Eculizumab is a safe and effective treatment in pediatric patients with atypical hemolytic uremic syndrome

Atypical hemolytic uremic syndrome (aHUS) is caused by alternative complement pathway dysregulation, leading to systemic thrombotic microangiopathy (TMA) and severe end-organ damage. Based on 2 prospective studies in mostly adults and retrospective data in children, eculizumab, a terminal complement inhibitor, is approved for aHUS treatment. Here we prospectively evaluated efficacy and safety of weight-based dosing of eculizumab in eligible pediatric patients with aHUS in an open-label phase II study. The primary end point was complete TMA response by 26 weeks. Twenty-two patients (aged 5 months-17 years) were treated; 16 were newly diagnosed, 12 had no prior plasma exchange/infusion during current TMA symptomatology, 11 received baseline dialysis, and 2 had prior renal transplants. By week 26, 14 achieved a complete TMA response, 18 achieved hematologic normalization, and 16 had 25% or better improvement in serum creatinine. Plasma exchange/infusion was discontinued in all, and 9 of the 11 patients who required dialysis at baseline discontinued, whereas none initiated new dialysis. Eculizumab was well tolerated; no deaths or meningococcal infections occurred. Bone marrow failure, wrist fracture, and acute respiratory failure were reported as unrelated severe adverse events. Thus, our findings establish the efficacy and safety of eculizumab for pediatric patients with aHUS and are consistent with proposed immediate eculizumab initiation following diagnosis in children

Adult Renal Size is Not a Suitable Marker for Nephron Numbers: An Individual Patient Data Meta-Analysis

Background: Renal size is often used as a marker for nephron numbers as estimation of glomerular numbers is not yet possible in vivo. However, the validity of an association between the two is questionable. As a proper marker for nephron number in an individual is needed in clinical practice, this study was designed to assess the association between renal size and nephron numbers. Methods: An individual patient data meta-analysis was performed on data retrieved with a PubMed and Embase search. Only studies were included that described individual human data on kidney size and nephron numbers determined by stereology, the gold standard methodology to estimate nephron numbers. As renal size increases until the end of puberty, and nephron numbers decline after the age of 60 years, only data from individuals aged 18-60 years without renal disease were included. Results: Six papers were identified that provided data on renal weight and nephron numbers from 114 individuals. Backward linear regression identified kidney weight and race as the only 2 significant factors explaining nephron numbers (R square 0.085, p=0.007). Controlling for race, there was a significant correlation between nephron number and kidney weight (r=0.231, r square=0.053, p=0.01). Conclusion: These data indicate that only ∼5% of the variation in nephron numbers is explained by differences in renal size. Renal size in adulthood should not be used as a marker for nephron numbers in an individual

Eculizumab treatment efficiently prevents C5 cleavage without C5a generation in vivo

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Sensitive, reliable and easy-performed laboratory monitoring of eculizumab therapy in atypical hemolytic uremic syndrome

Complement C5 inhibitor eculizumab treatment in atypical hemolytic uremic syndrome is effective, but associated with high costs. Complement inhibition monitoring in these patients has not been standardized. In this study we evaluated novel functional assays for application in routine follow-up. We documented that the Wieslab® complement screen assay showed a sensitivity of 1-2% of C5 activity by adding purified C5 or normal human serum to a C5 deficient serum. All the patient samples obtained during the treatment course, were completely blocked for terminal complement pathway activity for up to four weeks after the eculizumab infusion. Levels of complexes between eculizumab and C5 were inversely correlated to the complement activity (p=0.01). Moreover, titrating serum from eculizumab-treated patients into normal serum revealed that eculizumab was present in excess up to four weeks after infusion. Thus, we demonstrate sensitive, reliable and easy-performed assays which can be used to design individual eculizumab dosage regimens.publisher: Elsevier articletitle: Sensitive, reliable and easy-performed laboratory monitoring of eculizumab therapy in atypical hemolytic uremic syndrome journaltitle: Clinical Immunology articlelink: http://dx.doi.org/10.1016/j.clim.2015.05.018 content_type: article copyright: Copyright © 2015 The Authors. Published by Elsevier Inc.status: publishe

The Relationship between aerobic fitness and recovery from high intensity intermittent exercise

Hemolytic uremic syndrome (HUS), the leading cause of acute renal failure in childhood, can be caused by different serotypes of vero cytotoxin (VT; i.e., Shiga toxin)-producing Escherichia coli (VTEC). Recently, VT was shown to bind to polymorphonuclear leukocytes (PMNL) in the systemic circulation of patients with HUS. This study investigated whether VT bound to PMNL could be detected in persons in households with patients with HUS. Serum antibodies against E. coli O157 and, when available, fecal samples from patients with HUS and household members were studied for the presence of VTEC infection. The circulating PMNL of 82% of the household members were positive for VT, whereas stool and/or serum examination showed only 21% positivity. Thus, current methods underestimate the number of infected persons in households with patients with HUS

Increased arterial stiffness in young adults with end-stage renal disease since childhood

Increased arterial stiffness is a risk factor for mortality in adults over 40 yr of age with end-stage renal disease (ESRD). As no data exist on vascular changes in young adults with ESRD since childhood, a long-term outcome study was performed. All living Dutch adult patients with onset of ESRD between 1972 and 1992 at age 0 to 14 yr were invited for carotid artery and cardiac ultrasound and BP measurements. Data on clinical characteristics were collected by review of all medical charts. Carotid ultrasound data were compared with those of 48 age-matched and gender-matched healthy controls. Carotid artery and cardiac ultrasound was performed in 130 out of 187 eligible patients. Mean age was 29.0 (20.7 to 40.6) yr. Compared with controls, patients had a similar intima media thickness but a reduced mean arterial wall distensibility DC (40.0 versus 45.0 kPa(-1). 10(-3); 95% CI, -9.1 to -0.8; P <0.001), an increased stiffness parameter beta (4.2 versus 3.8; 95% CI, 0.05 to 0.68; P = 0.02), an increased elastic incremental modulus E-inc (0.35 versus 0.27 kPa . 10(3); 95% CI, 0.02 to 0.12; P <0.001). Multiple regression analyses in all subjects revealed that ESRD was associated with an increase in 0 and Einc. Arterial wall properties of patients currently on dialysis and transplanted patients were comparable. In all patients, current systolic hypertension was associated with increased E-inc and decreased DC. In conclusion, carotid arterial wall stiffness is increased in young adult patients with pediatric ESRD. Hypertension is a main determinant and might be a target for treatment of these potentially lethal arterial wall change