Quantitative and semi‐quantitative histopathological examination of renal biopsies in healthy individuals,and associations with kidney function

This study assesed the prevalence of histopathological changes in renal biopsies from healthy individuals, and the association with age, sex and smoking. Donor biopsies from 109 subjects were obtained from living kidney donors, and blood and urine samples were collected together with medical history. All biopsies were scored according to the Banff ‘97 classification with some modifications. The parameters included in this study were tubular atrophy, interstitial fibrosis, glomerulosclerosis, arteriosclerosis, arteriolohyalinosis and a sclerosis score. An alternative scoring system for tubular atrophy was examined (using ≤5% rather than <1% as a cut‐off for grade 0). Glomerular filtration rate was measured in most cases as chromium ethylenediaminetetra‐acetic acid (Cr‐EDTA) clearance. Age was a significant predictor for tubular atrophy, fibrosis and sclerosis. Pack‐years of smoking increased the risk of tubular atrophy, fibrosis and arteriolohyalinosis. The alternative scoring of tubular atrophy showed a stronger association with smoking, but a weaker association with age, compared with the original one. Limited histopathological changes are common in healthy kidney donors around 50 years of age with normal kidney function. We propose that a cut‐off of ≤5% yields a better definition of grade 0 tubular atrophy compared with the established cut‐off of >0%.     

Utilization and evaluation of living-related donors for patients with adult polycystic kidney disease

Adult onset polycystic kidney disease (ADPKD) cause 10% of all end-stage renal disease in the United States. Use of living-related donors for renal transplants provides significant advantages over cadaver donors. Presymptomatic testing to determine ADPKD status of potential donors by DNA linkage analysis is potentially more accurate than renal ultrasonography for related donors < 30 years old. To determine the utilization of living donor transplants and linkage studies, a survey was mailed to 202 transplant centers in the United Network of Organ Sharing. The 111 respondents reported 5,026 renal transplants done in 1988 of which 390 (7.8%) involved an ADPKD recipient. Only 7% of these 390 transplants utilized a living-related donor compared to the 20% rate reported for all renal transplants. DNA linkage studies were not used by any of the centers performing related donor transplants in 1988 and only 29% reported provision of risk counseling. We conclude that living-related transplants are underutilized for ADPKD recipients due to conservative transplant policies, concern about the inaccuracy of presymptomatic diagnosis, or decreased availability of asymptomatic donors in these families. DNA linkage analysis is also underutilized due to lack of knowledge of its availability and accuracy, concerns about its cost and misconceptions about the accuracy of ultrasonography. Since the accuracy of molecular genetics techniques for presymptomatic diagnosis of ADPKD continues to improve and because transplants from living-related donors convey significant advantages to recipients over cadaver transplants, we recommend that (1) a living-related transplant be considered when feasible for ADPKD patients, (2) genetic counseling and DNA linkage analysis for presymptomatic testing be utilized for related donors when applicable, and (3) communication be improved between renal transplant and genetic centers.     

The utilization of pre‐implantation genetic testing in the absence of governance: a real‐time experience

To create a diagnostic document describing the utilization of pre‐implantation genetic testing (PGT) in the absence of monitoring and regulation. Retrospective cohort study of couples undergoing PGT between 2004 and 2007 in Lebanon. The clinical indications for 192 PGT cycles performed during the study period were gender selection (96.3%), chromosomal aneuploidy (3.1%), and balanced translocation (0.5%). When gender selection was sought, the selection of a son was desired in 94.1% of cases. Of couples undergoing PGT for sex selection, 16.2% were childless, 8.6% had one child of the opposite gender, 28.1% had two same‐gender children, 29.7% had three same‐gender children, and 11.9% had four or more. Our findings demonstrate the morally questionable consequences of self‐regulated systems in which physicians are the sole gatekeepers of norms and ethics.     

Acquired cystic disease‐associated renal cell carcinoma is the most common subtype in long‐term dialyzed patients: Central pathology results according to the 2016 WHO classification in a multi‐institutional study

New pathological subtypes of renal cell carcinoma (RCC) were designated in the 2016 World Health Organization (WHO) classification corresponding to the features commonly seen in patients with end‐stage renal disease (ESRD). To determine the clinicopathological findings of new subtypes, we reanalyzed all sections from 315 kidneys in 291 ESRD patients bearing RCC tumors surgically resected in three Japanese institutes by the central pathologist. Clear cell RCC was diagnosed in 144 kidneys (45.7%), acquired cystic disease (ACD)‐associated RCC in 100 (31.7%), papillary RCC in 41 (13.0%), and other minor subtypes in 30 (9.52%). Multivariate analysis showed that longer duration of dialysis, young age, and male sex were independent prognostic clinical factors for the occurrence of ACD‐associated RCC. ACD‐associated RCC included more WHO/International Society of Urologic Pathology (ISUP) grade 3/4 cases compared to other RCCs. In contrast, other unfavorable findings were less frequent in ACD‐associated RCC, including the presence of a sarcomatoid component, lymphovascular invasion, and necrosis. In conclusion, ACD‐associated RCC is a common histology in Japanese patients with ESRD. In addition, ACD‐associated RCC showed more cases with a higher WHO/ISUP grade, but fewer cases with other unfavorable pathological features, suggesting a favorable prognosis of ACD‐associated RCC.     

The significance of pretransplant donor‐specific antibodies reactive with intact or denatured human leucocyte antigen in kidney transplantation

Antibodies recognizing denatured human leucocyte antigen (HLA) can co‐react with epitopes on intact HLA or recognize cryptic epitopes which are normally unaccessible to HLA antibodies. Their specificity cannot be distinguished by single antigen beads (SAB) alone, as they carry a mixture of intact and denatured HLA. In this study, we selected pretransplant sera containing donor‐specific HLA class I antibodies (DSA) according to regular SAB analysis from 156 kidney transplant recipients. These sera were analysed using a SAB preparation (iBeads) which is largely devoid of denatured HLA class I, and SAB coated with denatured HLA class I antigens. A total of 241 class I DSA were found by regular SAB analysis, of which 152 (63%) were also found by iBeads, whereas 28 (11%) were caused by reactivity with denatured DNA. Patients with DSA defined either by regular SAB or iBeads showed a significantly lower graft survival rate (P = 0·007) compared to those without HLA class I DSA, whereas reactivity to exclusively denatured HLA was not associated with decreased graft survival. In addition, DSA defined by reactivity to class I SAB or class I iBeads occurred more frequently in female patients and in patients with historic HLA sensitization, whereas reactivity to denatured HLA class I was not associated with any of these parameters. Our data suggest that pretransplant donor‐specific antibodies against denatured HLA are clinically irrelevant in patients already sensitized against intact HLA.     

HLA‐specific memory B‐cell detection in kidney transplantation: Insights and future challenges

Humoral alloimmunity mediated by anti‐human leucocyte antigen (HLA) antibodies is a major challenge in kidney transplantation and impairs the longevity of the transplanted organ. The immunological risk of an individual patient is currently mainly assessed by detection of HLA antibodies in the serum, which are produced by long‐lived bone marrow‐residing plasma cells. However, humoral alloimmunity is complex, and alloreactive memory B cells constitute an additional factor in the interplay of immune cells. These recirculating “silent” cells are responsible for the immunological recall response by differentiating into antibody‐producing cells upon antigen re‐encounter. Historically, due to the lack of appropriate and routinely applicable assays to determine the presence and HLA specificity of alloreactive memory B cells, their contribution to the humoral alloimmune response has clinically often been suspected but could not be determined. In this review, we give an overview of recent advances in techniques to detect alloreactive memory B cells and discuss their strengths and limitations. Furthermore, we summarize experiences with these techniques in alloimmunized individuals and transplant recipients, thereby emphasizing unmet needs to be addressed in future studies.     

Increased natural killer cell subsets with inhibitory cytokines and inhibitory surface receptors in patients with recurrent miscarriage and decreased or normal subsets in kidney transplant recipients late post‐transplant

Patients with recurrent miscarriage (RM) show up‐regulated cytotoxic natural killer (NK) cells that are suspected to play a causal role in abortion. In the present study, we investigated counter‐regulating inhibitory mechanisms and compared the results in RM patients with those of healthy controls (HC), patients with end‐stage renal disease (ESRD) and kidney transplant recipients late post‐transplant (TX). NK, NK T and T cell subsets were analysed in the peripheral blood of 31 RM, 14 female ESRD and nine female TX patients as well as 21 female HC using eight‐colour fluorescence flow cytometry. Compared with HC, RM patients showed significantly higher absolute numbers of CD56⁺ NK cells co‐expressing the phenotype interferon (IFN)‐γR⁺, IL‐4⁺, transforming growth factor (TGF)‐β⁺, IL‐4⁺ human leucocyte antigen D‐related (HLA‐DR)⁺, TGF‐β⁺HLA‐DR⁺, IL‐4⁺TGF‐β⁺, IL‐4⁺TGF‐β^–, IFN‐γ⁺ and/or IL‐10^–IFN‐γ⁺ (all P ≤ 0·01), more IL‐17⁺CD56^bright (P = 0·028) NK cells and more CD56^dimCD16⁺ NK cells co‐expressing IFN‐γR, IFN‐γ, IL‐4 and/or TGF‐β (all P ≤ 0·01). When the same cell subsets were analysed in ESRD or TX patients, cytokine‐producing NK cell subsets were not significantly different from those of HC. RM patients showed significantly higher absolute numbers of CD158a⁺, CD158b⁺, CD158a^–CD158e⁺ (all P < 0·05), NKG2D⁺NKG2A⁺, NKG2D ⁺NKG2A^–, NKG2D⁺ and/or NKG2A⁺ (all P ≤ 0·01) CD56⁺ NK cells and higher CD158a⁺, CD158b⁺ (all P < 0·05), NKG2D⁺ and/or NKG2A⁺ (all P < 0·01) CD56^dim+CD16⁺ NK cells than HC. In contrast, ESRD patients had normal and TX recipients had lower CD158a⁺ and NKG2D⁺NKG2A^–CD56⁺ NK cells and lower CD158a⁺CD56^dim+CD16⁺ NK cells (all P < 0·05) than HC. RM patients have abnormally high circulating NK cells expressing inhibitory cytokines and inhibitory surface receptors which might contribute to the pathogenesis of RM.     

Fate of full‐house immunofluorescence staining in renal allograft: A case report

Here, we report the case of a patient with renal allograft with full‐house immunofluorescence staining in the zero‐hour biopsy. Full‐house immunofluorescence staining is a well‐known characteristic of lupus nephritis. Previous studies have reported patients with full‐house immunofluorescence staining, but without other symptoms or serological findings; this condition is referred to as full‐house nephropathy. We identified only one case out of 2203 zero‐hour biopsies over 13 years. Zero‐hour biopsy presented no glomerular changes but showed full‐house immunofluorescence staining. Electron microscopy revealed a nonorganized electron‐dense deposit mainly in the mesangial lesion. Systemic lupus erythematosus (SLE)‐associated antibodies were negative, and complement deficiency was not observed in the donor patients. Deposition of immunoglobulin and complement levels markedly decreased within 1–3 years post transplantation. Neither donor nor recipient developed clinical or biological features of SLE; they showed good renal prognosis.     

Three‐dimensional localisation of NANOG,OCT4, and E‐cadherin in porcine pre‐ and peri‐implantation embryos

The expression patterns of NANOG and OCT4 have previously been reported to differ markedly between mammalian species indicating distinct species‐specific roles during development. We investigate the three‐dimensional expression pattern of NANOG and OCT4 in porcine pre‐ and peri‐implantation embryos. The expression of NANOG differed remarkably from that reported in other species. NANOG was not detected in the inner cell mass of hatched porcine blastocysts, but later appeared in the epiblast and hypoblast of spherical blastocysts where Rauber's layer had disintegrated. In pre‐gastrulating, filamentous embryos NANOG was localised to nuclei in a minor portion of the epiblast cells in which E‐CADHERIN seemed to be up‐regulated and OCT4 down‐regulated. Later NANOG was restricted to the potential PGCs. OCT4 was detected in inner cell mass, epiblast, and mesoderm, and we found that OCT4 expression, in contrast to earlier speculations, at least in hatched blastocysts, resembles the expression pattern in the mouse embryo. Developmental Dynamics, 2011. © 2010 Wiley‐Liss, Inc.     

Pharmacokinetics of mycophenolic acid and its phenyl glucuronide metabolite in kidney transplant recipients with renal impairment

Introduction

The aim of the study was to analyse the influence of renal impairment on the pharmacokinetic parameters (PK) of mycophenolic acid (MPA) and its glucuronide metabolite (MPAG) in renal transplant recipients.

Material and methods

The study included 43 adult patients during the maintenance period (> 6 months) following renal transplantation, treated with mycophenolate mofetil (MMF), calcineurin inhibitors (CNI) (tacrolimus or cyclosporine) and steroids. The study compared patients with normal renal function (n = 17; creatinine clearance (C_cr) > 60 ml/min) and with renal impairment (n = 26; C_cr < 60 ml/min). Areas under the 4-h curve (AUC_{0-4 h}) of MPA and MPAG were determined using a validated HPLC method.

Results

The renal impairment group showed significantly increased AUC_{0-4 h} and pre-dose (C₀) for MPAG compared to patients with normal renal function and increased MPA C₀. However, there was no significant difference in MPA AUC_{0-4 h} between patients with renal impairment and patients with normal renal function. In multivariate analysis some MPA and MPAG PK parameters were correlated with sex, CNI co-administered and body weight.

Conclusions

Although MPAG is an inactive metabolite, its accumulation in patients with renal impairment can be unfavourable. The results of our study indicate that solely MPA C₀ determination in patients receiving MMF may be insufficient in clinical practice because of great inter-patient variability of this PK parameter caused mainly by enterohepatic recirculation.     

Significance of the HLA-DQB matching in one-haplotype identical kidney transplant pairs and the matching analysis by the polymerase chain reaction (PCR) — heteroduplex — polymorphism method

Abstract: Sixty-five living related kidney transplant pairs were analyzed for matching at HLA class II loci by the polymerase chain reaction (PCR)- sequence specific oligonucleotide probe (SSOP) method. The retrospective HLA matching study revealed that there were many early graft loss cases despite the DQB compatibility, contrary to our expectation. There were 54 DRB1 one-mismatched cases, in which 7 of the 11 (64%) DQB zero-mismatched cases had lost their grafts, while the graft loss cases were only 10 of the 43 (23%) DQB one-mismatched pairs (P value=0.0006). The DQB matching of these cases was studied in detail, because the PCR-SSOP methods are based on the detection of sequence polymorphisms in a relatively narrow range, i.e., recognized sequences by SSOPs. The PCR - heteroduplex - polymorphism analysis method was developed to analyze the polymorphism in exon 2 of the DQB1 gene. However, all the pairs proved to be compatible for the DQB, demonstrating that the DQB compatibility was associated with a harmful influence on the graft outcome. These observations suggested that the DQB1 incompatibility might exert the low responsiveness to HLA haplo-identical allogeneic transplants.     

A pilot study of single nucleotide polymorphisms in the interleukin‐6 receptor and their effects on pre‐ and post‐transplant serum mediator level and outcome after allogeneic stem cell transplantation

Interleukin (IL)‐6 is an important regulator of immunity and inflammation in many diseases. Single nucleotide polymorphisms (SNPs) in the IL‐6 gene influence outcome after allogeneic stem cell transplantation (ASCT), but the possible importance of SNPs in the IL‐6 receptor has not been examined. We therefore investigated whether SNPs in the IL‐6R gene influenced biochemical characteristics and clinical outcomes after ASCT. We examined the IL‐6 promoter variant rs1800975 and the IL‐6R SNPs rs4453032, rs2228145, rs4129267, rs4845374, rs4329505, rs4845617, rs12083537, rs4845618, rs6698040 and rs4379670 in a 101 population‐based cohort of allotransplant recipients and their family donors. Patients being homozygous for the major alleles of the IL‐6R SNPs rs2228145 and rs4845618 showed high pretransplant CRP serum levels together with decreased sIL‐6R levels; the decreased IL‐6R levels persisted 6 months post‐transplant. In contrast, patients being homozygous for the minor allele of the IL‐6R SNP rs4379670 showed decreased pretransplant CRP levels. Furthermore, the IL‐6R rs4845618 donor genotype showed an association with severe acute graft‐versus‐host disease (GVHD), whereas the donor genotype of the IL‐6 SNP rs1800795 was associated with decreased survival 100 days post‐transplant. Finally, the recipient genotype of the IL‐6R SNP rs4329505 showed a strong association with 2‐years non‐relapse mortality, and this effect was also highly significant in multivariate analysis. IL‐6 and IL‐6R SNPs influence the clinical outcome after allogeneic stem cell transplantation.     

Genetic effects on the liability of developing pre‐eclampsia and gestational hypertension

Genetic factors are known to be important in the etiology of pre‐eclampsia and possibly also gestational hypertension, but the degree of genetic influence has not been quantified. To estimate the genetic and environmental effects on the liability of developing pre‐eclampsia and gestational hypertension, we cross‐linked the population‐based Swedish Twin Register and the Swedish Medical Birth Register. We included female twin pairs with known zygosity, both of whom gave birth in Sweden from 1973 through 1993; in all 917 monozygotic and 1,199 dizygotic twin pairs. For pre‐eclampsia, the estimates of heritability and nonshared environmental effect were 0.54 (95% confidence interval 0–0.71) and 0.46 (0.29–0.67), respectively; corresponding estimates for gestational hypertension were 0.24 (0–0.53) and 0.76 (0.47–1.00), respectively. When considering both diseases as a single entity (pregnancy‐induced hypertensive diseases), the heritability estimate was 0.47 (0.13–0.61). These results suggest that genetic factors are important in the development of pre‐eclampsia as well as gestational hypertension. The heritability estimates can be of importance when planning genetic linkage studies. In efforts to identify women with elevated risk of developing pre‐eclampsia during pregnancy, a question about family history of pre‐eclampsia should be included. Am. J. Med. Genet. 91:256–260, 2000. © 2000 Wiley‐Liss, Inc.     

Advantage of tacrolimus/mycophenolate mofetil regimen for cytotoxic T cell‐mediated defence and its inhibition by additive steroid administration in high‐risk liver transplant recipients

Our previous work revealed that the recipients with the highest pre‐existing numbers of CD8⁺ effector T cells (T_E) [hyperparathyroidism (HPT)_E recipients] occupied approximately 30% of adult transplant recipients performed in our hospital. HPT_E recipients demonstrated very poor clinical outcome compared with the remaining 70% of recipients with the lowest pre‐existing T_E (LPT_E recipient). This study aimed to clarify the best combined immunosuppressive regimen related to function of cytotoxic T lymphocytes (CTLs) for HPT_E recipients. Eighty‐one HPT_E recipients were classified into three types, according to the immunosuppressive regimens: type 1, tacrolimus (Tac)/glucocorticoid (GC); type 2, Tac/mycophenolate mofetil (MMF)/GC; and type 3, Tac/MMF. Frequencies of severe infection, rejection and hospital death were the highest in types 1 and 2, whereas the lowest occurred in type 3. The survival rate in type 3 was the highest (100%) during follow‐up until post‐operative day 2000. Regarding the immunological mechanism, in type 1 T_E perforin and interferon (IFN)‐γ were generated through the self‐renewal of CD8⁺ central memory T cells (T_CM), but decreased in the early post‐transplant period due to marked down‐regulation of interleukin (IL)‐12 receptor beta‐1 of T_CM. In type 2, the self‐renewal T_CM did not develop, and the effector function could not be increased. In type 3, in contrast, the effectors and cytotoxicity were correlated inversely with IL‐12Rβ1⁺ T_CM levels, and increased at the highest level around the pre‐transplant levels of IL‐12Rβ1⁺ T_CM. However, the immunological advantage of Tac/MMF therapy was inhibited strongly by additive steroid administration.     

A comprehensive non‐invasive framework for automated evaluation of acute renal transplant rejection using DCE‐MRI

The objective was to develop a novel and automated comprehensive framework for the non‐invasive identification and classification of kidney non‐rejection and acute rejection transplants using 2D dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI). The proposed approach consists of four steps. First, kidney objects are segmented from the surrounding structures with a geometric deformable model. Second, a non‐rigid registration approach is employed to account for any local kidney deformation. In the third step, the cortex of the kidney is extracted in order to determine dynamic agent delivery, since it is the cortex that is primarily affected by the perfusion deficits that underlie the pathophysiology of acute rejection. Finally, we use an analytical function‐based model to fit the dynamic contrast agent kinetic curves in order to determine possible rejection candidates. Five features that map the data from the original data space to the feature space are chosen with a k‐nearest‐neighbor (KNN) classifier to distinguish between acute rejection and non‐rejection transplants. Our study includes 50 transplant patients divided into two groups: 27 patients with stable kidney function and the remainder with impaired kidney function. All of the patients underwent DCE‐MRI, while the patients in the impaired group also underwent ultrasound‐guided fine needle biopsy. We extracted the kidney objects and the renal cortex from DCE‐MRI for accurate medical evaluation with an accuracy of 0.97 ± 0.02 and 0.90 ± 0.03, respectively, using the Dice similarity metric. In a cohort of 50 participants, our framework classified all cases correctly (100%) as rejection or non‐rejection transplant candidates, which is comparable to the gold standard of biopsy but without the associated deleterious side‐effects. Both the 95% confidence interval (CI) statistic and the receiver operating characteristic (ROC) analysis document the ability to separate rejection and non‐rejection groups. The average plateau (AP) signal magnitude and the gamma‐variate model functional parameter α have the best individual discriminating characteristics. Copyright © 2013 John Wiley & Sons, Ltd.     

Physiological aspects of Toll‐like receptor 4 activation in sepsis‐induced acute kidney injury

Sepsis‐induced acute kidney injury (SI‐AKI) is common and associated with high mortality. Survivors are at increased risk of chronic kidney disease. The precise mechanism underlying SI‐AKI is unknown, and no curative treatment exists. Toll‐like receptor 4 (TLR4) activates the innate immune system in response to exogenous microbial products. The result is an inflammatory reaction aimed at clearing a potential infection. However, the consequence may also be organ dysfunction as the immune response can cause collateral damage to host tissue. The purpose of this review is to describe the basis for how ligand binding to TLR4 has the potential to cause renal dysfunction and the mechanisms by which this may take place in gram‐negative sepsis. In addition, we highlight areas for future research that can further our knowledge of the pathogenesis of SI‐AKI in relation to TLR4 activation. TLR4 is expressed in the kidney. Activation of TLR4 causes cytokine and chemokine release as well as renal leucocyte infiltration. It also results in endothelial and tubular dysfunction in addition to altered renal metabolism and circulation. From a physiological standpoint, inhibiting TLR4 in large animal experimental SI‐AKI significantly improves renal function. Thus, current evidence indicates that TLR4 has the ability to mediate SI‐AKI by a number of mechanisms. The strong experimental evidence supporting a role of TLR4 in the pathogenesis of SI‐AKI in combination with the availability of pharmacological tools to target TLR4 warrants future human studies.