Half a Century of Haemodialysis: Two Patient Journeys

The history of renal replacement therapy (RRT) for end-stage kidney disease (ESKD) started in 1960 and has reached, in these six decades, goals initially unforeseen. This report describes two patients who commenced dialysis at the age of 17 and 27, for 53 and 45 years, respectively, whereby the modality of RRT was mostly in the form of home haemodialysis. The history of these two patients, who started RRT in distant parts of the world, Australia and Croatia, highlights not only the advances made over time, to significantly delay the onset and reduce the morbidity and mortality associated with ESKD, but also underlines the importance of empowerment and commitment, added values in home haemodialysis.

Long-Term Impact of Arteriovenous Fistula Ligation on Cardiac Structure and Function in Kidney Transplant Recipients: A 5-Year Follow-Up Observational Cohort Study

Background

The long-term effects of arteriovenous fistula (AVF) ligation on cardiovascular structure following kidney transplantation remain uncertain. A prospective randomized, controlled trial (RCT) examined the effect of AVF ligation at 6 months on cardiovascular magnetic resonance imaging (CMR)-derived parameters in 27 kidney transplant recipients compared with 27 controls. A mean decrease in left ventricular mass (LVM) of 22.1 g (95% CI, 15.0 to 29.1) was observed compared with an increase of 1.2 g (95% CI, -4.8 to 7.2) in the control group (P<0.001). We conducted a long-term follow-up observational cohort study in the treated cohort to determine the evolution of CMR-derived parameters compared with those documented at 6 months post-AVF ligation.

Methods

We performed CMR at long-term follow-up in the AVF ligation observational cohort from our original RCT published in 2019. Results were compared with CMR at 6 months postintervention. The coprimary end point was the change in CMR-derived LVM and LVM index at long-term follow-up from imaging at 6 months postindex procedure.

Results

At a median of 5.1 years (interquartile range, 4.7-5.5 years), 17 patients in the AVF ligation group were studied with repeat CMR with a median duration to follow-up imaging of 5.1 years (IQR, 4.7-5.5 years). Statistically significant further reductions in LVM (-17.6±23.0 g, P=0.006) and LVM index (-10.0±13.0 g/m², P=0.006) were documented.

Conclusions

The benefit of AVF ligation on LVM and LVM index regression appears to persist long term. This has the potential to lead to a significant reduction in cardiovascular mortality.

Multimodality Tachycardia-Induced Stress Testing Predicts a Low-Risk Group for Early Cardiovascular Mortality After Renal Transplantation

Background

Cardiovascular events remain a major cause of death in kidney transplant recipients. The optimal noninvasive workup to prevent peritransplant cardiac mortality remains contentious.

Methods

We conducted a retrospective analysis to assess the renal transplantation cardiovascular assessment protocol within a single-center population over a 5-year period. Asymptomatic patients aged less than 45 years with no history of cigarette smoking, without diabetes mellitus, and dialysis-dependent for less than 24 months did not undergo cardiac testing before listing. All other asymptomatic patients underwent a noninvasive, tachycardia-induced stress test, where a target heart rate of 85% predicted for age and gender was required. The primary endpoints were rates of acute myocardial infarction (AMI) and cardiovascular death at 30 days after renal transplantation.

Results

Between 2015 and 2019, 380 recipients underwent cardiac evaluation: 79 (20.8%) were deemed low cardiovascular risk and placed on the renal transplant waitlist without further assessment; 270 (71.1%) underwent a tachycardia-induced stress test; and 31 (8.1%) were deemed high risk and proceeded directly to invasive coronary angiography (ICA). In the 5-year follow-up, 3 patients (0.8%) experienced an AMI 30 days after renal transplantation, all of which occurred in the high-risk “direct to ICA” cohort. No events were documented in the low-risk cohort or in patients who had a negative tachycardia-induced stress test. There were no cardiovascular deaths within 30 days after transplantation.

Conclusion

A negative tachycardia-induced cardiac stress test, achieving 85% of predicted heart rate, was associated with a 0% AMI rate and no cardiovascular deaths at 30 days after renal transplantation.

Development of de novo HLA donor specific antibodies (HLA-DSA), HLA antibodies (HLA-Ab) and allograft rejection post blood transfusion in kidney transplant recipients

BACKGROUND

Blood transfusion during the post-operative period of kidney transplantation is common as part of a life-saving procedure, especially in the event of acute blood loss. However, there have been conflicting opinions since the pre-cyclosporine era. The risk of sensitization post-transfusion remains the main limiting factor following transfusion in kidney transplant recipients. Thus, the objective of this study is to assess the development of de novo HLA-DSA, HLA-Ab and allograft rejection post blood transfusion.

METHODOLOGY

This is a retrospective cohort study recruiting all kidney transplant recipients in South Australia from January 2010 till December 2018. Following that, the incidence of blood transfusion within one week post-operatively were traced (transfusion group). The outcomes were compared with all other transplant recipients (non-transfusion group). Recipient's demographic, donor characteristics and immunological risk profiles were obtained from the transplant unit database, while the biopsy report, history of blood transfusion, latest serum creatinine and follow-up status was gathered from the electronic medical system (OASIS). The HLA-DSA and HLA-Ab results were collected from the NOMS database. Finally, the survival data were merged with the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry for South Australia recipients graft survival.

RESULTS

A total of 699 patients were eligible for analysis. The mean age was 50.64 ± 13.23 years old. There were more elderly (>65 years old) and females who needed transfusion. The majority had glomerulonephritis as the primary disease. There was no statistical difference in donor characteristics, cold ischemic time and immunological risk between the transfusion and non-transfusion group. There was no difference in the development of de novo HLA-DSA, HLA-Ab and rejection episodes between the group and the results were consistent in a model adjusted for all potential confounders. Median graft survival in days between the transfusion vs non-transfusion group was 1845 IQR (961,2430) and 1250 IQR (672,2013).

CONCLUSION

Blood transfusion under strong immunosuppressive cover within a one-week post-operative period is safe with no significant association with the development of de novo HLA-DSA, HLA-Ab or clinical rejection.

Bone Marrow-Derived Progenitor Cells Mediate Immune Cell Regulation

Human bone marrow (BM) derived mesenchymal stem cells (MSC) have high capacity to propagate ex vivo with superior reparative, immunosuppressive, and anti-inflammatory properties. Here we describe standardized protocols and culture conditions that enable the isolation, expansion and maintenance of a highly purified and homogenous population of human MSC. These third party-derived off-the-shelf MSC from healthy human bone marrow donors can potently inhibit mitogenically or allogeneically activated human T cells in proliferation assays. The standard operating procedures described in this chapter can be applied to researchers aiming to enhance MSC immunosuppressive properties and defining MSC mechanisms of action. Importantly, these assays can be incorporated into clinical protocols where the safety and efficacy of human BM MSC can be verified in diseases that are modulated by T cell responses.

An overview on small molecule-induced differentiation of mesenchymal stem cells into beta cells for diabetic therapy

The field of regenerative medicine provides enormous opportunities for generating beta cells from different stem cell sources for cellular therapy. Even though insulin-secreting cells can be generated from a variety of stem cell types like pluripotent stem cells and embryonic stem cells, the ideal functional cells should be generated from patients' own cells and expanded to considerable levels by non-integrative culture techniques. In terms of the ease of isolation, plasticity, and clinical translation to generate autologous cells, mesenchymal stem cell stands superior. Furthermore, small molecules offer a great advantage in terms of generating functional beta cells from stem cells. Research suggests that most of the mesenchymal stem cell-based protocols to generate pancreatic beta cells have small molecules in their cocktail. However, most of the protocols generate cells that mimic the characteristics of human beta cells, thereby generating "beta cell-like cells" as opposed to mature beta cells. Diabetic therapy becomes feasible only when there are robust, functional, and safe cells for replacing the damaged or lost beta cells. In this review, we discuss the current protocols used to generate beta cells from mesenchymal cells, with emphasis on small molecule-mediated conversion into insulin-producing beta cell-like cells. Our data and the data presented from the references within this review would suggest that although mesenchymal stem cells are an attractive cell type for cell therapy they are not readily converted into functional mature beta cells.

Development of a Coaxial 3D Printing Platform for Biofabrication of Implantable Islet-Containing Constructs

Over the last two decades, pancreatic islet transplantations have become a promising treatment for Type I diabetes. However, although providing a consistent and sustained exogenous insulin supply, there are a number of limitations hindering the widespread application of this approach. These include the lack of sufficient vasculature and allogeneic immune attacks after transplantation, which both contribute to poor cell survival rates. Here, these issues are addressed using a biofabrication approach. An alginate/gelatin-based bioink formulation is optimized for islet and islet-related cell encapsulation and 3D printing. In addition, a custom-designed coaxial printer is developed for 3D printing of multicellular islet-containing constructs. In this work, the ability to fabricate 3D constructs with precise control over the distribution of multiple cell types is demonstrated. In addition, it is shown that the viability of pancreatic islets is well maintained after the 3D printing process. Taken together, these results represent the first step toward an improved vehicle for islet transplantation and a potential novel strategy to treat Type I diabetes.

Weekend effect on early allograft outcome after kidney transplantation- a multi-centre cohort study

Weekend surgery may be associated with a higher risk of early complications, but the effect of the timing of kidney transplant surgery on early allograft outcome remains uncertain. The aim of this study is to evaluate whether the association between weekend transplant surgery and allograft failure was modified by prevalent vascular disease. Using data from the Australia and New Zealand Dialysis and Transplant registry, we examined the association between weekend status and 90-day and 1-year allograft failure in deceased donor transplant recipients between 1994-2012. Two-way interaction between vascular disease and weekend status was examined. Of 6622 recipients, 1868 (28.2%) received transplants during weekends. Compared with weekday transplants, weekend transplants were associated with an adjusted hazard ratio (HR) for 90-day and 1-year allograft failure of 0.99 (0.78-1.25; P = 0.917) and 0.93 (0.76-1.13, P = 0.468), respectively. There was a significant interaction between prevalent vascular disease and weekend status for 90-day allograft failure (P_interaction = 0.008) but not at 1-year, such that patients with vascular disease were more likely to experience 90-day allograft failure if transplanted on weekend (versus weekdays), particularly failures secondary to vascular complications. Timing of transplantation does not impact on allograft outcome, although those with vascular disease may benefit from more intensive post-transplant follow-up for potential vascular complications.

Murine and Non-Human Primate Dendritic Cell Targeting Nanoparticles for in Vivo Generation of Regulatory T-Cells

Porous silicon nanoparticles (pSiNP), modified to target dendritic cells (DC), provide an alternate strategy for the delivery of immunosuppressive drugs. Here, we aimed to develop a DC-targeting pSiNP displaying c-type lectin, dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN), and CD11c monoclonal antibodies. The in vivo tracking of these fluorescent DC-targeting nanoparticles was assessed in both C57BL/6 mice and common marmosets ( Callithrix jacchus) by intravenous injection (20 mg/kg). Rapamycin and ovalbumin (OVA)_323-339 peptide loaded pSiNP were employed to evaluate their ability to generate murine CD4⁺CD25⁺FoxP3⁺ regulatory T-cells in vivo within OVA sensitized mice. In vivo, pSiNP migrated to the liver, kidneys, lungs, and spleen in both mice and marmosets. Flow cytometry confirmed pSiNP uptake by splenic and peripheral blood DC when functionalized with targeting antibodies. C57BL/6 OVA sensitized mice injected with CD11c-pSiNP loaded with rapamycin + OVA_323-339 produced a 5-fold higher number of splenic regulatory T-cells compared to control mice, at 40 days post-pSiNP injection. These results demonstrate the importance of the immobilized targeting antibodies to enhance cellular uptake and enable the in vivo generation of splenic regulatory T-cells.

Urine-derived cells for human cell therapy

Desirable cells for human cell therapy would be ones that can be generated by simple isolation and culture techniques using a donor sample obtained by non-invasive methods. To date, the different donor-specific cells that can be isolated from blood, skin, and hair require invasive methods for sample isolation and incorporate complex and costly reagents to culture. These cells also take considerable time for their in-vitro isolation and expansion. Previous studies suggest that donor-derived cells, namely urine stem cells and renal cells, may be isolated from human urine samples using a cost-effective and simple method of isolation, incorporating not such complex reagents. Moreover, the isolated cells, particularly urine stem cells, are superior to conventional stem cell sources in terms of favourable gene profile and inherent multipotent potential. Transdifferentiation or differentiation of human urine-derived cells can generate desirable cells for regenerative therapy. In this review, we intended to discuss the characteristics and therapeutic applications of urine-derived cells for human cell therapy. Conclusively, with detailed study and optimisation, urine-derived cells have a prospective future to generate functional lineage-specific cells for patients from a clinical translation point of view.

Successful pregnancy in a recipient of an ABO-incompatible renal allograft

Kidney transplantation restores fertility in patients with end-stage renal disease, with many successful pregnancies after kidney transplantation being reported. However, there are little data regarding pregnancy in women transplanted under modern-era desensitisation protocols that utilise rituximab, plasma exchange and intravenous immunoglobulin, including ABO-incompatible transplants. Pregnancies in ABO-incompatible recipients can pose new challenges from an immunological perspective. Here, we report a case of successful pregnancy using in vitro fertilisation, in a renal transplant recipient who underwent desensitisation two years prior, that included use of rituximab and plasma exchange to receive an ABO-incompatible transplant from her husband and subsequent father of the baby. We believe this was the first case of successful pregnancy after ABO-incompatible kidney transplantation in Australia and New Zealand. This case also highlights the difficulties faced in conception following transplantation and demonstrates that in vitro fertilisation utilising ovulation induction can be successfully utilised for conception in this cohort. This recipient also had gestational diabetes, worsening renal function and preterm delivery which are important complications often seen in pregnancies of solid organ transplant recipients.

Oxygen-permeable microwell device maintains islet mass and integrity during shipping

Islet transplantation is currently the only minimally invasive therapy available for patients with type 1 diabetes that can lead to insulin independence; however, it is limited to only a small number of patients. Although clinical procedures have improved in the isolation and culture of islets, a large number of islets are still lost in the pre-transplant period, limiting the success of this treatment. Moreover, current practice includes islets being prepared at specialized centers, which are sometimes remote to the transplant location. Thus, a critical point of intervention to maintain the quality and quantity of isolated islets is during transportation between isolation centers and the transplanting hospitals, during which 20-40% of functional islets can be lost. The current study investigated the use of an oxygen-permeable PDMS microwell device for long-distance transportation of isolated islets. We demonstrate that the microwell device protected islets from aggregation during transport, maintaining viability and average islet size during shipping.

Local Sphingosine Kinase 1 Activity Improves Islet Transplantation

Pancreatic islet transplantation is a promising clinical treatment for type 1 diabetes, but success is limited by extensive β-cell death in the immediate posttransplant period and impaired islet function in the longer term. Following transplantation, appropriate vascular remodeling is crucial to ensure the survival and function of engrafted islets. The sphingosine kinase (SK) pathway is an important regulator of vascular beds, but its role in the survival and function of transplanted islets is unknown. We observed that donor islets from mice deficient in SK1 (Sphk1 knockout) contain a reduced number of resident intraislet vascular endothelial cells. Furthermore, we demonstrate that the main product of SK1, sphingosine-1-phosphate, controls the migration of intraislet endothelial cells in vitro. We reveal in vivo that Sphk1 knockout islets have an impaired ability to cure diabetes compared with wild-type controls. Thus, SK1-deficient islets not only contain fewer resident vascular cells that participate in revascularization, but likely also a reduced ability to recruit new vessels into the transplanted islet. Together, our data suggest that SK1 is important for islet revascularization following transplantation and represents a novel clinical target for improving transplant outcomes.

Immunodepletion and Hypoxia Preconditioning of Mouse Compact Bone Cells as a Novel Protocol to Isolate Highly Immunosuppressive Mesenchymal Stem Cells

Compact bones (CB) are major reservoirs of mouse mesenchymal stem cells (mMSC). Here, we established a protocol to isolate MSC from CB and tested their immunosuppressive potential. Collagenase type II digestion of BM-flushed CB from C57B/6 mice was performed to liberate mMSC precursors from bone surfaces to establish nondepleted mMSC. CB cells were also immunodepleted based on the expression of CD45 (leukocytes) and TER119 (erythroid cells) to eliminate hematopoietic cells. CD45^-TER119^- CB cells were subsequently used to generate depleted mMSC. CB nondepleted and depleted mMSC progenitors were cultured under hypoxic conditions to establish primary mMSC cultures. CB depleted mMSC compared to nondepleted mMSC showed greater cell numbers at subculturing and had increased functional ability to differentiate into adipocytes and osteoblasts. CB depleted mMSC had high purity and expressed key mMSC markers (>85% Sca-1, CD29, CD90) with no mature hematopoietic contaminating cells (<5% CD45, CD11b) when subcultured to passage 5 (P5). Nondepleted mMSC cultures, however, were less pure and heterogenous with <72% Sca-1⁺, CD29⁺, and CD90⁺ cells at early passages (P1 or P2), along with high percentages of contaminating CD11b⁺ (35.6%) and CD45⁺ (39.2%) cells that persisted in culture long term. Depleted and nondepleted mMSC nevertheless exhibited similar potency to suppress total (CD3⁺), CD4⁺ and CD8⁺ T cell proliferation, in a dendritic cell allostimulatory one-way mixed lymphocyte reaction. CB depleted mMSC, pretreated with proinflammatory cytokines IFN-γ, TNF-α, and IL-17A, showed superior suppression of CD8⁺ T cell, but not CD4⁺ T cell proliferation, relative to untreated-mMSC. In conclusion, CB depleted mMSC established under hypoxic conditions and treated with selective cytokines represent a novel source of potent immunosuppressive MSC. As these cells have enhanced immune modulatory function, they may represent a superior product for use in clinical allotransplantation.

Prolonged Ischemic Time, Delayed Graft Function, and Graft and Patient Outcomes in Live Donor Kidney Transplant Recipients

The association between prolonged cold ischemic time (CIT) and graft and patient outcomes in live donor kidney transplant recipients remains unclear. The aims of this study were to examine the association of CIT with delayed graft function and graft loss in live donor kidney transplant recipients and those who participated in the Australian Paired Kidney Exchange program using data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry. Of 3717 live donor transplant recipients between 1997 and 2012 who were followed for a median of 6.6 years (25 977 person-years), 224 (25%) experienced CIT >4-8 h. Donor age was an effect modifier between CIT and graft outcomes. In recipients who received kidneys from older donors aged >50 years, every hour of increase in CIT was associated with adjusted odds of 1.28 (95% confidence interval [CI] 1.07-1.53, p = 0.007) for delayed graft function, whereas CIT >4-8 h was associated with adjusted hazards of 1.93 (95% CI 1.21-3.09, p = 0.006) and 1.91 (95% CI 1.05-3.49, p = 0.035) for overall and death-censored graft loss, respectively, compared with CIT of 1-2 h. Attempts to reduce CIT in live donor kidney transplants involving older donor kidneys may lead to improvement of graft outcomes.

HLA-DQ Mismatches and Rejection in Kidney Transplant Recipients

BACKGROUND AND OBJECTIVES

The current allocation algorithm for deceased donor kidney transplantation takes into consideration HLA mismatches at the ABDR loci but not HLA mismatches at other loci, including HLA-DQ. However, the independent effects of incompatibilities for the closely linked HLA-DQ antigens in the context of HLA-DR antigen matched and mismatched allografts are uncertain. We aimed to determine the effect of HLA-DQ mismatches on renal allograft outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using data from the Australia and New Zealand Dialysis and Transplant Registry, we examined the association between HLA-DQ mismatches and acute rejections in primary live and deceased donor kidney transplant recipients between 2004 and 2012 using adjusted Cox regression models.

RESULTS

Of the 788 recipients followed for a median of 2.8 years (resulting in 2891 person-years), 321 (40.7%) and 467 (59.3%) received zero and one or two HLA-DQ mismatched kidneys, respectively. Compared with recipients who have received zero HLA-DQ mismatched kidneys, those who have received one or two HLA-DQ mismatched kidneys experienced greater numbers of any rejection (50 of 321 versus 117 of 467; P<0.01), late rejections (occurring >6 months post-transplant; 8 of 321 versus 27 of 467; P=0.03), and antibody-mediated rejections (AMRs; 12 of 321 versus 38 of 467; P=0.01). Compared with recipients of zero HLA-DQ mismatched kidneys, the adjusted hazard ratios for any and late rejections in recipients who had received one or two HLA-DQ mismatched kidneys were 1.54 (95% confidence interval [95% CI], 1.08 to 2.19) and 2.85 (95% CI, 1.05 to 7.75), respectively. HLA-DR was an effect modifier between HLA-DQ mismatches and AMR (P value for interaction =0.02), such that the association between HLA-DQ mismatches and AMR was statistically significant in those who have received one or two HLA-DR mismatched kidneys, with adjusted hazard ratio of 2.50 (95% CI, 1.05 to 5.94).

CONCLUSIONS

HLA-DQ mismatches are associated with acute rejection, independent of HLA-ABDR mismatches and initial immunosuppression. Clinicians should be aware of the potential importance of HLA-DQ matching in the assessment of immunologic risk in kidney transplant recipients.

Angiotensin II type 1 receptor antibody precipitating acute vascular rejection in kidney transplantation

Atypical non HLA antibodies are increasingly recognised as causes of immunological injury in allotransplantation. In this report we describe a non HLA sensitized male renal allograft recipient who developed acute vascular rejection on a "for cause" biopsy (Banff v2, g2, ptc 3) at day 4 post first renal allograft in the presence of elevated angiotensin II type 1 receptor antibodies (AT1R-Ab level 14.1). The acute rejection was treated with pulse corticosteroid therapy, anti-thymocyte globulin (ATG × 6), plasma exchange (1.5 plasma volume replacement x6) and oral candesartan. Serum creatinine improved and follow up biopsy confirmed resolution of rejection following treatment. AT1R-Ab should be considered when rejection is diagnosed in the absence of HLA antibodies.

Interleukin-17A-Induced Human Mesenchymal Stem Cells Are Superior Modulators of Immunological Function

Interferon-γ (IFN-γ)-preactivated mesenchymal stem cells (MSC-γ) are highly immunosuppressive but immunogenic in vivo due to their inherent expression of major histocompatibility (MHC) molecules. Here, we present an improved approach where we modified human bone marrow-derived MSC with interleukin-17A (MSC-17) to enhance T cell immunosuppression but not their immunogenicity. MSC-17, unlike MSC-γ, showed no induction or upregulation of MHC class I, MHC class II, and T cell costimulatory molecule CD40, but maintained normal MSC morphology and phenotypic marker expression. When cocultured with phytohemagglutinin (PHA)-activated human T cells, MSCs-17 were potent suppressors of T cell proliferation. Furthermore, MSC-17 inhibited surface CD25 expression and suppressed the elaboration of Th1 cytokines, IFN-γ, tumor necrosis factor-α (TNF-α), and IL-2 when compared with untreated MSCs (UT-MSCs). T cell suppression by MSC-17 correlated with increased IL-6 but not with indoleamine 2,3-dioxygenase 1, cyclooxygenase 1, and transforming growth factor β-1. MSC-17 but not MSC-γ consistently induced CD4(+) CD25(high) CD127(low) FoxP3(+) regulatory T cells (iTregs) from PHA-activated CD4(+) CD25(-) T cells. MSC-induced iTregs expressed CD39, CD73, CD69, OX40, cytotoxic T-lymphocyte associated antigen-4 (CTLA-4), and glucocorticoid-induced TNFR-related protein (GITR). These suppressive MSCs-17 can engender Tregs to potently suppress T cell activation with minimal immunogenicity and thus represent a superior T cell immunomodulator for clinical application.

Nocardiosis presenting as a lung mass in a kidney transplant recipient

Nocardiosis is a potentially life-threatening disease in renal transplant recipients. It is an uncommon infection with high lethality if left untreated. We report a case of a 67 year-old kidney transplant recipient who developed pulmonary nocardiosis and presented with pleural effusion along with an underlying lung mass, which was successfully treated with trimethoprim-sulphamethoxazole in conjunction with a reduction in immunosuppressive therapy. Five months later, graft function remains stable with complete regression of radiological abnormalities and absence of symptoms. Nocardiosis should be suspected in the presence of pulmonary symptoms in a transplant patient with unusual radiological presentation.

Islet cell transplantation in Australia: screening, remote transplantation, and incretin hormone secretion in insulin independent patients

Islet cell transplantation has emerged as a treatment modality for type 1 diabetes in the last 15 years due to the Edmonton protocol leading to consistent and sustained exogenous insulin independence post-transplantation. In recent years, consortia that involve both local and remote islet cell centers have been established, with local centers responsible for processing and shipping of islet cells, and remote centers only transplanting them. There are, however, few data on patient outcomes at remote centers. A tendency for high fasting glucose despite insulin independence was noted by us and others with an unknown mechanism. This review provides a brief history of islet cell transplantation, and focuses on the South Australian remote center experience: the challenges, screening criteria, and the impact on incretin hormone secretion of insulin independent transplant patients.

The immune phenotype may relate to cancer development in kidney transplant recipients

High regulatory T-cell (Treg) numbers predict recurrent cutaneous squamous cell carcinoma in kidney transplant recipients, and the Treg immune phenotype may identify kidney transplant recipients at risk of developing squamous cell carcinoma and/or solid-organ cancer. To investigate this, a total of 116 kidney transplant recipients, of whom 65 had current or past cancer, were immune-phenotyped and followed up prospectively for a median of 15 months. Higher Treg (CD3+CD4+FOXP3+CD25(Hi)CD127(Lo)) proportion and numbers significantly increased the odds of developing cancer (odds ratios (95% CI) 1.61 (1.17-2.20) and 1.03 (1.00-1.06), respectively) after adjusting for age, gender, and duration of immunosuppression. Class-switched memory B cells (CD19+CD27+IgD-) had a significant association to cancer, 1.04 (1.00-1.07). Receiver operator characteristic (ROC) curves for squamous cell carcinoma development within 100 days of immune phenotyping were significant for Tregs, memory B cells, and γδ T cells (AUC of 0.78, 0.68, and 0.65, respectively). After cancer resection, Treg, NK cell, and γδ T-cell numbers fell significantly. Immune-phenotype profiles associated with both squamous cell carcinoma and solid-organ cancer in kidney transplant recipients and depended on the presence of cancer tissue. Thus, immune profiling could be used to stratify kidney transplant recipients at risk of developing cancers to identify those who could qualify for prevention therapy.

Multicenter Australian trial of islet transplantation: improving accessibility and outcomes

Whilst initial rates of insulin independence following islet transplantation are encouraging, long-term function using the Edmonton Protocol remains a concern. The aim of this single-arm, multicenter study was to evaluate an immunosuppressive protocol of initial antithymocyte globulin (ATG), tacrolimus and mycophenolate mofetil (MMF) followed by switching to sirolimus and MMF. Islets were cultured for 24 h prior to transplantation. The primary end-point was an HbA1c of <7% and cessation of severe hypoglycemia. Seventeen recipients were followed for ≥ 12 months. Nine islet preparations were transported interstate for transplantation. Similar outcomes were achieved at all three centers. Fourteen of the 17 (82%) recipients achieved the primary end-point. Nine (53%) recipients achieved insulin independence for a median of 26 months (range 7-39 months) and 6 (35%) remain insulin independent. All recipients were C-peptide positive for at least 3 months. All subjects with unstimulated C-peptide >0.2 nmol/L had cessation of severe hypoglycemia. Nine of the 17 recipients tolerated switching from tacrolimus to sirolimus with similar graft outcomes. There was a small but significant reduction in renal function in the first 12 months. The combination of islet culture, ATG, tacrolimus and MMF is a viable alternative for islet transplantation.

Early exposure of interferon-γ inhibits signal transducer and activator of transcription-6 signalling and nuclear factor κB activation in a short-term monocyte-derived dendritic cell culture promoting 'FAST' regulatory dendritic cells

Interferon (IFN)-γ is a cytokine with immunomodulatory properties, which has been shown previously to enhance the generation of tolerogenic dendritic cells (DC) when administered early ex vivo in 7-day monocyte-derived DC culture. To generate tolerogenic DC rapidly within 48 h, human monocytes were cultured for 24 h with interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the presence (IFN-γ-DC) or absence of IFN-γ (500 U/ml) (UT-DC). DC were matured for 24 h with TNF-α and prostaglandin E(2) (PGE(2) ). DC phenotype, signal transducer and activator of transcription-6 (STAT-6) phosphorylation and promotion of CD4(+) CD25(+) CD127(neg/low) forkhead box P3 (FoxP3)(hi) T cells were analysed by flow cytometry. DC nuclear factor (NF)-κB transcription factor reticuloendotheliosis viral oncogene homologue B (RELB) and IL-12p70 protein expression were also determined. Phenotypically, IFN-γ-DC displayed reduced DC maturation marker CD83 by 62% and co-stimulation molecules CD80 (26%) and CD86 (8%). IFN-γ treatment of monocytes inhibited intracellular STAT6, RELB nuclear translocation and IL-12p70 production. IFN-γ-DC increased the proportion of CD4(+) CD25(+) CD127(neg/low) foxp3(hi) T cells compared to UT-DC from 12 to 23%. IFN-γ-DC primed T cells inhibited antigen-specific, autologous naive T cell proliferation by 70% at a 1:1 naive T cells to IFN-γ-DC primed T cell ratio in suppression assays. In addition, we examined the reported paradoxical proinflammatory effects of IFN-γ and confirmed in this system that late IFN-γ exposure does not inhibit DC maturation marker expression. Early IFN-γ exposure is critical in promoting the generation of regulatory DC. Early IFN-γ modulated DC generated in 48 h are maturation arrested and promote the generation of antigen-specific regulatory T cells, which may be clinically applicable as a novel cellular therapy for allograft rejection.

Ultrastructural analysis, zinc transporters, glucose transporters and hormones expression in New world primate (Callithrix jacchus) and human pancreatic islets

The New world primates (NWP) Callithrix jacchus separated from man approximately 50 million years ago and is a potential alternative small non-human primate model for diabetes research. Ultrastructure, and gene expression of pancreatic islets and the recently described diabetes auto antigenic zinc transporters families in human, NWP and pig pancreas were studied. Morphologically NWP islets were larger than pig islets and similar in size to human islets. NWP islets alpha cells had high dense core surrounded by a limiting membrane, beta cells by the mixed morphology of the granule core, and delta cells by moderate opaque core. Antibody staining for insulin, glucagon, somatostatin and Glucagon-like peptide-1 (GLP-1) showed that the distribution pattern of the different cell types within islets was comparable to pig and human islets. In all three species protein expression of zinc transporter ZnT8 was detected in most of the insulin producing beta cells whereas Zip14 expression was widely expressed in alpha and beta cells. In both human and NWP little or no expression of Glut2 was observed compared to Glut1 and glucokinase at the protein level, however the messenger RNA level of Glut2 was greater than Glut1 and glucokinase. In contrast all three glucose transporters were expressed in pig islets at the protein level. The expression of Zip14 in islets is reported for the first time. In conclusion NWP pancreatic islets express comparable islet cell types and distribution to humans and pigs. Importantly, marmosets have a similar glucose transporter profile to humans, making this non-endangered primate species a useful animal model for pancreatic biology.

Uremia impairs monocyte and monocyte-derived dendritic cell function in hemodialysis patients

Patients with chronic renal failure maintained on intermittent hemodialysis have frequent infections and a suboptimal response to vaccinations. Dendritic cells are potent antigen-presenting cells essential for the initiation and maintenance of innate and adaptive immunity. In this study we used uremic sera from hemodialysis patients to measure its impact on monocyte and monocyte-derived dendritic cell function in vitro. Monocytes from healthy and uremic subjects were isolated using immunomagnetic beads and differentiated into dendritic cells in the presence of either complete sera or sera from hemodialysis patients. Dendritic cells from normal patients cultured in uremic sera had decreased endocytosis and impaired maturation. These cells, however, had enhanced IL-12p70 production and increased allogeneic T-cell proliferation compared to cells of normal subjects cultured in normal sera. Monocyte derived dendritic cells of hemodialysis patients cultured in either normal or uremic sera were functionally impaired for endocytosis and maturation but had enhanced IL-12p70 production and allogeneic T-cell proliferation only when cultured with uremic sera. High concentrations of urea in normal sera inhibited all aspects of normal dendritic cell function in vitro. Our study suggests that hemodialysis regimes tailored to remove uremic toxins more efficiently may improve immune functions of these patients.

Uremia impairs blood dendritic cell function in hemodialysis patients

Patients on hemodialysis have a general immunodeficiency involving both innate and adaptive responses. As the mechanisms contributing to this defect are uncertain, we sought to study the effects of uremia on circulating dendritic cells (DC) in hemodialysis patients. Immunomagnetic beads were used to isolate myeloid and plasmacytoid DCs from healthy donors. Immune-related functions were determined in these cells cultured in either a complete media containing ABO-compatible serum or media containing sera from uremic patients. The myeloid cells were analyzed for costimulatory molecule expression and allo-stimulatory capability following lipopolysaccharide stimulation. The production of interferon-alpha following herpes-simplex virus stimulation by the plasmacytoid cells was also measured. Myeloid DCs incubated with uremic sera demonstrated impaired maturation and decreased allo-stimulatory capacity. Similarly, herpes virus-stimulated plasmacytoid DCs incubated with uremic sera produced significantly less interferon-alpha compared with cells incubated in the complete media. Both small and large molecule uremic toxins inhibited DC functions in vitro. Use of more efficient dialysis to improve small molecule clearance reversed the inhibition of uremic sera on myeloid but not plasmacytoid DC function. We have shown that the immunodeficiency of hemodialysis patients is due to dialyzable uremic toxins.

Dendritic cells mediate NK cell help for Th1 and CTL responses: two-signal requirement for the induction of NK cell helper function

Early stages of viral infections are associated with local recruitment and activation of dendritic cells (DC) and NK cells. Although activated DC and NK cells are known to support each other's functions, it is less clear whether their local interaction in infected tissues can modulate the subsequent ability of migrating DC to induce T cell responses in draining lymph nodes. In this study, we report that NK cells are capable of inducing stable type 1-polarized "effector/memory" DC (DC1) that act as carriers of NK cell-derived helper signals for the development of type 1 immune responses. NK cell-induced DC1 show a strongly elevated ability to produce IL-12p70 after subsequent CD40 ligand stimulation. NK-induced DC1 prime naive CD4+ Th cells for high levels of IFN-gamma, but low IL-4 production, and demonstrate a strongly enhanced ability to induce Ag-specific CD8+ T cell responses. Resting NK cells display stringent activation requirements to perform this novel, DC-mediated, "helper" function. Although their interaction with K562 cells results in effective target cell killing, the induction of DC1 requires a second NK cell-activating signal. Such costimulatory signal can be provided by type I IFNs, common mediators of antiviral responses. Therefore, in addition to their cytolytic function, NK cells also have immunoregulatory activity, induced under more stringent conditions. The currently demonstrated helper activity of NK cells may support the development of Th1- and CTL-dominated type 1 immunity against intracellular pathogens and may have implications for cancer immunotherapy.

Dendritic cells, T cell tolerance and therapy of adverse immune reactions

Dendritic cells (DC) are uniquely able to either induce immune responses or to maintain the state of self tolerance. Recent evidence has shown that the ability of DC to induce tolerance in the steady state is critical to the prevention of the autoimmune response. Likewise, DC have been shown to induce several type of regulatory T cells including Th2, Tr1, Ts and NKT cells, depending on the maturation state of the DC and the local microenvironment. DC have been shown to have therapeutic value in models of allograft rejection and autoimmunity, although no success has been reported in allergy. Several strategies, including the use of specific DC subsets, genetic modification of DC and the use of DC at various maturation stages for the treatment of allograft rejection and autoimmune disease are discussed. The challenge for the future use of DC therapy in human disease is to identify the appropriate DC for the proposed therapy; a task made more daunting by the extreme plasticity of DC that has recently been demonstrated. However, the progress achieved to date suggests that these are not insurmountable obstacles and that DC may become a useful therapeutic tool in transplantation and autoimmune disease.

Human myeloid dendritic cells transduced with an adenoviral interleukin-10 gene construct inhibit human skin graft rejection in humanized NOD-scid chimeric mice

Human myeloid DC were generated from peripheral blood mononuclear cells by monocyte adhesion and subsequent culture with rhGM-CSF and rhIL-4. We transduced immature (day 5 of culture) myeloid DC with an E1-deleted replication-deficient adenoviral vector encoding the cytokine IL-10 (AdV IL-10) and a control adenovirus MX-17 (AdV MX 17). Human DC transduced with AdV IL-10 showed inhibition of the mixed leukocyte culture, reduced cell surface expression of co-stimulatory molecules (CD80/CD86) and were unable to produce the potent allo-stimulatory cytokine, interleukin-12. In order to test the in vivo properties of these cells a humanized immunodeficient mouse skin transplantation model was developed. Immunodeficient NOD-scid mice were engrafted with human skin, reconstituted via intraperitoneal injection with allogeneic mononuclear cells (MNC) mixed with 1 x 10(6) DC that were autologous to the skin donor and that had been transduced with either AdV IL-10 or AdV MX-17. Skin grafts were removed at day 7 and 14 after reconstitution and studied histologically for evidence of rejection. In animals that received DC modified with AdV IL-10 there was reduced skin graft rejection as characterized by reduced mononuclear cell infiltration and less dermo-epidermal junction destruction compared with those animals that received DC modified with the control virus alone. Injection of equivalent numbers of donor-derived fibroblasts transduced with AdV IL-10 were ineffective at modifying rejection of skin grafts. Immunosuppressive cytokine gene therapy targeting human DC is a novel means of inhibition of the alloimmune response.

Shoulder appearances at MR imaging in long-term dialysis recipients

PURPOSE

To examine shoulder appearances at magnetic resonance (MR) imaging in long-term dialysis recipients.

MATERIALS AND METHODS

Twenty-two chronic dialysis recipients underwent 1.0-T MR imaging with a combination of T1-, T2-, and T2*-weighted sequences. Rotator cuff tendon thickening was graded as present or absent by a musculoskeletal radiologist, who also measured the supraspinatus and subscapularis tendon thicknesses with electronic calipers. The long-axis dimension and location of focal osseous lesions, in addition to their T1, T2, and T2* signal intensities, were noted.

RESULTS

Supraspinatus (n = 9) and subscapularis (n = 10) tendon thickening was frequently observed. Six (27%) of the 22 patients had combined thickening of the supraspinatus and subscapularis tendons without substantial involvement of the infraspinatus or teres minor tendons. These patients had undergone dialysis longer (median, 19.2 years; range, 16.3-22.8 years) than had the other patients (median, 11.7 years; range, 5.8-19.3 years; P: =.004). The 29 intraosseous lesions had high, intermediate, and low T2 signal intensity in six (21%), nine (31%), and 14 (48%) instances, respectively.

CONCLUSION

Supraspinatus and/or subscapularis tendon thickening is common in chronic dialysis recipients. Bone lesions in such patients are of variable T2 signal intensity and usually subchondral or adjacent to the greater tuberosity.