Impact of first-line use of caplacizumab on treatment outcomes in immune thrombotic thrombocytopenic purpura

BACKGROUND

The von Willebrand factor-directed nanobody caplacizumab has greatly changed the treatment of immune thrombotic thrombocytopenic purpura (iTTP) in recent years. Data from randomized controlled trials established efficacy and safety.

OBJECTIVES

This study aims to address open questions regarding patient selection, tailoring of therapy duration, obstacles in prescribing caplacizumab in iTTP, effect on adjunct treatment, and outcomes in the real-world setting.

METHODS

We report retrospective, observational cohorts of 113 iTTP episodes treated with caplacizumab and 119 historical control episodes treated without caplacizumab. We aggregated data from the caplacizumab phase II/III trials and real-world data from France, the United Kingdom, Germany, and Austria (846 episodes, 396 treated with caplacizumab, and 450 historical controls).

RESULTS

Caplacizumab was efficacious in iTTP, independent of the timing of therapy initiation, but curtailed the time of active iTTP only when used in the first-line therapy within 72 hours after diagnosis and until at least partial ADAMTS13-activity remission. Aggregated data from multiple study populations showed that caplacizumab use resulted in significant absolute risk reduction of 2.87% for iTTP-related mortality (number needed to treat 35) and a relative risk reduction of 59%.

CONCLUSION

Caplacizumab should be used in first line and until ADAMTS13-remission, lowers iTTP-related mortality and refractoriness, and decreases the number of daily plasma exchange and hospital stay. This trial is registered at www.

CLINICALTRIALS

gov as #NCT04985318.

Treatment of fabry disease with migalastat-outcome from a prospective 24 months observational multicenter study (FAMOUS)

AIMS

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by a deficiency of the lysosomal enzyme α-galactosidase A (GLA/AGAL) resulting in lysosomal accumulation of globotriaosylceramide (Gb3). Patients with amenable GLA mutations can be treated with migalastat, an oral pharmacologic chaperone increasing endogenous AGAL activity. In this prospective observational multicenter study safety as well as cardiovascular, renal, and patient-reported outcomes and disease biomarkers were assessed after 12 and 24 months of migalastat treatment under "real world" conditions.

METHODS AND RESULTS

54 patients (26 females) (33 of these [61.1%] pre-treated with enzyme replacement therapy) with amenable mutations were analyzed. Treatment was generally safe and well tolerated. 153 events per 1,000 patient-years were detected. Overall left ventricular mass index decreased after 24 months (all: -7.5 ± 17.4 g/m2, p = 0.0118; females: -4.6 ± 9.1 g/m2, p = 0.0554; males: -9.9 ± 22.2 g/m2, p = 0.0699). After 24 months, females and males presented with a moderate yearly loss of eGFR (-2.6 and -4.4 ml/min/1.73 m2 per year; p = 0.0317 and p = 0.0028, respectively). FD-specific manifestations/symptoms remained stable (all p > 0.05). 76.9% of females and 50% of males suffered from pain, which has not improved under treatment. FD-specific disease scores (DS3 and MSSI) remained stable during treatment. AGAL activities and plasma lyso-Gb3 values remained stable, although some male patients presented with increasing lyso-Gb3 levels over time.

CONCLUSIONS

Treatment with migalastat was generally safe and resulted in most patients in an amelioration of left ventricular mass. However, due to the heterogeneity of FD phenotypes, it is advisable that the treating physician monitors the clinical response regularly.

The patient journey of patients with Fabry disease, Gaucher disease and Mucopolysaccharidosis type II: A German-wide telephone survey

Background

Lysosomal Storage Diseases (LSD) are rare and multisytemic diseases which are caused by lysosomal enzyme deficiencies leading into accumulation of waste products due to an interruption in the decomposition process. Due to the low prevalence and therefore limited disease awareness as well as the fact that LSD patients present with unspecific symptoms the final diagnosis is often made after a long delay. The aim of this German-wide survey was to characterize the period between onset of symptoms and final diagnosis regarding e.g. self-perceived health, symptom burden and false diagnoses for patients with selected LSDs (Fabry disease (FD), Gaucher disease (GD) and Mucopolysaccharidosis type II (MPS II).

Methods

The study was conducted as a telephone based cross-sectional survey. All patients living in Germany with a confirmed diagnosis of FD, GD or MPS II were eligible to participate. The questionnaire was provided in advance in order to enable the participants to prepare for the interview. Only descriptive analyses were carried out. Single analyses were not carried out for all three patient groups due low case numbers.

Results

Of the overall population, 39 patients have been diagnosed with FD, 19 with GD and 11 with MPS II with the majority of patients being index patients. The majority of FD patients reported their current health status as “satisfactory” or better (79.5%). Self-perceived health status was observed to be at least stable or improving for the majority of FD patients compared to the year prior to diagnosis. The most frequently reported symptoms for patients with FD were paraesthesias (51.3%), whereas patients with GD reported a tendency for bleeding, blue spots or coagulation disorder (63.2%) as well as hepatomegaly and/or splenomegaly (63.2%) as the most commonly appearing symptoms. The number of patients reporting misdiagnoses was n = 5 (13.5%) for patients with FD and n = 5 (27.8%) for patients with GD. The median duration of the diagnostic delay was 21.0 years for FD, 20.0 years for GD and 2.0 years for MPS II.

Conclusions

This study showed that self-perceived status of health for patients might improve once the final correct diagnoses has been made and specific treatment was available. Furthermore, it was observed that diagnostic delay is still high in Germany for a relevant proportion of affected patients. Further challenges in the future will still be to increase awareness for these diseases across the entire healthcare sector to minimize the diagnostic delay.

Bridging the Gap Between Vessels and Nerves in Fabry Disease

Purpose

Fabry disease frequently includes pain as an early disease feature, which was characterized as a dysfunctional processing of somatosensory information in various studies. The pathomechanism involves the mutation in the x-chromosomal GLA-gene and a consequent reduction of the α-galactosidase. This results in an insufficient reduction of globotriaosylceramide (GL3). Interestingly, an accumulation of GL3 was shown in both vascular endothelial cells and nerve tissue. This implicates that both an endothelial and nerve-dependent dysfunction may be considered as prominent mechanisms in pain pathogeneses.

Patients and Methods

The exploration of endothelial and C-fiber-dependent microcirculatory changes was conducted in a healthy cohort (n = 22) and in patients with polyneuropathy (n = 21) and Fabry disease (n = 15). Microcirculatory measurements were conducted using a laser speckle contrast analysis (LASCA) in combination with a thermoprobe controlling system, which applied a constant heat stimulus (42°C). Additionally, nerve fiber function was assessed via Quantitative Sensory Testing and heart rate variability (HRV).

Results

The results indicated a characteristic perfusion profile in the control group as well as both patient groups. Fabry patients had the smallest increase of endothelial-dependent perfusion as compared to the others [% increase as compared to Fabry: control + 129% (p = 0.002), PNP + 126% (p = 0.019)]. The sensory testing indicated a dysfunctional processing of A-delta fibers in Fabry disease as compared to healthy controls [cold detection threshold (CDT): p = 0.004, mechanical pain threshold (MPT): p = 0.007] and PNP patients (MPT: p = 0.001).

Conclusion

Our results point to both an endothelial and a nerve-dependent dysfunction in Fabry disease. Therefore, not only direct changes in nerve fiber tissue may contribute to an altered sensory processing. Indeed, evidence of a perfusion change in vasa nervorum could also contribute to the dysfunctional processing of sensory information, which likely occurs under physical stress.

Treatment of Fabry's Disease With Migalastat: Outcome From a Prospective Observational Multicenter Study (FAMOUS)

Fabry's disease (FD) is an X-linked lysosomal storage disorder caused by the deficient activity of the lysosomal enzyme α-galactosidase A (α-Gal A) leading to intracellular accumulation of globotriaosylceramide (Gb3). Patients with amenable mutations can be treated with migalastat, a recently approved oral pharmacologic chaperone to increase endogenous α-Gal A activity. We assessed safety along with cardiovascular, renal, and patient-reported outcomes and disease biomarkers in a prospective observational multicenter study after 12 months of migalastat treatment under "real-world" conditions. Fifty-nine (28 females) patients (34 (57.6%) pretreated with enzyme replacement therapy) with amenable mutations were recruited. Migalastat was generally safe and well tolerated. Females and males presented with a reduction of left ventricular mass index (primary end point) (-7.2 and -13.7 g/m² , P = 0.0050 and P = 0.0061). FD-specific manifestations and symptoms remained stable (all P > 0.05). Both sexes presented with a reduction of estimated glomerular filtration rate (secondary end point) (-6.9 and -5.0 mL/minute/1.73 m² ; P = 0.0020 and P = 0.0004, respectively), which was most prominent in patients with low blood pressure (P = 0.0271). α-Gal A activity increased in male patients by 15% from 29% to 44% of the normal wild-type activity (P = 0.0106) and plasma lyso-Gb3 levels were stable in females and males (P = 0.3490 and P = 0.2009). Reevaluation of mutations with poor biochemical response revealed no marked activity increase in a zero activity background. We conclude that therapy with migalastat was generally safe and resulted in an amelioration of left ventricular mass. In terms of impaired renal function, blood pressure control seems to be an unattended important goal.

Self-reported medication in community-dwelling older adults in Germany: results from the Berlin Initiative Study

Background

Older adults have the highest drug utilization due to multimorbidity. Although the number of people over age 70 is expected to double within the next decades, population-based data on their medication patterns are scarce especially in combination with polypharmacy and potentially inappropriate medication (PIM). Our objective was to analyse the frequency of polypharmacy, pattern of prescription (PD) and over-the-counter (OTC) drug usage, and PIMs according to age and gender in a population-based cohort of very old adults in Germany.

Methods

Cross-sectional baseline data of the Berlin Initiative Study, a prospective cohort study of community-dwelling adults aged ≥70 years with a standardized interview including demographics, lifestyle variables, co-morbidities, and medication assessment were analysed. Medication data were coded using the Anatomical Therapeutic Chemical (ATC) classification. Age- and sex-standardized descriptive analysis of polypharmacy (≥5 drugs, PD and OTC vs. PD only and regular and on demand drugs vs regular only), medication frequency and distribution, including PIMs, was performed by age (</≥80) and gender.

Results

Of 2069 participants with an average age of 79.5 years, 97% (95%CI [96%;98%]) took at least one drug and on average 6.2 drugs (SD = 3.5) with about 40 to 66% fulfilling the criteria of polypharmacy depending on the definition. Regarding drug type more female participants took a combination of PD and OTC (male: 68%, 95%CI [65%;72%]); female: 78%, 95%CI [76%;80%]). Most frequently used were drugs for cardiovascular diseases (85%, 95%CI [83%;86%]). Medication frequency increased among participants aged ≥80 years, especially for cardiovascular drugs, antithrombotics, psychoanaleptics and dietary supplements. Among the top ten prescription drugs were mainly cardiovascular drugs including lipid-lowering agents (simvastatin), beta-blockers (metoprolol, bisoprolol) and ACE inhibitors (ramipril). The most common OTC drug was acetylsalicylic acid (35%; 95%CI [33%;37%])). Dose-independent PIM were identified for 15% of the participants.

Conclusions

Polypharmacy was excessive in older adults, with not only PD but also OTC drugs contributing to the high point prevalence. The medication patterns reflected the treatment of chronic diseases in this age group. There was even an increase in medication frequency between below and above 80 years especially for drugs of cardiovascular diseases, antithrombotic medication, psychoanaleptics, and dietary supplements.

Control of blood pressure and risk of mortality in a cohort of older adults: the Berlin Initiative Study

Aims

To assess whether blood pressure (BP) values below 140/90 mmHg during antihypertensive treatment are associated with a decreased risk of all-cause mortality in community-dwelling older adults.

Methods and results

Within the Berlin Initiative Study, we assembled a cohort of patients ≥70 years treated with antihypertensive drugs at baseline (November 2009–June 2011). End of prospective follow-up was December 2016. Cox proportional hazards models yielded adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause mortality associated with normalized BP [systolic BP (SBP) <140 mmHg and diastolic BP (DBP) <90 mmHg] compared with non-normalized BP (SBP ≥140 mmHg or DBP ≥90 mmHg) overall and after stratification by age or previous cardiovascular events. Among 1628 patients (mean age 81 years) on antihypertensive drugs, 636 exhibited normalized BP. During 8853 person-years of follow-up, 469 patients died. Compared with non-normalized BP, normalized BP was associated with an increased risk of all-cause mortality (incidence rates: 60.3 vs. 48.5 per 1000/year; HR 1.26; 95% CI 1.04–1.54). Increased risks were observed in patients ≥80 years (102.2 vs. 77.5 per 1000/year; HR 1.40; 95% CI 1.12–1.74) and with previous cardiovascular events (98.3 vs. 63.6 per 1000/year; HR 1.61; 95% CI 1.14–2.27) but not in patients aged 70–79 years (22.6 vs. 22.7 per 1000/year; HR 0.83; 95% CI 0.54–1.27) or without previous cardiovascular events (45.2 vs. 44.4 per 1000/year; HR 1.16, 95% CI 0.90–1.48).

Conclusion

Blood pressure values below 140/90 mmHg during antihypertensive treatment may be associated with an increased risk of mortality in octogenarians or elderly patients with previous cardiovascular events.

Prevalence of reduced kidney function and albuminuria in older adults: the Berlin Initiative Study

Background

Although CKD is said to increase among older adults, epidemiologic data on kidney function in people ≥70 years of age are scarce. The Berlin Initiative Study (BIS) aims to fill this gap by evaluating the CKD burden in older adults.

Methods

The BIS is a prospective population-based cohort study whose participants are members of Germany's biggest insurance company. This cross-sectional analysis (i) gives a detailed baseline characterization of the participants, (ii) analyses the representativeness of the cohort's disease profile, (iii) assesses GFR and albuminuria levels across age categories, (iv) associates cardiovascular risk factors with GFR as well as albuminuria and (v) compares means of GFR values according to different estimating equations with measured GFR.

Results

A total of 2069 participants (52.6% female, mean age 80.4 years) were enrolled: 26.1% were diabetic, 78.8% were on antihypertensive medication, 8.7% had experienced a stroke, 14% a myocardial infarction, 22.6% had cancer, 17.8% were anaemic and 26.5% were obese. The distribution of comorbidities in the BIS cohort was very similar to that in the insurance 'source population'. Creatinine and cystatin C as well as the albumin:creatinine ratio (ACR) increased with increasing age. After multivariate adjustments, reduced GFR and elevated ACR were associated with most cardiovascular risk factors. The prevalence of a GFR <60 mL/min/1.73 m 2 ranged from 38 to 62% depending on the estimation equation used.

Conclusions

The BIS is a very well-characterized, representative cohort of older adults. Participants with an ACR ≥30 had significantly higher odds for most cardiovascular risk factors compared with an ACR <30 mg/g. Kidney function declined and ACR rose with increasing age.

Beta Trace Protein does not outperform Creatinine and Cystatin C in estimating Glomerular Filtration Rate in Older Adults

Despite intense research the optimal endogenous biomarker for glomerular filtration rate (GFR) estimation has not been identified yet. We analyzed if ß-trace protein (BTP) improved GFR estimation in elderly. 566 participants aged 70+ from the population-based Berlin Initiative Study were included in a cross-sectional validation study. BTP, standardized creatinine and cystatin C were measured in participants with iohexol clearance measurement as gold standard method for measured GFR (mGFR). In a double logarithmic linear model prediction of mGFR by BTP was assessed. Analyses with BTP only and combined with creatinine and cystatin C were performed. Additionally, performance of GFR estimating equations was compared to mGFR. We found that the combination of all three biomarkers showed the best prediction of mGFR (r² = 0.83), whereat the combination of creatinine and cystatin C provided only minimally diverging results (r² = 0.82). Single usage of BTP showed worst prediction (r² = 0.67) within models with only one biomarker. Subgroup analyses (arterial hypertension, diabetes, body mass index ≤23 and >30) demonstrated a slight additional benefit of including BTP into the prediction model for diabetic, hypertensive and lean patients. Among BTP-containing GFR equations the Inker BTP-based equation showed superior performance. Especially the use of cystatin C renders the addition of BTP unnecessary.

IL-17 Expression in the Time Course of Acute Anti-Thy1 Glomerulonephritis

BACKGROUND

Interleukin-17 (IL-17) is a new pro-inflammatory cytokine involved in immune response and inflammatory disease. The main source of IL-17 is a subset of CD4+ T-helper cells, but is also secreted by non-immune cells. The present study analyzes expression of IL-17 in the time course of acute anti-thy1 glomerulonephritis and the role of IL-17 as a potential link between inflammation and fibrosis.

METHODS

Anti-thy1 glomerulonephritis was induced into male Wistar rats by OX-7 antibody injection. After that, samples were taken on days 1, 5, 10 (matrix expansion phase), 15 and 20 (resolution phase). PBS-injected animals served as controls. Proteinuria and histological matrixes score served as the main markers for disease severity. In in vitro experiments, NRK-52E cells were used. For cytokine expressions, mRNA and protein levels were analyzed by utilizing RT-PCR, in situ hybridization and immunofluorescence.

RESULTS

Highest IL-17 mRNA-expression (6.50-fold vs. con; p<0.05) was found on day 5 after induction of anti-thy1 glomerulonephritis along the maximum levels of proteinuria (113 ± 13 mg/d; p<0.001), histological glomerular-matrix accumulation (82%; p<0.001) and TGF-β1 (2.2-fold; p<0.05), IL-6 mRNA expression (36-fold; p<0.05). IL-17 protein expression co-localized with the endothelial cell marker PECAM in immunofluorescence. In NRK-52E cells, co-administration of TGF-β1 and IL-6 synergistically up-regulated IL-17 mRNA 4986-fold (p<0.001).

CONCLUSIONS

The pro-inflammatory cytokine IL-17 is up-regulated in endothelial cells during the time course of acute anti-thy1 glomerulonephritis. In vitro, NRK-52E cells secrete IL-17 under pro-fibrotic and pro-inflammatory conditions.

Iohexol plasma clearance measurement in older adults with chronic kidney disease-sampling time matters

BACKGROUND

Accurate and precise measurement of GFR is important for patients with chronic kidney disease (CKD). Sampling time of exogenous filtration markers may have great impact on measured GFR (mGFR) results, but there is still uncertainty about optimal timing of plasma clearance measurement in patients with advanced CKD, for whom 24-h measurement is recommended. This satellite project of the Berlin Initiative Study evaluates whether 24-h iohexol plasma clearance reveals a clinically relevant difference compared with 5-h measurement in older adults.

METHODS

In 104 participants with a mean age of 79 years and diagnosed CKD, we performed standard GFR measurement over 5 h (mGFR300) using iohexol plasma concentrations at 120, 180, 240 and 300 min after injection. With an additional sample at 1440 min, we assessed 24-h GFR measurement (mGFR1440). Study design was cross-sectional. Calculation of mGFR was conducted with a one compartment model using the Brochner-Mortensen equation to calculate the fast component. mGFR values were compared with estimated GFR values (MDRD, CKD-EPI, BIS1, Revised Lund-Malmö and Cockcroft-Gault).

RESULTS

In all 104 subjects, mGFR1440 was lower than mGFR300 (23 ± 8 versus 29 ± 9 mL/min/1.73 m(2), mean ± SD; P < 0.001). mGFR1440 was highly correlated with mGFR300 (r = 0.9). The mean absolute difference mGFR300 - mGFR1440 was 5.9 mL/min/1.73 m(2) corresponding to a mean percentage difference of 29%. In individuals with eGFRCKD-EPI ≤ 30 mL/min/1.73 m(2), percentage difference of mGFR300 and mGFR1440 was even higher (35%). To predict mGFR1440 from mGFR300, we developed the correction formula: mGFR1440 = -2.175 + 0.871 × mGFR300 (1-fold standard error of estimate: ±2.3 mL/min/1.73 m(2)). The GFR estimating equation with the best accuracy and precision compared with mGFR300 and mGFR1440 was the Revised Lund Malmö.

CONCLUSIONS

In elderly CKD patients, measurement of iohexol clearance up to 5 h leads to a clinically relevant overestimation of GFR compared with 24-h measurement. In clinical care, this effect should be bore in mind especially for patients with considerably reduced GFR levels. A new correction formula has been developed to predict mGFR1440 from mGFR300. For accurate GFR estimates in elderly CKD patients, we recommend the Revised Lund Malmö equation.

[Home-based infusion therapy--a feasible approach for chronically ill patients? A new path to provide superior patient care exemplified for Fabry's disease]

BACKGROUND

As there are scarce data from Germany addressing home-based infusion therapy in chronically ill patients, a study on transferring infusion therapy from in-patient-treatment to home care, exemplified for Fabry's disease, was conducted.

METHODS

A total of 69 patients on enzyme replacement infusion therapy (ERT with agalsidase alfa every two weeks) were enrolled in the open, non-controlled, multicentre, non-interventional observational study. After uneventful ERT in a hospital setting, intravenous treatment was administered at home by a specially-trained nurse. Primary outcome measure was change in patient satisfaction measured by an eleven-item Likert scale.

RESULTS

The in-home observation period lasted between 96 und 401 days (median 180; IQR 166-184). Patient satisfaction increased significantly with home-based therapy (p = 0.001). A quality of life analysis (SF-36) demonstrated significant improvements in role-physical (p = 0.003), bodily pain (p = 0.032), vitality (p < 0.001), social functioning (p = 0.020), role-emotional (p = 0.007), mental well-being (p = 0.007) and mental sum score (p = 0.002). Home infusions turned out to be safe and were well tolerated.

CONCLUSION

Chronically ill patients with need for regular infusion therapy may benefit from a home care setting. Home-based infusion therapy as exemplified by agalsidase alfa ERT in Fabry's disease is a viable option for patients who received uneventful infusions within the hospital.

Fabry disease - underestimated in the differential diagnosis of multiple sclerosis?

Objective

Fabry disease is a rare X-linked inherited lysosomal storage disorder affecting multiple organ systems. It includes central nervous system involvement via micro- and macroangiopathic cerebral changes. Due to its clinical symptoms and frequent MRI lesions, Fabry disease is commonly misdiagnosed as multiple sclerosis. We present an overview of cases from Fabry centres in Germany initially misdiagnosed with multiple sclerosis and report the clinical, MR-tomographical, and laboratory findings.

Methods

Eleven Fabry patients (one male, ten females) initially diagnosed with multiple sclerosis were identified from 187 patient records (5.9%) and analyzed for presenting symptoms, results of the initial diagnostic workup, and the clinical course of the disease.

Results

Four patients were identified as having a “possible” history of MS, and 7 patients as “definite” cases of multiple sclerosis (revised McDonald criteria). On average, Fabry disease was diagnosed 8.2 years (±9.8 years) after the MS diagnosis, and 12.8 years after onset of first symptoms (±10.3 years). All patients revealed white matter lesions on MRI. The lesion pattern and results of cerebrospinal fluid examination were inconsistent and non-specific. White matter lesion volumes ranged from 8.9 mL to 34.8 mL (mean 17.8 mL±11.4 mL). There was no association between extra-neurological manifestations or enzyme activity and lesion load.

Conclusion

There are several anamnestic and clinical hints indicating when Fabry disease should be considered a relevant differential diagnosis of multiple sclerosis, e.g. female patients with asymmetric, confluent white matter lesions on MRI, normal spinal MR imaging, ectatic vertebrobasilar arteries, proteinuria, or lack of intrathecally derived immunoglobulin synthesis.

Two novel equations to estimate kidney function in persons aged 70 years or older

BACKGROUND

In older adults, current equations to estimate glomerular filtration rate (GFR) are not validated and may misclassify elderly persons in terms of their stage of chronic kidney disease.

OBJECTIVE

To derive the Berlin Initiative Study (BIS) equation, a novel estimator of GFR in elderly participants.

DESIGN

Cross-sectional. Data were split for analysis into 2 sets for equation development and internal validation.

SETTING

Random community-based population of a large insurance company.

PARTICIPANTS

610 participants aged 70 years or older (mean age, 78.5 years).

INTERVENTION

Iohexol plasma clearance measurement as gold standard.

MEASUREMENTS

GFR, measured as the plasma clearance of the endogenous marker iohexol, to compare performance of existing equations of estimated GFR with measured GFR of the gold standard; estimation of measured GFR from standardized creatinine and cystatin C levels, sex, and age in the learning sample; and comparison of the BIS equations (BIS1: creatinine-based; BIS2: creatinine- and cystatin C-based) with other estimating equations and determination of bias, precision, and accuracy in the validation sample.

RESULTS

The new BIS2 equation yielded the smallest bias followed by the creatinine-based BIS1 and Cockcroft-Gault equations. All other equations considerably overestimated GFR. The BIS equations confirmed a high prevalence of persons older than 70 years with a GFR less than 60 mL/min per 1.73 m2 (BIS1, 50.4%; BIS2, 47.4%; measured GFR, 47.9%). The total misclassification rate for this criterion was smallest for the BIS2 equation (11.6%), followed by the cystatin C equation 2 (15.1%) proposed by the Chronic Kidney Disease Epidemiology Collaboration. Among the creatinine-based equations, BIS1 had the smallest misclassification rate (17.2%), followed by the Chronic Kidney Disease Epidemiology Collaboration equation (20.4%).

LIMITATION

There was no validation by an external data set.

CONCLUSION

The BIS2 equation should be used to estimate GFR in persons aged 70 years or older with normal or mild to moderately reduced kidney function. If cystatin C is not available, the BIS1 equation is an acceptable alternative.

PRIMARY FUNDING SOURCE

Kuratorium für Dialyse und Nierentransplatation (KfH) Foundation of Preventive Medicine.

Everolimus in patients with autosomal dominant polycystic kidney disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is a slowly progressive hereditary disorder that usually leads to end-stage renal disease. Although the underlying gene mutations were identified several years ago, efficacious therapy to curtail cyst growth and prevent renal failure is not available. Experimental and observational studies suggest that the mammalian target of rapamycin (mTOR) pathway plays a critical role in cyst growth.

METHODS

In this 2-year, double-blind trial, we randomly assigned 433 patients with ADPKD to receive either placebo or the mTOR inhibitor everolimus. The primary outcome was the change in total kidney volume, as measured on magnetic resonance imaging, at 12 and 24 months.

RESULTS

Total kidney volume increased between baseline and 1 year by 102 ml in the everolimus group, versus 157 ml in the placebo group (P=0.02) and between baseline and 2 years by 230 ml and 301 ml, respectively (P=0.06). Cyst volume increased by 76 ml in the everolimus group and 98 ml in the placebo group after 1 year (P=0.27) and by 181 ml and 215 ml, respectively, after 2 years (P=0.28). Parenchymal volume increased by 26 ml in the everolimus group and 62 ml in the placebo group after 1 year (P=0.003) and by 56 ml and 93 ml, respectively, after 2 years (P=0.11). The mean decrement in the estimated glomerular filtration rate after 24 months was 8.9 ml per minute per 1.73 m2 of body-surface area in the everolimus group versus 7.7 ml per minute in the placebo group (P=0.15). Drug-specific adverse events were more common in the everolimus group; the rate of infection was similar in the two groups.

CONCLUSIONS

Within the 2-year study period,as compared with placebo, everolimus slowed the increase in total kidney volume of patients with ADPKD but did not slow the progression of renal impairment [corrected]. (Funded by Novartis; EudraCT number, 2006-001485-16; ClinicalTrials.gov number, NCT00414440.)

Pharmacological management of renal fibrotic disease

Chronic kidney diseases frequently advance to end-stage renal failure, and the number of patients affected is steadily increasing worldwide. At the molecular level, progression of renal insufficiency correlates closely with ongoing pathological matrix protein expansion (i.e., renal fibrosis), in a manner independent of the underlying disorder. Overactivity of the renin-angiotensin system and of the TGF-beta system have been identified as key mediators of kidney matrix accumulation, and are principal targets in the management of chronic renal disease. This review provides a recent overview of the therapeutic options that are clinically established, and of novel molecular strategies that will approach clinical practice in the near future.

Curcumin blocks fibrosis in anti-Thy 1 glomerulonephritis through up-regulation of heme oxygenase 1

BACKGROUND

Induction of heme oxygenase 1 (HO-1) has been shown to be beneficial in a variety of pathologic settings. Curcumin, a polyphenolic compound, has antifibrotic effects in lung models of fibrosis, and is known to induce HO-1 in renal tubular cells. In this study, we determined whether curcumin has antifibrotic properties in glomerular fibrosis and if these effects are mediated by induction of HO-1.

METHODS

Curcumin effects on HO-1 expression in cultured mesangial cells and in glomeruli in vivo were analyzed by Northern and Western blotting. The dose-dependent effect of curcumin on glomerular fibrosis was tested in the anti-Thy 1 glomerulonephritis model. Curcumin was applied at doses of 10 to 200 mg/kg body weight by intraperitoneal injection from days 3 to 5 after induction of disease. On day 6, glomeruli were harvested and markers of fibrosis [plasminogen activator inhibitor-1 (PAI-1), transforming growth factor-beta (TGF-beta), fibronectin, periodic acid-Schiff (PAS) staining] were analyzed. The effect of HO-1 inhibition was tested in a second experiment were nephritic rats were treated with curcumin (100 mg/kg body weight) or the combination of curcumin and the HO-1 inhibitor zinc protoporphyrin (100 microg/kg).

RESULTS

Curcumin potently induced mesangial cell HO-1 expression in vitro and up-regulated glomerular HO-1 expression in nephritic animals in vivo. Curcumin treatment led to a significant, dose-dependent reduction of markers of fibrosis and proteinuria, with maximal inhibition at doses of 50 to 100 mg/kg. Beneficial effects of curcumin on markers of fibrosis and proteinuria were lost after HO-1 inhibition.

CONCLUSION

Curcumin has antifibrotic effects in glomerular disease, which are mediated through an induction of HO-1.

Curcumin blocks fibrosis in anti-Thy 1 glomerulonephritis through up-regulation of heme oxygenase 1

BACKGROUND

Induction of heme oxygenase 1 (HO-1) has been shown to be beneficial in a variety of pathologic settings. Curcumin, a polyphenolic compound, has antifibrotic effects in lung models of fibrosis, and is known to induce HO-1 in renal tubular cells. In this study, we determined whether curcumin has antifibrotic properties in glomerular fibrosis and if these effects are mediated by induction of HO-1.

METHODS

Curcumin effects on HO-1 expression in cultured mesangial cells and in glomeruli in vivo were analyzed by Northern and Western blotting. The dose-dependent effect of curcumin on glomerular fibrosis was tested in the anti-Thy 1 glomerulonephritis model. Curcumin was applied at doses of 10 to 200 mg/kg body weight by intraperitoneal injection from days 3 to 5 after induction of disease. On day 6, glomeruli were harvested and markers of fibrosis [plasminogen activator inhibitor-1 (PAI-1), transforming growth factor-beta (TGF-beta), fibronectin, periodic acid-Schiff (PAS) staining] were analyzed. The effect of HO-1 inhibition was tested in a second experiment were nephritic rats were treated with curcumin (100 mg/kg body weight) or the combination of curcumin and the HO-1 inhibitor zinc protoporphyrin (100 microg/kg).

RESULTS

Curcumin potently induced mesangial cell HO-1 expression in vitro and up-regulated glomerular HO-1 expression in nephritic animals in vivo. Curcumin treatment led to a significant, dose-dependent reduction of markers of fibrosis and proteinuria, with maximal inhibition at doses of 50 to 100 mg/kg. Beneficial effects of curcumin on markers of fibrosis and proteinuria were lost after HO-1 inhibition.

CONCLUSION

Curcumin has antifibrotic effects in glomerular disease, which are mediated through an induction of HO-1.

Glomerular activin A overexpression is linked to fibrosis in anti-Thy1 glomerulonephritis

BACKGROUND

Activin A, a member of the transforming growth factor-beta (TGF-beta) superfamily of proteins, shares many biological features with the pro-fibrotic cytokine TGF-beta1, which is primarily responsible for the accumulation of extracellular matrix proteins in renal disease. This study was designed to identify regulators of activin A production in glomerular mesangial cells and test if activin A acts as a pro-fibrotic cytokine in mesangial cells.

METHODS

The effect of inflammatory cytokines on activin A production and the effect of exogenous activin A on mediators of fibrosis were analysed in cultured rat mesangial cells. Expression of activin A and of established mediators of fibrosis was analysed in a rat model of glomerular fibrosis (anti-Thy1 glomerulonephritis).

RESULTS

In cultured mesangial cells, interleukin-1 and basic fibroblast growth factor, both mediators of glomerular inflammatory injury, dose-dependently increased activin A expression. Incubation with activin A significantly stimulated TGF-beta1, PAI-1 and connective tissue growth factor RNA expression and increased production of extracellular matrix proteins in mesangial cells. In rats with anti-Thy1 glomerulonephritis, expression of glomerular activin A mRNA and protein paralled the expression of TGF-beta and other indices of fibrosis, showing little change from normal on day 1, a marked, 70-fold increase of activin protein production on day 6, and a subsequent decrease at day 12. Antifibrotic therapy with the angiotensin-converting enzyme inhibitor enalapril significantly reduced glomerular activin A production.

CONCLUSION

Taken together, the results of this study link overexpression of activin A to glomerular matrix protein expansion in vivo and in vitro, suggesting that activin A acts as pro-fibrotic cytokine in renal disease.

Platelet inhibition limits TGF-β overexpression and matrix expansion after induction of anti-thy1 glomerulonephritis

BACKGROUND

Although a role of platelets is well established in atherosclerosis, only little is known about their contribution to pathologic renal matrix expansion. The present study analyzes the effect of the platelet inhibitor clopidogrel on the early injury and subsequent repair phase of experimental anti-thy1 glomerulonephritis.

METHODS

In male Sprague-Dawley rats, acute anti-thy1 glomerulonephritis was induced by intravenous injection of OX-7 antibody. In protocol 1 (injury), clopidogrel was given starting 5 days before antibody injection. One day after disease induction, parameters of mesangial cell injury (glomerular cell number, inducible NO synthesis, and macrophage infiltration) were analyzed. In protocol 2 (repair), clopidogrel treatment was started one day after antibody injection. On day 6, parameters of glomerular repair [glomerular matrix score, expression of transforming growth factor (TGF)-beta 1, fibronectin, and plasminogen activator inhibitor (PAI)-1] and thrombosis (aneurysm formation and fibrinogen deposition) were determined. In both protocols, an additional group of rats was treated with the angiotensin-converting enzyme (ACE) inhibitor enalapril.

RESULTS

In the injury protocol, platelet inhibition did not affect mesangial cell lysis, glomerular NO production, and macrophage infiltration, while ACE inhibition was protective. In the repair protocol, clopidogrel significantly limited aneurysm formation and fibrinogen deposition, as well as glomerular matrix expansion, TGF-beta 1, fibronectin, and PAI-1 expression. In comparison, enalapril was less effective in preventing glomerular thrombosis, but was significantly superior to clopidogrel in limiting matrix protein expression and accumulation.

CONCLUSION

The present study shows that platelets play a significant role in the sequence from mesangial cell injury to renal matrix expansion in anti-thy1 glomerulonephritis. The results, directly comparing renin-angiotensin-system and platelet inhibition, suggest that platelets contribute less than angiotensin II to TGF-beta overexpression and matrix accumulation in this model of acute glomerular wound repair.

Impact of PGE1 on cyclosporine A induced up-regulation of TGF-beta1, its receptors, and related matrix production in cultured mesangial cells

Transforming growth factor-beta1 (TGF-beta1) plays a major role in cyclosporine A (CsA) induced glomerulosclerosis. We have recently shown that CsA up-regulates the expression of TGF-beta1 and its receptors type I (TbetaR-I) and type II (TbetaR-II) in rat mesangial cells (MCs). Prostaglandins of the E series (PGEs) are known to exert substantial anti-fibrotic effects. Here, we assessed the effect of PGE1 on CsA induced up-regulation of TGF-beta1, TbetaR-I, TbetaR-II and related matrix production in MCs. Co-incubation with PGE1 reduced CsA induced up-regulation of TGF-beta1 and TbetaR-II at the mRNA and protein level. Alike, PGE1 reduced TbetaR-I protein expression, which is posttranscriptionally up-regulated by CsA. Whereas a low PGE(1) concentration decreased CsA induced production of fibronectin (FN) and plasminogen activator inhibitor type-1 (PAI-1), a higher PGE1 concentration did not change FN production, but further increased PAI-1 production. In vivo studies will show, whether treatment with PGE1 analogues will be useful in preventing CsA induced glomerulosclerosis.

Angiotensin-converting enzyme inhibition but not beta-adrenergic blockade limits transforming growth factor-beta overexpression in acute normotensive anti-thy1 glomerulonephritis

OBJECTIVE

Recent experimental studies in chronic kidney disease have suggested that sympathicolytic drugs, similar to angiotensin II antagonism, limit renal fibrosis independent of blood pressure control. Using the model of acute and normotensive anti-thy1 glomerulonephritis, we analysed the action of beta-adrenergic blockade (as compared with angiotensin-converting enzyme inhibition) on renal overexpression of the profibrotic cytokine transforming growth factor (TGF)-beta.

METHODS

One day after induction of anti-thy1 glomerulonephritis, rats were given increasing doses of the beta-blockers metoprolol or nebivolol (0.1-fold, one-fold, 10-fold and 20-fold of the known blood pressure dose) until day 6 and the 20-fold dose until day 12. Additional animals were treated with a high dose of the angiotensin-converting enzyme inhibitor enalapril. At the end of each experiment, blood pressure and heart rate were recorded, glomerular matrix expansion was scored histologically, and protein expression of TGF-beta(1), fibronectin and plasminogen activator inhibitor-1 was determined in the supernatant of cultured glomeruli.

RESULTS

Metoprolol and nebivolol reduced heart rate in a dose-dependent manner. Blood pressure was normal in untreated animals and not significantly affected by either treatment. Compared with untreated nephritic rats, TGF-beta(1) overexpression was not significantly changed by metoprolol or nebivolol in any dose or treatment period. In contrast, TGF-beta(1) levels were significantly reduced by enalapril both 6 and 12 days after disease induction (-52 and -63%, respectively). The changes in glomerular matrix score, fibronectin and plasminogen activator inhibitor-1 production closely followed expression of TGF-beta(1).

CONCLUSIONS

In a model of acute and normotensive glomerular fibrosis, beta-adrenergic antagonism does not reduce TGF-beta overexpression, suggesting that its pressure-independent antifibrotic action may be limited to chronic renal diseases. The beneficial effect of angiotensin II inhibition even on acute matrix expansion may be a relevant mechanism as to the explanation of its superiority in treating fibrotic renal diseases.

Angiotensin II and progressive renal insufficiency

The inhibition of angiotensin II through angiotensin converting enzyme inhibitors or angiotensin receptor blockers has become the foundation of medical treatment of progressive chronic renal disease. Although these drugs provide a significant improvement over earlier treatments, they only slow the progression of renal disease, implying the need for additional drugs that could be combined with antiangiotensin treatment. Potentially valuable novel drug targets include downstream mediators of angiotensin II such as transforming growth factor-b, plasminogen activator inhibitor-1, and endothelin-1. In addition, recent evidence points to aldosterone as a major player in progressive renal disease, indicating that multiple points of the renin-angiotensin-aldosterone system might have to be targeted. This paper reviews the experimental and clinical evidence indicating that targeting these cytokines and hormones could provide additional benefits to antiangiotensin treatment in chronic renal disease.

Cyclosporine A up-regulates the expression of TGF-beta1 and its receptors type I and type II in rat mesangial cells

BACKGROUND

Chronic cyclosporine A (CsA) nephropathy is a well described side effect of CsA treatment. CsA has been shown to induce the synthesis of extracellular matrix (ECM) proteins in mesangial cells (MCs) in vitro, and glomerulosclerosis in vivo. Transforming growth factor-beta1 (TGF-beta1) is a potent stimulus for the synthesis of ECM proteins in MCs. We investigated whether CsA up-regulates the expression of TGF-beta1 and its receptors type I (TbetaR-I) and type II (TbetaR-II) in cultured rat MCs, and whether this effect translates into enhanced matrix protein accumulation.

METHODS

Resting MCs were incubated in the presence or absence of CsA and anti-TGF-beta1 antibodies. Time- and concentration-dependent expression of TGF-beta1, TbetaR-I and TbetaR-II were measured at both the mRNA (competitive reverse transcription PCR) and protein level (enzyme-linked immunosorbent assay (ELISA) and western blotting). Fibronectin (FN) and plasminogen activator inhibitor type-1 (PAI-1) synthesis were measured by ELISA.

RESULTS

Compared with untreated controls, CsA stimulated mRNA production of TGF-beta1 (maximum at 72 h, 500 ng/ml CsA: 2.1+/-0.5-fold, P<0.001) and TbetaR-II (maximum at 72 h, 1000 ng/ml CsA: 2.4+/-0.4-fold, P<0.005) time- and dose-dependently. TbetaR-I mRNA concentrations remained unchanged. Protein concentrations were analysed at 96 h: TGF-beta1, 220+/-32 vs 86+/-24 pg/ml, P<0.001 (500 ng/ml CsA vs control); TbetaR-I, 2.0+/-0.5-fold, P<0.005 (1000 ng/ml CsA vs control); TbetaR-II, 2.5+/-0.7-fold, P<0.05 (1000 ng/ml CsA vs control). CsA (500 ng/ml) also enhanced the production of FN (1.6-fold, P<0.05) and PAI-1 (2.0-fold, P<0.05). Co-incubation with neutralizing anti-TGF-beta1 antibodies reduced (P<0.05) CsA-induced expression of TbetaR-I (1.0+/-0.1-fold), TbetaR-II (1.3+/-0.1-fold) and PAI-1 (1.3-fold), but not FN production (1.6-fold).

CONCLUSIONS

Pharmacologically relevant concentrations of CsA time- and dose-dependently up-regulate the expression of TGF-beta1 and, via autocrine mechanisms, its receptors type I and II in rat MCs. Whereas up-regulation of PAI-1 is mediated by TGF-beta1, up-regulation of FN is-at least in part-either directly induced by CsA or mediated by factors other than TGF-beta1.

TNF-alpha and IL-1alpha induce apoptosis in subconfluent rat mesangial cells. Evidence for the involvement of hydrogen peroxide and lipid peroxidation as second messengers

Apoptosis of mesangial cells (MC) plays a role in glomerulonephritis (GN). In this study we investigated cytokine-induced apoptosis of cultured rat MC by morphological and biochemical features. TNF-alpha and IL-1alpha induced apoptosis in rat MC in a time- and concentration-dependent fashion. RT-PCR experiments revealed that MC express the TNF-receptor 1 (p60) gene constitutively. TNF-alpha as well as IL-1alpha stimulated the production of reactive oxygen species (ROS) and induced lipid peroxidation. Coincubation with catalase inhibited TNF-alpha and IL-1alpha induced apoptosis as well as lipid peroxidation. TNF-alpha, but not IL-1alpha increased the expression of c-jun. These results provide evidence that TNF-alpha and IL-1alpha induce apoptosis in rat MC with hydrogen peroxide and lipid peroxidation as second messengers. Increased c-jun expression may be a downstream intracellular signal of TNF-alpha-, but not IL-1alpha-induced apoptosis.

Silibinin protects against cisplatin-induced nephrotoxicity without compromising cisplatin or ifosfamide anti-tumour activity

Cisplatin is one of the most active cytotoxic agents in the treatment of testicular cancer, but its clinical use is associated with side-effects such as ototoxicity, neurotoxicity and nephrotoxicity. Long-term kidney damage from cisplatin particularly affects the proximal tubular apparatus and can be detected by increased urinary excretion of brush-border enzymes, such as L-alanine-aminopeptidase (AAP), and magnesium. In the current study, the flavonoid silibinin was used as a nephroprotectant for cisplatin-induced nephropathy in a rat animal model. Infusion of silibinin before cisplatin results in a significant decrease in glomerular (indicated by creatinine clearance and serum urea level) and tubular kidney toxicity (excretion of brush-border enzymes and magnesium). Silibinin given alone had no effect on renal function. In order to exclude an inhibition of the anti-tumour activity of cisplatin and 4-hydroperoxy-ifosfamide by co-administration of silibinin, in vitro studies were performed in three established human testicular cancer cell lines. Dose-response curves for cisplatin (3-30 000 nmol) combined with non-toxic silibinin doses (7.25 x 10(-6) or 7.25 x 10(-5) mol l-1) did not deviate significantly from those of cisplatin alone as measured by relative cell survival during a 5 day assay using the sulphorhodamine-B staining technique. Also silibinin did not influence the cytotoxic activity of 4-hydroperoxy-ifosfamide (30-10 000 nmol) in vitro. In summary, these in vitro data rule out a significant inhibition of the anti-tumour activity of the major nephrotoxic components, cisplatin and 4-hydroperoxy-ifosfamide, by co-administration of silibinin in a human germ cell tumour cell line model. Together with these demonstrated cytoprotection effects in the rat animal model, these data form the basis for a randomised clinical trial of silibinin for the protection of cisplatin-associated nephrotoxicity in patients with testicular cancer.

Cisplatin nephrotoxicity and protection by silibinin

BACKGROUND

The anticancer drug cisplatin is know to have toxic side-effects on different segments of the nephron. The flavonoid silibinin has previously been shown to be protective in models of hepatotoxicity. The aim of the present study was to evaluate, whether silibinin can also ameliorate alterations in renal glomerular and tubular function and tubular morphology induced by cisplatin.

METHODS

In a rat model renal damage was induced by a single injection of cisplatin (5 mg/kg body weight). The protective effects of silibinin were studied in rats that received the flavonoid (200 mg/kg body weight, i.v.) 1 h prior to the administration of cisplatin. Kidney function was monitored by analysing urinary markers of glomerular and tubular function over a period of 11 days. Animals of a second group, with identical treatment, were sacrificed 4 days after drug application for an evaluation of tubular morphology at the light-microscopical level.

RESULTS

Administration of cisplatin caused a decline in kidney function within a day following treatment. Symptoms observed were for example decreases in creatinine clearance and increases in proteinuria, in the urinary activity of the proximal tubular enzymes alanine aminopeptidase and N-acetyl-beta-D-glucosaminidase and in renal magnesium wasting. The effects of cisplatin on creatinine clearance and proteinuria were totally prevented by a pretreatment of the animals with silibinin. Impairment of proximal tubular function was ameliorated, that is enzymuria and magnesium wasting was less pronounced. Silibinin alone had no effect on kidney function. Treatment with silibinin distinctly diminished morphological alterations observed in the S3-segment of the proximal tubule 4 days after cisplatin administration.

CONCLUSION

The effects of cisplatin on glomerular and proximal tubular function as well as proximal tubular morphology could totally or partly be ameliorated by silibinin. It is concluded the silibinin can act as a nephroprotectant and it is suggested that it could have beneficial effects on the kidney in clinical settings.