a molecular study analyzing the predictive capacity of serum RanGTPase AP1 (RANGAP1) for diagnosing ACR during the first year after heart transplantation (HT). We included the serum samples of 75 consecutive HT patients, extracted after clinical stability, to determine the RANGAP1 levels through ELISA. In addition, various clinical, analytical, and echocardiographic variables, as well as endomyocardial biopsy results, were collected. RANGAP1 levels were higher in patients who developed ACR (median 63.15 ng/mL; (inter-quartile range (IQR), 36.61–105.69) vs. 35.33 ng/mL (IQR, 19.18–64.59); p = 0.02). Receiver operating characteristic (ROC) curve analysis confirmed that RANGAP1 differentiated between patients with and without ACR (area under curve (AUC), 0.70; p = 0.02), and a RANGAP1 level exceeding the cut-off point (≥90 ng/mL) was identified as a risk factor for the development of ACR (OR, 6.8; p = 0.006). Two independent predictors of ACR identified in this study were higher RANGAP1 and N-terminal pro-brain natriuretic peptide levels. The analysis of the ROC curve of the model showed a significant AUC of 0.77, p = 0.001. Our findings suggest that RANGAP1 quantification facilitates risk prediction for the occurrence of ACR and could be considered as a novel non-invasive biomarker of ACR.

Tissue presentation of human pegivirus infection in liver transplanted recipients

Human pegivirus-1 (HPgV-1) is known for its protective role in HIV co-infected individuals. This immunomodulatory effect raised questions concerning the possible role of HPgV-1 infection and the risk of rejection in liver transplanted patients. We aimed to evaluate the possible protective effect of HPgV-1 on graft outcome of liver transplanted patients. A total of 283 patients were recruited. Formalin-fixed paraffin-embedded tissue samples were collected from the explanted liver. HBV-DNA, HCV-RNA, and HPgV-1-RNA were determined using PCR and multiplex RT-PCR assays. The clinical course of patients including the occurrence of acute cellular rejection was compared between HPgV-1-infected vs. uninfected patients. HBV-DNA, HCV-RNA and HPgV-1-RNA were detected in 42.6%, 4.9%, and 7.8% of samples, respectively. None of the HPgV-1-infected patients experienced graft rejection. Group LASSO logistic regression revealed that HPgV-1 infection was the only factor which significantly reduced the odds of graft rejection (OR = 0.5, 95% CI = 0.29–0.89). No significant association was found between the presence of HPgV-1 with HBV and HCV infections. The lack of graft rejection in HPgV-1-infected liver transplanted patients might indicate a possible role of this virus for graft surveillance. Since these are still preliminary findings, prospective studies should further elucidate the role of HPgV-1 in liver transplantation outcomes.

Lower Platelet Count Following Rabbit Antithymocyte Globulin Induction Is Associated With Less Acute Cellular Rejection in Heart Transplant Recipients

BackgroundUnlike lymphodepletion, a decrease in platelet count following induction immunosuppressive therapy with polyclonal rabbit antithymocyte globulin (rATG) is deemed as an adverse event. However, this phenomenon may represent a particular rATG antirejection mechanism. MethodsThis retrospective single-center study included 156 patients who received a heart transplant (HTx) between 2010 and 2018. All patients received rATG induction therapy for 5 days. Absolute lymphocyte count (ALC) and platelet counts were assessed on days 0, 7, and 14 following HTx. The primary outcome of the study was the first occurrence of acute cellular rejection (ACR) defined as grade ≥ 1B within 24 months after HTx. ResultsBoth ALC and platelet counts decreased rapidly after induction. During the 24-month follow-up period, 17% of patients had ACR. Patients with ACR had significantly higher platelet count on day 7 (145 vs 104, P < .001) and higher ALC on day 14 (162 vs 130, P = .035) than those without rejection. Patients in the highest platelet count quartile showed more ACR (50% in quartile 4 vs 0% in quartile 1, P = .006) as well as a higher cumulative total rejection score. Univariate analysis showed that ACR was associated with platelet count on day 7, recipient age, and pretransplant cytomegalovirus IgG serology. In multivariable regression analysis, platelet count on day 7 was the most accurate predictor of ACR. ConclusionsLower platelet count after induction with rATG is associated with less ACR. This suggests platelet involvement in antirejection mechanisms of rATG and a possible rationale for targeting platelets in future immunosuppressive strategies.

Impact on Outcome of Preoperative Plasmapheresis in Sensitized Lung Transplant Recipients

Presence of donor specific HLA antibodies (DSA) before lung transplantation may jeopardize the prognosis. Preoperative plasmapheresis (PP) for desensitization may improve graft outcomes but may have complications, mainly bleeding and infections. The primary objective of this study was to evaluate the efficacy of PP in term of level of DSA (micro fluorescent intensity (MFI)) and occurrence of antibody mediated rejection (AMR). Secondary outcomes included perioperative surgical revision, occurrence of pneumonia, and ICU mortality. We reviewed the charts of patients with preoperative DSA from 2015 to 2018. Patient's DSA were identified and followed by Luminex Single Antigen assay at three time points: before transplantation, in early (< 15 days) and late (up to 6 weeks) postoperative periods. PP was performed when MFI was >1,000 and was associated with an induction treatment. 3 sessions of postoperative plasmapheresis were performed when preoperative MFI was >3,000. Patients without PP represented control group. 205 patients were included, in whom 29 had PP (14%). During the predefined time frame, the kinetic of sum of DSA MFI did not differ between the two groups (ANOVA p=0.47) (Figure). Course of the highest MFI value seemed to stabilize in the PP group and differed from the control group (ANOVA p<0.005). They were no difference between the 2 groups in the occurrence of acute cellular rejection (38% vs 61%) or AMR (20% vs 17%). The PP group had more surgical revision in the first postoperative 48h (28% vs 10%; p=0.005). The incidence density rate of pneumonia was similar between the 2 groups (2.4±2.7 vs 3.1±4.7; p=0.11). ICU mortality rate was significantly higher in patients with PP (21% vs 8%; p=0.04). Our results suggested that PP stabilized the course of highest DSA and probably had an impact on the rate of episodes of AMR. However, the increase rate of surgical revision and ICU mortality rate suggested that such treatment should be used in selected patients.

The Use of Artificial Intelligence (AI) Machine Learning to Determine Myocyte Damage in Cardiac Transplant Acute Cellular Rejection

Cardiac transplant patients must be on lifelong surveillance for the occurrence of acute cellular rejection (ACR). Despite potent immunosuppressants, ACR occurs when recipient T cells recognize donor antigens to cause cardiac myocyte destruction. Identifying myocyte damage is critical for determining the grade of rejection, and thus greatly impacts treatment decisions. The aim of this study is to determine if a machine learning algorithm can reach acceptable performance of identifying myocyte damage representative of ACR from benign conditions. AI technology has recently been under robust investigation in cancer pathology but is in its infancy in transplant pathology. This is the first AI algorithm to our knowledge, to identify myocyte damage in cardiac transplant patients. All regions of myocyte damage were annotated by a board-certified cardiac pathologist at a high-volume cardiac transplant center. Cases diagnosed as antibody-mediated rejection (AMR) were excluded. Annotations were extracted using the Openslide software and fed into a convolutional neural network which used the locked VGG16 base for transfer learning. Keras was used for AI modeling and training. Four annotation classes were included in the algorithm (normal, healing injury, Grade 1R1A and Grade 1R2). A total of 19,617 annotations (10,855 regions of ACR, 5002 healing injury, 3760 normal) were completed from 200 hematoxylin and eosin slides scanned using a Leica Aperio AT2 digital whole slide scanner at 40X magnification. The AI algorithm successfully distinguished myocyte damage (Grade 1R2) from non-myocyte damage (Grade 1R1A) with 94% validation accuracy. ACR was distinguished from healing injury with 98-99% validation accuracy, and from normal cardiac myocytes with 99% validation accuracy. This study provides evidence for the first time, that a machine learning algorithm can be taught and validated to distinguish myocyte damage ACR from non-myocyte damage ACR. To our knowledge, this is one of the first AI tools developed in cardiac transplant pathology that may be used as an adjunct tool to decrease inter-observer diagnostic variability and reduce diagnostic error amongst pathologists.

Safe and Successful Treatment of Acute Cellular Rejection of an Intestine and Abdominal Wall Transplant With Vedolizumab.

Background.Graft survival rates after intestinal transplantation (ITx) are still the lowest in comparison to other solid organ transplants. One of the main reasons is the frequent occurrence of acute cellular rejection (ACR). Vedolizumab is an antibody against α4β7+ integrin involved in gut-homing of T cells which has been approved for inflammatory bowel diseases (IBD). We report its off-label use to treat ACR after ITx.Methods.Following abdominal wall transplantation (AWTx) and ITx, clinical course was followed biochemically. Sequential small intestinal biopsies were taken preceding, during, and after ACR treatment with vedolizumab, following the standard therapy regime for IBD. Rejection was diagnosed histologically, and proinflammatory (α4β7+, interleukin-17+) and regulatory (FoxP3+) T cells were analyzed by immunohistochemistry.Results.ACR in both the ITx and AWTx resolved upon vedolizumab treatment, which was safe, evidenced by clearing an astrovirus and primary cytomegalovirus infection. Only a slight reduction of α4β7+ cells in the mucosa was observed, and α4β7+ and regulatory T cells could still move into the lamina propria upon infection.Conclusions.Vedolizumab is a safe treatment option for ACR after ITx but its mechanism is probably not only based on inhibition of gut-selective T-cell homing.

Predicting urine output after kidney transplantation: development and internal validation of a nomogram for clinical use.

ABSTRACTPurpose:To analyze pre-transplantation and early postoperative factors affecting post-transplantation urine output and develop a predictive nomogram.Patients and Methods:Retrospective analysis of non-preemptive first transplanted adult patients between 2001-2016. The outcomes were hourly diuresis in mL/Kg in the 1st (UO1) and 8th (UO8) postoperative days (POD). Predictors for both UO1 and UO8 were cold ischemia time (CIT), patient and donor age and sex, HLA I and II compatibility, pre-transplantation duration of renal replacement therapy (RRT), cause of ESRD (ESRD) and immunosuppressive regimen. UO8 predictors also included UO1, 1st/0th POD plasma creatinine concentration ratio (Cr1/0), and occurrence of acute cellular rejection (AR). Multivariable linear regression was employed to produce nomograms for UO1 and UO8.Results:Four hundred and seventy-three patients were included, mostly deceased donor kidneys’ recipients (361, 70.4%). CIT inversely correlated with UO1 and UO8 (Spearman's p=-0.43 and −0.37). CR1/0 inversely correlated with UO8 (p=-0.47). On multivariable analysis UO1 was mainly influenced by CIT, with additional influences of donor age and sex, HLA II matching and ESRD. UO1 was the strongest predictor of UO8, with significant influences of AR and ESRD.Conclusions:The predominant influence of CIT on UO1 rapidly wanes and is replaced by indicators of functional recovery (mainly UO1) and allograft's immunologic acceptance (AR absence). Mean absolute errors for nomograms were 0.08 mL/Kg h (UO1) and 0.05 mL/Kg h (UO8).

Transient increase of activated regulatory T cells early after kidney transplantation

Regulatory T cells (Tregs) are crucial in controlling allospecific immune responses. However, studies in human kidney recipients regarding the contribution of polyspecific Tregs have provided differing results and studies on alloreactive Tregs are missing completely. In this retrospective study, we specifically analyzed activated CD4+CD25highFOXP3+GARP+ Tregs in 17 patients of a living donor kidney transplantation cohort longitudinally over 24 months by flow cytometry (FOXP3: forkhead box protein 3, GARP: glycoprotein A repetitions predominant). We could demonstrate that Tregs of patients with end-stage renal disease (ESRD) are already pre-activated when compared to healthy controls. Furthermore, even though total CD4+CD25highFOXP3+ Treg numbers decreased in the first three months after transplantation, frequency of activated Tregs increased significantly representing up to 40% of all peripheral Tregs. In a cohort of living donor kidney transplantation recipients with stable graft function, frequencies of activated Tregs did not correlate with the occurrence of acute cellular rejection or chronic graft dysfunction. Our results will be important for clinical trials using adoptive Treg therapy after kidney transplantation. Adoptively transferred Tregs could be important to compensate the Treg loss at month 3, while they have to compete within the Treg niche with a large number of activated Tregs.

OR16. HLA epitope-mismatch more precisely predicts the development of de novo donor specific antibody and acute cellular rejection after lung transplant

Aim Development of de novo HLA donor-specific antibody (dnDSA) after lung transplant (LuTx) is prevalent and associated with poorer transplant outcomes. Understanding pre-LuTx determinants helps to minimize dnDSA. The aim of this study was to investigate the impact of HLA-Epitope Mismatch Load (EpiMML) in the development of dnDSA in LuTx recipients. Methods 572 recipients received LuTx during 10/2012–10/2017 and were retrospectively analyzed for the formation of dnDSA (Mean Fluorescence Intensity ⩾ 1000). Antigenic mismatches were recorded among 422 recipients. EpiMMLs were determined by HLA-Matchmaker (Version 02) among 168 recipients who had four-digit high resolution typing. There were 18 recipients who were typed by both high and low resolution. Acute Cellular Rejection (ACR) and Antibody Mediated Rejection (AMR) were assessed for LuTx outcomes. Results Of the 572 patients, 55% developed dnDSA; 25% Class I, 39% Class II, and 36% both Class I and II. In Class II, the most prevalent dnDSA was DQ (216/235; 92%). EpiMMLs for Class I, Class II, as well as single loci of HLA-A, B, C, DR, and DQ were all significantly higher from patients with positive dnDSA than from patient with negative dnDSA (Table 1a). However, for antigen-level mismatches, only HLA-A and DQ correlated with the development of dnDSA. As shown in Table 1b, certain mismatched epitopes were more frequent among patients who developed dnDSA than those who did not. Among a subgroup of 120 recipients, EpiMMLs of Class II, especially DQ, were significantly associated with the occurrence of ACR (p = 0.02 and 0.005, respectively). There was no remarkable relevance between EpiMMLs and AMR. Conclusions Compared to HLA antigen mismatching, EpiMML is a better predictor of dnDSA development in LuTx recipients. Increasing EpiMMLs, particularly for HLA-DQ, identify patients at the highest risk to develop dnDSA and ACR. Collectively, these data support the use of EpiMML assessment especially for optimizing post-transplantation immunosuppression in LuTx recipients. Download : Download high-res image (242KB) Download : Download full-size image Download : Download high-res image (182KB) Download : Download full-size image

Multicentre, randomised, placebo-controlled trial of extract of Japanese herbal medicine Daikenchuto to prevent bowel dysfunction after adult liver transplantation (DKB 14 Study)

IntroductionThis multicentre randomised controlled clinical trial will aim to determine the ability of an extract (TJ-100) of Daikenchuto (traditional Japanese herbal medicine; Kampo) to prevent bowel dysfunction in at least...

Impact of cytochrome P450 3A5 polymorphism in graft livers on the frequency of acute cellular rejection in living-donor liver transplantation.

We investigated whether the cytochrome P450 3A5*3 (CYP3A5*3) genotype affects tacrolimus pharmacokinetics and the risk of acute cellular rejection in living-donor liver transplant patients in Japan. Between July 2004 and June 2011, we enrolled 410 living-donor liver transplant patients receiving tacrolimus. Biopsy specimens of intestinal mucosa and graft liver at surgery were obtained to examine the mRNA expression of CYP3A subfamilies as well as the genotyping of CYP3A5*3 polymorphism. The CYP3A5 genotype in the native intestine had no significant effect on the occurrence of acute cellular rejection between postoperative days 14 and 23 in cases with identical or compatible ABO blood types (11.5% for the CYP3A5*1 allele vs. 7.4% for CYP3A5*3/*3; P=0.2643), although the concentration/dose ratio of tacrolimus was significantly higher in patients with the intestinal CYP3A5*3/*3 genotype than in those with the CYP3A5*1 allele for 5 post-transplant weeks. However, patients who received a graft liver with the CYP3A5*1 allele showed a higher rate of acute cellular rejection than those who received a graft liver with the CYP3A5*3/*3 genotype (14.5 vs. 5.7%; P=0.0134). The relative risk for acute cellular rejection associated with the CYP3A5*1 liver allele was 2.629 (P=0.018, Cox regression model). Consequently, graft liver CYP3A5*1 genotype might increase the risk for acute cellular rejection after living-donor liver transplantation, possibly by associating with the local hepatic tacrolimus concentration. The target level of tacrolimus may be affected by the CYP3A5*3 genotype of the liver, rather than by that of the small intestine, after postoperative day 14.

Cytokine gene polymorphisms in acute cellular rejection following living donor liver transplantation: analysis of 155 donor-recipient pairs.

Despite improvements in immunosuppressive therapy, acute cellular rejection (ACR) remains an important cause of graft loss in patients undergoing liver transplantation. Recently, associations between cytokine gene polymorphisms in recipients and the occurrence of ACR have been reported. However, most studies did not investigate gene polymorphisms in donors or were limited by the number of cases investigated. We examined 155 living donor liver transplantation (LDLT) patients treated at Nagoya University or Kyoto University from 2004 to 2009. The following gene polymorphisms in recipients and donors were analyzed: tumor necrosis factor A (TNF-A) T-1031C, interleukin 2 (IL-2) T-330G, IL-10C-819T, IL-13C-1111T, and transforming growth factor B (TGF-B) T29C. Forty-seven recipients (30.3%) developed early ACR. Of the investigated gene polymorphisms, the IL-13 -1111C/C genotype in recipients was significantly associated with a higher incidence of ACR relative to the other two genotypes (OR=2.64, 95% CI 1.19-5.86, p=0.017), while we showed the lack of association between investigated gene polymorphisms in donors and ACR incidence. The IL-13 -1111C/C genotype in recipients might be a risk factor for ACR in LDLT, and this might contribute to individualized immunosuppression strategies for recipients. On the other hand, the current study showed no associations of cytokine gene polymorphisms in donors with ACR incidence.

Genetic Variants of STAT-4 Affect the Development of Graft Fibrosis After Liver Transplantation for HCV-Induced Liver Disease

Hepatitis C virus (HCV) reinfection after liver transplantation may lead to recirrhosis and seems to be influenced by genetic factors. The aim of our study was to evaluate the role of STAT-4-polymorphisms in the development of HCV-related graft disease based on protocol biopsies. One hundred sixty transplant patients with HCV recurrence were genotyped for STAT-4 (rs7574865) by polymerase chain reaction. Fibrosis stages were determined based on Desmet and Scheuer classification. SPSS was used for the statistical analysis of genotype distribution and of time to the development of advanced fibrosis among the genotypes. During a comparable observation period of 86.2 months (P=0.654), 65 patients (46.5%) developed advanced fibrosis. Advanced fibrosis was observed significantly more frequent in patients (n=34) with at least one T-allele (53.1 vs. 32.3%; P=0.013) compared with homozygotes for G-allele (n=31). Significant differences in the duration of advanced fibrosis development were detected between patients with at least one T-allele compared with G-allele (34.4 vs. 49.0 months; P=0.022). No impact was observed regarding the outcome of interferon-based antiviral treatment (P=0.297) and the occurrence of acute cellular rejection (P=0.365). Present results indicate a possible impact of genetic confounders in the recipient on graft fibrogenesis, thus explaining significantly different graft behavior observed after transplantation for HCV-associated liver disease. STAT-4-T-allele is identified as fibrogenic factor and seems to have a negative impact on HCV-induced fibrosis development.

Genetic Variants of STAT-4 Affect the Development of Graft Fibrosisafter Liver Transplantation for HCV-Induced Liver Disease

Background: HCV-re-infection after liver transplantation may lead to re-cirrhosis and seems to be influenced by genetic factors. Aim of our study was to evaluate the role of STAT-4-polymorphisms in the development of HCV-related graft disease based on protocol biopsies. Methods: 160 transplant patients with HCV-recurrence were genotyped for STAT-4 (rs7574865) by polymerase chain reaction. Fibrosis stages were determined based on Desmet and Scheuer classification. SPSS was used for the statistical analysis of genotype distribution and of time to the development of advanced fibrosis among the genotypes. Results: During a comparable observation period of 86.2 (54.1) months (p=0.654), 65 (46.5%) patients developed advanced fibrosis. Advanced fibrosis was observed significantly more frequent in patients with at least one T-allele (n=64) compared to homozygotes (n=96) for G-allele (53.1% vs. 32.3%; p=0.013). Significant differences in the duration of advanced fibrosis development were detected between patients with at least one T-allele compared to G-allele (34.4 vs. 49.0 months; p=0.022). No impact was observed regarding the outcome of interferon-based antiviral treatment (p=0.297) and the occurrence of acute cellular rejection (p=0.365). Conclusion: Present results indicate a possible impact of genetic confounders in the recipient on graft fibrogenesis, thus explaining significantly different graft behavior observed after transplantation for HCV-associated liver disease. T-allele seems to have a negative impact on fibrosis development and further risk factors should be investigated.

Recipient Interleukin-28B Rs12979860 C/T Polymorphism and Acute Cellular Rejection After Liver Transplantation

Interleukin-28 (IL-28B) rs12979860 C/T polymorphism is known to predict the outcome of antiviral therapy in hepatitis C. In addition to its interferon-like and antiviral functions, IL-28B possesses the ability to modulate CD8 T cells function. This study aimed to investigate whether recipient IL-28B polymorphism may have a role in predicting the occurrence of acute cellular rejection (ACR) after liver transplantation (LT). Two hundred fifty-one consecutive LT recipients were enrolled. All the patients underwent per protocol liver biopsies at 1, 3, and 12 months after LT. ACR episodes in the first post-LT year were recorded and graded according to the Banff score. At least one moderate to severe (Banff score ≥ 5) ACR episode was reported in 75 patients (29.9%). ACR was associated with IL-28B polymorphism: C/C=21/102 (20.6%), C/T=43/126 (34.1%), and T/T=11/23 (47.8%) (P=0.003). At logistic regression analysis, IL-28B polymorphism was found to be a predictor of ACR (P=0.012) together with cytomegalovirus reactivation (P=0.023). The association between IL-28B polymorphism and ACR occurrence was evident in tacrolimus but not in cyclosporine-treated patients. ACR episodes occurred more frequently from hepatitis C virus (HCV) negatives carrying the IL-28B C/C genotype (17.8%) to HCV negatives carrying at least one T allele or HCV positives carrying at least one C allele (33.3%) to HCV positives carrying the T/T genotype (50.0%, P=0.002). HCV etiology in association with the carriage of IL-28B T/T genotype predicted the highest frequency of ACR. Recipient's IL-28B genotyping could be a useful tool in individualizing immunosuppressive therapy according to the risk of ACR occurrence.

Transforming growth factor β1 polymorphisms and progression of graft fibrosis after liver transplantation for hepatitis C virus--induced liver disease

Re-infection with the hepatitis C virus (HCV) is an important development after liver transplantation (LT); it can lead to graft fibrosis. The aim of this study was to assess the role of transforming growth factor β1 (TGF-β1) polymorphisms in the development of HCV-related graft disease by evaluating protocol liver biopsies. A total of 192 patients with a recurrence of HCV infection after LT were genotyped for TGF-β1 codon 10 (C→T) and codon 25 (G→C) using the polymerase chain reaction. Histological evaluation of 614 protocol liver biopsies obtained from these patients was undertaken using the classification of Desmet and Scheuer to stage the degree of fibrosis. Mild stages of fibrosis (0-2) were compared to advanced stages of fibrosis (3-4) that developed during the period of infection with the virus. Correlations between the prevalence of TGF-β1 genotypes and the different degrees of fibrosis that developed were determined. No statistically significant differences were found for genotype distributions (codons 10 and 25) with respect to recipient age, donor sex, occurrence of acute cellular rejection, and response to antiviral therapy. However, the C allele at codon 25 was significantly less frequent in the group with advanced fibrosis (P = 0.001). Furthermore, a positive association was found between progression of fibrosis and male recipient sex (P = 0.024), donor age (P = 0.041), and viral genotype 1b (P = 0.002). In conclusion, this study, in which the evolution of hepatic fibrosis was assessed histologically in a large cohort of patients with HCV re-infection after LT, has demonstrated that the C allele at codon 25 of the TGF-β1 gene is a marker for the development of graft fibrosis.

Relationship between the interleukin-28b gene polymorphism and the histological severity of hepatitis C virus-induced graft inflammation and the response to antiviral therapy after liver transplantation

Up to 30% of liver transplants will develop graft cirrhosis within 5 years after liver transplantation (LT) due to recurrent HCV-infection forwarding accelerated graft damage. Genetic variants of cytokines involved in the immune response may contribute to the degree of graft inflammation, fibrosis progression, and antiviral therapy outcome. The aim of our study was to analyze biochemical and histological inflammation extent based on protocol liver biopsies and to evaluate the role of genetic variants of IL-28b in HCV-related graft disease and antiviral treatment response. 183 patients, who underwent liver transplantation for HCV-induced liver disease, were genotyped for IL-28b (rs8099917, G ≥ T) by TaqMan Genotyping Assay. 56 of 159 patients have been successfully treated with interferon-based antiviral therapy. 605 protocol liver biopsies performed 0.5 to 10 and more than 10 years after transplantation were evaluated according to Desmet and Scheuer classification of inflammation and fibrosis. Prevalence of IL-28b-genotypes was correlated with histological severity of graft damage, levels of aminotransferases, occurrence of acute cellular rejection, pre-treatment viremia, and antiviral therapy outcome. Significant association of IL-28b-genotype distribution was observed to the median grade of inflammation (p < 0.001), mean levels of aminotransferases (ALT: p = 0.001, AST: p = 0.003), median pre-treatment viremia level within 1 year after LT (p = 0.046) and interferon-based antiviral therapy failure (p < 0.001). Among successfully treated patients, G-allele was significantly less frequent, and the genotype GG was not present at all. No differences were observed regarding acute cellular rejection (p = 0.798) and fibrosis stages (p = 0.586). IL-28b polymorphism seems to influence the degree of graft inflammation at biochemical and histological levels. G-allele might serve as a marker for graft inflammation and as a predictor for unfavorable antiviral therapy outcome in HCV-re-infected LT-population.

Impact of acute cellular rejection on coagulation and fibrinolysis biomarkers within the immediate post-operative period in pediatric liver transplantation

We studied restoration of the coagulation and fibrinolysis system in pediatric patients following liver transplantation and biomarkers of blood coagulation and fibrinolysis for suspecting the occurrence of acute cellular rejection. Coagulation activity recovered rapidly within two days following transplantation, but it took approximately 21-28 days for full recovery of the coagulation and fibrinolysis factors synthesized in the liver. PAI-1 levels were significantly higher in patients at the time of acute cellular rejection compared with levels after control of AR, and levels on days 14 and 28 in patients without AR. Plasma protein C and plasminogen levels at the time of rejection were significantly lower than those on day 14 in patients without AR. Statistical analysis suggested that an increase in plasma PAI-1 at a single time point in the post-operative period is a reliable marker among the coagulation and fibrinolysis factors for suspecting the occurrence of acute cellular rejection. These data suggested that appropriate anticoagulation may be required for 14 days after liver transplantation in order to avoid vascular complications and measurement of plasma PAI-1 levels may be useful for suspecting the occurrence of acute cellular rejection in pediatric patients following liver transplantation.