Kidney injury enhances renal G-CSF expression and modulates granulopoiesis and human neutrophil CD177 in vivo.

Kidney injury significantly increases overall mortality. Neutrophilic granulocytes (neutrophils) are the most abundant human blood leukocytes. They are characterized by a high turnover rate, chiefly controlled by granulocyte colony stimulating factor (G-CSF). The role of kidney injury and uremia in regulation of granulopoiesis has not been reported. Kidney transplantation, which inherently causes ischemia-reperfusion injury of the graft, elevated human neutrophil expression of the surface glycoprotein CD177. CD177 is among the most G-CSF-responsive neutrophil genes and reversibly increased on neutrophils of healthy donors who received recombinant G-CSF. In kidney graft recipients, a transient rise in neutrophil CD177 correlated with renal tubular epithelial G-CSF expression. In contrast, CD177 was unaltered in patients with chronic renal impairment and independent of renal replacement therapy. Under controlled conditions of experimental ischemia-reperfusion and unilateral ureteral obstruction injuries in mice, renal G-CSF mRNA and protein expression significantly increased and systemic neutrophilia developed. Human renal tubular epithelial cell G-CSF expression was promoted by hypoxia and proinflammatory cytokine interleukin 17A in vitro. Clinically, recipients of ABO blood group-incompatible kidney grafts developed a larger rise in neutrophil CD177. Their grafts are characterized by complement C4d deposition on the renal endothelium, even in the absence of rejection. Indeed, complement activation, but not hypoxia, induced primary human endothelial cell G-CSF expression. Our data demonstrate that kidney injury induces renal G-CSF expression and modulates granulopoiesis. They delineate differential G-CSF regulation in renal epithelium and endothelium. Altered granulopoiesis may contribute to the systemic impact of kidney injury.

[Weakness of the extremities in a 73-year-old male patient]. / 73-jähriger Patient mit Kraftlosigkeit in den Extremitäten.

A patient undergoing cyclosporine therapy presented with muscle weakness. This was preceded by diarrhea and treated with ciprofloxacin. Rhabdomyolysis was diagnosed clinically and biochemically. This was presumably drug-induced triggered by a combined therapy with cyclosporine, amlodipine, simvastatin and ciprofloxacin. The case presented demonstrates that during therapy with several substances which inhibit the degradation of simvastatin, the additional administration of ciprofloxacin should be considered with extreme caution.

[Allocation systems in transplantation medicine: Advantages and disadvantages]. / Allokationssysteme in der Transplantationsmedizin: Vor- und Nachteile.

Donor organs for transplantations are a scarce commodity; therefore, allocation systems are needed that guarantee an ethically acceptable distribution to patients on the waiting list (equal treatment and fairness) but also take the probability of survival of the transplant in each recipient into consideration. In this article the allocation systems for lung, liver, kidney and pancreas transplants are presented.For lung transplantations an allocation system based on the lung allocation score (LAS) is currently used. The LAS predicts the probability of survival on the waiting list and the survival rate following transplantation. Organs with a limited range of utilization are distributed in a so-called mini-match procedure.For post-mortem kidney and pancreas transplantations a relatively complex but transparent allocation system has been created in which patients are subdivided into groups, each of which has its own allocation rules. The allocation is principally carried out according to criteria of fairness of distribution and according to the prospects of success. The probability of a mismatch also plays a role. The urgency is important for children and for patients who do not have the possibility of dialysis. Combined pancreas and kidney transplantations have priority over kidney transplantations alone.The criterion for the urgency of liver transplantation in Germany is currently the model for end-stage liver disease (MELD), which aims to reduce the waiting list mortality and to prioritize transplantations for those most in need. Because the system insufficiently describes the priority of transplantation for patients with tumors or genetic liver diseases, there is an additional set of rules for so-called standard exceptions.

Long-term impact of CMV infection on allografts and on patient survival in renal transplant patients with protocol biopsies.

Cytomegalovirus (CMV) infection is a frequent complication of early posttransplantation. This study examines its impact on chronic allograft changes, long-term graft loss, and patient survival. We studied 594 patients who had protocol biopsies at 6 wk, and 3 and 6 mo posttransplantation. Chronic allograft changes were evaluated according to the updated Banff classification [interstitial fibrosis/tubular atrophy (IF/TA), vascular and glomerular lesions]. Follow-up data were available for up to 10 yr. CMV infection was diagnosed in 153 of 594 patients (26%) in the first year after transplantation, mostly within the first 3 mo. Graft survival was reduced in patients with CMV (P = 0.03) as well as the combined allograft/patient survival (P = 0.008). Prevalence of IF/TA at 6 wk after transplantation was already threefold higher in patients who experienced CMV infection later on compared with patients without CMV (P = 0.005). In multivariate analyses, CMV viremia or disease was not a significant factor for graft loss or death. In conclusion, patients with CMV infection posttransplantation show more chronic allograft changes early on, even before CMV infection, and development of IF/TA is not more prevalent in patients with CMV. Our data do not support a significant role of CMV in patient and graft outcomes.

Urinary miR-210 as a mediator of acute T-cell mediated rejection in renal allograft recipients.

MicroRNAs (miRNAs) are small ribonucleotides regulating gene expression. Circulating miRNAs are remarkably stable in the blood. We tested whether miRNAs are also detectable in urine and may serve as new predictors of outcome in renal transplant patients with acute rejection. We profiled urinary miRNAs of stable transplant patients and transplant patients with acute rejection. The miR-10a, miR-10b and miR-210 were strongly deregulated in urine of the patients with acute rejection. We confirmed these data in urine of a validation cohort of 62 patients with acute rejection, 19 control transplant patients without rejection and 13 stable transplant patients with urinary tract infection by quantitative RT-PCR. The miR-10b and miR-210 were downregulated and miR-10a upregulated in patients with acute rejection compared to controls. Only miR-210 differed between patients with acute rejection when compared to stable transplant patients with urinary tract infection or transplant patients before/after rejection. Low miR-210 levels were associated with higher decline in GFR 1 year after transplantation. Selected miRNAs are strongly altered in urine of the patients with acute renal allograft rejection. The miR-210 levels identify patients with acute rejection and predict long-term kidney function. Urinary miR-210 may thus serve as a novel biomarker of acute kidney rejection.

Early posttransplantation hemoglobin level corresponds with chronic renal dysfunction in heart transplant recipients.

BACKGROUND: The risk factors for moderate or severe chronic renal dysfunction (MSCRD) among heart transplant recipients may be distinct from those previously recognized owing to recently improved clinical care. METHODS: We examined the clinical records of 88 adult patients who underwent first heart transplantations from 2000 to 2005 and survived 2 years. MSCRD was defined as a glomerular filtration rate (GFR) <60 mL/min/1.73 m(2) at 2 years after transplantation. Fifty patients were included in the MSCRD group and 38 in the non-MSCRD group. RESULTS: Loss of renal function was observed largely during the first 9 months after transplantation in the MSCRD group. The pretransplantation GFR was lower in the MSCRD group. Besides older age in the MSCRD group, there were no differences in baseline characteristics, immunosuppressive regimens, incidences of acute rejection episodes, cardiac allograft vasculopathy, or severe infections. The MSCRD group showed permanent lower posttransplantation hemoglobin levels. In multivariate logistic regression analysis, recipient age, pretransplantation GFR, postoperative intensive care unit stay and hemoglobin level at 9 month were unfavorable factors for posttransplantation MSCRD. CONCLUSIONS: In addition to recipient age and pretransplantation GFR as well established risk factors, our results suggest a prognostic value of a low early hemoglobin level for the development of chronic renal dysfunction after heart transplantation.

Diffusion tensor imaging and tractography for assessment of renal allograft dysfunction-initial results.

OBJECTIVES: To evaluate MR diffusion tensor imaging (DTI) as non-invasive diagnostic tool for detection of acute and chronic allograft dysfunction and changes of organ microstructure. METHODS: 15 kidney transplanted patients with allograft dysfunction and 14 healthy volunteers were examined using a fat-saturated echo-planar DTI-sequence at 1.5 T (6 diffusion directions, b = 0, 600 s/mm²). Mean apparent diffusion coefficient (ADC) and mean fractional anisotropy (FA) were calculated separately for the cortex and for the medulla and compared between healthy and transplanted kidneys. Furthermore, the correlation between diffusion parameters and estimated GFR was determined. RESULTS: The ADC in the cortex and in the medulla were lower in transplanted than in healthy kidneys (p < 0.01). Differences were more distinct for FA, especially in the renal medulla, with a significant reduction in allografts (p < 0.001). Furthermore, in transplanted patients a correlation between mean FA in the medulla and estimated GFR was observed (r = 0.72, p < 0.01). Tractography visualized changes in renal microstructure in patients with impaired allograft function. CONCLUSIONS: Changes in allograft function and microstructure can be detected and quantified using DTI. However, to prove the value of DTI for standard clinical application especially correlation of imaging findings and biopsy results is necessary.

The molecular phenotype of 6-week protocol biopsies from human renal allografts: reflections of prior injury but not future course.

We assessed the molecular phenotype of 107 6-week protocol biopsies from human renal allografts, using Affymetrix microarrays. Transcript changes were summarized as nonoverlapping pathogenesis-based transcript sets (PBTs) reflecting inflammation (T cells, macrophages, IFNG effects) and the injury-repair response of the parenchyma, stroma and microcirculation-increased ('injury-up') and decreased ('injury-down') transcripts. The molecular changes were highly correlated with each other, even when all rejection and borderline cases were excluded. Inflammation and injury-down PBTs correlated with histologic inflammation and tubulitis, and the inflammation transcripts were greater in kidneys diagnosed as T cell-mediated or borderline rejection. Injury-up PBTs did not correlate with histopathology but did correlate with kidney function: thus functional disturbances are represented in transcript changes but not in histopathology. PBT changes correlated with prior delayed graft function. However, there was little difference between live donor kidneys and deceased donor kidneys that had not shown delayed graft function. Molecular changes did not predict future biopsies for clinical indications, rejection episodes, functional deterioration or allograft loss. Thus while detecting T cell-mediated inflammation, the molecular phenotype of early protocol biopsies mostly reflects the injury-repair response to implantation stresses, and has little relationship to future events and outcomes.

[Current problems of kidney transplantation]. / Aktuelle Probleme der Nierentransplantation.

The long-term problems after kidney transplantation have changed considerably in recent years. While formerly immunosuppression and prevention of acute rejection were of prime concern, now attention focuses on chronic alterations of the transplanted organ and long-term survival of the patients. The transplantation procedure itself has evolved into a standardized technique with a high level of surgical quality. Problems involving organ preservation and ischemia/reperfusion damage also play a role, especially in view of chronic aspects. Monitoring of long-term complications should follow a program for the transplanted organ as well as a program for the patient. Monitoring kidney function should address the organ more precisely than has previously been the case. Serum creatinine level and proteinuria alone provide insufficient information and only change long after cellular deterioration has begun. Hence it is imperative that new testing methods be developed. One possibility is offered by protocol biopsies that allow histological and molecular analysis of the kidney at regular intervals. The patient programs concentrate on diagnostics and treatment of the cardiovascular diseases. Furthermore, the patients must be screened for occurrence of neoplasia. There are no prospective studies covering all cardiovascular risk factors after kidney transplantation. This pertains particularly to the subject of hypertension.

Endothelial microparticles as a diagnostic aid in Churg-Strauss vasculitis-induced cardiomyopathy.

Churg-Strauss Syndrome (CSS) is characterized by allergic rhinitis, asthma and prominent blood and tissue eosinophilia. Although CSS can affect any organ system, isolated cardiac manifestation is a rare feature that is often characterized by rapidly progressive congestive heart failure. We present the case of a 48-year-old woman with acute dyspnoea and chest pain. Her past medical history was significant for asthma and frequently relapsing minimal-change glomerulonephritis. Echocardiogram and coronary angiography revealed cardiomyopathy and coronary small-vessel vasculitis in the presence of blood eosinophilia and elevated IgE. In the absence of infective agents, neoplastic diseases and further vasculitic manifestations, a flow cytometry-based analysis of markedly elevated endothelial microparticles supported the diagnosis of CSS. Cardiomyopathy resolved completely after initiation of immunosuppressive treatment with corticosteroids and cyclophosphamide pulses. Elevated endothelial, leukocytic and platelet-derived microparticles decreased during follow-up and closely paralleled vasculitic activity. Endothelial microparticles might be an additional tool to diagnose and monitor cases of suspected vasculitic cardiac involvement in CSS.

Expression of pro- and antifibrotic genes in protocol biopsies from renal allografts with interstitial fibrosis and tubular atrophy.

AIM: Better understanding of early onset of interstitial fibrosis and tubular atrophy (IF/TA), as the morphological surrogate of renal allograft deterioration might improve outcome after renal transplantation. MATERIAL AND METHODS: We quantified mRNA expression of 3 profibrotic (transforming growth factor-beta (TGF-beta), tissue transglutaminase (tTG), tissue inhibitor of matrix metalloproteases (TIMP-1)) and 1 antifibrotic (matrix metalloprotease-2 (MMP-2)) molecule in protocol biopsies from renal allografts. From 107 transplants, two sequential protocol biopsies (6 weeks and 6 months) were analyzed. We evaluated a control group showing no IF/TA in both biopsies (n = 65) and a IF/TA group developing IF/TA at 6 months (n = 42). Expression data were correlated with clinical and histological risk factors for IF/TA and allograft function. RESULTS: The expression of the genes correlated strongly with each other, particularly the profibrotic genes and in patients who developed IF/TA. Analyzing protocol biopsies from stable grafts, not all patients in both groups showed increased gene expression. In patients with increased gene expression a significantly higher tTG expression (matrix stabilization) at 6 weeks and a significantly lower MMP-2 expression (failure in matrix degradation) at 6 months were observed in the IFTA group compared to controls. Multivariate logistic regression revealed donor age positively and TIMP-1 expression at 6 weeks inversely correlated with IF/TA at 6 months. CONCLUSIONS: We conclude that a disturbance in the equilibrium of pro- and antifibrotic pathways is decisive for early onset of IF/TA in renal allografts: insufficient degradation of exaggerated matrix production apparently changes the balance in the direction of IF/TA.

Acute tubular injury in protocol biopsies of renal grafts: prevalence, associated factors and effect on long-term function.

Acute tubular injury (ATI) is commonly observed in renal allografts, especially early after transplantation. This study analyzes prevalence and associated clinical conditions of ATI in serial protocol biopsies (pBx) and indication biopsies (iBx), and its impact on long-term graft function. 612 pBx from 204 patients taken at 6 weeks, 3 and 6 months, and 151 iBx performed within the first year of transplantation were evaluated. Prevalence of ATI in pBx was 40% (6 weeks), 34% (3 months) and 37% (6 months), and 46% in iBx. ATI was associated with delayed graft function and prolonged cold ischemia time in pBx, and with acute rejections in iBx. The GFR at 1 and 2 years after transplantation correlated inversely with the frequency of ATI in both pBx and iBx (p < 0.001). Prevalence of chronic changes at 6 months was not significantly related to ATI (patients without ATI: 36%, patients with multiple ATI findings: 54%). ATI is linked to inferior long-term graft function. While this suggests lack of recovery from ATI with permanent allograft damage, the underlying molecular mechanisms need yet to be uncovered. Prevention of the potential pathogenetic factors identified in this study might be the key point to attain good long-term graft function.

Peritubular capillaritis in renal allografts: prevalence, scoring system, reproducibility and clinicopathological correlates.

While glomerulitis is graded according to the Banff classification, no criteria for scoring peritubular capillaritis (PTC) have been established. We retrospectively applied PTC-scoring criteria to 688 renal allograft (46 preimplantation, 461 protocol, 181 indication) biopsies. A total of 26.3% of all analyzed biopsies had peritubular capillaritis (implant 0%, protocol 17.6%, indication 45.5%; p < 0.0001). The most common capillaritis pattern was of moderate severity (5-10 luminal cells), focal in extent (10-50% of PTC), with a minority of neutrophils. A total of 24% of C4d- compared with 75% of C4d+ biopsies showed capillaritis (p < 0.0001). More than 80% of biopsies with glomerulitis had peritubular capillaritis. A total of 50.4% of biopsies with borderline or T-cell mediated rejection (TCMR) and 14.1% of biopsies without TCMR or antibody-mediated rejection (ABMR) showed capillaritis (p < 0.0001). The inter-observer reproducibility of the PTC-scoring features was fair to moderate. Diffuse capillaritis detected in early protocol biopsies had significant negative prognostic impact in terms of glomerular filtration rate 2 years posttransplantation. Indication biopsies show a significantly higher prevalence of capillaritis than protocol biopsies (45.5% vs. 17.6%; p < 0.0001). Capillaritis is more frequent and pronounced in ABMR, but can be observed in TCMR cases. Thus, scoring of peritubular capillaritis is feasible and can provide prognostic and diagnostic information in renal allograft biopsies.

Course and relevance of arteriovenous fistulas after renal transplant biopsies.

Arteriovenous fistulas (AVFs) after renal transplant biopsy are considered harmless. However, verification of the clinical course has not been thoroughly documented. We evaluated the data of our outpatient renal transplant biopsy program regarding the clinical course of AVFs after 2824 biopsies since 2000. We also reviewed all selective renal transplant embolizations. AVFs were the most frequent biopsy complications (8.3%). Seventy-seven percent of AVFs disappeared spontaneously. Renal function in patients with AVFs was not different compared to those without during 2 years of observation. There were no differences in AVFs comparing protocol or indication biopsies, needle size, the time after transplantation, the use of acetylic salicylic acid or serum-creatinine at biopsy. Living or younger donors were less likely to get postbiopsy AVFs. Ten embolizations were performed. Only one patient was from our outpatient biopsy program. Nine others were biopsied as inpatients in the course of complications during 6 weeks after transplant. Six of nine successfully embolized patients profited with improvement of renal function. Large AVFs occur most commonly shortly after transplantation in patients with poor graft function. There is no established test predicting which patient will benefit from embolization; however, Doppler-determined resistive index may help in this regard.

Infiltrates in protocol biopsies from renal allografts.

In renal transplantation, clinical decisions are based primarily on the Banff classification of biopsies. However, the incorporation of 'minor or nonspecific' cellular infiltrates into the Banff classification and their interpretation is uncertain. We analyzed 833 protocol and 306 indicated biopsies to test whether such infiltrates are harmless or whether they have a bearing on outcomes. We characterized morphology, localization and cellular composition of infiltrates, and correlated these findings to the Banff classification and allograft outcome. We found that protocol biopsies had the same prevalence of infiltrates as indication biopsies (87% vs. 87%). Diffuse cortical infiltrates, the hallmark of cellular rejection were more common in indication biopsies and related to tubulitis and a rise in serum creatinine. However, in biopsies with cellular rejection according to Banff criteria, we observed an increase in all infiltrate types (specific and nonspecific) and all cell types (T cells, B cells, histiocytes). The only predictor of allograft function outcome was persistent inflammation in sequential biopsies, irrespective of type, localization and composition of the cellular infiltrates. As detected by sequential biopsies, persistence of any inflammation including those infiltrates currently not considered by the Banff classification should be regarded as a morphological correlate of ongoing allograft damage.

Lymphatic neoangiogenesis in human renal allografts: results from sequential protocol biopsies.

Neoangiogenesis of lymphatic vessels may be important for the cellular immune response in renal transplants. To determine the prevalence and chronology of lymph vessel proliferation and its relation to cellular infiltrates and allograft function, we analyzed sequential protocol biopsies (n = 162), taken at 6, 12 and 26 weeks after transplantation. Biopsies were stained with an antibody against podoplanin and lymphatic vessel density was quantified per square millimeter. The prevalence of lymph vessel-positive biopsies and the lymph vessel density were similar at 6, 12 and 26 weeks after transplantation. Biopsies with acute cellular rejection showed no significantly different lymph vessel density compared to those below the threshold for acute rejection or chronic allograft nephropathy. While lymphatic neoangiogenesis was equally prevalent in biopsies with and without infiltrates, the lymph vessel density was significantly higher in areas with cellular infiltrates than in areas without. Graft function at 1 year after transplantation was better in cases with lymph vessels in their infiltrates compared to cases with lymph vessel-free infiltrates. In conclusion, lymphangiogenesis not only shows a clear association with cellular infiltrates but might also have an impact on the pathogenicity of these cellular infiltrates.

Pivotal role of xanthine oxidase in the initiation of tubulointerstitial renal injury in rats with hyperlipidemia.

Hyperlipidemia can induce or aggravate renal tubulointerstitial injury. Experiments in a complex rat model with chronic glomerulonephritis and long-standing, coexisting hyperlipidemia suggested that induction of xanthine oxidase (XO), with increased oxygen radical generation, is involved in aggravation of tubulointerstitial injury. To separate the role of XO in the initial events of lipid-mediated tubulointerstitial injury, short-term experiments with diet-induced hyperlipidemia over 21 and 35 days were performed in otherwise healthy rats. XO expression in relation to the antioxidant enzymes was examined in the cortical tubulointerstitium (TIS) and proximal tubules (PT). Subsequent experiments with XO inhibition were performed, examining tubulointerstitial infiltration with ED1-positive cells and expression of adhesion molecules and monocyte chemoattractant protein-1 (MCP-1) as indicators of early injurious events. Hyperlipidemia increased XO activity in TIS by 40 and 86%, and in PT by 28 and 90% at days 21 and 35, compared with controls on regular diet. This increased activity was associated with increased reactive oxygen species. Among the antioxidant enzymes, glutathione peroxidase activity increased in TIS by 40% and in PT by 90%. Histological evaluation showed a three-fold increase in ED1-positive cells and increased MCP-1 and vascular cell adhesion molecule-1 (VCAM-1) expression at day 35 in the TIS. Inhibition of XO prevented tubulointerstitial ED1 cell infiltration, together with a decreased expression of MCP-1 and VCAM-1. These results point to an important role for XO in the early stage of hyperlipidemia-associated renal injury, mediating macrophage infiltration by a putatively redox-dependent upregulation of MCP-1 and VCAM-1.

Biocompatibility parameters of different dialysis membranes assessed during systemic inflammation.

BACKGROUND: We explored whether biocompatible dialyzer membranes modulate the inflammatory response during blood contact in patients with systemic inflammation. METHODS: 15 patients with end-stage renal disease and systemic inflammation (mean serum C-reactive protein 86 +/- 4 mg/l) were randomly treated with Cuprophan (CU), polyamide (PA) and vitamin-E coated (VEC) membrane-based dialyzers. RESULTS: Changes in blood pressure, capillary blood oxygen saturation and differential blood counts during the hemodialysis session were not significantly different between the three dialyzers. Baseline blood levels of activated circulating complement (C3a) were more than 100 times above normal, and unlike expected they decreased during hemodialysis treatments (CU: from 7,389 +/- 783 to 5,423 +/- 761 ng/ml; PA: from 7,379 +/- 980 to 5,690 +/- 714 ng/ml; VEC: from 7.377 +/- 714 to 5,360 +/- 1,005 ng/ml; all n.s.). No significant differences between treatments were found with respect to changes in blood concentrations of TNF-alpha, interleukin-6 and interleukin-1 receptor antagonist as well as ICAM-1 (CU: from 451 +/- 41 to 477 +/- 41 ng/ml; PA: from 437 +/- 42 to 449 +/- 40 ng/ml; VEC: from 461 +/- 43 to 460 +/- 47 ng/ml). Furthermore, generation of reactive oxygen species by mononuclear blood cells was comparable during hemodialysis with the CU, PA and VEC dialyzer. CONCLUSION: The choice of dialyzer membrane material does not affect most aspects of biocompatibility when patients have significant systemic inflammation. This confounding variable should be taken into account in studies exploring the effects of biocompatible dialyzer membranes.

Life-threatening complications of extracorporeal treatment in patients with severe eosinophilia.

We report three patients with massive eosinophilia of different etiology who developed bronchoconstriction, hypotension, and shock shortly after dialysis or leukapheresis had been begun. In two cases, ethylene oxide-free materials had been used ruling out an allergic reaction related to this compound. Degranulation of eosinophils with release of eosinophil peroxidase may have caused the observed adverse reactions, as suggested by in vitro experiments with blood from the three patients. Our observations draw attention to the fact that extracorporeal therapies may initiate life-threatening complications in patients with severe eosinophilia.