Pre-transplant HLA Antibodies and Delayed Graft Function in the Current Era of Kidney Transplantation.

Delayed graft function (DGF) occurs in a significant proportion of deceased donor kidney transplant recipients and was associated with graft injury and inferior clinical outcome. The aim of the present multi-center study was to identify the immunological and non-immunological predictors of DGF and to determine its influence on outcome in the presence and absence of human leukocyte antigen (HLA) antibodies. 1,724 patients who received a deceased donor kidney transplant during 2008-2017 and on whom a pre-transplant serum sample was available were studied. Graft survival during the first 3 post-transplant years was analyzed by multivariable Cox regression. Pre-transplant predictors of DGF and influence of DGF and pre-transplant HLA antibodies on biopsy-proven rejections in the first 3 post-transplant months were determined by multivariable logistic regression. Donor age ≥50 years, simultaneous pre-transplant presence of HLA class I and II antibodies, diabetes mellitus as cause of end-stage renal disease, cold ischemia time ≥18 h, and time on dialysis >5 years were associated with increased risk of DGF, while the risk was reduced if gender of donor or recipient was female or the reason for death of donor was trauma. DGF alone doubled the risk for graft loss, more due to impaired death-censored graft than patient survival. In DGF patients, the risk of death-censored graft loss increased further if HLA antibodies (hazard ratio HR=4.75, P < 0.001) or donor-specific HLA antibodies (DSA, HR=7.39, P < 0.001) were present pre-transplant. In the presence of HLA antibodies or DSA, the incidence of biopsy-proven rejections, including antibody-mediated rejections, increased significantly in patients with as well as without DGF. Recipients without DGF and without biopsy-proven rejections during the first 3 months had the highest fraction of patients with good kidney function at year 1, whereas patients with both DGF and rejection showed the lowest rate of good kidney function, especially when organs from ≥65-year-old donors were used. In this new era of transplantation, besides non-immunological factors, also the pre-transplant presence of HLA class I and II antibodies increase the risk of DGF. Measures to prevent the strong negative impact of DGF on outcome are necessary, especially during organ allocation for presensitized patients.

[Anti B-cell-antibody treatment for maintenance of remission in granulomatosis with polyangiitis and microscopic polyangiitis]. / Anti-B-Zell-Antikörpertherapie zur Remissionserhaltung bei Granulomatose mit Polyangiitis und mikroskopischer Polyangiitis.

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are the most frequent primary necrotizing small vessel vasculitides. In these formerly fatal diseases remission can be induced by stage- and activity-adapted immunosuppressive regimens in the majority of patients. This does not lead to drug-free long-term remission or even cure. Consequently, maintenance of remission medication is needed. Recent randomized controlled trials demonstrated that maintenance treatment with the anti-B-cell antibody Rituximab, administered 6-monthly as opposed to azathioprine leads to a significantly lower relapse rate but a similar profile of adverse events. These data enabled the extension of the approval of Rituximab for maintenance of remission treatment of GPA and MPA in Germany in 2018. Guidelines and expert recommendations concerning measures of infection prevention and vaccination of immunosuppressed patients as well as the management of hypogammaglobulinemia and cytopenia on Rituximab are presented in this review.

Equally Interchangeable? How Sex and Gender Affect Transplantation.

Organ transplantation as an option to overcome end-stage diseases is common in countries with advanced healthcare systems and is increasingly provided in emerging and developing countries. A review of the literature points to sex- and gender-based inequity in the field with differences reported at each step of the transplant process, including access to a transplantation waiting list, access to transplantation once waitlisted, as well as outcome after transplantation. In this review, we summarize the data regarding sex- and gender-based disparity in adult and pediatric kidney, liver, lung, heart, and hematopoietic stem cell transplantation and argue that there are not only biological but also psychological and socioeconomic issues that contribute to disparity in the outcome, as well as an inequitable access to transplantation for women and girls. Because the demand for organs has always exceeded the supply, the transplant community has long recognized the need to ensure equity and efficiency of the organ allocation system. In the spirit of equity and equality, the authors call for recognition of these inequities and the development of policies that have the potential to ensure that girls and women have equitable access to transplantation.

[Renal manifestation in ANCA-associated vasculitis]. / Nierenbeteiligung bei ANCA-assoziierten Vaskulitiden.

In patients with ANCA-associated vasculitis renal involvement is frequently seen and the severity of renal manifestation is very important for therapeutic strategies and prognosis. Clinically rapid loss of renal function, nephritic sediment and proteinuria in a non-nephrotic range are characterizing a focal segmental necrotizing pauci-immune glomerulonephritis with extrarenal proliferations. Induction treatment depends on the severity of manifestations. With a normal renal function methotrexate can be used in combination with steroids. In patients with organ threatening involvement but creatinine below 500 µmol/l cyclophosphamide pulses or Rituximab should be used together with steroids, initially with i. v. pulses. Rituximab is more effective in PR3-ANCA vasculitis and should be used in relapsing disease, in young patients to avoid gonadal toxicity and in patients with an increased risk of malignancies. In patients on dialysis or with creatinine > 500 µmol/l plasma exchange should be added. Maintenance treatment (mainly with azathioprine) is necessary as at least 50 % of the patients develop relapses. Rituximab seems more effective, however it is not approved for maintenance treatment and no long-term data are available. Adjuvant treatment, long-term side effects and the increased incidence of cardiovascular events have to be included in the follow-up of vasculitis patients. In end-stage renal disease patients relapses occur but are more difficult to diagnose and treat with higher incidence of infections. Transplantation should be offered as patient and transplant survival is good.

Noninvasive diagnosis of chronic kidney diseases using urinary proteome analysis.

BACKGROUND: In spite of its invasive nature and risks, kidney biopsy is currently required for precise diagnosis of many chronic kidney diseases (CKDs). Here, we explored the hypothesis that analysis of the urinary proteome can discriminate different types of CKD irrespective of the underlying mechanism of disease. METHODS: We used data from the proteome analyses of 1180 urine samples from patients with different types of CKD, generated by capillary electrophoresis coupled to mass spectrometry. A set of 706 samples served as the discovery cohort, and 474 samples were used for independent validation. For each CKD type, peptide biomarkers were defined using statistical analysis adjusted for multiple testing. Potential biomarkers of statistical significance were combined in support vector machine (SVM)-based classifiers. RESULTS: For seven different types of CKD, several potential urinary biomarker peptides (ranging from 116 to 619 peptides) were defined and combined into SVM-based classifiers specific for each CKD. These classifiers were validated in an independent cohort and showed good to excellent accuracy for discrimination of one CKD type from the others (area under the receiver operating characteristic curve ranged from 0.77 to 0.95). Sequence analysis of the biomarkers provided further information that may clarify the underlying pathophysiology. CONCLUSIONS: Our data indicate that urinary proteome analysis has the potential to identify various types of CKD defined by pathological assessment of renal biopsies and current clinical practice in general. Moreover, these approaches may provide information to model molecular changes per CKD.

Circulating ADAM17 Level Reflects Disease Activity in Proteinase-3 ANCA-Associated Vasculitis.

ANCA-associated vasculitides are characterized by inflammatory destruction of small vessels accompanied by enhanced cleavage of membrane-bound proteins. One of the main proteases responsible for ectodomain shedding is disintegrin and metalloproteinase domain-containing protein 17 (ADAM17). Given its potential role in aggravating vascular dysfunction, we examined the role of ADAM17 in active proteinase-3 (PR3)-positive ANCA-associated vasculitis (AAV). ADAM17 concentration was significantly increased in plasma samples from patients with active PR3-AAV compared with samples from patients in remission or from other controls with renal nonvascular diseases. Comparably, plasma levels of the ADAM17 substrate syndecan-1 were significantly enhanced in active AAV. We also observed that plasma-derived ADAM17 retained its specific proteolytic activity and was partly located on extracellular microparticles. Transcript levels of ADAM17 were increased in blood samples of patients with active AAV, but those of ADAM10 or tissue inhibitor of metalloproteinases 3, which inhibits ADAMs, were not. We also performed a microRNA (miR) screen and identified miR-634 as significantly upregulated in blood samples from patients with active AAV. In vitro, miR-634 mimics induced a proinflammatory phenotype in monocyte-derived macrophages, with enhanced expression and release of ADAM17 and IL-6. These data suggest that ADAM17 has a prominent role in AAV and might account for the vascular complications associated with this disease.

Diagnosis and Prediction of CKD Progression by Assessment of Urinary Peptides.

Progressive CKD is generally detected at a late stage by a sustained decline in eGFR and/or the presence of significant albuminuria. With the aim of early and improved risk stratification of patients with CKD, we studied urinary peptides in a large cross-sectional multicenter cohort of 1990 individuals, including 522 with follow-up data, using proteome analysis. We validated that a previously established multipeptide urinary biomarker classifier performed significantly better in detecting and predicting progression of CKD than the current clinical standard, urinary albumin. The classifier was also more sensitive for identifying patients with rapidly progressing CKD. Compared with the combination of baseline eGFR and albuminuria (area under the curve [AUC]=0.758), the addition of the multipeptide biomarker classifier significantly improved CKD risk prediction (AUC=0.831) as assessed by the net reclassification index (0.303±-0.065; P<0.001) and integrated discrimination improvement (0.058±0.014; P<0.001). Correlation of individual urinary peptides with CKD stage and progression showed that the peptides that associated with CKD, irrespective of CKD stage or CKD progression, were either fragments of the major circulating proteins, suggesting failure of the glomerular filtration barrier sieving properties, or different collagen fragments, suggesting accumulation of intrarenal extracellular matrix. Furthermore, protein fragments associated with progression of CKD originated mostly from proteins related to inflammation and tissue repair. Results of this study suggest that urinary proteome analysis might significantly improve the current state of the art of CKD detection and outcome prediction and that identification of the urinary peptides allows insight into various ongoing pathophysiologic processes in CKD.

Circulating endothelial cells as potential diagnostic biomarkers in primary central nervous system vasculitis.

OBJECTIVE: Histological evidence is considered the only proof of primary central nervous system vasculitis (PCNSV). However, brain biopsy is often omitted or delayed because of the invasiveness and possible complications of the procedure. Circulating endothelial cells (CEC) were shown to be elevated in patients with active antineutrophil cytoplasmic antibody-associated vasculitis. We hypothesise that CEC are also elevated in patients with active PCNSV and may contribute to the diagnosis. METHODS: CEC were assessed in 18 patients, 3 of whom had biopsy-proven PCNSV and 15 clinical, cerebrospinal fluid and imaging data, highly suggestive of PCNSV. In 3 of these 15 patients CEC assessment was performed after initiation of successful immunosuppressive therapy. CEC numbers of all patients were compared to those of 16 healthy volunteers and 123 subjects with cerebrovascular risk factors and/or ischaemic stroke, who had been studied in our group before. CEC were assessed by immunomagnetic isolation from peripheral blood. RESULTS: In patients with proven and suspected active PCNSV, CEC were extremely elevated (>400 cells/ml in most of the patients) and significantly higher than in healthy and disease controls (p≤0.01 for each group). CEC significantly decreased with immunosuppressive treatment. CONCLUSIONS: For the first time it is shown that CEC are significantly elevated in patients with active PCNSV in contrast to other pathologies associated with brain infarction and correlate with disease activity. Sensitivity and specificity of the method for diagnosing PCNSV and the use of the method for treatment monitoring should be addressed in future prospective studies with a larger patient group.

Aldosterone modulates endothelial permeability and endothelial nitric oxide synthase activity by rearrangement of the actin cytoskeleton.

Aldosterone (Aldo) is involved in vascular remodeling and inflammation; however, the mechanisms are imperfectly defined. We hypothesized that Aldo alters endothelial integrity and modifies paracellular permeability. Human umbilical vein endothelial cells were exposed to Aldo (10(-9) mol/L) and alterations in paracellular permeability, assembly of tight and adherens junctions and activation of intracellular signaling pathways were determined. Aldo increased endothelial permeability for molecules ≤ 70 kDa within 60 minutes. A transient loss of cortical actin with formation of actin stress fibers and disruption of continuous adherens and tight junction strands accompanied these changes. Mineralocorticoid receptor blockade, inhibition of RhoA, or disruption of extracellular-regulated protein kinase1/2 signaling pathways attenuated the Aldo-related effects. Moreover, Aldo-induced cytoskeletal rearrangement led to rapid dephosphorylation of protein kinase B and subsequent deactivation of endothelial nitric oxide synthase. Ex vivo tracer flux experiments with Evans blue-conjugated albumin demonstrated a concordant response to Aldo in freshly isolated umbilical arteries. Furthermore, low-dose cortisol (3 × 10(-10) to 3 × 10(-9) mol/L) mimics the effect of Aldo on endothelial integrity, and Aldo, by upregulating11ß-hydroxysteroid dehydrogenase type 2, might even aggravate this deleterious effect of low-dose cortisol. We suggest that these mechanisms may contribute to the vasculopathy induced by inappropriate mineralocorticoid receptor activation.

Efficacy and safety of rituximab treatment in patients with antineutrophil cytoplasmic antibody-associated vasculitides: results from a German registry (GRAID).

OBJECTIVE: Rituximab (RTX) therapy is a treatment option in patients with refractory antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). We investigated the tolerability and clinical efficacy of RTX in a cohort of patients with refractory AAV. METHODS: Clinical and safety data of patients with AAV treated with RTX were retrospectively assessed from the data of a German national registry. RESULTS: In total, 58 patients were included in this analysis (50/58 with granulomatosis with polyangiitis; 8/58 with microscopic polyangiitis who received at least 1 cycle, 17 patients who received 2 cycles, and 3 patients who received 3 cycles of RTX). Response was classified as complete and partial in 22 (40%) and in 29 cases (52.7%), respectively. Four patients (7.3%) were classified as nonresponders. CONCLUSION: RTX was well tolerated with good clinical efficacy in patients with refractory AAV.

Joint European League Against Rheumatism and European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis.

OBJECTIVES: To develop recommendations for the management of adult and paediatric lupus nephritis (LN). METHODS: The available evidence was systematically reviewed using the PubMed database. A modified Delphi method was used to compile questions, elicit expert opinions and reach consensus. RESULTS: Immunosuppressive treatment should be guided by renal biopsy, and aiming for complete renal response (proteinuria <0.5 g/24 h with normal or near-normal renal function). Hydroxychloroquine is recommended for all patients with LN. Because of a more favourable efficacy/toxicity ratio, as initial treatment for patients with class III-IV(A) or (A/C) (±V) LN according to the International Society of Nephrology/Renal Pathology Society 2003 classification, mycophenolic acid (MPA) or low-dose intravenous cyclophosphamide (CY) in combination with glucocorticoids is recommended. In patients with adverse clinical or histological features, CY can be prescribed at higher doses, while azathioprine is an alternative for milder cases. For pure class V LN with nephrotic-range proteinuria, MPA in combination with oral glucocorticoids is recommended as initial treatment. In patients improving after initial treatment, subsequent immunosuppression with MPA or azathioprine is recommended for at least 3 years; in such cases, initial treatment with MPA should be followed by MPA. For MPA or CY failures, switching to the other agent, or to rituximab, is the suggested course of action. In anticipation of pregnancy, patients should be switched to appropriate medications without reducing the intensity of treatment. There is no evidence to suggest that management of LN should differ in children versus adults. CONCLUSIONS: Recommendations for the management of LN were developed using an evidence-based approach followed by expert consensus.

Circulating endothelial cells and stroke: influence of stroke subtypes and changes during the course of disease.

BACKGROUND: Circulating endothelial cells (CECs) are a novel and valuable marker of endothelial damage in a variety of vascular disorders. There is limited information as to CEC counts and the time course of CECs in subtypes of stroke. METHODS: We studied 49 patients with stroke (18 with atherothrombotic infarction in the territory of the middle cerebral artery, 16 with cardioembolic stroke, and 15 with lacunar stroke). We also included 16 healthy controls and 64 disease controls. CECs were isolated and enumerated with lectin-augmented CD146-driven immunomagnetic isolation. Neurologic deficit was assessed with the European Stroke Scale (ESS) and the National Institutes of Health Stroke Scale (NIHSS). Recovery was assessed with the modified Rankin scale (mRS). RESULTS: Healthy controls had low numbers of CECs (median, 8 cells/mL; mean, 9 cells/mL; range, 0-16 cells/mL; n = 16). Patients with stroke had markedly elevated numbers of CECs at presentation. Patients with atherothrombotic infarction had 32 cells per milliliter (mean, 42 cells/mL; range, 24-116 cells/mL; n = 18; P < .001 when compared to controls). Patients with lacunar stroke had 68 cells per milliliter (mean, 68 cells/mL; range, 8-144 cells/mL; n = 15; P < .001 when compared to controls). Patients with cardioembolic stroke had 46 cells per milliter (mean, 54 cells/mL; range, 24-116 cells/mL; n = 16; P < .001 when compared to healthy controls). There was a tendency towards higher numbers of CECs in lacunar stroke. The number of CECs peaked at day 7 in patients with atherothrombotic infarction and came back to normal at day 90. In contrast, CECs in patients with acute lacunar stroke and cardioembolic stroke decreased progressively until day 90. CONCLUSIONS: CECs are markers of endothelial damage and/or repair in stroke. Differences during the course of disease are likely to reflect different pathophysiology.

Safety and clinical outcomes of rituximab therapy in patients with different autoimmune diseases: experience from a national registry (GRAID).

INTRODUCTION: Evidence from a number of open-label, uncontrolled studies has suggested that rituximab may benefit patients with autoimmune diseases who are refractory to standard-of-care. The objective of this study was to evaluate the safety and clinical outcomes of rituximab in several standard-of-care-refractory autoimmune diseases (within rheumatology, nephrology, dermatology and neurology) other than rheumatoid arthritis or non-Hodgkin's lymphoma in a real-life clinical setting. METHODS: Patients who received rituximab having shown an inadequate response to standard-of-care had their safety and clinical outcomes data retrospectively analysed as part of the German Registry of Autoimmune Diseases. The main outcome measures were safety and clinical response, as judged at the discretion of the investigators. RESULTS: A total of 370 patients (299 patient-years) with various autoimmune diseases (23.0% with systemic lupus erythematosus, 15.7% antineutrophil cytoplasmic antibody-associated granulomatous vasculitides, 15.1% multiple sclerosis and 10.0% pemphigus) from 42 centres received a mean dose of 2,440 mg of rituximab over a median (range) of 194 (180 to 1,407) days. The overall rate of serious infections was 5.3 per 100 patient-years during rituximab therapy. Opportunistic infections were infrequent across the whole study population, and mostly occurred in patients with systemic lupus erythematosus. There were 11 deaths (3.0% of patients) after rituximab treatment (mean 11.6 months after first infusion, range 0.8 to 31.3 months), with most of the deaths caused by infections. Overall (n = 293), 13.3% of patients showed no response, 45.1% showed a partial response and 41.6% showed a complete response. Responses were also reflected by reduced use of glucocorticoids and various immunosuppressives during rituximab therapy and follow-up compared with before rituximab. Rituximab generally had a positive effect on patient well-being (physician's visual analogue scale; mean improvement from baseline of 12.1 mm). CONCLUSIONS: Data from this registry indicate that rituximab is a commonly employed, well-tolerated therapy with potential beneficial effects in standard of care-refractory autoimmune diseases, and support the results from other open-label, uncontrolled studies.

Reconstruction of nasal deformity in Wegener's granulomatosis: contraindication or benefit?

BACKGROUND: Saddle-nose deformity is a well-recognized stigma of patients affected by Wegener granulomatosis (WG). However, plastic surgical repair is seldom performed. In this study, the authors aimed to evaluate their own patients exclusively reconstructed by costal cartilage L-strut of the nose for this specific deformity. METHODS: During a 5-year-period, four women with an average age of 33 years underwent reconstructive rhinoplasty of their saddle-nose deformity caused by WG, which in every case was in remission regarding the nose at the time of surgery. Restoration of the nasal framework was performed by an L-shaped rib cartilage graft. RESULTS: The external form and function of the newly reconstructed nose was preserved during an average follow-up period of 42 months for all the patients. No resorption of the rib cartilage graft was observed. A review of the literature found a total of 22 nasal reconstructions for patients affected by WG. CONCLUSION: According to this patient series and a review of the literature, external nasal reconstruction for patients affected by WG appears to be safe and effective if the disease is in remission before any operation. Despite concern that high-dose immune suppression therapy may increase the risk of failure in primary nasal dorsal repair, this could not be observed in the patients of this series, all of whom were receiving immunosuppressive medication. Therefore, nasal reconstruction to improve the physical appearance and thus the psychological well-being of these chronically ill patients seems to be justified.

Urinary excretion of twenty peptides forms an early and accurate diagnostic pattern of acute kidney injury.

Early and accurate detection of acute kidney injury (AKI) is needed to prevent the progression to chronic kidney disease and to improve outcome. Here we used capillary electrophoresis-mass spectrometry to identify urinary peptides predictive of AKI in a training set of 87 urine samples longitudinally collected from patients in an intensive care unit. Within this patient cohort, 16 developed AKI while 14 maintained normal renal function. The sequence of twenty peptides significantly associated with AKI was identified. They were found to be degradation products of six proteins. These formed a diagnostic pattern. Peptides of albumin, α-1-antitrypsin, and ß-2-microglobulin were upregulated but fragments of fibrinogen α and collagens 1 α(I) and 1 α(III) were downregulated in AKI. After cross-validation of the training set, a good diagnostic performance of the marker pattern was found with an area under the ROC curve of 0.91. This was confirmed in a blinded validation set of 20 patients in the intensive care unit and 31 allogeneic hematopoietic stem cell transplantation patients, of which 13 had and 18 had not experienced an episode of AKI. In comparison to more established markers of AKI such as serum cystatin C and urinary kidney injury molecule-1, interleukin-18, and neutrophil gelatinase associated-lipocalin, the proteomic marker pattern was found to be of superior prognostic value, detecting AKI up to 5 days in advance of the rise in serum creatinine.

Effect of cAMP derivates on assembly and maintenance of tight junctions in human umbilical vein endothelial cells.

BACKGROUND: Endothelial tight and adherens junctions control a variety of physiological processes like adhesion, paracellular transport of solutes or trafficking of activated leukocytes. Formation and maintenance of endothelial junctions largely depend on the microenvironment of the specific vascular bed and on interactions of the endothelium with adjacent cell types. Consequently, primary cultures of endothelial cells often lose their specific junctional pattern and fail to establish tight monolayer in vitro. This is also true for endothelial cells isolated from the vein of human umbilical cords (HUVEC) which are widely used as model for endothelial cell-related studies. RESULTS: We here compared the effect of cyclic 3'-5'-adenosine monophosphate (cAMP) and its derivates on formation and stabilization of tight junctions and on alterations in paracellular permeability in HUVEC. We demonstrated by light and confocal laser microscopy that for shorter time periods the sodium salt of 8-bromoadenosine-cAMP (8-Br-cAMP/Na) and for longer incubation periods 8-(4-chlorophenylthio)-cAMP (pCPT-cAMP) exerted the greatest effects of all compounds tested here on formation of continuous tight junction strands in HUVEC. We further demonstrated that although all compounds induced protein kinase A-dependent expression of the tight junction proteins claudin-5 and occludin only pCPT-cAMP slightly enhanced paracellular barrier functions. Moreover, we showed that pCPT-cAMP and 8-Br-cAMP/Na induced expression and membrane translocation of tricellulin. CONCLUSIONS: pCPT-cAMP and, to a lesser extend, 8-Br-cAMP/Na improved formation of continuous tight junction strands and decreased paracellular permeability in primary HUVEC. We concluded that under these conditions HUVEC represent a feasible in vitro model to study formation and disassembly of endothelial tight junctions and to characterize tight junction-associated proteins.

Naturally occurring human urinary peptides for use in diagnosis of chronic kidney disease.

Because of its availability, ease of collection, and correlation with physiology and pathology, urine is an attractive source for clinical proteomics/peptidomics. However, the lack of comparable data sets from large cohorts has greatly hindered the development of clinical proteomics. Here, we report the establishment of a reproducible, high resolution method for peptidome analysis of naturally occurring human urinary peptides and proteins, ranging from 800 to 17,000 Da, using samples from 3,600 individuals analyzed by capillary electrophoresis coupled to MS. All processed data were deposited in an Structured Query Language (SQL) database. This database currently contains 5,010 relevant unique urinary peptides that serve as a pool of potential classifiers for diagnosis and monitoring of various diseases. As an example, by using this source of information, we were able to define urinary peptide biomarkers for chronic kidney diseases, allowing diagnosis of these diseases with high accuracy. Application of the chronic kidney disease-specific biomarker set to an independent test cohort in the subsequent replication phase resulted in 85.5% sensitivity and 100% specificity. These results indicate the potential usefulness of capillary electrophoresis coupled to MS for clinical applications in the analysis of naturally occurring urinary peptides.

Circulating endothelial cells: markers and mediators of vascular damage.

About 30 years ago circulating endothelial cells (CEC) were first observed in peripheral blood. Since then CEC have been established as a reliable indicator of vascular injury and damage and more sophisticated detection techniques, such as immunomagnetic isolation and fluorescence-activated cell sorting (FACS), have become available. However even today there remains controversy as to the best approach to isolate and enumerate these cells. Here, we review the isolation and enumeration of CEC with an emphasis on CD146-driven immunomagnetic isolation and FACS as the two competing techniques. We describe advantages and pitfalls of both approaches. Moreover, we provide a list of clinical studies in this field and describe the possible clinical utility of CEC as a surrogate marker for vascular damage and dysfunction. In addition, we review the phenotype of CEC and discuss mechanisms of detachment. Recent evidence has also revealed interesting interactions between CEC and healthy endothelium in vitro although the relevance of these findings for human vascular disease in vivo remains unclear. Finally, we highlight differences between circulating endothelial cells and endothelial progenitor cells. In summary, CEC must be regarded as a sensitive and specific marker of endothelial damage as well as a potential mediator in vascular disease.

Osteopontin in antineutrophil cytoplasmic autoantibody-associated vasculitis: relation to disease activity, organ manifestation and immunosuppressive therapy.

BACKGROUND: Osteopontin is a pleiotropic cytokine involved in the recruitment and retention of neutrophils to sites of inflammation, which are the primary targets cells in antineutrophil cytoplasmic autoantibody-associated vasculitis (AAV). Osteopontin may play a role in the pathogenesis of AAV. METHODS: 24 patients with systemic AAV and six patients with limited granulomatous disease were included. 19 patients were followed up at 6 and 12 months after the initiation of immunosuppressive therapy. 21 matched healthy volunteers and 20 body mass index and glomerular filtration rate-matched patients with IgA nephropathy were included as controls. Plasma levels of osteopontin were measured by ELISA. Disease activity was gauged by the Birmingham vasculitis activity score (BVAS) and C-reactive protein (CRP). RESULTS: Osteopontin levels are elevated compared with controls (healthy p<0.001; IgA p<0.001).Osteopontin levels decrease significantly during follow-up (p=0.02). Osteopontin levels correlate with disease activity (BVAS r=0.93; CRP r=0.73; all p<0.001) as well as erythrocyturia (r=0.7, p<0.001) and proteinuria (r=0.54, p=0.007). CONCLUSIONS: Active AAV is characterised by increased plasma levels of osteopontin, which decrease dramatically with successful therapy. Osteopontin may mediate the inflammatory process in AAV through the recruitment of neutrophils.

Circulating endothelial cells are an early predictor in renal cell carcinoma for tumor response to sunitinib.

BACKGROUND: Tyrosine kinase inhibitors (TKI) have enriched the therapeutic options in patients with renal cell carcinoma (RCC), which frequently induce morphological changes in tumors. However, only little is known about the biological activity of TKI. Circulating endothelial cells (CEC) have been associated with endothelial damage and, hence, may serve as a putative marker for the biological activity of TKI. The main objective of our study was to evaluate the predictive value of CEC, monocytes, and soluble vascular endothelial growth factor receptor (sVEGFR)-2 in RCC patients receiving sunitinib treatment. METHODS: Analyses of CEC, monocytes, and sVEGFR-2 were accomplished for twenty-six consecutive patients with metastatic RCC who received treatment with sunitinib (50 mg, 4 wks on 2 wks off schedule) at our institution in 2005 and 2006. RESULTS: In RCC patients CEC are elevated to 49 ± 44/ml (control 8 ± 8/ml; P = 0.0001). Treatment with sunitinib is associated with an increase in CEC within 28 days of treatment in patients with a Progression free survival (PFS) above the median to 111 ± 61 (P = 0.0109), whereas changes in patients with a PFS below the median remain insignificant 69 ± 61/ml (P = 0.1848). Monocytes and sVEGFR2 are frequently altered upon sunitinib treatment, but fail to correlate with clinical response, defined by PFS above or below the median. CONCLUSIONS: Sunitinib treatment is associated with an early increase of CEC in responding patients, suggesting superior endothelial cell damage in these patients as a putative predictive biomarker.