Comparison of the hemoglobin variability in non-chronic kidney disease or end-stage renal disease participants and patients with CKD and ESRD

INTRODUCTION

Hemoglobin (Hb) variability occurs frequently in hemodialysis (HD) patients during erythropoietin (EPO) therapy. Guidelines define a narrow target range for the anemia treatment in these patients that is difficult to adhere to in practice. Our aim was to evaluate whether the Hb variability in HD patients is higher compared to non-chronic kidney disease or end-stage renal disease (ESRD) participants and patients with CKD stage I or II.

MATERIALS AND METHODS

Monthly blood samples were assessed prospectively in 100 non-CKD or ESRD participants and 57 patients with CKD stage I or II, and retrospectively in 74 HD patients without changes in EPO or iron dose for 6 months. Variability was calculated and compared between the different groups.

RESULTS

Hb variability was significantly higher in HD patients compared to the other groups, corresponding to results of previous studies. There were no significant differences between non-CKD or ESRD participants and patients with CKD stage I or II in terms of standard deviation (SD), residual SD, fluctuations across threshold, Hb cycling, and mean absolute change of Hb every 30 days (p > 0.05), but a significant difference compared to HD patients (p < 0.001). There were no significant differences between the groups in time in target and area under the curve (AUC) (p > 0.05).

CONCLUSION

Hb variability is a common phenomenon in all groups independently of the method used for assessment and even without EPO therapy. The target range is difficult to achieve for HD patients and should be reconsidered in the future to avoid unsettling both the patients and the staff.

Development of a list with renally relevant drugs as a tool to increase medicines optimisation in patients with chronic kidney disease

OBJECTIVES

Chronic kidney disease (CKD) is a common disorder all over the world. Therapeutic goals are early detection of declining renal function and implementation of adequate pharmacological treatments regarding underlying and secondary diseases. As therapy becomes more complex with increasing stages of CKD, a decision-making tool for healthcare professionals could help to ensure safe drug treatment in patients with CKD in the outpatient setting. Therefore, a list of renally relevant drugs as a decision-making tool was developed to improve medicines optimisation for CKD patients in the outpatient setting long term.

METHODS

A renally relevant drug list (RRD-list) with renally relevant drugs, based on data from a study on medicines optimisation in patients with CKD from June 2015 to March 2018, was developed at the nephrological outpatient clinic at the Klinikum Fulda, Germany. The whole study is published elsewhere. A clinical pharmacist reviewed the patients' medications, current drug-related problems and all nephrologists' recommendations, and categorised all detected drugs into renally relevant and non-renally relevant groups. The 10 most frequently detected renally relevant drug groups were summarised in the RRD-list and extended by treatment alternatives and advice.

RESULTS

The medication of 160 patients, who were receiving overall 1376 drugs, was analysed; 831 drugs were defined as renally relevant. Drug-related problems were caused by 543 renally relevant drugs. The nephrologists made 292 recommendations regarding 28 drug classes. Considering the 10 most frequent drug groups, in total 16 renally relevant drug groups with 36 drug classes were added to the RRD-list.

CONCLUSIONS

The RRD-list could be an essential tool for all healthcare professionals in their daily work, such as general practitioners and community pharmacists, for the treatment of patients with renal insufficiency.

[KDIGO 2021 guideline glomerulonephritis - focus on ANCA-associated vasculitides and anti-glomerular basement membrane glomerulonephritis]

In 2021 new KDIGO (Kidney Disease: Improving Global Outcomes) guidelines for the management of glomerular diseases were published.For ANCA-associated glomerulonephritis the new recommendations comprise a more rapid steroid taper during induction treatment with cyclophosphamide or rituximab, the advice against routine use of plasma exchange, the choice of drug for and duration of maintenance treatment in accordance with predictors of relapse. A kidney transplant should be performed after at least 6 months of remission irrespective of the ANCA titer in ANCA-associated disease, and 6 months after absence of anti-GBM-antibodies in anti-GBM-disease.

Medicines optimization for patients with chronic kidney disease in the outpatient setting: the role of the clinical pharmacist

OBJECTIVES

Medicines optimization (MO) in patients with chronic kidney disease (CKD) is at high risk at transition points of different ambulatory care levels such as nephrologists in outpatient clinics and general practitioners (GPs). We examined if adding a clinical pharmacist to the therapeutic team promotes implementation of nephrologists' drug therapy recommendations by GPs' and reduces drug-related problems (DRPs).

METHODS

A prospective, controlled intervention study was conducted in the nephrology outpatient clinic of the Klinikum Fulda, Germany. The control and intervention phases took place successively. Patients with CKD stage 3-5 and at least one concomitant disease, for example, arterial hypertension or type-2 diabetes were recruited consecutively in three subgroups (naive, 1 contact, ≥2 contacts with nephrologist) from June 2015 to May 2019. GPs' acceptance and frequency of DRPs without (control group [CG]) and with (intervention group [IG]) pharmacist's interventions were compared after 6 months. Interventions include educational training events for GPs between control- and intervention phase, medication therapy management and pharmaceutical patient counselling.

KEY FINDINGS

In total, 256 patients (CG = 160, IG = 96) were recruited into the study. GPs' acceptance of nephrologists' medication recommendations increased significantly among naive patients and those with one prior contact with the nephrologist (CG/IG: naive = 72.8%/95.5%, 1 contact = 81.1%/94.4%; P < 0.001). DRPs per patient were significantly reduced in all subgroups (P < 0.001).

CONCLUSIONS

Interdisciplinary collaboration between the nephrologist, GPs and clinical pharmacist resulted in better MO for patients with CKD.

Chemokine/Cytokine Levels Correlate with Organ Involvement in PR3-ANCA-Associated Vasculitis

Background: ANCA-associated vasculitis (AAV) is a rare small vessel disease characterized by multi-organ involvement. Biomarkers that can measure specific organ involvement are missing. Here, we ask whether certain circulating cytokines and chemokines correlate with renal involvement and if distinct cytokine/chemokine patterns can differentiate between renal, ear/nose/throat, joints, and lung involvement of AAV. Methods: Thirty-two sets of Birmingham vasculitis activity score (BVAS), PR3-ANCA titers, laboratory marker, and different cytokines were obtained from 17 different patients with AAV. BVAS, PR3-ANCA titers, laboratory marker, and cytokine concentrations were correlated to different organ involvements in active AAV. Results: Among patients with active PR3-AAV (BVAS > 0) and kidney involvement we found significant higher concentrations of chemokine ligand (CCL)-1, interleukin (IL)-6, IL21, IL23, IL-28A, IL33, monocyte chemoattractant protein 2 (MCP2), stem cell factor (SCF), thymic stromal lymphopoietin (TSLP), and thrombopoietin (TPO) compared to patients without PR3-ANCA-associated glomerulonephritis. Patients with ear, nose, and throat involvement expressed higher concentrations of MCP2 and of the (C-X-C motif) ligand-12 (CXCL-12) compared to patients with active AAV and no involvement of these organs. Conclusion: We identified distinct cytokine patterns for renal manifestation and for ear, nose and throat involvement of PR3-AAV. Distinct plasma cytokines might be used as non-invasive biomarkers of organ involvement in AAV.

[Coronavirus disease 2019 pandemic from a nephrological perspective]

Hintergrund

Die Coronavirus-disease-2019(COVID-19)-Pandemie hat auch die Nephrologie weltweit vor große Herausforderungen gestellt. Zum einen stellen Patienten mit Nierenerkrankungen in diesem Zusammenhang eine besonders vulnerable Patientengruppe dar, und zum anderen sind die Nieren bei schweren COVID-19-Verläufen nach den Lungen am häufigsten vom Organversagen betroffen.

Material und Methoden

Um zuverlässige Daten zu COVID-19-Prävalenz und -Mortalität bei Dialysepatienten in Deutschland zu erheben, hat die Deutsche Gesellschaft für Nephrologie bereits während der 1. Welle der Pandemie im Frühjahr 2020 ein Register aufgebaut. Wöchentlich wurden Angaben zu Anzahl und Verlauf der COVID-19-Dialysepatienten in Deutschland erhoben und ausgewertet.

Ergebnisse

Die Prävalenz von COVID-19 bei Dialysepatienten in Deutschland zeigte einen doppelgipfligen Verlauf ähnlich wie in der Allgemeinbevölkerung. Während diese im Frühjahr bei Dialysepatienten auf 1,4 % stieg, fiel sie im Sommer deutlich ab und erreichte im Dezember im Rahmen der 2. Pandemiewelle einen Wert von ca. 1,9 %, trotz mittlerweile flächendeckend eingeführter umfangreicher Hygienemaßnahmen in den Dialysezentren. Ähnlich wie in anderen Industriestaaten weisen auch Dialysepatienten in Deutschland eine sehr hohe COVID-19-Letalität von etwa 20 % auf.

Schlussfolgerung

Aus der ermittelten Letalität bei Dialysepatienten lassen sich unmittelbare Konsequenzen für Hygienemaßnahmen in den Dialyseeinrichtungen sowie zu Impfstrategie und -priorisierung dieser Patientengruppe und des sie behandelnden Personals ableiten. Eine Konsequenz des häufigen Befalls der Niere im Rahmen einer Infektion mit dem „severe acute respiratory syndrome coronavirus 2“ (SARS-CoV-2) bei zuvor noch nicht an einer fortgeschrittenen Nierenerkrankung leidenden Patienten sollte die konsequente nephrologische Nachsorge sein.

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.

Chronic Induction of C-Reactive Protein by Hemodialysis, but Not by Peritoneal Dialysis Therapy

Objective

Evaluation of the inflammatory activity in patients on chronic peritoneal dialysis (PD) and patients on chronic hemodialysis (HD) in comparison to patients with chronic renal insufficiency without dialysis treatment and healthy volunteers.

Design

Open, non randomized prospective study.

Setting

Nephrology Department, including HD and PD therapy in a university hospital.

Patients

Twenty -four patients on chronic PD, 21 patients on chronic HD therapy using a cuprophan dialyzer, 16 patients with chronic renal insufficiency without dialysis treatment, and 33 healthy volunteers; 8 additional patients before and after initiation of chronic HD therapy. All patients and controls were without infection or immunosuppressive therapy.

Main Outcome Measures

As a marker of the inflammatory activity in the different patient groups, C-reactive protein (CAP) was measured serially using a sensitive, enzyme-Iinked, immunosorbent assay in order to detect values below the detection limit of standard assays.

Results

All patient groups had CAP levels higher than the normal controls (p < 0.01). Patients on HD had CAP levels significantly higher than PD patients (p < 0.01) whose levels were comparable to patients without dialysis therapy. Accordingly, longitudinal measurements before and after initiation of chronic HD showed a significant increase in CAP levels after the beginning of HD treatment (p < 0.04).

Conclusions

The results suggest that induction of the inflammatory activity is lower during PD compared to HD, since stimulation by the dialyzer membrane, dialysate buffer, or bacterial fragments in the dialysate is avoided. This observation might indicate a possible lower risk of long-term complications in patients with PD.

[Anti B-cell-antibody treatment for maintenance of remission in granulomatosis with polyangiitis and microscopic 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.

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.

[Renal manifestation in ANCA-associated vasculitis]

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.

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.

Clinical outcomes and safety of rituximab treatment for patients with systemic lupus erythematosus (SLE) - results from a nationwide cohort in Germany (GRAID)

OBJECTIVE

The objective of this article is to evaluate the safety and clinical outcome of rituximab treatment in systemic lupus erythematosus (SLE) patients refractory to standard of care therapy in a real-life setting in Germany.

METHODS

The GRAID registry included patients with different autoimmune diseases who were given off-label treatment with rituximab. Data on safety and clinical response were collected retrospectively. In SLE patients, clinical parameters included tender and swollen joint counts, fatigue, myalgia, general wellbeing, Raynaud's and the SLEDAI index. Laboratory tests included dsDNA antibody titres, complement factors, hematologic parameters and proteinuria. Finally, the investigators rated their patients as non-, partial or complete responders based on clinical grounds.

RESULTS

Data from 85 SLE patients were collected, 69 female and 16 male, with a mean disease duration of 9.8 years. The mean follow-up period was 9.6 ± 7.4 months, resulting in 66.8 patient years of observation. A complete response was reported in 37 patients (46.8%), partial response in 27 (34.2%), no response in 15 (19.0%). On average, major clinical as well as laboratory efficacy parameters improved substantially, with the SLEDAI decreasing significantly from 12.2 to 3.3 points. Concerning safety, one infusion reaction leading to discontinuation of treatment occurred. Infections were reported with a rate of 19.5 (including six severe infections) per 100 patient years.

CONCLUSION

With the restrictions of a retrospective data collection, the results of this study confirm data of other registries, which suggest a favourable benefit-risk ratio of rituximab in patients with treatment-refractory SLE.

[Resistant arterial hypertension and a prominent sternum in a 77-year-old woman]

The case of a 77-year-old woman who was admitted with resistant arterial hypertension is reported. In view of a history of pheochromocytoma 2 years ago, catecholamine levels were examined and found to be elevated; in addition, MIBG scintigraphy showed a positive area in the anterior mediastinum. Computer tomography showed a tumor in the sternum. Histology confirmed metastasis from the pheochromocytoma, and the corpus was removed surgically. Currently, the patient is without any evidence of relapse.

Coping strategies and depressiveness in primary systemic vasculitis--what is their impact on health-related quality of life?

OBJECTIVE

To investigate the influence of disease-related coping strategies and depressiveness on health-related quality of life (HRQOL) in primary systemic vasculitis (PSV) patients.

METHODS

One hundred and twenty-two patients with definite diagnosis of PSV were examined in a cross-sectional study. HRQOL (SF-36), depressiveness (BDI), illness perception (B-IPQ) and coping strategies (FKV-LIS) were measured using validated instruments. Additional disease-related and demographic data were retrieved from the patients' records.

RESULTS

HRQOL in PSV patients was reduced compared with the SF-36 norm sample. Specific organ manifestation, size of vessel involvement and disease activity were not related to HRQOL. Linear regression modelling revealed a questionable relationship of emotional to physical HRQOL (P = 0.003, potential suppression effect of BDI), whereas both domains were influenced by depressiveness (P ≤ 0.001). Physical HRQOL was additionally related to fatigue and widowed marital status, while emotional HRQOL was associated with a depressive coping style.

CONCLUSION

HRQOL is impaired in PSV as compared with the general population. Current depressiveness strongly affects physical as well as mental HRQOL. Cognitive intervention strategies should be established in order to improve quality of life in PSV patients.

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.

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.

Abstract 515: Aldosterone Modulates Endothelial Paracellular Permeability by Opening Intercellular Junctions

Aldosterone (Ald) is involved in vascular remodeling and inflammation; however, the mechanisms are imperfectly defined. We hypothesized that Ald alters endothelial integrity and modifies paracellular permeability. Human umbilical vein endothelial cells (HUVEC) were exposed to Ald (10 -9 mol/L) and alterations in paracellular permeability, assembly of tight and adherens junctions, and activation of intracellular signaling pathways were determined. Ald increased endothelial paracellular permeability for molecules up to 70 kDa within 60 min. A transient loss of cortical actin with formation of actin stress fibers, and disruption of continuous adherens and tight junction strands, accompanied the changes. Mineralocorticoid receptor (MR) blockade, inhibition of RhoA or disruption of extracellular regulated protein kinase (ERK) 1/2 signaling pathways attenuated the Ald-related effects. Moreover, the observed changes of the actin cytoskeleton and intercellular junction architecture were accompanied by a rapid dephosphorylation of protein kinase B (AKT) as well as deactivation of endothelial NO synthase (eNOS). Ex vivo tracer flux experiments with Evans Blue (EB)-conjugated albumin demonstrated concordant response to Ald in freshly isolated umbilical arteries. In summary, Ald leads to increased permeability of endothelial monolayer or isolated arteries. These alterations are associated with a temporal opening of Intercellular junctions and diminished eNOS activity, and depend on activation of the RhoA/ERK pathway. We conclude that these mechanisms could contribute to Ald-induced vasculopathy.

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: 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.

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.

Hypercalcemia and pneumocystis Pneumonia after kidney transplantation: report of an exceptional case and literature review

Pneumocystis jirovecii remains an important pathogen in solid organ transplant recipients. Although the overall incidence may be decreasing, after the adoption of effective prophylactic measures, the risk has not been abolished, and pneumocystis pneumonia (PCP) can be observed even many years after successful transplantation. Hypercalcemia develops frequently after renal transplantation and is commonly associated with preexisting secondary hyperparathyroidism. But the pathogenesis of hypercalcemia occurring later in the course of transplantation may be different, and other disease states, such as malignancy and opportunistic infections, must be considered. Hypercalcemia in conjunction with PCP is being increasingly reported in renal transplant patients. In all the cases, respiratory symptoms were prominent, hypercalcemia was of mild-to-moderate severity, parathyroid hormone concentration was decreased, and 1,25(OH)(2) D levels were extraordinarily or inappropriately high. We report the first case to our knowledge of severe hypercalcemia accompanying PCP, in a patient with previous total parathyroidectomy.

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.

Plasma exchange for renal vasculitis and idiopathic rapidly progressive glomerulonephritis: a meta-analysis

BACKGROUND

Plasma exchange may be effective adjunctive treatment for renal vasculitis. We performed a systematic review and meta-analysis of randomized controlled trials of plasma exchange for renal vasculitis.

STUDY DESIGN

Systematic review and meta-analysis of articles identified from electronic databases, bibliographies, and studies identified by experts. Data were abstracted in parallel by 2 reviewers.

SETTING & POPULATION

Adults with idiopathic renal vasculitis or rapidly progressive glomerulonephritis.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials that compared standard care with standard care plus adjuvant plasma exchange in adult patients with either renal vasculitis or idiopathic rapidly progressive glomerulonephritis.

INTERVENTION

Adjuvant plasma exchange.

OUTCOME

Composite of end-stage renal disease or death.

RESULTS

We identified 9 trials including 387 patients. In a fixed-effects model, the pooled RR for end-stage renal disease or death was 0.80 for patients treated with adjunctive plasma exchange compared with standard care alone (95% CI, 0.65-0.99; P = 0.04). No significant heterogeneity was detected (P = 0.5; I(2) = 0%). The effect of plasma exchange did not differ significantly across the range of baseline serum creatinine values (P = 0.7) or number of plasma exchange treatments (P = 0.8). The RR for end-stage renal disease was 0.64 (95% CI, 0.47-0.88; P = 0.006), whereas the RR for death alone was 1.01 (95% CI, 0.71-1.4; P = 0.9).

LIMITATIONS

Although the primary result was statistically significant, there is insufficient statistical information to reliably determine whether plasma exchange decreases the composite of end-stage renal disease or death.

CONCLUSIONS

Plasma exchange may decrease the composite end point of end-stage renal disease or death in patients with renal vasculitis. Additional trials are required given the limited data available.

Addressing the challenge of defining valid proteomic biomarkers and classifiers

Background

The purpose of this manuscript is to provide, based on an extensive analysis of a proteomic data set, suggestions for proper statistical analysis for the discovery of sets of clinically relevant biomarkers. As tractable example we define the measurable proteomic differences between apparently healthy adult males and females. We choose urine as body-fluid of interest and CE-MS, a thoroughly validated platform technology, allowing for routine analysis of a large number of samples. The second urine of the morning was collected from apparently healthy male and female volunteers (aged 21-40) in the course of the routine medical check-up before recruitment at the Hannover Medical School.

Results

We found that the Wilcoxon-test is best suited for the definition of potential biomarkers. Adjustment for multiple testing is necessary. Sample size estimation can be performed based on a small number of observations via resampling from pilot data. Machine learning algorithms appear ideally suited to generate classifiers. Assessment of any results in an independent test-set is essential.

Conclusions

Valid proteomic biomarkers for diagnosis and prognosis only can be defined by applying proper statistical data mining procedures. In particular, a justification of the sample size should be part of the study design.

Detection of circulating microparticles by flow cytometry: influence of centrifugation, filtration of buffer, and freezing

The clinical importance of microparticles resulting from vesiculation of platelets and other blood cells is increasingly recognized, although no standardized method exists for their measurement. Only a few studies have examined the analytical and preanalytical steps and variables affecting microparticle detection. We focused our analysis on microparticle detection by flow cytometry. The goal of our study was to analyze the effects of different centrifugation protocols looking at different durations of high and low centrifugation speeds. We also analyzed the effect of filtration of buffer and long-term freezing on microparticle quantification, as well as the role of Annexin V in the detection of microparticles. Absolute and platelet-derived microparticles were 10- to 15-fold higher using initial lower centrifugation speeds at 1500 × g compared with protocols using centrifugation speeds at 5000 × g (P < 0.01). A clear separation between true events and background noise was only achieved using higher centrifugation speeds. Filtration of buffer with a 0.2 μm filter reduced a significant amount of background noise. Storing samples for microparticle detection at -80°C decreased microparticle levels at days 28, 42, and 56 (P < 0.05 for all comparisons with fresh samples). We believe that staining with Annexin V is necessary to distinguish true events from cell debris or precipitates. Buffers should be filtered and fresh samples should be analyzed, or storage periods will have to be standardized. Higher centrifugation speeds should be used to minimize contamination by smaller size platelets.

Recommendations for biomarker identification and qualification in clinical proteomics

Clinical proteomics has yielded some early positive results-the identification of potential disease biomarkers-indicating the promise for this analytical approach to improve the current state of the art in clinical practice. However, the inability to verify some candidate molecules in subsequent studies has led to skepticism among many clinicians and regulatory bodies, and it has become evident that commonly encountered shortcomings in fundamental aspects of experimental design mainly during biomarker discovery must be addressed in order to provide robust data. In this Perspective, we assert that successful studies generally use suitable statistical approaches for biomarker definition and confirm results in independent test sets; in addition, we describe a brief set of practical and feasible recommendations that we have developed for investigators to properly identify and qualify proteomic biomarkers, which could also be used as reporting requirements. Such recommendations should help put proteomic biomarker discovery on the solid ground needed for turning the old promise into a new reality.

Elevation of serum CXCL13 in SLE as well as in sepsis

Recent studies have demonstrated that CXCL13 serum levels correlate significantly with systemic lupus erythematosus (SLE) disease activity. However, experimental studies show that CXCL13 production can also be induced by bacterial exposure as well as in response to inflammatory cytokines. This report asks whether CXCL13 serum levels are elevated in patients with evidence of bacterial infections and whether there is a correlation with the C-reactive protein (CRP) levels or the severity of illness in critically ill patients. CXCL13 levels were compared in 39 patients with active SLE (without concomitant infection), 40 non-SLE patients with sepsis, and 40 healthy controls by enzyme-linked immunosorbent assay (ELISA) methodology. We also tested storage conditions and freeze–thaw cycles for stability of CXCL13 in serum samples. Our studies demonstrated that the median CXCL13 serum levels were significantly elevated in patients with SLE [median 83 pg/ml (interquartile range 38–366)] or sepsis [359 pg/ml (151–459)] compared with healthy controls [32 pg/ml (27–41), p < 0.001]. The CXCL13 serum levels correlated with disease activity in SLE (CXCL13 vs. SLEDAI r = 0.65, p < 0.001), but were not associated with severity of illness score in critically ill patients (CXCL13 vs. SOFA r = −0.15, p = 0.35). However, CXCL13 serum levels were clearly associated with CRP levels in both sepsis ( r = 0.45, p = 0.003) and SLE ( r = 0.39, p = 0.02). In conclusion, CXCL13 is a stable serum marker for disease activity in SLE patients, but concomitant infections can also lead to increased CXCL13 levels.

New and emerging treatment approaches to lupus

The main goal in systemic lupus erythematosus (SLE) is to achieve remission, as this has a major impact on patient and renal survival. Furthermore, early treatment success has been shown to improve long-term prognosis. Treatment in severe SLE, especially in lupus nephritis, has traditionally been a standardized schematic therapy with cyclophosphamide and prednisolone followed by azathioprine. However, animal and human studies have increased our pathogenetic knowledge of this autoimmune disease with emerging new treatment targets. New and future therapeutic approaches are focused on B-cell depletion, T-cell downregulation and co-stimulatory blockade, cytokine inhibition, or the modulation of complement. Many different biological agents have been used in recent and ongoing studies, but up to now breakthroughs emerging from randomized Phase III trials have been rare. However, the future remains exciting with progress towards safe treatments with which to control the disease in the long run.

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.

Removal of elevated circulating angiopoietin-2 by plasma exchange--a pilot study in critically ill patients with thrombotic microangiopathy and anti-glomerular basement membrane disease

In critically ill patients, the massive release of angiopoietin-2 (Ang-2) from Weibel-Palade bodies interferes with protective angiopoietin-1 (Ang-1)/Tie2 signalling in endothelial cells, thus leading to vascular inflammation and subsequent organ-dysfunction. We hypothesised that plasma exchange (PE) is efficient for lowering excess Ang-2 levels in critically ill patients with thrombocytic microangiopathy (TMA) or anti-glomerular basement membrane (anti-GBM) disease. Plasma Ang-1 and Ang-2 were measured by immuno-luminometric assays in patients with TMA (n=9) or anti-GBM disease (n=4) before and after up to four PE sessions. Twenty apparently healthy volunteers served as controls. Median (IQR) plasma levels of Ang-2 were markedly increased in patients with TMA (7.3 (2.4-21.1) ng/ml) and anti-GBM disease (5.8 (3.4-7.0) ng/ml) compared to healthy controls (1.0 (0.9-1.4) ng/ml, p <0.001). Moreover, Ang-1 plasma levels were decreased in both, TMA (1.02 (0.62-1.62) ng/ml) and anti-GBM disease patients (0.74 (0.59-3.62) ng/ml) compared to healthy controls (2.5 (1.93-3.47) ng/ml, p <0.005). During a total of 32 treatments, PE effectively lowered elevated mean (SD) Ang-2 plasma levels by 36.7 ± 19.6% per treatment (p <0.0001), whereas low Ang-1 plasma levels remained unchanged (0.3 ± 58.5%; p=0.147). Ang-2 levels declined to almost normal values during ≤4 PE treatments (Friedman´s test p<0.0001). PE is an effective method to remove excess circulating Ang-2. It remains to be elucidated if the removal of Ang-2 is crucial to ameliorate endothelial damage in critically ill patients with severely altered endothelial integrity.

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.

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.