Outcomes of pregnancy in simultaneous pancreas and kidney transplant recipients: A single-center retrospective study.

Simultaneous pancreas and kidney (SPK) transplantation, in uremic women with insulin-dependent diabetes, increases the chance of a successful pregnancy and minimizes the risk to infants. The aim of this study was to document pregnancy and explore the challenges in this cohort of women. Retrospective analysis of women who underwent pancreas transplantation between January 1, 1998 and 8 January, 2019 was conducted. Seventeen pregnancies were identified in 13 women. Mean transplant-to-pregnancy interval was 4.6 years (range, 1.1-10.2 years). Eleven pregnancies resulted in live birth (65%), and six (35%) ended in miscarriage/fetal loss at a median gestational age of 8.5 weeks. Mean gestational age at delivery was 34.9 weeks (SD ±3 weeks). Preeclampsia and C-section rates were 77% and 67%, respectively. Adverse fetal and graft outcomes were observed in 100% of unplanned pregnancies, compared to 10% of planned pregnancies (P < .001). One kidney allograft was lost during pregnancy; one pancreas and two kidney allografts were lost within 3 years of pregnancy. This is a high-risk group for grafts and offspring. Pre-pregnancy planning is vital. A multidisciplinary approach by obstetric and transplant teams is important pre-pregnancy, antenatally, and peripartum. This is the largest published series of pregnancies in SPK recipients from a single center.

Pre-pregnancy counselling for women with chronic kidney disease: a retrospective analysis of nine years' experience.

BACKGROUND: Women with chronic kidney disease have an increased risk of maternal and fetal complications in pregnancy. Pre-pregnancy counselling is recommended but the format of the counselling process and the experience of the patient have never been assessed. This study examines the experience of women with chronic kidney disease attending pre-pregnancy counselling and evaluates their pregnancy outcomes. METHODS: This is a cross-sectional assessment of 179 women with chronic kidney disease attending a pre-pregnancy counselling clinic (2003-2011) with retrospective evaluation of aetiology, comorbidity, treatment and adverse pregnancy outcome compared with 277 hospital controls. It includes an analysis of descriptive data and free text content from 72 questionnaire responders. RESULTS: 65/72 (90%) of women found the clinic informative. 66 women (92%) felt that the consultation had helped them decide about pursuing pregnancy. 12 women (17%) found the multidisciplinary process intimidating. Free text comments supported the positive nature of the counselling experience, but also highlighted issues of access and emotional impact. Adverse pregnancy outcome rates were significantly higher in women with chronic kidney disease: 7/35 (20%) had pre-eclampsia (p < 0.001), 8/35 (23%) infants were small for gestational age (p < 0.001), 11/35 (31%) had preterm deliveries (<37 weeks) (p < 0.001) and 5/35 (14%) had a pregnancy loss compared with 4%, 10%, 8% and 3% of controls respectively. CONCLUSIONS: Women with a diverse range of renal disease severity and complexity attend pre-pregnancy counselling. Factors affecting pregnancy include hypertension, proteinuria and teratogenic medication. It is important to be able to inform women of the risks to them and their babies before pregnancy in order to facilitate informed-decision making. Most women with chronic kidney disease attending a pre-pregnancy counselling clinic report a positive experience.

The use of eculizumab in renal transplantation.

The complement system plays a vital role in mediating disease processes within renal allografts. Eculizumab is a humanized monoclonal antibody that targets complement protein C5, inhibiting cleavage into C5a and C5b, and therefore preventing formation of the membrane attack complex (MAC). It has been used primarily within renal transplantation to treat atypical hemolytic-uremic syndrome (aHUS) and antibody-mediated rejection (AMR) post-transplant, and also as prophylaxis in transplants at high risk for these conditions. Eculizumab appears to be effective in protecting renal allografts when post-transplant aHUS or AMR occur, although the published cases report relatively short follow-up. It is unclear how long treatment should continue (a particularly important issue given the expense of the drug), or whether eculizumab contributes to the development of accommodation in humans. When used for prophylaxis, eculizumab also appears to be effective. Some highly sensitized patients have developed either acute AMR or features of chronic AMR despite administration of the drug - this suggests that complement activation is not the only mechanism responsible for AMR. All patients should receive vaccination against Neisseria meningitidis prior to receiving eculizumab. Clinical trials, predominantly in antibody-incompatible renal transplantation, are ongoing to determine the optimal use of C5 inhibition.

Non-invasive biomarkers to guide management following renal transplantation: the need for a multiplatform approach.

PURPOSE OF REVIEW: Balancing the level of anti-rejection therapy is the key challenge facing clinicians managing recipients of a solid organ transplant. Identification of biomarkers in non-invasive samples will allow serial monitoring which can prompt changes in therapy at an earlier stage without the need for invasive tests, and before significant damage to the graft or side effects have occurred. In this review we provide an update on the present status of such biomarker discovery in renal transplantation. RECENT FINDINGS: Previous studies focusing on candidate biomarkers have identified a number of genes that have the potential to identify patients undergoing rejection. Advances in technology now allow screening of samples for markers which have led to identification of further genes as well as adding microRNAs and proteins to the list. Similarly, by studying patients in whom anti-rejection therapy has been withdrawn, a gene signature for operational tolerance has been described. SUMMARY: It has become clear that to obtain a test suitable for clinical purposes, combinations of markers are required to identify specific clinical phenotypes. Identification and validation of such marker sets in large cohorts is urgently required to allow progression to clinical trials with the ultimate goal of offering recipients personalized anti-rejection therapy regimes.

Incidence, Risk Factors, and Effect on Allograft Survival of Glomerulonephritis Post-transplantation in a United Kingdom Population: Cohort Study.

Background: Post-transplant glomerulonephritis (PTGN) has been associated with inferior long-term allograft survival, and its incidence varies widely in the literature. Methods: This is a cohort study of 7,623 patients transplanted between 2005 and 2016 at four major transplant UK centres. The diagnosis of glomerulonephritis (GN) in the allograft was extracted from histology reports aided by the use of text-mining software. The incidence of the four most common GN post-transplantation was calculated, and the risk factors for disease and allograft outcomes were analyzed. Results: In total, 214 patients (2.8%) presented with PTGN. IgA nephropathy (IgAN), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), and membranoproliferative/mesangiocapillary GN (MPGN/MCGN) were the four most common forms of post-transplant GN. Living donation, HLA DR match, mixed race, and other ethnic minority groups were associated with an increased risk of developing a PTGN. Patients with PTGN showed a similar allograft survival to those without in the first 8 years of post-transplantation, but the results suggest that they do less well after that timepoint. IgAN was associated with the best allograft survival and FSGS with the worst allograft survival. Conclusions: PTGN has an important impact on long-term allograft survival. Significant challenges can be encountered when attempting to analyze large-scale data involving unstructured or complex data points, and the use of computational analysis can assist.

Efficacy and toxicity of sunitinib in patients with metastatic renal cell carcinoma with severe renal impairment or on haemodialysis.

OBJECTIVE: To further investigate the effect of sunitinib, which is currently a standard of care for the treatment of metastatic renal cell carcinoma (mRCC), in patients with severe renal impairment or those undergoing dialysis. PATIENTS AND METHODS: Clinical databases were used to identify all patients with mRCC treated with sunitinib in seven institutions internationally. Databases were searched to identify only those patients with an estimated glomerular filtration rate of < 30 mL/min/1.73 m² or those who had end-stage renal disease requiring dialysis. Baseline characteristics, adverse event data, response and progression-free survival were recorded. RESULTS: Nineteen patients met the inclusion criteria, 10 of whom were undergoing haemodialysis. Of the nine non-dialysis-dependent patients at drug initiation, the median estimated glomerular filtration rate was 27 mL/min/1.73 m² (range 23-29). Baseline characteristics included a median age of 61 years (range 44-77); 17 patients had a Karnofsky performance status of >80; eight patients had more than two metastatic sites and 17 had undergone prior nephrectomy. The estimated median progression-free survival of this cohort was 43 weeks (range 7 to 158+) and progression has not yet been reached in six patients. Partial response or stable disease was observed as best response in 15 patients. The most common treatment-related adverse events included fatigue, diarrhoea, hand-foot skin reaction (HFSR), nausea and vomiting and rash. Grade three treatment-related adverse events including fatigue (seven patients), HFSR (two patients), diarrhoea (one patient), rash (one patient) and stomatitis (one patient) occurred in a total of 12 patients. Only one patient experienced a grade four adverse event (HFSR). Only diarrhoea (P = 0.0002), HFSR (P < 0.0001) and neutropenia (P = 0.001) were more common in patients undergoing haemodialysis compared with non-dialysis-dependent patients. Four of the non-dialysis dependent patients started at a dose of 50 mg compared with three of the patients undergoing haemodialysis. However five and two of the patients undergoing haemodialysis started at doses of 37.5 mg and 25 mg daily, respectively, compared with four and one of the non-dialysis-dependent patients. All patients took sunitinib for 4 out of every 6 weeks. Dose reductions during treatment were performed in eight patients but only one patient required discontinuation of treatment. CONCLUSION: These data suggest that patients with severe renal impairment or end-stage renal disease on haemodialysis can be safely treated with sunitinib at doses of 25-50 mg daily for 4 weeks followed by a 2-week break. The observed efficacy of therapy is similar to that reported in patients with normal renal function. These preliminary results warrant confirmation in a larger cohort of patients.

Pivotal role of CD4+ T cells in renal fibrosis following ureteric obstruction.

Tubulointerstitial fibrosis is a common consequence of a diverse range of kidney diseases that lead to end-stage renal failure. The degree of fibrosis is related to leukocyte infiltration. Here, we determined the role of different T cell populations on renal fibrosis in the well-characterized mouse model of unilateral ureteric obstruction. Depletion of CD4(+) T cells in wild-type mice with a monoclonal antibody significantly reduced the amount of interstitial expansion and collagen deposition after 2 weeks of obstruction. Reconstitution of lymphopenic RAG knockout mice with purified CD4(+) but not CD8(+) T cells, prior to ureteric obstruction, resulted in a significant increase in interstitial expansion and collagen deposition. Wild-type mice had significantly greater interstitial expansion and collagen deposition compared with lymphopenic RAG(-/-) mice, following ureteric obstruction; however, macrophage infiltration was equivalent in all groups. Thus, our results suggest that renal injury with subsequent fibrosis is likely to be a multifactorial process, with different arms of the immune system involved at different stages. In this ureteric obstruction model, we found a critical role for CD4(+) T cells in kidney fibrosis. These cells could be a potential target of therapeutic intervention to prevent excessive fibrosis and loss of function due to renal injury.

Endogenous ligands for TLR2 and TLR4 are not involved in renal injury following ureteric obstruction.

BACKGROUND: Toll-like receptors (TLRs) are a recently described arm of innate immunity. As well as responding to conserved molecular patterns found on pathogens, TLRs can also respond to endogenous ligands. Those described for TLR2 and TLR4 include molecules released following tissue injury including heat shock proteins and matrix proteins. We hypothesised that following injury, TLRs on renal tubular cells are activated by these endogenous ligands, resulting in cytokine production and cellular infiltration which propagate the fibrotic process. METHODS: We performed unilateral ureteric obstruction (UUO) in wild-type C57BL/6, TLR2 knockout and TLR4 knockout mice. Gene expression of TGF-beta and TNF-alpha within renal tissue was analysed by real-time PCR. Kidneys were also scored for the level of tubulointerstitial fibrosis, collagen type IV deposition and macrophage infiltration. RESULTS: No significant difference was found in the degree of tubulointerstitial fibrosis, collagen type IV deposition or macrophage infiltration 14 days after UUO between the 3 groups. Renal TNF-alpha and TGF-beta gene expression was also similar in all groups 3 days after UUO. CONCLUSIONS: TLR2 and TLR4 do not play a significant role in the development of tubulointerstitial fibrosis following obstruction.

Development of a multivariable gene-expression signature targeting T-cell-mediated rejection in peripheral blood of kidney transplant recipients validated in cross-sectional and longitudinal samples.

BACKGROUND: Acute T-cell mediated rejection (TCMR) is usually indicated by alteration in serum-creatinine measurements when considerable transplant damage has already occurred. There is, therefore, a need for non-invasive early detection of immune signals that would precede the onset of rejection, prior to transplant damage. METHODS: We examined the RT-qPCR expression of 22 literature-based genes in peripheral blood samples from 248 patients in the Kidney Allograft Immune Biomarkers of Rejection Episodes (KALIBRE) study. To account for post-transplantation changes unrelated to rejection, we generated time-adjusted gene-expression residuals from linear mixed-effects models in stable patients. To select genes, we used penalised logistic regression based on 27 stable patients and 27 rejectors with biopsy-proven T-cell-mediated rejection, fulfilling strict inclusion/exclusion criteria. We validated this signature in i) an independent group of stable patients and patients with concomitant T-cell and antibody-mediated-rejection, ii) patients from an independent study, iii) cross-sectional pre-biopsy samples from non-rejectors and iv) longitudinal follow-up samples covering the first post-transplant year from rejectors, non-rejectors and stable patients. FINDINGS: A parsimonious TCMR-signature (IFNG, IP-10, ITGA4, MARCH8, RORc, SEMA7A, WDR40A) showed cross-validated area-under-ROC curve 0.84 (0.77-0.88) (median, 2.5th-97.5th centile of fifty cross-validation cycles), sensitivity 0.67 (0.59-0.74) and specificity 0.85 (0.75-0.89). The estimated probability of TCMR increased seven weeks prior to the diagnostic biopsy and decreased after treatment. Gene expression in all patients showed pronounced variability, with up to 24% of the longitudinal samples in stable patients being TCMR-signature positive. In patients with borderline changes, up to 40% of pre-biopsy samples were TCMR-signature positive. INTERPRETATION: Molecular marker alterations in blood emerge well ahead of the time of clinically overt TCMR. Monitoring a TCMR-signature in peripheral blood could unravel T-cell-related pro-inflammatory activity and hidden immunological processes. This additional information could support clinical management decisions in cases of patients with stable but poor kidney function or with inconclusive biopsy results.

Role of the complement system in rejection.

The complement system plays a complex role in transplantation, beginning with effects on reperfusion injury and continuing with stimulation of the adaptive immune response. Recent evidence has emphasised the importance of the late components of the complement cascade in the mediation of post-ischaemic damage, which are apparently triggered by the classical, alternative or lectin pathways of complement activation, depending on the organ affected. In studies of renal allograft rejection, the local synthesis of complement component C3 seems to influence the T-cell response more strongly than circulating complement protein, raising the possibility that there is co-operation between locally derived C3 and antigen presentation in the graft. Class switching of alloantibody to a high-affinity IgG response is also highly dependent on C3. In addition, the finding that capillary-bound C4d is a robust marker for humoral rejection has started a new investigation into the significance of alloantibodies in acute and chronic allograft rejection. There are several selective and nonselective inhibitors suitable for clinical development; clearly it is time for more concerted effort to evaluate their role in clinical transplantation.

Systematic assessment of the influence of complement gene polymorphisms on kidney transplant outcome.

The importance of the innate immune system, including complement, in causing transplant injury and augmenting adaptive immune responses is increasingly recognized. Therefore variability in graft outcome may in part be due to genetic polymorphism in genes encoding proteins of the immune system. This study assessed the relationship between single nucleotide polymorphisms (SNPs) in complement genes and outcome after transplantation. Analysis was performed on two patient cohorts of 650 and 520 transplant recipients. 505 tagged SNPs in 47 genes were typed in both donor and recipient. The relationships between SNPs and graft survival, serum creatinine, delayed graft function and acute rejection were analyzed. One recipient SNP in the gene encoding mannose binding lectin was associated with graft outcome after correction for analysis of multiple SNPs (p=6.41 × 10(-5)). When further correction was applied to account for analysis of the effect of SNPs in both donor and recipient this lost significance. Despite association p values of <0.001 no SNP was significantly associated with clinical phenotypes after Bonferroni correction. In conclusion, the variability seen in transplant outcome in this patient cohort cannot be explained by variation in complement genes. If causal genetic effects exist in these genes, they are too small to be detected by this study.

Low-dose mycophenolate mofetil is an effective and safe treatment to permit phased reduction in calcineurin inhibitors in chronic allograft nephropathy.

BACKGROUND: Chronic allograft nephropathy (CAN) is the most common cause of long-term renal-allograft dysfunction and the second most common cause of transplant loss. There are concerns that prolonged patient exposure to calcineurin inhibitors (CNIs) exacerbates or promotes the process of CAN. METHODS: In our unit, we carried out an observational study over the period 2000 to 2003 using low-dose mycophenolate mofetil (MMF) to facilitate a phased reduction in the dose of CNI in a group of patients with CAN. Low doses of MMF were chosen to minimize adverse effects and to reduce levels of CNIs without the attendant risks of under-immunosuppression. RESULTS: A step-wise reduction in mean reciprocalised creatinine was evident over the run-in period (mean 1/creatinine before MMF=0.005739-0.000083*month; R=0.77) with a step-wise monthly improvement postintroduction of MMF and dose reduction of CNI (mean 1/creatinine after MMF=0.004609+0.000049*month; R=0.74) (P<0.0001). The mean Cockroft-Gault estimated creatinine clearances were 47.1+/-24.2, 37.2+/-16.3, and 41.6+/-21.1 mL/min at time [t]=-12, t=0 and t=+12 months, respectively. Low-dose MMF therapy was well tolerated (only 7/89 patients stopped MMF because of side-effects in the first 12 months), and acute rejection was noted in only one patient. At latest follow-up, only 17 transplant losses had occurred, of which 6 patients had died with a functioning graft. CONCLUSIONS: Low-dose MMF was well tolerated and resulted in prolonged graft survival.

Campath, calcineurin inhibitor reduction and chronic allograft nephropathy (3C) study: background, rationale, and study protocol.

BACKGROUND: Kidney transplantation is the best treatment for patients with end-stage renal failure, but uncertainty remains about the best immunosuppression strategy. Long-term graft survival has not improved substantially, and one possible explanation is calcineurin inhibitor (CNI) nephrotoxicity. CNI exposure could be minimized by using more potent induction therapy or alternative maintenance therapy to remove CNIs completely. However, the safety and efficacy of such strategies are unknown. METHODS/DESIGN: The Campath, Calcineurin inhibitor reduction and Chronic allograft nephropathy (3C) Study is a multicentre, open-label, randomized controlled trial with 852 participants which is addressing two important questions in kidney transplantation. The first question is whether a Campath (alemtuzumab)-based induction therapy strategy is superior to basiliximab-based therapy, and the second is whether, from 6 months after transplantation, a sirolimus-based maintenance therapy strategy is superior to tacrolimus-based therapy. Recruitment is complete, and follow-up will continue for around 5 years post-transplant. The primary endpoint for the induction therapy comparison is biopsy-proven acute rejection by 6 months, and the primary endpoint for the maintenance therapy comparison is change in estimated glomerular filtration rate from baseline to 2 years after transplantation. The study is sponsored by the University of Oxford and endorsed by the British Transplantation Society, and 18 centers for adult kidney transplant are participating. DISCUSSION: Late graft failure is a major issue for kidney-transplant recipients. If our hypothesis that minimizing CNI exposure with Campath-based induction therapy and/or an elective conversion to sirolimus-based maintenance therapy can improve long-term graft function and survival is correct, then patients should experience better graft function for longer. A positive outcome could change clinical practice in kidney transplantation. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01120028 and ISRCTN88894088.

Pregnancy in pancreas-kidney transplant recipients: report of three cases and review of the literature.

Seventy-three pregnancies in 43 women with SPK have now been described by the US National Transplantation Pregnancy Registry (NTPR) (established in 1991), which contains self-reported data from questionnaires and hospital records. These women have high rates of complications despite normoglycaemia and restoration of renal function. We describe the pregnancies of three SPK recipients in the UK managed in joint renal obstetric clinics and discuss the antenatal and postnatal complications specific to SPK transplants.

Minireview: functions of the renal tract epithelium in coordinating the innate immune response to infection.

Infection of the urinary tract remains one of the most common infections affecting mankind. Renal epithelial cells, being one of the first cells to come into contact with invading organisms, are in a key position to coordinate host defense. The epithelium not only provides a physical barrier to infection, but can also augment the immune response via the production of a number of inflammatory mediators and antimicrobial proteins. Recent work has demonstrated that cells of the innate immune system, including epithelial cells, express toll-like receptors (TLRs), with the capacity to recognize bacterial components. Although the exact mechanisms remain unclear, engagement of TLRs can lead to epithelial cell activation and the production of inflammatory mediators. These include complement proteins, other bactericidal peptides, and chemotactic cytokines. The resulting inflammatory infiltrate serves to aid bacterial clearance, but can also lead to renal damage. In this review, we describe how renal epithelial cells contribute to the innate immune response to ascending urinary tract infection. We specifically relate previous work to more recent developments in this field. An improved understanding of the mechanisms involved may highlight potential therapeutic avenues to aid bacterial clearance and prevent the renal scarring associated with infection.