Bert-Jan F. de Rooij

Lectin complement pathway gene profile of donor and recipient determine the risk of bacterial infections after orthotopic liver transplantation

Infectious complications after orthotopic liver transplantation (OLT) are a major clinical problem. The lectin pathway of complement activation is liver‐derived and a crucial effector of the innate immune defense against pathogens. Polymorphisms in lectin pathway genes determine their functional activity. We assessed the relationship between these polymorphic genes and clinically significant bacterial infections, i.e., sepsis, pneumonia, and intra‐abdominal infection, and mortality within the first year after OLT, in relation to major risk factors in two cohorts from different transplant centers. Single‐nucleotide polymorphisms in the mannose‐binding lectin gene (MBL2), the ficolin‐2 gene (FCN2), and the MBL‐associated serine protease gene (MASP2) of recipients and donors were determined. Recipients receiving a donor liver in the principal cohort with polymorphisms in all three components i.e., MBL2 (XA/O; O/O), FCN2+6359T, and MASP2+371A, had a cumulative risk of an infection of 75% as compared to 18% with wild‐type donor livers (P = 0.002), an observation confirmed in the second cohort (P = 0.04). In addition, a genetic (mis)match between donor and recipient conferred a two‐fold higher infection risk for each separate gene. Multivariate Cox analysis revealed a stepwise increase in infection risk with the lectin pathway gene profile of the donor (hazard ratio = 4.52; P = 8.1 × 10−6) and the donor‐recipient (mis)match genotype (hazard ratio = 6.41; P = 1.9 × 10−7), independent from the other risk factors sex and antibiotic prophylaxis (hazard ratio > 1.7 and P < 0.02). Moreover, patients with a lectin pathway gene polymorphism and infection had a six‐fold higher mortality (P = 0.9 × 10−8), of which 80% was infection‐related. Conclusion: Donor and recipient gene polymorphisms in the lectin complement pathway are major determinants of the risk of clinically significant bacterial infection and mortality after OLT. (HEPATOLOGY 2010;)

Mannose-binding lectin and Ficolin-2 gene polymorphisms predispose to cytomegalovirus (re)infection after orthotopic liver transplantation

BACKGROUND & AIMS The lectin pathway of complement activation is a crucial effector cascade of the innate immune response to pathogens. Cytomegalovirus (CMV) infection occurs frequently in immunocompromised patients after orthotopic liver transplantation (OLT). Single-nucleotide polymorphisms (SNPs) in the lectin pathway genes determine their liver-derived protein level and functional activity. We examined the association between these SNPs and the risk for CMV infection in OLT. METHODS OLT patients (n = 295) were genotyped for recipient and donor SNPs in mannose-binding lectin (MBL2), Ficolin-2 (FCN2) and MBL-associated serine protease (MASP2) genes. RESULTS Combined analysis of independently associated variant MBL2 [HR 1.65, p<0.02] and wild-type FCN2 [1.85; p<0.02] SNPs in the donor liver showed an increased risk of CMV infection for either and both risk genotypes [HR 2.02 and HR 3.26, respectively, p = 0.004], especially in CMV Donor-/Recipient+ (D-/R+) patients [HR 4.7 and HR 10.0, respectively, p = 0.01]. A genetic donor-recipient mismatch for MBL2 and FCN2 increased the CMV risk independently, also combined [HR 5.35; p<0.001], particularly in CMV D-/R+ patients [HR 16.6; p = 0.009]. Multivariate Cox analysis showed a consistent stepwise increase in CMV infection risk with the gene profile of the donor [up to HR 2.77; p<0.005] and the combined MBL2 and FCN2 donor-recipient mismatch profile [up to HR 4.57; p<0.001], independent from donor-recipient CMV serostatus, also at higher CMV (re)infection cut-off values. CONCLUSIONS MBL2 and FCN2 risk alleles of donor liver and recipient constitute independent risk factors for CMV infection after OLT. Patients with these risk genes probably need intensified CMV monitoring and anti-viral therapy.

Risk factors for infection after liver transplantation

Infection is a common cause of morbidity and mortality after liver transplantation. Risk factors relate to transplantation factors, donor and recipient factors. Transplant factors include ischaemia-reperfusion damage, amount of intra-operative blood transfusion, level and type of immunosuppression, rejection, and complications, prolonged intensive care stay with dialysis or ventilation, type of biliary drainage, repeat operations, re-transplantation, antibiotics, antiviral regimen, and environment. Donor risk factors include infection, prolonged intensive care stay, quality of the donor liver (e.g. steatosis), and viral status. For the recipient the most important are MELD score >30, malnutrition, renal failure, acute liver failure, presence of infection or colonisation, and immune status for viruses like cytomegalovirus. In recent years it has become clear that genetic polymorphisms in innate immunity, especially the lectin pathway of complement activation and in Toll-like receptors importantly contribute to the infection risk after liver transplantation. Therefore, the risk for infections after liver transplantation is a multifactorial problem and all factors need attention to reduce this risk.

Matrix metalloproteinase 2 genotype is associated with nonanastomotic biliary strictures after orthotopic liver transplantation.

Background: Nonanastomotic biliary strictures (NAS) are a serious complication after orthotopic liver transplantation (OLT). Matrix metalloproteinases (MMPs) are involved in connective tissue remodelling in chronic liver disease and complications after OLT.

High peak alanine aminotransferase determines extra risk for nonanastomotic biliary strictures after liver transplantation with donation after circulatory death

Orthotopic liver transplantation (OLT) with donation after circulatory death (DCD) often leads to a higher first week peak alanine aminotransferase (ALT) and a higher rate of biliary nonanastomotic strictures (NAS) as compared to donation after brain death (DBD). This retrospective study was to evaluate whether an association exists between peak ALT and the development of NAS in OLT with livers from DBD (n = 399) or DCD (n = 97) from two transplantation centers. Optimal cutoff value of peak ALT for risk of development of NAS post‐DCD‐OLT was 1300 IU/l. The 4‐year cumulative incidence of NAS after DCD‐OLT was 49.5% in patients with a high ALT peak post‐OLT, compared with 11.3% in patients with a low ALT peak. (P < 0.001). No relation between peak ALT and NAS was observed after DBD‐OLT. Multivariate analysis revealed peak ALT ≥1300 IU/l [adjusted hazard ratio (aHR) = 3.71, confidence interval (CI) (1.26–10.91)] and donor age [aHR = 1.04, CI 1.00–1.07] to be independently associated with development of NAS post‐DCD‐OLT. A peak ALT of <1300 IU/l carries a risk for NAS similar to DBD‐OLT. Thus, in DCD‐OLT, but not in DBD‐OLT, peak ALT discriminates patients at high or low risk for NAS.

MMP-2 is a disease-modifying gene in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the bile ducts, frequently necessitating orthotopic liver transplantation (OLT), often accompanied by inflammatory bowel disease (IBD). Matrix metalloproteinases (MMPs) are associated with fibrotic diseases caused by the involvement in tissue remodelling.

MMP-2 and MMP-9 Serum Levels Change but their Gene Promoter Polymorphisms are not Associated with Late Phase I/R Injury or Rejection after Orthotopic Liver Transplantation

Introduction. Matrix metalloproteinases (MMPs) are involved in connective tissue remodeling processes asso- ciated with chronic liver disease and complications after orthotopic liver transplantation (OLT). Genetic variations in the promoter region of the MMP-2 and MMP-9 genes are thought to contribute not only to their transcription rate but may also have predisposing clinical impact. Methods. MMP-2 and MMP-9 gene promoter polymorphisms were analyzed in 109 patients who underwent an OLT. The relationship between these MMP polymorphisms in the donor and recipient DNA with the development of ische- mia/reperfusion (I/R) injury and rejection after OLT was evaluated. In addition, serum MMP-2 and MMP-9 levels were determined to illustrate potential phenotypical consequences in these patients. Results. The MMP-2 and -9 genotypes of the donor and recipient or a donor/recipient mismatch and chimerism were not associated with the development of late phase I/R injury or rejection in the OLT patients, although serological differences in the MMP levels did occur. The MMP-2 and -9 genotype distribution did also not have a major impact on the respective serum levels in patients that underwent an OLT. Conclusions. MMP-2 and MMP-9 gene polymorphisms do not seem to contribute to late phase I/R injury or rejection after liver transplantation. Serological changes in the MMP-2 and MMP-9 levels appear to occur independent of the MMP genotype after transplantation of the liver.

Recipient's Genetic R702W NOD2 Variant Is Associated with an Increased Risk of Bacterial Infections after Orthotopic Liver Transplantation

Introduction Orthotopic liver transplantation (OLT) is accompanied by a significant postoperative infection risk. Immunosuppression to prevent rejection increases the susceptibility to infections, mainly by impairing the adaptive immune system. Genetic polymorphisms in the lectin complement pathway of the donor have recently been identified as important risk determinants of clinically significant bacterial infection (CSI) after OLT. Another genetic factor involved in innate immunity is NOD2, which was reported to be associated with increased risk of spontaneous bacterial peritonitis in cirrhotic patients. Methods We assessed association of three genetic NOD2 variants (R702W, G908R and 3020insC) with increased risk of CSI after OLT. 288 OLT recipient-donor pairs from two tertiary referral centers were genotyped for the three NOD2 variants. The probability of CSI in relation to NOD2 gene variants was determined with cumulative incidence curves and log-rank analysis. Results The R702W NOD2 variant in the recipient was associated with CSI after OLT. Eight out of 15 (53.3%) individuals with a mutated genotype compared to 80/273 (29.3%) with wild type genotype developed CSI (p=0.027, univariate cox regression), illustrated by a higher frequency of CSI after OLT over time (p=0.0003, log rank analysis). Multivariate analysis (including the donor lectin complement pathway profile) showed independence of this R702W NOD2 association from other risk factors (HR 2.0; p=0.04). The other NOD2 variants, G908R and 3020insC, in the recipient were not associated with CSI. There was no association with CSI after OLT for any of the NOD2 variants in the donor. Conclusion The mutated NOD2 R702W genotype in the recipient is independently associated with an increased risk of bacterial infections after liver transplantation, indicating a predisposing role for this genetic factor impairing the recipient’s innate immune system.

Sequential Liver Chemistry Profiling and Abdominal Ultrasound Assessments to Predict Biliary Strictures after Liver Transplantation

Background: After orthotopic liver transplantation (OLT) early detection of biliary strictures is important. Our aim was to evaluate the predictive value of routine serum liver chemistry profiling and abdominal ultrasound as non- invasive diagnostic tools in detecting biliary strictures after OLT. Methods: We performed a retrospective study in which 141 primary OLTs, performed between 1992 and 2007 with more than 1 year follow-up, were included. Routinely assessed serum levels of alkaline phosphatase, alanine-aminotransferase, aspartate-aminotransferase, gamma-glutamyl transpeptidase and bilirubin at 3, 6, 9 and 12 months, and abdominal ultrasounds performed at 3, 6 and 12 months after OLT were evaluated. All biliary strictures requiring intervention occurring after 3 months were included. Time-dependent Cox regression analysis was performed to identify predictive factors for the development of biliary strictures. Results: Eighteen grafts developed non-anastomotic strictures (12.8%) and 18 grafts (12.8%) developed anastomotic strictures requiring intervention. An elevated gamma-glutamyl transpeptidase (HR 1.24 per 100 IU/L; p = 0.05) and dilated bile ducts on ultrasound (HR 3.45; p < 0.01) were found to have an independent predictive value for the development of biliary strictures requiring intervention. Bilirubin and the other studied liver enzymes were not independently predictive. Conclusion: Dilated bile ducts on ultrasound and elevated gamma-glutamyltranspeptidase after OLT are independent predictive factors for the development of biliary strictures requiring intervention. Routine assessment by serum gGT and US at 3-month intervals during the first year post-OLT is useful to screen for biliary strictures post-OLT.

337 Donor and Recipient Lectin Complement Pathway Genes Determine the Risk of Clinically Significant Infections After Orthotopic Liver Transplantation

Donor and Recipient Lectin Complement Pathway Genes Determine the Risk of Clinically Significant Infections After Orthotopic Liver Transplantation Bert-Jan F. de Rooij, Bart van Hoek, Rogier W. Ten Hove, Anja Roos, Lee H. Bouwman, Alexander F. Schaapherder, Robert J. Porte, Mohamed R. Daha, Johan J. van der Reijden, Minneke J. Coenraad, Jan Ringers, Andrzej G. Baranski, Bouke Hepkema, Daniel W. Hommes, Hein W. Verspaget