Outcome of Extended Right Lobe Liver Transplantations.

Split-liver transplantation offers a solution to the organ shortage problem. However, the outcomes of extended right lobe liver transplantation (ERLT) and whether it is a suitable alternative to full-size liver transplantation (FSLT) remain controversial. We compared the outcomes of ERLT and FSLT in adult recipients of 43,409 first deceased donor liver transplantations using Cox regression. We also analyzed 612 ERLT and 1224 FSLT 1:2 matched cases to identify factors that affect ERLT outcome. The risk of graft loss was significantly higher following ERLT than following FSLT during the first posttransplantation year in the matched and unmatched collective (hazard ratio [HR], 1.39 and 1.27 and P = 0.01 and 0.006, respectively). Every additional hour of cold ischemia time (CIT) increased the risk of 1-year graft loss by 10% in the ERLT group compared with only 3% in the FSLT group (P = 0.003 and <0.001, respectively). Importantly, the outcome of ERLT and FSLT did not differ significantly if the CIT was below 10 hours (HR, 0.71; P = 0.22). One-year graft and patient survival were lower in high-risk ERLT recipients with a Model for End-Stage Liver Disease (MELD) score of ≥20 (HR, 1.88; P = 0.03 and HR, 2.03; P = 0.02). In the male recipient-male donor combination, ERLT recipients had a higher risk of 1-year graft loss than FSLT recipients (HR, 2.44; P = 0.006). This was probably because of the significantly higher MELD score in ERLT recipients (P = 0.004). ERLT in adults is an adequate alternative to FSLT and offers an elegant solution to the problem of organ shortage as long as the cold storage is less than 10 hours and the recipient's MELD score is <20.

Should kidney allografts from old donors be allocated only to old recipients?

In several deceased donor kidney allocation systems, organs from elderly donors are allocated primarily to elderly recipients. The Eurotransplant Senior Program (ESP) was implemented in 1999, and since then, especially in Europe, the use of organs from elderly donors has steadily increased. The proportion of ≥60-year-old donors reported to the Collaborative Transplant Study (CTS) by European centers has doubled, from 21% in 2000-2001 to 42% in 2016-2017. Therefore, in the era of organ shortage it is a matter of debate whether kidney organs from elderly donors should only be allocated to elderly recipients or whether <65-year-old recipients can also benefit from these generally as "marginal" categorized organs. To discuss this issue, a European Consensus Meeting was organized by the CTS on April 12, 2018, in Heidelberg, in which 36 experts participated. Based on available evidence, it was unanimously concluded that kidney organs from 65- to 74-year-old donors can also be allocated to 55- to 64-year-old recipients, especially if these organs are from donors with no history of hypertension, no increased creatinine, no cerebrovascular death, and no other reasons for defining a marginal donor, such as diabetes or cancer.

Progressive improvement in short-, medium- and long-term graft survival in kidney transplantation patients in Ireland - a retrospective study.

It is often quoted that while short-term graft survival in kidney transplantation has improved in recent years, it has not translated into a commensurate improvement in long-term graft survival. We considered whether this was true of the entire experience of the national kidney transplant program in Ireland. A retrospective analysis of the National Kidney Transplant Service (NKTS) database was undertaken to investigate patient and graft survival for all adult first deceased donor kidney transplant recipients in Ireland, 1971-2015. Three thousand two hundred and sixty recipients were included in this study. Kaplan-Meier methods were used to estimate survival at each time period post transplant for the various eras of transplantation. Uncensored graft survival has improved over the course of the program in Ireland at various time points despite risk factors for graft failure progressively increasing over successive eras. For example the graft survival at 15 years post transplant has increased from 10% in 1971-1975 to 45% by 1996-2000. Ireland has experienced a progressive improvement in long-term graft survival following kidney transplantation. Whether these trends are attributable to biological or nonbiological factors is unclear but likely involves a combination of both.

Immunosuppression with mammalian target of rapamycin inhibitor and incidence of post-transplant cancer in kidney transplant recipients.

BACKGROUND: Evidence is limited regarding the effect of de novo therapy with mammalian target of rapamycin (mTOR) inhibitors on cancer risk after kidney transplantation. METHODS: Collaborative Transplant Study data from 78 146 adult recipients of first deceased-donor kidney transplants (1999-2013) were analysed (4279 mTOR inhibitor, 73 867 no mTOR inhibitor) using standard methods. Propensity score matching was performed for analysis of basal cell and squamous cell skin cancer. RESULTS: Standardized incidence ratios (SIR) versus a matched non-transplant population showed reduced tumour incidence in recipients with de novo mTOR inhibitor therapy compared with no mTOR inhibitor for non-melanoma skin cancer (NMSC) (SIR 5.1 versus 6.1; P =0.019) but not non-NMSC cancers (SIR 1.6 versus 1.7; P =0.35). Within propensity score-matched groups (n = 4265), multivariable Cox regression analysis showed a trend to reduced NMSC with mTOR inhibition [hazard ratio (HR) 0.77; P =0.063] but not for all non-NMSC tumours (HR 0.94; P= 0.59). A significant effect for mTOR inhibition was observed for basal cell carcinoma of the skin (HR 0.56; P= 0.004) but not squamous cell carcinoma (HR 0.87; P= 0.54). CONCLUSIONS: De novo mTOR inhibition was associated with a substantially and significantly reduced risk of basal cell carcinoma of the skin after kidney transplantation. A significant reduction of the incidence of other cancers was not found.

Efficacy and safety of antibody induction therapy in the current era of kidney transplantation.

BACKGROUND: Antibody induction with polyclonal rabbit-antithymocyte globulin (rATG) or an interleukin-2 receptor antagonist (IL-2RA) is widely used in kidney transplantation. METHODS: Collaborative Transplant Study data from 38 311 first deceased-donor kidney transplants (2004-13) were analysed. Transplants were classified as 'normal risk' or 'increased risk' according to current guidelines. Cox regression analysis was applied to subpopulations of propensity score-matched recipients. RESULTS: rATG or IL-2RA induction was given to 64% of increased-risk and 53% of normal-risk patients, respectively. rATG and IL-2RA induction were each associated with reduced risk for graft loss versus no induction in increased-risk patients [hazard ratio (HR) 0.85, P = 0.046 and HR 0.89, P = 0.011, respectively]. The HR values for incidence of treated rejection in increased-risk patients for rATG and IL-2RA versus no induction were 0.75 (P = 0.037) and 0.77 (P < 0.001), respectively. In the normal risk subpopulation, neither induction therapy significantly affected the risk of graft loss or treated rejection. Hospitalization for infection was increased by rATG (P < 0.001) and IL-2RA (P < 0.001) induction. In contrast to patients transplanted during 1994-2003, among patients transplanted during 2004-13, rATG did not significantly affect the risk of non-Hodgkin's lymphoma versus no induction (P = 0.68). CONCLUSION: Induction therapy following kidney transplantation should be targeted to increased-risk transplants. In this analysis, a beneficial effect of antibody induction in normal-risk transplants could not be demonstrated.

Personalized treatment supported by automated quantitative fluid analysis in active neovascular age-related macular degeneration (nAMD)-a phase III, prospective, multicentre, randomized study: design and methods.

INTRODUCTION: In neovascular age-related macular degeneration (nAMD) the exact amount of fluid and its location on optical coherence tomography (OCT) have been defined as crucial biomarkers for disease activity and therapeutic decisions. Yet in the absence of quantitative evaluation tools, real-world care outcomes are disappointing. Artificial intelligence (AI) offers a practical option for clinicians to enhance point-of-care management by analysing OCT volumes in a short time. In this protocol we present the prospective implementation of an AI-algorithm providing automated real-time fluid quantifications in a clinical real-world setting. METHODS: This is a prospective, multicentre, randomized (1:1) and double masked phase III clinical trial. Two-hundred-ninety patients with active nAMD will be randomized between a study arm using AI-supported fluid quantifications and another arm using conventional qualitative assessments, i.e. state-of-the-art disease management. The primary outcome is defined as the mean number of injections over 1 year. Change in BCVA is defined as a secondary outcome. DISCUSSION: Automated measurement of fluid volumes in all retinal compartments such as intraretinal fluid (IRF), and subretinal fluid (SRF) will serve as an objective tool for clinical investigators on which to base retreatment decisions. Compared to qualitative fluid assessment, retreatment decisions will be plausible and less prone to error or large variability. The underlying hypothesis is that fluid should be treated, while residual persistent or stable amounts of fluid may not benefit from further therapy. Reducing injection numbers without diminishing the visual benefit will increase overall patient safety and relieve the burden for healthcare providers. TRIAL-REGISTRATION: EudraCT-Number: 2019-003133-42.

Can PIRCHE-II Matching Outmatch Traditional HLA Matching?

We analyzed in a cohort of 68,606 first deceased donor kidney transplantations reported to the Collaborative Transplant Study whether an epitope-based matching of donor-recipient pairs using the Predicted Indirectly ReCognizable HLA Epitopes algorithm (PIRCHE-II) is superior to currently applied HLA antigen matching. PIRCHE-II scores were calculated based on split antigen HLA-A, -B, -DRB1 typing and adjusted to the 0-6 range of HLA mismatches. PIRCHE-II scores correlated strongly with the number of HLA mismatches (Spearman ρ = 0.65, P < 0.001). In multivariable analyses both parameters were found to be significant predictors of 5-year death-censored graft loss with high prognostic power [hazard ratio (HR) per adjusted PIRCHE-II score = 1.102, per HLA mismatch = 1.095; z-value PIRCHE-II: 9.8, HLA: 11.2; P < 0.001 for both]. When PIRCHE-II scores and HLA mismatches were analyzed simultaneously, their predictive power decreased but remained significant (PIRCHE-II: P = 0.002; HLA: P < 0.001). Influence of PIRCHE-II was especially strong in presensitized and influence of HLA mismatches in non-sensitized recipients. If the level of HLA-incompatibility was low (0-3 mismatches), PIRCHE-II scores showed a low impact on graft survival (HR = 1.031) and PIRCHE-II matching did not have additional significant benefit (P = 0.10). However, if the level of HLA-incompatibility was high (4-6 mismatches), PIRCHE-II improved the positive impact of matching compared to applying the traditional HLA matching alone (HR = 1.097, P = 0.005). Our results suggest that the PIRCHE-II score is useful and can be included into kidney allocation algorithms in addition to HLA matching; however, at the resolution level of HLA typing that is currently used for allocation it cannot fully replace traditional HLA matching.

Rare Malignant Indications for Liver Transplantation: A Collaborative Transplant Study Report.

Introduction: Hepatocellular carcinoma (HCC) is by far the leading malignant indication for liver transplantation (LT). Few other malignancies, including cholangiocellular carcinoma (CCC), metastases from neuroendocrine tumors (NET), and sarcomas of the liver (LSAR), also are commonly accepted indications for LT. However, there is limited information on their outcome after LT. Methods: Graft and patient survival in 14,623 LTs performed in patients with hepatocellular carcinoma, CCC, NET, and LSAR from 1988 to 2017 and reported to the Collaborative Transplant Study were analyzed. Results: The study group consisted of 13,862 patients who had HCC (94.8%), 498 (3.4%) who had CCC, 100 (0.7%) who had NET, and 163 (1.1%) who had LSAR. CCC patients showed a 5-year graft survival rate of 32.1%, strikingly lower than the 63.2% rate in HCC, 51.6% rate in NET, and 64.5% rate in LSAR patients (P < 0.001 for all vs. CCC). Multivariable Cox regression analysis revealed a significantly higher risk of graft loss and death due to cancer during the first five post-transplant years in CCC vs. HCC patients (HR 1.77 and 2.56; P < 0.001 for both). The same risks were increased also in NET and LSAR patients but did not reach statistical significance. Conclusion: Among patients with rare malignant indications for LT, CCC patients showed significantly impaired graft as well as patient survival compared to HCC patients. The observed differences might challenge traditional decision-making processes for LT indication and palliative treatment in specific hepatic malignancies.

Analysis of de novo donor-specific HLA-DPB1 antibodies in kidney transplantation.

HLA matching and avoidance of unacceptable mismatches are important aspects in the selection of donors for solid organ transplantation. The impact of HLA-DPB1 incompatibility on the outcomes of kidney transplantation is not fully understood. We investigated a potential effect of mismatching for HLA-DPB1 at allele, eplet, or Terasaki epitope (TerEp) level on the formation of de novo donor-specific antibodies (dnDSA) and also asked whether polymorphisms associated with HLA-DPB1 expression level may influence dnDSA induction. Furthermore, we analyzed the correlation between graft survival and HLA-DPB1 mismatches defined by different approaches. A cohort of 366 patients who received a kidney transplant at the Heidelberg University Hospital, Germany, with availability of pre- and post-transplant HLA antibody results by single antigen testing as well as of donor and recipient HLA-DPB1 high-resolution typing were analyzed retrospectively. Susceptibility to increased HLA-DPB1 expression was predicted by the linked dimorphism rs9277534 A/G of the HLA-DPB1 gene. Neither HLA-DPB1 mismatches at allele, eplet or TerEp level nor exposure to donor's high HLA-DPB1 expression were significantly associated with the risk of developing dnDSA against HLA-DPB1. However, HLA-DPB1 eplet and TerEp mismatches had a significant negative impact on graft survival (p < 0.001 and p = 0.003, respectively). Matching for HLA-DPB1 at epitope instead of allele level appears to have potential to improve graft survival in kidney transplantation.

Critical evaluation of a possible role of HLA epitope matching in kidney transplantation.

Human leukocyte antigen (HLA) matching is one of the cornerstones of organ allocation in deceased-donor kidney transplantation. Increased numbers of HLA allele mismatches are associated with a higher risk of immunological rejection, de novo donor-specific HLA antibody development and graft failure. HLA epitopes are defined as the specific portions of HLA molecules to which antibodies and T-cell receptors bind with their paratopes. The same epitope can be present on different HLA alleles. Therefore, HLA matching at the epitope instead of allele level theoretically offers a more precise assessment of donor-recipient HLA compatibility and may more effectively prevent sensitization against foreign tissue. In this review, we describe the different options proposed to define clinically relevant HLA epitopes and critically discuss the potential role of HLA epitope matching in kidney transplantation.

Pretransplant Cancer in Kidney Recipients in Relation to Recurrent and De Novo Cancer Incidence Posttransplantation and Implications for Graft and Patient Survival.

BACKGROUND: Whether kidney transplant recipients who were treated for a malignant tumor before transplantation are at an increased risk of developing a tumor posttransplantation has not been adequately quantified and characterized. METHODS: We studied more than 270 000 patients on whom pretransplant and posttransplant malignancy data were reported to the Collaborative Transplant Study. More than 4000 of these patients were treated for pretransplant malignancy. The posttransplant tumor incidence in these patients was compared to that in recipients without a pretransplant tumor. Cox regression, considering multiple confounders, was applied. RESULTS: Significant increases in posttransplant tumor incidence with hazard ratio ranging from 2.10 to 5.47 (all P < 0.001) were observed for tumors in the site-specific pretransplant locations, suggesting tumor recurrences. There were also significantly increased de novo tumors in new locations with hazard ratio ranging from 1.28 to 1.89. Pretransplant basal cell carcinoma of the skin and male genital cancer were associated with significantly increased death-censored graft survival, suggesting impaired immune responsiveness against transplanted kidneys. Time interval from pretransplant tumor occurrence to transplantation and posttransplant mammalian target of rapamycin inhibitor treatment was not found to be of significant relevance in this study. CONCLUSIONS: Patients who experienced a pretransplant tumor are at significant risk of tumor recurrence, regardless of the length of interval between tumor treatment and transplantation. There is also some increased risk for de novo tumors, suggesting impaired immune surveillance. Impaired tumor immunity appears to extend to a lower rate of transplant rejection because patients with pretransplant tumors tended to show improved death-censored graft survival.

Hematopoietic-Extrinsic Cues Dictate Circadian Redistribution of Mature and Immature Hematopoietic Cells in Blood and Spleen.

Circadian oscillations in circulating leukocyte subsets including immature hematopoietic cells have been appreciated; the origin and nature of these alterations remain elusive. Our analysis of wild-type C57BL/6 mice under constant darkness confirmed circadian fluctuations of circulating leukocytes and clonogenic cells in blood and spleen but not bone marrow. Clock gene deficient Bmal1-/- mice lacked this regulation. Cell cycle analyses in the different hematopoietic compartments excluded circadian changes in total cell numbers, rather favoring shifting hematopoietic cell redistribution as the underlying mechanism. Transplant chimeras demonstrate that circadian rhythms within the stroma mediate the oscillations independently of hematopoietic-intrinsic cues. We provide evidence of circadian CXCL12 regulation via clock genes in vitro and were able to confirm CXCL12 oscillation in bone marrow and blood in vivo. Our studies further implicate cortisol as the conveyor of circadian input to bone marrow stroma and mediator of the circadian leukocyte oscillation. In summary, we establish hematopoietic-extrinsic cues as causal for circadian redistribution of circulating mature/immature blood cells.

Relevance of donor-specific antibody monitoring after kidney transplantation: Findings from the Collaborative Transplant Study and the Heidelberg Transplant Center.

Monitoring of donor-specific HLA antibodies (DSA) has become part of the clinical routine in kidney transplantation. This paper gives a brief overview on data from the Collaborative Transplant Study (CTS) and the Heidelberg Transplant Center on the clinical relevance of post-transplant DSA monitoring in patients undergoing renal transplantation. The obtained findings underline the importance of DSA monitoring in the post-operative course in immunologically high-risk patients and patients with deterioration of graft function. Especially in patients with a pre-activated immune system, a gap in the immunosuppressive therapy appear to lead to persistence, reappearance or de novo occurrence of strong, complement-activating DSA, resulting in severe antibody-mediated rejection (AMR) and, without timely intervention, in AMR-related graft loss.

Correction: Helios expression and Foxp3 TSDR methylation of IFNy+ and IFNy- Treg from kidney transplant recipients with good long-term graft function.

[This corrects the article DOI: 10.1371/journal.pone.0173773.].

Helios expression and Foxp3 TSDR methylation of IFNy+ and IFNy- Treg from kidney transplant recipients with good long-term graft function.

BACKGROUND: There is circumstantial evidence that IFNy+ Treg might have clinical relevance in transplantation. IFNy+ Treg express IFNy receptors and are induced by IFNy. In the present study we investigated in kidney transplant recipients with good long-term stable graft function the absolute cell counts of IFNy+ Treg subsets and whether their expression of Foxp3 is stable or transient. METHOD: Helios expression determined by eight-color-fluorescence flow cytometry and methylation status of the Foxp3 Treg specific demethylation region (TSDR) served as indicators for stability of Foxp3 expression. Methylation status was investigated in enriched IFNy+ and IFNy- Treg preparations originating from peripheral blood using high resolution melt analysis. A total of 136 transplant recipients and 52 healthy controls were studied. RESULTS: Proportions of IFNy+ Treg were similar in patients and healthy controls (0.05% and 0.04% of all CD4+ lymphocytes; p = n.s.). Patients also had similar absolute counts of IFNy producing Helios+ and Helios- Treg (p = n.s.). Most of the IFNy+ and IFNy- Treg in transplant recipients had a methylated Foxp3 TSDR, however, there was a sizeable proportion of IFNy+ and IFNy- Treg with demethylated Foxp3 TSDR. Male and female patients showed more frequently methylated IFNy+ and IFNy- Treg than male and female controls (all p<0.05). CONCLUSIONS: Kidney transplant recipients with good long-term stable graft function have similar levels of IFNy+ Treg as healthy controls. IFNy+ and IFNy- Treg subsets in patients consist of cells with stable and cells with transient Foxp3 expression; however, patients showed more frequently methylated IFNy+ and IFNy- Treg than controls. The data show increased levels of Treg subsets with stable as well as transient Foxp3 expression in patients with stable allograft acceptance compared to healthy controls.

IFNy+ and IFNy- Treg subsets with stable and unstable Foxp3 expression in kidney transplant recipients with good long-term graft function.

BACKGROUND: Treg are a heterogenous cell population. In the present study we attempted to identify Treg subsets that might contribute to stable and good long-term graft function. METHOD: Lymphocyte and Treg subsets were studied in 136 kidney transplant recipients with good long-term graft function and in 52 healthy control individuals using eight-color-fluorescence flow cytometry. Foxp3 TSDR methylation status was investigated in enriched IFNy+ and IFNy- Treg preparations using high resolution melt analysis. RESULTS: Compared with healthy controls, patients showed strong associations of IFNy secreting Helios+ and Helios- Treg with Treg that co-expressed perforin and/or CTLA4 (CD152; p<0.01). Moreover they showed associations of IFNy-Helios+ Treg with Treg that produced TGFß and/or perforin and of IFNy-Helios- Treg with TGFß production (all p<0.01). Only in patients, but not in healthy controls, were IFNy- Helios+ and Helios- Treg associated with higher CD45+, CD3+, (CD4+), CD19+ lymphocyte counts (p<0.001). In addition IFNy-Helios+ Treg were associated with CD16+56+ lymphocytes (p<0.001). Enriched IFNy- Treg from female but not male patients showed an association of Foxp3 methylation with higher total Treg and higher Helios+IFNy-, CXCR3+Lselectin+ (CD183+CD62L+), CXCR3-Lselectin+ and CD28+HLADR+ Treg subsets (p<0.01). Enriched IFNy+ Treg from male patients showed an association of demethylated Foxp3 with total Treg and IL10-TFGß+ Treg counts, and in enriched IFNy- Treg an association of methylated Foxp3 with APO1/FasR+FasL+ (CD95+CD178+) Treg (p<0.01). CONCLUSIONS: Kidney recipients with good long-term graft function possess IFNy+ and IFNy- Treg with stable and unstable Foxp3 expression in the blood. They co-express CD28, HLADR, CTLA4, CXCR3, Lselectin, TGFß, perforin and FasL and might contribute to the establishment and maintenance of good long-term graft function.

Deleterious impact of HLA-DRB1 allele mismatch in sensitized recipients of kidney retransplants.

BACKGROUND: Whether mismatches between donor and recipient of a kidney transplant at the HLA allele level can elicit an immune response strong enough to impact graft survival is not known. METHODS: We examined the influence of HLA-DRB1 allele level mismatch on graft survival based on high-resolution typing, utilizing blood samples and clinical data provided by the Collaborative Transplant Study. HLA-DRB1*04 was selected as a model for this investigation because it is the most common HLA-DRB1 allele group and consists of several alleles with relatively high frequencies, allowing for analysis of transplants matched at the antigen level but mismatched at the allele level. Nine hundred and ninety-six recipient/donor pairs were typed for HLA-DRB1 at high resolution. RESULTS: No effect of HLA-DRB1*04 allele mismatch was observed in first transplants. However, in retransplants, HLA-DRB1*04 allele mismatch was associated with significantly decreased graft survival, albeit only in sensitized (PRA>5%) patients (hazard ratio 3.98, P=0.014). CONCLUSION: Our finding reinforces the concept that HLA compatibility significantly influences the outcome of kidney transplants, in sensitized retransplant recipients even at the allele level.

The collaborative transplant study registry.

The Collaborative Transplant Study (CTS) was initiated in 1982. Over the last 30 years, it has collected information on over half a million kidney, liver, heart, lung, and pancreas transplant procedures. Participation is voluntary and the study has strictly scientific objectives. Analyses of the CTS database serve as an international reference source in the field of solid organ transplantation.