Post-Transplant Immunosuppression in Autoimmune Liver Disease.

Autoimmune liver diseases (AILDs) are a group of conditions where immune-mediated liver damage can lead to the need for transplantation. Collectively, they account for almost a quarter of all liver transplants. Outcomes in terms of graft and patient survival for all liver transplants have improved markedly over decades with improvements in patient selection, surgical techniques and longer-term care and this is also seen in patients with AILDs. The current five- and ten-year survival rates post-transplant in autoimmune disease are excellent, at 88% and 78%, respectively. A key factor in maintaining good outcomes post liver transplant for these autoimmune conditions is the immunosuppression strategy. These patients have increased the rates of rejection, and autoimmune conditions can all recur in the graft ranging from 12 to 60% depending on the population studied. Immunosuppressive regimens are centred on calcineurin inhibitors, often combined with low dose corticosteroids, with or without the addition of antimetabolite therapy. There is no clear evidence-based immunosuppressive regimen for these conditions, and a tailored approach balancing the individuals' immunological profile against the risks of immunosuppression is often used. There are disease-specific considerations to optimised graft function including the role of ursodeoxycholic acid in both primary biliary cholangitis and primary sclerosing cholangitis and the role and timing of colectomy in primary sclerosing cholangitis in inflammatory bowel disease patients. However, unmet needs still exist in the management of AILDs post liver transplantation particularly in building the evidence base for optimal immunosuppression as well as mitigating the risk of recurrent disease.

Inflammatory conditions play a role in recurrence of PSC after liver transplantation: An international multicentre study.

Background & Aims: Liver transplantation (LT) for primary sclerosing cholangitis (PSC) is complicated by recurrence of PSC (rPSC) in up to 25% of recipients. Recurrence has been shown to be detrimental for both graft and patient survival. For both PSC and rPSC, a medical cure is not available. To predict and ideally to prevent rPSC, it is imperative to find risk factors for rPSC that can be potentially modified. Therefore, we aimed to identify such factors for rPSC in a large international multicentre study including 6 centres in PSC-prevalent countries. Methods: In this international multicentre, retrospective cohort study, 531 patients who underwent transplantation for PSC were included. In 25% of cases (n = 131), rPSC was diagnosed after a median follow-up of 6.72 (3.29-10.11) years post-LT. Results: In the multivariable competing risk model with time-dependent covariates, we found that factors representing an increased inflammatory state increase the risk for rPSC. Recurrent cholangitis before LT as indication for LT (hazard ratio [HR] 3.6, 95% CI 2.5-5.2), increased activity of inflammatory bowel disease after LT (HR 1.7, 95% CI 1.08-2.75), and multiple acute cellular rejections (HR: non-linear) were significantly and independently associated with an increased risk of rPSC. In contrast to the findings of previous studies, pretransplant colectomy was not found to be independently protective against the development of rPSC. Conclusions: An increased inflammatory state before and after LT may play a causal and modifiable role in the development of rPSC. Pretransplant colectomy did not reduce the risk of rPSC per se. Recurrent cholangitis as indication for LT was associated with an increased risk of rPSC. Impact and implications: Recurrence of PSC (rPSC) negatively affects survival after liver transplant (LT). Modifiable risk factors could guide clinical management and prevention of rPSC. We demonstrate that an increased inflammatory state both before and after LT increases the incidence of rPSC. As these are modifiable factors, they could serve as targets for future studies and therapies. We also added further evidence to the ongoing debate regarding preventive colectomy for rPSC by reporting that in our multicenter study, we could not find an independent association between colectomy and risk of rPSC.

Does mucosal inflammation drive recurrence of primary sclerosing cholangitis in liver transplantion recipients with ulcerative colitis?

BACKGROUND: Liver transplantation remains the only effective evidence based treatment for advanced primary sclerosing cholangitis. However, recurrence of disease occurs in approximately 18%. AIMS: This study aimed to assess risk factors of recurrence of primary sclerosing cholangitis. METHODS: A retrospective cohort study was performed on patients undergoing transplantation for recurrence of primary sclerosing cholangitis in two academic centers (Leuven, Belgium and Leiden, The Netherlands). Besides other risk factors, the degree of mucosal inflammation was assessed as a potential risk factor using histological Geboes scores. RESULTS: 81 patients were included, of which 62 (76.5%) were diagnosed with ulcerative colitis. Seventeen patients (21.0%) developed rPSC during a median follow-up time of 5.2 years. In a subset of 42 patients no association was found between the degree of mucosal inflammation and recurrence, using both original Geboes scores and multiple cut-off points. In the total cohort, cytomegaloviremia post-transplantation (HR: 4.576, 95%CI 1.688-12.403) and younger receiver age at time of liver transplantation (HR: 0.934, 95%CI 0.881-0.990) were independently associated with an increased risk of recurrence of disease. CONCLUSION: This study found no association between the degree of mucosal inflammation and recurrence of primary sclerosing cholangitis. An association with recurrence was found for cytomegaloviremia post-liver transplantation and younger age at time of liver transplantation.

PCR-Based Sequence Analysis on Multiple Genes Other than 16S rRNA Gene for Differentiation of Phytoplasmas.

Differentiation and classification of phytoplasmas have been primarily based on the highly conserved 16S rRNA gene, for which "universal" primers are available. To date, 36 ribosomal (16Sr) groups and more than 150 subgroups have been delineated by RFLP analysis of 16S rRNA gene sequences. However, in recent years, the use of moderately conserved genes as additional genetic markers has enhanced the resolving power in delineating distinct phytoplasma strains among members of some 16Sr subgroups.This chapter describes the methodology of amplification, differentiation, and classification of phytoplasma based on less-conserved non-ribosomal genes, named rp and secY. Actual and virtual RFLP analyses of amplicons obtained by semi-universal or group-specific rp and secY gene-based primers are used for finer differentiation of phytoplasma strains within a given group. The rp and secY gene-based classification not only readily resolves 16Sr subgroups within a given 16Sr group, but also provides finer differentiation of closely related phytoplasma strains within a given 16Sr subgroup.