Adolescence-onset atypical hemolytic uremic syndrome: is it different from infant-onset?

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a rare, mostly complement-mediated thrombotic microangiopathy. The majority of patients are infants. In contrast to infantile-onset aHUS, the clinical and genetic characteristics of adolescence-onset aHUS have not been sufficiently addressed to date. METHODS: A total of 28 patients (21 girls, 7 boys) who were diagnosed as aHUS between the ages of ≥10 years and <18 years were included in this study. All available data in the Turkish Pediatric aHUS registry were collected and analyzed. RESULTS: The mean age at diagnosis was 12.8±2.3 years. Extra-renal involvement was noted in 13 patients (46.4%); neurological involvement was the most common (32%). A total of 21 patients (75%) required kidney replacement therapy. Five patients (17.8%) received only plasma therapy and 23 (82%) of the patients received eculizumab. Hematologic remission and renal remission were achieved in 25 (89.3%) and 17 (60.7%) of the patients, respectively. Compared with the infantile-onset aHUS patients, adolescent patients had a lower complete remission rate during the first episode (p = 0.002). Genetic analyses were performed in all and a genetic variant was detected in 39.3% of the patients. The mean follow-up duration was 4.9±2.6 years. At the last visit, adolescent patients had lower eGFR levels (p = 0.03) and higher rates of chronic kidney disease stage 5 when compared to infantile-onset aHUS patients (p = 0.04). CONCLUSIONS: Adolescence-onset aHUS is a rare disease but tends to cause more permanent renal dysfunction than infantile-onset aHUS. These results may modify the management approaches in these patients.

Isolated nocturnal and isolated daytime hypertension associate with altered cardiovascular morphology and function in children with chronic kidney disease: findings from the Cardiovascular Comorbidity in Children with Chronic Kidney Disease study.

INTRODUCTION: Prevalence of isolated nocturnal hypertension (INH) and isolated daytime hypertension (IDH) is around 10% in adults. Data in children, especially in chronic kidney disease (CKD), are lacking. The aim of this cross-sectional multicenter cohort study was to define the prevalence of INH and IDH and its association with cardiovascular morphology and function, that is, pulse wave velocity (PWV), carotid intima-media thickness (cIMT), or left ventricular mass index (LVMI) in children with CKD. METHODS: Ambulatory blood pressure (BP) monitoring profiles were analyzed in 456 children with CKD stages III-V participating in the Cardiovascular Comorbidity in Children with Chronic Kidney Disease Study (64.3% males, 71.3% congenital anomaly of the kidney and urinary tract, age 12.5 ±â€Š3.2 years, estimated glomerular filtration rate 29 ±â€Š12 ml/min per 1.73 m). Baseline PWV, cIMT, and LVMI were compared in normotension, INH, IDH, or sustained 24-h hypertension. RESULTS: Prevalence of sustained hypertension was 18.4%, of INH 13.4%, and of IDH 3.7%. PWV SDS (SD score) and cIMT SDS were significantly higher in sustained hypertension and INH, and PWV SDS was significantly higher in IDH, compared with normotension. LVMI was significantly increased in sustained hypertension, but not in INH or IDH. Determinants of INH were smallness for gestational age, older age, higher height SDS and parathyroid hormone, and shorter duration of CKD. In logistic regression analysis, day/night-time hypertension or ambulatory BP monitoring pattern (normal, INH, IDH, sustained hypertension) were independently associated with cardiovascular outcome measures: elevated night-time BP was associated with increased cIMT, PWV, and left ventricular hypertrophy; INH was associated with cIMT. CONCLUSION: INH is present in almost one out of seven children with predialysis CKD; INH and nocturnal hypertension in general are associated with alterations of arterial morphology and function.

An analysis of the levels of the soluble form of the endothelial protein C receptor in children with Henoch-Schönlein Purpura.

The pathogenesis of Henoch-Schönlein Purpura (HSP) has not been clearly defined. Inflammatory cytokines have been associated with HSP but there are only a few reports that have focused on coagulation. The endothelial protein C receptor (EPCR), which has anticoagulant and antiinflammatory activity, is the key component of the protein C pathway. Recent studies have implicated the soluble form of EPCR (sEPCR) in Wegener's granulomatosis, Behçet's disease, and systemic lupus erythematosus. The aim of this study was to evaluate the levels of sEPCR in HSP children. Twenty-two children with HSP and 17 healthy children were included. We found no significant differences (P > .05) between patient and control groups in the levels of von Willebrand factor and thrombomodulin. The median sEPCR values in the HSP group were lower than the control group (79 vs. 102 ng/mL, respectively) (P > .05). The mean sEPCR value in HSP patients with severe abdominal pain was lower than without (88.8 ± 54.9 vs. 108.2 ± 66.3 ng/mL, respectively) (P > .05). In addition, the mean IL-6 serum levels were significantly elevated in HSP patients during the acute stage of HSP (2.1 ± 1.7 vs. 1.5 ± 1.2 pg/mL, P = .038). We also observed a slight negative correlation between the levels of sEPCR and IL-6 (R = -.135, P > .05). To our knowledge, this was the first study to analyze sEPCR levels in HSP. Our results did not conclusively identify a direct role of sEPCR in HSP, but our findings warrant further investigations, especially in severe HSP cases characterized by gastrointestinal bleeding or renal involvement.

Etiology and outcome of acute kidney injury in children.

The aim of this prospective, multicenter study was to define the etiology and clinical features of acute kidney injury (AKI) in a pediatric patient cohort and to determine prognostic factors. Pediatric-modified RIFLE (pRIFLE) criteria were used to classify AKI. The patient cohort comprised 472 pediatric patients (264 males, 208 females), of whom 32.6% were newborns (median age 3 days, range 1-24 days), and 67.4% were children aged >1 month (median 2.99 years, range 1 month-18 years). The most common medical conditions were prematurity (42.2%) and congenital heart disease (CHD, 11.7%) in newborns, and malignancy (12.9%) and CHD (12.3%) in children aged >1 month. Hypoxic/ischemic injury and sepsis were the leading causes of AKI in both age groups. Dialysis was performed in 30.3% of newborns and 33.6% of children aged >1 month. Mortality was higher in the newborns (42.6 vs. 27.9%; p < 0.005). Stepwise multiple regression analysis revealed the major independent risk factors to be mechanical ventilation [relative risk (RR) 17.31, 95% confidence interval (95% CI) 4.88-61.42], hypervolemia (RR 12.90, 95% CI 1.97-84.37), CHD (RR 9.85, 95% CI 2.08-46.60), and metabolic acidosis (RR 7.64, 95% CI 2.90-20.15) in newborns and mechanical ventilation (RR 8.73, 95% CI 3.95-19.29), hypoxia (RR 5.35, 95% CI 2.26-12.67), and intrinsic AKI (RR 4.91, 95% CI 2.04-11.78) in children aged >1 month.