Skin microvascular dysfunction as an early cardiovascular marker in primary hyperoxaluria type I

BACKGROUND

Primary hyperoxaluria type 1 (PH1) is an orphan inborn error of oxalate metabolism leading to hyperoxaluria, progressive renal failure, oxalate deposition, and increased cardiovascular complications. As endothelial dysfunction and arterial stiffness are early markers of cardiovascular risk, we investigated early endothelial and vascular dysfunction in young PH1 patients either under conservative treatment (PH1-Cons) or after combined kidney liver transplantation (PH1-T) in comparison to healthy controls (Cont-H) and patients with a past of renal transplantation (Cont-T).

METHODS

Skin microvascular function was non-invasively assessed by laser Doppler flowmetry before and after stimulation by current, thermal, or pharmacological (nitroprussiate (SNP) or acetylcholine (Ach)) stimuli in young PH1 patients and controls.

RESULTS

Seven PH1-Cons (6 F, median age 18.2) and 6 PH1-T (2 F, median age 13.3) were compared to 96 Cont-H (51 F, median age 14.2) and 6 Cont-T (4 F, median age 14.5). The endothelium-independent vasodilatation (SNP) was severely decreased in PH1-T compared to Cont-H. Ach, current-induced vasodilatation (CIV), and thermal response was increased in PH1-Cons and Cont-T compared to controls.

CONCLUSIONS

PH1-T patients displayed severely decreased smooth muscle capacity to vasodilate. An exacerbated endothelial-dependent vasodilation suggests a role for silent inflammation in the early dysfunction of microcirculation observed in PH1-Cons and Cont-T.

Abdominal wall complications following renal transplantation in adult recipients - factors associated with interventional management in one unit

Background

Abdominal wall surgical site complications following renal transplantation can be challenging to manage. A sub-group of these recipients will require operative management or advanced wound care such as negative pressure wound therapy (NPWT). The aim of this study was to determine if there were any preoperative, intraoperative and postoperative characteristics in our recipients’ cohort which were associated with the requirement for such interventions.

Methods

A retrospective review of medical records was performed for all recipients who sustained abdominal wall complications following renal transplantation at our centre from 2006 to 2016.

Results

A total of 64/828 recipients (7.7%) had abdominal wall complications. The mean weight for these patients was 84.9 kg (±16.6 kg) and the mean body mass index was 30.2 (±5.1). Forty-five recipients (70%) had a superficial wound dehiscence while nine (14%) had a complete fascial dehiscence. Operative intervention was required in 13/64 patients (20%) and was more likely to be required in the presence of a fascial dehiscence (9/9, 100%) or a wound collection (10/31, 32%) (p < 0.001, p = 0.021). NPWT was used in 17/64 patients (27%) and was more commonly required in patients with diabetes mellitus (10/24, 42%), a complete fascial dehiscence (5/9, 56%) or evidence of infection (16/44, 36%) (p = 0.039, p = 0.034, p = 0.008).

Conclusions

The requirement for either operative management or the use of NPWT in the management of abdominal wall complications following renal transplantation in our experience was more common in recipients with diabetes mellitus, and in the setting of either complete fascial dehiscence, abdominal wall wound collections and/ or infection.

Validation of diagnostic utility of fasting plasma glucose and HbA1c in stable renal transplant recipients one year after transplantation

Background

The use of HbA1c ≥6.5% for diagnosis of diabetes has been challenged for post-transplantation diabetes mellitus (PTDM) also known as new onset diabetes after transplantation (NODAT) due to a low sensitivity early after renal transplantation. PTDM diagnosed with an oral glucose tolerance test (OGTT) is highly predictable for long-term patient mortality. HbA1c was introduced for diagnosis based on the risk of developing diabetic retinopathy. The utility of HbA1c measures versus glucose criteria has not been widely assessed in stable transplant patients but still HbA1c is widely used in this population. The aim of the present analyses was to validate the utility of fasting plasma glucose (FPG) together with HbA1c in diagnosing PTDM in stable renal transplant recipients (RTRs).

Methods

OGTT’s were performed one year after transplantation in 494 consecutive RTRs without diabetes. FPG and HbA1c were obtained the same day, before starting the OGTT. Validation was performed using C-statistics and logistic regression analyses.

Results

PTDM was diagnosed in 51 patients (10.3%) by glucose criteria, 38 (74%) patients were diagnosed by FPG ≥7.0 mmol/L [126.1 mg/dl], and 13 (26%) only by 2-h plasma glucose. Six of the latter had HbA1c ≥6.5%. Only seven patients out of the 51 (13.7%) PTDM patients remained undiagnosed when HbA1c ≥6.5% was used together with FPG, and five of these regressed to normal after a median follow-up of 14 months. ROC curves including FPG and HbA1c versus OGTT derived criteria revealed an AUC of 0.858.

Conclusions

Combining standard diagnostic FPG and HbA1c criteria captured almost all patients with persistent PTDM in stable RTRs. The combined use of the criteria appears to be an applicable diagnostic strategy for PTDM without the need of an OGTT one year post-transplant.

Trial registration

Retrospectively registered.

Novel markers of graft outcome in a cohort of kidney transplanted patients: a cohort observational study

Renal biopsy (RBx) informs about kidney transplantation (KTx) prognosis. In our observational study the prevalence of histological anomalies and the prognostic role of CD45, vimentin (VIM) and periostin (POSTN) in KTx-RBx have been evaluated. One hundred forty-six KTx-RBx (2009-2012) were analysed for general histology and in immunohistochemistry for CD45, VIM and POSTN. Clinical data of the 146-KTx patients were collected at the RBx time (T0), 6 and 12 months before and after RBx. Follow-up time was 21 ± 14 months. Glomerulosclerosis was 20% glomeruli/biopsy. Tubular atrophy (TA), Interstitial infiltrate (I-Inf) and interstitial fibrosis (IF) were slight in 21-18% and 25%, moderate in 22-30% and 26% and severe in 30-18% and 28% of patients. Fifty-eight percent of patients had lesions compatible with IF-TA. CD45, VIM and POSTN correlated to each-other and to TA, I-Inf and IF. VIM and POSTN correlated to GS. CD45 and VIM correlated directly to renal function (RF) and 25(OH)VitD, while POSTN inversely to 25(OH)VitD. Thirty patients restarted dialysis (HD+). HD+ had lower T0-eGFR, and higher CD45, VIM and POSTN than HD-. POSTN resulted the strongest in discriminate for HD+ . CD45, VIM and POSTN correlate to each-other and predict graft outcome. POSTN was the strongest in discriminate for HD+. 25(OH)VitD might influence inflammation and fibrosis in KTx.

Multiple cerebral abscesses in a renal transplant recipient: Two swords in one scabbard!

Although rare, both Cladophialophora bantiana (C. bantiana) and Toxoplasma gondii have been known to be associated with brain abscess in renal transplant recipients (RTRs), however co-infection has never been reported till date. In the present case, 40 years old renal transplant recipient on curtailed immunosuppressive therapy presented with progressive headache and altered sensorium. The computed tomography of head showed multiple ring-enhancing discrete lesions in the left frontal lobe, with moderate perilesional oedema. Left frontal craniotomy and aspiration revealed thick yellowish brown pus, which on culture showed the growth of dematiaceous fungal hyphae “C. bantiana” and co-infection with “Toxoplasma” was confirmed by PCR as well as serology (both IgM and IgG – Toxoplasma) positivity. Stereotactic aspiration/open craniotomy and drainage is imperative to arrive at microbiological diagnosis and provide timely therapy to the patient.

Late Cytomegalovirus Infection in Kidney Transplant Recipients after a Six-Month Prevention Protocol

BACKGROUND

Despite a reduction in the incidence of cytomegalovirus (CMV) infections after kidney transplantation, less is known about late CMV infection in kidney transplant recipients.

OBJECTIVE

To assess incidence of CMV infection in a cohort of patients under a high surveillance CMV prevention protocol and identify factors associated with late CMV infection.

METHODS

Analysis of a consecutive cohort of 181 kidney allograft recipients between January 2012 and Aug 2015. CMV prevention-protocol consisted of 6-month universal prophylaxis and pre-emptive therapy for high-risk group (D+/R- or patients submitted to lymphocyte-depleting agent for induction or rejection treatment) and pre-emptive therapy for standard-risk group (D±/R+). Stopping valganciclovir was followed by CMV screening in the next two appointments.

RESULTS

CMV infection was identified in 73 of 181 patients; the rate in high-risk group and standard-risk group was similar (p=0.443). However, in the latter group, the infection occurred mostly in the first 6 months. Late CMV infection occurred in 25 of 181 patients (5 of standard-risk group and 20 of high-risk group), after a median (IQR) of 253 (230.3-312.3) days after transplantation and 55 (41-89.5) days after the protocol period. Screening for CMV after valganciclovir discontinuation revealed 56% of late CMV infections. In high-risk group, D+/R- was associated with late CMV infection (HR 2.7, p=0.039) and in standard-risk group; lower age was associated with late CMV infection (HR 0.89, p=0.02).

CONCLUSION

The incidence of CMV infection was similar to that reported in the literature. In high-risk patients, antigenemia surveillance during prophylaxis did not appear to reduce late CMV infections. Antigenemia screening after valganciclovir had limited results in the diagnosis of late CMV infection. D+/R- was associated to late CMV infection in high-risk group. Lower age appeared to influence late CMV infection in standard-risk group.

Clinical aspects of tacrolimus use in paediatric renal transplant recipients

The calcineurin inhibitor tacrolimus, cornerstone of most immunosuppressive regimens, is a drug with a narrow therapeutic window: underexposure can lead to allograft rejection and overexposure can result in an increased incidence of infections, toxicity and malignancies. Tacrolimus is metabolised in the liver and intestine by the cytochrome P450 3A (CYP3A) isoforms CYP3A4 and CYP3A5. This review focusses on the clinical aspects of tacrolimus pharmacodynamics, such as efficacy and toxicity. Factors affecting tacrolimus pharmacokinetics, including pharmacogenetics and the rationale for routine CYP3A5*1/*3 genotyping in prospective paediatric renal transplant recipients, are also reviewed. Therapeutic drug monitoring, including pre-dose concentrations and pharmacokinetic profiles with the available "reference values", are discussed. Factors contributing to high intra-patient variability in tacrolimus exposure and its impact on clinical outcome are also reviewed. Lastly, suggestions for future research and clinical perspectives are discussed.

Management of chronic renal allograft dysfunction and when to re-transplant

Despite the advances in renal transplantation over the last decades, chronic allograft dysfunction remains the largest concern for patients, their families, clinicians and other members of the multi-disciplinary team. Although we have made progress in improving patient and renal allograft survival within the first year after transplantation, the rate of transplant failure with requirement for commencement of dialysis or re-transplantation has essentially remained unchanged. It is important that paediatric and adult nephrologists and transplant surgeons, not only manage their patients and their renal transplants but provide the best chronic kidney disease management during the time of decline of renal allograft function. The gold standard for patients with Stage V chronic kidney disease is to have pre-emptive living donor transplants, where possible and the same is true for healthy renal transplant recipients with declining renal allograft function. The consideration for children and young people as they embark on their end-stage kidney disease journey is the risk-benefit profile of giving the best immunologically matched and good quality renal allografts as they may require multiple renal transplantation operations during their lifetime.

Pregnancy in renal transplant patients: Renal function markers and maternal-fetal outcomes

OBJECTIVES

We aimed to evaluate laboratory markers in women who got pregnant after renal transplantation.

STUDY DESIGN

Cross-sectional prospective study.

MAIN OUTCOME MEASURES

Renal function parameters and maternal and fetal data were assessed in renal transplant recipients.

RESULTS

Forty-three women who got pregnant after renal transplantation (mean age, 28.5 years; mean gestational age, 35.6 weeks) were included. Most patients (53.5%) received a renal transplant from a deceased donor. Podocyturia was not significantly correlated with other renal function markers. Mean period from transplantation to pregnancy was approximately 5 years; this period was not associated with obstetric complications or changes in renal markers. A gradual increase was observed in the following parameters during pregnancy and puerperium: serum creatinine levels (P < 0.001), proteinuria (P < 0.001), urinary protein/creatinine ratio (P < 0.001), and albumin/creatinine ratio (P < 0.001). The sensitivity and specificity of protein/creatinine ratio in predicting preeclampsia were high (96.0% and 94.0%, respectively). Elevated serum creatinine levels, urinary albumin/creatinine ratio, and retinol-binding protein levels in the third trimester were associated with prematurity (P < 0.001). Preeclampsia was the main cause of renal function decline at the end of pregnancy (65.0% of cases). Approximately four (9.5%) pregnant women presented with premature rupture of membranes and 18 (42.0%) with a urinary tract infection.

CONCLUSIONS

Proteinuria, urinary protein/creatinine ratio, and retinol-binding protein levels were elevated in patients with preeclampsia. Using these markers to assess renal function during pregnancy may be clinically useful for detecting and monitoring renal injury in renal transplant recipients.

Association of silicone breast implants and acute renal allograft rejection

Silicone may, like any other adjuvant, induce an inflammatory reaction and diseases. There is no data about its use in renal transplant recipients. Increased immunogenicity of silicon may manifest by activation of both the innate and the adaptive immune system cells what promotes a chronic pro-inflammatory response. Dendritic cells, macrophages, fibroblasts and T-cells have all been found at the capsule/silicone implant contact zone. Additionally, silicon may induce mononuclear cells to secrete proinflammatory cytokines IL-1β, IL-6 and TNF-α. Herein, we present two patients who developed acute rejection after breast augmentation and reconstruction with silicone-gel implants. By influencing the immunological and inflammatory response, silicone-gel may be involved in promotion of acute allograft rejection in renal transplant recipients. Further studies are needed to prove our hypothesis.

Use of single-dose perioperative antimicrobial therapy is acceptable in recipients of living-donor renal transplants in the rituximab era

OBJECTIVE

The aim of this study was to evaluate the efficacy of single-dose perioperative antimicrobial therapy as infection prophylaxis in recipients of living-donor renal transplants in the rituximab era.

PATIENTS AND METHODS

Between 2009 and 2017, 84 recipients underwent living-donor renal transplantation (LDRT) at Okayama University Hospital; 3 with vascular/urinary complications requiring additional surgery were excluded from this analysis. Data including recipient characteristics, antimicrobial prophylaxis and administration of rituximab were retrospectively examined for an association with perioperative infections. Prophylactic antimicrobial agents, selected according to the Results of preoperative urine cultures, were administered just before incision. Perioperative infections, which consisted of surgical site infections, remote infections, and urinary tract infections, were defined as a positive culture indicating required administration of additional antimicrobial agents.

RESULTS

Among the 81 recipients, prophylactic cefazolin, ampicillin/sulbactam, and others were administered to 66 (82%), 13 (16%), and 2 (3%) recipients, respectively. Twenty-one (26%) received single-dose antimicrobial prophylaxis, while 60 (74%) received multiple doses up to 7 days. Rituximab was used in 59 (72.8%) recipients. The incidence of urinary tract infection, surgical site infection and remote infection was 13 (16%), 1 (1%), and 0, respectively. Univariate analysis could not demonstrate any significant risk factors for postoperative urinary tract infections, including a single dose vs multiple doses of antimicrobial therapy (P = 0.069) and administration of rituximab (P = 0.717).

CONCLUSIONS

Our data suggest that the use of single-dose perioperative antimicrobial therapy is acceptable for prophylaxis of infections in patients undergoing LDRT, even in the rituximab era.

Difference in IgA1 O-glycosylation between IgA deposition donors and IgA nephropathy recipients

IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis, and disease recurrence often occurs after transplantation. On the other hands, Asymptomatic IgA deposition (IgAD) is occasionally observed in donated kidney. It is recognized that IgAD does not progress to IgAN, but the mechanism has not demonstrated yet. In IgAN, aberrant IgA1 O-glycan structure in the hinge region (HR) of serum IgA is suggested as one of the most convincing key mediators. However, little is known about IgA1 O-glycan structure in IgAD patients. Herein, we investigated the prevalence of IgAD in living renal transplant donors in our cohort. IgAD was observed in 21(13.0%) among 161 renal transplant donors and have statistically significant blood relationship with IgAN recipients (28.6% in relatives vs. 9.8% in non-relatives, respectively; p = 0.0073). Next, we evaluated the IgA1 O-glycan structure of serum IgA from IgAN recipients (n = 26), IgAD donors (n = 17), and non-IgAD helthy donors (n = 27) using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The numbers of GalNAc and Gal and the Gal/GalNAc ratio in the HR of the IgAN recipients had significantly lower comparing to the IgAD and non-IgAD healthy donors. The decreased Gal/GalNAc ratio in IgAN recipients means the increased ratio of galactose-deficient IgA1. To the best of our knowledge, this is the first report to compare the O-glycan structures in IgAN recipients and IgAD donors using MALDI-TOF MS. We concluded that IgAD was more common in IgAN related donors. Overall, decreased GalNAc and Gal contents in HR could play a material pathogenic role in IgAN.

Time-intensity curve analysis of contrast-enhanced ultrasound is unable to differentiate renal dysfunction in the early post-transplant period - a prospective study

Background

Contrast enhanced ultrasonography (CEUS) assessment of kidney allografts mainly focuses on graft rejection. However, studies on delayed graft function (DGF) without acute rejection are still lacking. The aim of this study was to build a time-intensity curve (TIC) using CEUS in non-immunological DGF to understand the utility of CEUS in early transplantation.

Methods

Twenty-eight patients in the short-term postoperative period (<14 days) were divided according to the need for dialysis (early graft function [EGF] and [DGF]) and 37 subjects with longer than 90 days follow-up were divided into creatinine tertiles. Time to peak [TTP] and rising time [RT were compared between groups.

Results

EGF and DGF were similar, except for creatinine. In comparison to the late group, medullary TTP and RT were shorter in the early group as well as the delay regarding contrast arrival in the medulla (in relation to cortex) and reaching the medullary peak (in relation to artery and cortex). In the late group, patients with renal dysfunction showed shorter temporal difference to reach medullary peak in relation to artery and cortex.

Conclusions

Although it was not possible to differentiate EGF and DGF using TIC, differences between early and late groups point to blood shunting in renal dysfunction.

Mineral and Bone Disease in Kidney Transplant Recipients

PURPOSE OF REVIEW

Despite metabolic improvements following kidney transplantation, transplant recipients still often suffer from complex mineral and bone disease after transplantation.

RECENT FINDINGS

The pathophysiology of post-transplant disease is unique, secondary to underlying pre-transplant mineral and bone disease, immunosuppression, and changing kidney function. Changes in modern immunosuppression regimens continue to alter the clinical picture. Modern management includes reducing cumulative steroid exposure and correcting the biochemical abnormalities in mineral metabolism. While bone mineral density screening appears to help predict fracture risk and anti-osteoporotic therapy appears to have a positive effect on bone mineral density, more data regarding specific treatment is necessary. Patients with mineral and bone disease after kidney transplantation require special care in order to properly manage and mitigate their mineral and bone disease. Recent changes in clinical management of transplant patients may also be changing the implications on patients' mineral and bone disease.

Less renal allograft fibrosis with valganciclovir prophylaxis for cytomegalovirus compared to high-dose valacyclovir: a parallel group, open-label, randomized controlled trial

BACKGROUND

Cytomegalovirus (CMV) prophylaxis may prevent CMV indirect effects in renal transplant recipients. This study aimed to compare the efficacy of valganciclovir and valacyclovir prophylaxis for CMV after renal transplantation with the focus on chronic histologic damage within the graft.

METHODS

From November 2007 through April 2012, adult renal transplant recipients were randomized, in an open-label, single-center study, at a 1:1 ratio to 3-month prophylaxis with valganciclovir (n = 60) or valacyclovir (n = 59). The primary endpoint was moderate-to-severe interstitial fibrosis and tubular atrophy assessed by protocol biopsy at 3 years evaluated by a single pathologist blinded to the study group. The analysis was conducted in an intention-to-treat population.

RESULTS

Among the 101 patients who had a protocol biopsy specimen available, the risk of moderate-to-severe interstitial fibrosis and tubular atrophy was significantly lower in those treated with valganciclovir (22% versus 34%; adjusted odds ratio, 0.31; 95% confidence interval, 0.11-0.90; P = 0.032 by multivariate logistic regression). The incidence of CMV disease (9% versus 2%; P = 0.115) and CMV DNAemia (36% versus 42%; P = 0.361) were not different at 3 years.

CONCLUSIONS

Valganciclovir prophylaxis, as compared with valacyclovir, was associated with a reduced risk of moderate-to-severe interstitial fibrosis and tubular atrophy in patients after renal transplantation.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ( ACTRN12610000016033 ). Registered on September 26, 2007.

The Clinical Effects of Sildenafil for Erection in Patients after Kidney Transplantation: A Meta-Analysis

BACKGROUND

With the wide use of sildenafil in kidney-transplanted patients, it is vital to recognize the effectiveness and safety in clinical practice.

METHODS

Full-text articles involving the application of sildenafil after renal transplantation searched out in multiple databases were reviewed. All the meta-analyses were performed with Review Manager 5.0 software and bias analysis of the studies were conducted to examine the quality of articles. In addition, to estimate possible publication bias, funnel plot and the Egger's test were used.

RESULT

Finally 7 articles eventually satisfied the inclusion criteria. The penetration ability and maintenance frequency in sildenafil group were much larger than those of control group. Except orgasmic function, domains of the International Index of Erectile Function have showed larger scores in sildenafil group than those of control group. No significant difference of the concentration of cyclosporine was observed between sildenafil and control group.

CONCLUSION

In conclusion, this study showed that treatment with sildenafil in renal allograft recipients with erectile dysfunction is a valid and safe option.

Cancer risk after renal transplantation in South Korea: a nationwide population-based study

Background

This study aimed to evaluate patterns of posttransplant malignancies among renal transplant recipients (RTRs) in South Korea using nationwide data.

Methods

The nationwide cohort assessed in this study included RTRs from January 1, 2010, to December 31, 2014. We analyzed cancer incidence during the time course after renal transplantation. Additionally, we calculated standardized incidence ratios (SIRs) to evaluate the risk of malignancies in RTRs.

Results

A total of 1343 RTRs (871 males and 472 females, mean age 48.5 ± 11.6 years) were assessed. Among them, 104 (7.7%) developed malignancies after transplantation, most commonly in the thyroid cancer (23.1%). The SIR for all cancers was 3.54; particularly, the SIRs for renal cancer, myeloma, and non-Hodgkin lymphoma were 16.31, 24.02, and 28.64, respectively. Females showed a higher risk of malignancy than males (SIRs: 4.04 for women and 3.26 for men). The median interval between transplantation and malignancy diagnosis was 27.2 months (range 12.3–54.8 months).

Conclusions

RTRs in South Korea demonstrated a high risk of malignancy after transplantation compared with the general population. This indicates that close surveillance and routine screening for cancer in RTRs are needed.

Sequential monitoring of TIM-3 mRNA expression in blood and urine samples of renal transplant recipients

BACKGROUND

T cell immunoglobulin and mucin domain 3 (TIM-3), as a co-inhibitory receptor expressed on Th1, Th17, CD8T, FoxP3 + Treg and innate immune cells, plays an important role in suppression of T cell-mediated immune responses, tolerance induction and T cell exhaustion. In this study, we evaluated sequential alterations of TIM-3 mRNA expression level in blood and urine samples of renal transplant recipients to predict approaching clinical episodes.

METHODS

A total of 52 adult renal transplant recipients (31 male and 21 female) were enrolled in this study. All the patients received kidney transplant from living unrelated donors. TIM-3 mRNA expression in peripheral blood mononuclear cells (PBMCs) and urinary cells were quantified using Real Time TaqMan polymerase chain reaction (PCR) at 4 different time points (pre-transplantation, 2, 90 and 180 days post-transplantation).

RESULT

TIM-3 mRNA expression level on days 2, 90 and 180 after transplantation was significantly higher in blood and urine samples of patients with graft dysfunction (GD) compared with patients with well-functioning graft (WFG). Our results also showed a high correlation between blood and urinary level of TIM-3 mRNA expression. The data from Receiver Operating Characteristic (ROC) Curve Analysis showed that blood and urinary TIM-3 mRNA expression level at month 3 and 6 could discriminate graft dysfunction (GD) from well-functioning graft (WFG) with high specificity and sensitivity.

CONCLUSION

Our data suggested that serial monitoring of TIM-3 mRNA level in the blood and urine samples of renal transplant recipients could be a useful non-invasive biomarker for prediction and diagnosis of allograft dysfunction.

Long-term outcome of pediatric renal transplantation in boys with posterior urethral valves

PURPOSE

To determine whether there is a difference in the outcome of renal transplantation (RT) in patients with posterior urethral valves (PUV) and children with non-uropathy related end stage renal disease.

METHODS

Data were acquired retrospectively. We analyzed possible factors that influence the function of renal allografts and graft survival. Between 1995 and 2016 there were 149 RT. Out of them, there were 27 boys with PUV, who received 29 kidneys. Thirty patients, who received a total of 31 renal grafts due to a non-uropathic (NU) diagnosis, served as control group. Mean follow-up was 7.4 to 10.2 years.

RESULTS

There was no difference in estimated graft survival between patients with PUV and NU patients. Graft failure occurred in 23.1% of PUV patients and 34.5% patients of the NU group. There was no statistically significant disparity in graft function between the two groups. Age at transplantation and donor age were the only factors that had a significant impact on renal function. There was a higher incidence of UTI in the PUV group (96%) than in the NU group (67%). Vesicostomy was the favourable intervention in regards of graft function.

CONCLUSIONS

RT in PUV patients is successful with the same outcome as in NU patients. Bladder dysfunction may not have a major impact on graft function and graft survival. It seems that the type of pre-transplant surgical procedures may influence outcome. Therefore, these interventions -if necessary- should be limited to a minimum.

TYPE OF STUDY

Retrospective Comparative Study LEVEL OF EVIDENCE: Level III.

Prediction of mizoribine pharmacokinetic parameters by serum creatinine in renal transplant recipients

PURPOSE

Mizoribine (MZR) is an immunosuppressive agent with extensive inter-individual differences in pharmacokinetics (PK). Here, we investigated the PK characteristics of MZR in renal transplant recipients and gave equations for prediction of some critical PK parameters.

METHODS

A total of 40 renal transplant recipients participated in this prospective study and were administered MZR orally twice daily in the range of 1.1-8.9 mg kg^-1 day^-1. Steady-state concentrations of MZR were detected before (0 h) and 0.5, 1, 2, 3, 4, 5, 6, 8, and 12 h after administration by high-performance liquid chromatography method. Another 38 patients with newly detected trough concentration (C₀) were enrolled to validate the obtained C₀ predictive equation.

RESULTS

Significant inter-individual differences in MZR PK parameters were observed. Patients with decreasing creatinine clearance rate (CCr) had significantly decreased terminal elimination rate constant (k_el) and apparent total body clearance (Cl/F), while other PK parameters including apparent terminal half-life (t_1/2), peak time (T_max), peak concentration (C_max), area under the curve (AUC_0-12h), apparent volume of distribution (V/F), and mean residence time (MRT) were significantly increased. Correlation coefficients between AUC_0-12h and C₀/C_max were 0.894 and 0.916, respectively (both p < 0.001). A serum creatinine (SCr)-based predictive C₀ equation [C₀ = (2.160 × SCr - 54.473) × Dose] was established and validated by C₀ from another 38 patients. Besides, significant linear correlations between k_el/t_1/2 and CCr were also found (r² = 0.668 and 0.484, respectively), and equations predicting k_el/t_1/2 were also obtained (k_el = 0.015 + 0.002 × CCr, t_1/2 = 13.601 - 0.139 × CCr).

CONCLUSIONS

Renal function plays as an essential factor that contributes to great inter-individual MZR PK variation. Both C₀ and C_max are suitable for evaluating MZR exposure in the body. SCr could be applied to predict C₀ and t_1/2 of MZR.

Early renal arterial rupture and arterial pseudoaneurysm in graft kidneys from the same deceased donor

Vascular complications are serious problems after kidney transplantation. An aneurysm or rupture in a graft artery is a rare but potentially devastating complication, which may lead to renal function impairment, graft loss, or even death. In this paper, we present two rare vascular complications in the early postoperative course after renal transplantation from the same deceased donor. In the first case, a 49-year-old woman who had spontaneous graft arterial rupture 13 days after kidney transplantation presented with sudden distension in the right lower abdomen. In the second case, a 56-year-old woman recipient with a graft renal arterial pseudoaneurysm presented with decreased urine output and deteriorating renal function 32 days after transplantation. Immediate surgical repair was performed, and fibrin sealant was applied to strengthen the fragile renal arterial wall. Although the function of both graft kidneys recovered well after surgery, the first graft kidney was removed 2 months later because of repeated fungal and bacterial infections. Aggressive surgical reconstruction may preserve graft kidneys in patients with vascular complications after kidney transplantation, but recovery of the graft condition remains a demanding challenge in renal transplantation.

Is Early Complement Activation in Renal Transplantation Associated with Later Graft Outcome?

BACKGROUND/AIMS

Complement activation is important in post-transplantation renal injury, but data on its role as predictor of transplant outcome/complications when assessed in donor kidneys are lacking.

METHODS

In human renal transplant biopsies with delayed graft function (DGF, n=12), antibody mediated rejection (ABMR, n=8), T-cell mediated rejection (TCMR, n=11), 1 year protocol biopsies (control, n=10) and corresponding zero-biopsies we performed immunohistochemical analyses of 6 complement factors using FFPE sections and correlated the findings with kidney function, as assessed by serum creatinine, and morphological changes including interstitial fibrosis and tubular atrophy (IF/TA).

RESULTS

In DGF, TCMR and ABMR significant complement deposition was observed, which was less pronounced in corresponding zero-biopsies. Zero-biopsies with subsequent ABMR showed glomerular complement factor D and C3c expression. Moreover, glomerular C3c and C9 and tubular MASP-2 and Collectin-11 expression in zero-biopsies significantly correlated with serum creatinine at diagnosis of DGF, TCMR or ABMR. Glomerular C1q was significantly increased in ABMR, but not in DGF and TCMR. In contrast, peritubular C1q was significantly enhanced in DGF and TCMR compared to zero-biopsies. Using C3d as a surrogate marker for complement activity we could confirm that stained complement factors are frequently associated with complement activity.

CONCLUSION

Complement deposition strongly correlated with histopathological changes observed in renal transplants. All 3 complement pathways were operational in biopsies with DGF, TCMR and ABMR albeit with differential abundance and localization. Since complement deposition in zero-biopsies correlated with graft function and morphological changes, early specific complement inhibition in renal transplantation may be a new therapeutic option to prevent graft loss.

Current strategies to predict and manage sequelae of posterior urethral valves in children

Posterior urethral valves (PUV) constitute a significant urological cause of chronic kidney disease (CKD) in children. The condition is characterised by the unique pathophysiology of the evolution of bladder dysfunction after relief of obstruction, which contributes to CKD. Improvements in prenatal diagnosis followed by selective foetal intervention have not yet produced improvement in long-term renal outcomes, although better patient selection may alter this in the future. Proactive management with surveillance, pharmacotherapy, timed voiding, double voiding, and/or assisted bladder-emptying, is being increasingly offered to those with severe bladder dysfunction and has the potential of reducing the burden of renal disease. Clinicians are currently able to counsel regarding the prognosis using serum creatinine and other emerging markers. However, much of this work remains to be validated. Satisfactory graft survival rates are now reported with aggressive management of bladder dysfunction in children who are candidates for renal transplantation. Knowledge gaps exist in identifying early markers of renal injury, risk stratification, and in understanding patient and carer perspectives in PUV.

Impact of immune suppressive agents on the BK-Polyomavirus non coding control region

BACKGROUND

Reactivation of the BK-Polyomavirus (BKPyV) can cause a polyomavirus associated nephropathy in approx. 10% of kidney transplant recipients. In these cases, current therapy is based on the reduction of immunosuppression. Since BKPyV-transcription is driven by the Non-Coding-Control-Region (NCCR) we were interested whether NCCR-activity is affected by immunosuppressive agents.

METHODS

Plasma samples from 45 BKPyV-positive patients after renal transplantation were subjected to PCR-analysis. NCCR-amplicons were cloned into a plasmid that allows the quantification of early and late NCCR-activity by tdTomato and eGFP expression, respectively. HEK293T-cells were transfected with the reporter-plasmids, treated with immunosuppressive agents, and subjected to FACS-analysis. In addition, H727-cells were infected with patient derived BKPyV, treated with mTOR-inhibitors, and NCCR activity was analysed using qRT-PCR.

RESULTS

While tacrolimus and cyclosporine-A did not affect NCCR-promoter-activity, treatment with mTOR1-inhibitor rapamycin resulted in the reduction of early, but not late-NCCR-promoter-activity. Treatment with dual mTOR1/2 inhibitors (INK128 or pp242) led to significant inhibition of early, however, concomitantly enhanced late-promoter-activity. In BKPyV infected cells both rapamycin and INK128 reduced early expression, however, INK128 resulted in higher late-mRNA levels when compared to rapamycin treatment.

CONCLUSIONS

Our results demonstrate that mTOR1-inhibitors are able to reduce early-expression of wildtype and rearranged NCCRs, which might contribute to previously described inhibition of BKPyV-replication. Dual mTOR1/2-inhibitors, however, additionally might shift viral early into late-expression promoting synthesis of viral structural proteins and particle production.

Contribution of diminished kidney transplant GFR to increased circulating chemokine ligand 27 level

Background

Inflammatory chemokine ligands (CCLs) play an important role in cardiovascular disease and allograft injury. CCLs may independently associate with diminished estimated glomerular filtration rate (eGFR) in stable renal transplant recipients (RTR).

Methods

Plasma levels of 19 CCLs (1, 2, 3, 4, 5, 8, 11, 13, 15, 17, 21, 24, 26, 27, CXCL5, 8, 10, 12 and 13) were measured in a cohort of 101 RTR. The cohort was divided according to CKD-EPI equation into three groups; group 1: eGFR ≥ 60 ml/min, group 2: eGFR 30–59.9 ml/min and group 3 eGFR ≤ 29.9 ml/min. ANOVA, Krusklwallis, Mann- Whitney Spearman correlation and regression analysis tests were used to determine association between reduced eGFR and inflammatory CCLs plasma levels measured by multiplex techniques. 20 healthy subjects with eGFR above 90 ml/min were included as control. Significance was sat at < 0.05.

Results

Levels of CCLs 1, 4, 15, 27, CXCL8 and CXCL10 were significantly different among the four studied groups. Multivariate regression analysis (MVA) between eGFR and all CCLs demonstrated that CCL27 was the only ligand to remain significantly associated with diminished eGFR {P = 0.021 and r = − 0.35,(P = 0.001)}. In a second MVA between CCL 27 and patient’s demographics and laboratory variables, diminished eGFR, and elevated PTH, out of the twenty one available variables remained significantly associated with elevated CCL27levels.

Conclusion

Diminished eGFR in stable RTR is associated with elevated plasma levels of CCL27. This association may explain, at least in part, the independent contribution of reduced eGFR to enhanced inflammation in RTR.