Children with Alport syndrome develop renal failure early in life. Since the safety and efficacy of preemptive nephroprotective therapy are uncertain we conducted a randomized, placebo-controlled, ...double-blind trial in 14 German sites of pediatric patients with ramipril for three to six years plus six months follow-up to determine these parameters. Pretreated children and those whose parents refused randomization became an open-arm control, which were compared to prospective real-world data from untreated children. The co-primary endpoints were safety (adverse drug reactions) and efficacy (time to progression). Out of 66 oligosymptomatic children, 22 were randomized and 44 joined the open-arm comparison. Ramipril therapy showed no safety issues (total of 216.4 patient-years on ramipril; adverse event rate-ratio 1.00; 95% confidence interval 0.66-1.53). Although not significant, our results cautiously showed that ramipril therapy was effective: in the randomized arm, Ramipril decreased the risk of disease progression by almost half (hazard ratio 0.51 (0.12–2.20)), diminished the slope of albuminuria progression and the decline in glomerular filtration. In adjusted analysis, indications of efficacy were supported by prospective data from participants treated open label compared with untreated children, in whom ramipril again seemed to reduce progression by almost half (0.53 (0.22-1.29)). Incorporating these results into the randomized data by Bayesian evidence synthesis resulted in a more precise estimate of the hazard-ratio of 0.52 (0.19-1.39). Thus, our study shows the safety of early initiation of therapy and supports the hope to slow renal failure by many years, emphasizing the value of preemptive therapy. Hence, screening programs for glomerular hematuria in children and young adults could benefit from inclusion of genetic testing for Alport-related gene-variants.
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Introduction: Mycophenolate mofetil (MMF) is an ester prodrug of the immunosuppressant mycophenolic acid (MPA) and is recommended and widely used for maintenance immunosuppressive therapy in solid ...organ and stem-cell transplantation as well as in immunological kidney diseases. MPA is a potent, reversible, noncompetitive inhibitor of the inosine monophosphate dehydrogenase (IMPDH), a crucial enzyme in the de novo purine synthesis in T- and B-lymphocytes, thereby inhibiting cell-mediated immunity and antibody formation. The use of therapeutic drug monitoring (TDM) of MMF is still controversial as outcome data of clinical trials are equivocal.
Areas covered: This review covers in great depth the existing literature on TDM of MMF in the field of pediatric (kidney) transplantation. In addition, the relevance of TDM in immunological kidney diseases, in particular childhood nephrotic syndrome is highlighted.
Expert opinion: TDM of MMF has the potential to optimize therapy in pediatric transplantation as well as in nephrotic syndrome. Limited sampling strategies to estimate MPA exposure increase its feasibility. Future perspectives rather encompass approaches reflecting total immunosuppressive load than single drug TDM.
Mycophenolate mofetil (MMF) plays an increasingly important role in the treatment of children with nephrotic syndrome, especially in steroid sparing protocols. Recent publications show the ...relationship of exposure to its active moiety mycophenolic acid (MPA) and clinical efficacy. Performance of full-time pharmacokinetic (PK) profiles, however, is inconvenient and laborious. Established limited sampling strategies (LSS) to estimate the area under the concentration (AUC) versus time curve of MPA (MPA-AUC) in pediatric renal transplant recipients cannot be easily transferred to children suffering from nephrotic syndrome, mainly because of the lack of concomitant immunosuppressive therapy. We therefore aimed for the generation and validation of a LSS to estimate MPA exposure to facilitate therapeutic drug monitoring in children with nephrotic syndrome.
We performed 27 complete PK profiles in 23 children in remission mean age (±SD):12.3 ± 4.26 years to generate and validate an LSS. Sampling time points were before administration (C0) and 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours after the administration of MMF. MPA was measured by enzyme multiplied immunoassay technique. There was no concomitant treatment with calcineurin inhibitors.
Mean daily dose of MMF was 927 ± 209 mg/m of body surface area resulting in a mean MPA-AUC0-12 value of 59.2 ± 29.3 mg × h/L and a predose level of 3.03 ± 2.24 mg/L. Between-patient variability of dose-normalized MPA-AUC0-12 was high (coefficient of variation: 45.5%). Correlation of predose levels with the corresponding MPA-AUC0-12 was moderate (r = 0.59) in a subgroup of 18 patients (20 PK profiles, generation group). An algorithm based on 3 PK sampling time points during the first 2 hours after MMF dosing (estimated AUC0-12 = 8.7 + 4.63 × C0 + 1.90 × C1 + 1.52 × C2) was able to predict MPA-AUC with a low percentage prediction error (3.88%) and a good correlation of determination (r = 0.90). Validation of this algorithm in a randomized separate group of 6 patients (7 PK profiles, validation group) resulted in comparably good correlation (r = 0.95) and low percentage prediction error (5.57%).
An abbreviated profile within the first 2 hours after MMF dosing gives a good estimate of MPA exposure in children with nephrotic syndrome and hence has the potential to optimize MMF therapy.
The outcome of extremely low-birth-weight (ELBW) and very low-birth-weight (VLBW) infants has substantially improved in recent years. As acute kidney injury is frequent in these infants due to ...various risk factors, there is an increasing demand for renal replacement therapy in these patients. Data on that topic, however, are scarce. We review the available literature on that topic and report our experience on temporary dialysis in three extremely immature infants (two ELBW and one VLBW) with acute kidney failure. Peritoneal dialysis (PD) was performed for 19, 23, and 44 days until recovery of native renal function. At recent follow-up of 18 and 24 months, two patients are in good clinical condition with chronic kidney disease stages 1 and 4, respectively. One patient deceased at the age of 12 months due to secondary liver failure. The dialysis regimen applied in our study differed significantly from older infants with extremely short dwell times and accordingly high numbers of daily cycles. The use of rigid acute PD catheters was associated with less catheter-related complications (leakage, dislocation, and obstruction) as compared to ascites drainage catheters. In summary, PD was technically feasible and effective also in extremely immature infants, but frequent adjustments of dialysis regimens and high numbers of daily cycles posed immense efforts on both, parents and medical staff.
Abstract
Background and Aims
Response to calcineurin inhibitors (CNI) is associated with a significant improvement in long-term kidney survival of children with non-genetic steroid resistant ...nephrotic syndrome (SRNS). On the contrary, these agents are considered non-efficacious in monogenic SRNS and are contraindicated according to the latest International Pediatric Nephrology Association (IPNA) Clinical Practice Recommendations for SRNS. However, there is evidence suggesting that remission with CNI therapy in this subgroup of children with SRNS is possible, but no studies to date have assessed this question in a systematic way. We aimed to study the incidence of response to CNI in children with monogenic SRNS, factors predictive of remission and the effect of treatment on kidney survival.
Method
Retrospective cohort study of children 0–18 years with genetically confirmed SRNS treated with a CNI for at least 3 months. Demographic, clinical, genetic, biochemical, histopathologic and treatment data were collected at various time points; at clinical diagnosis, 6, 12, 24 months from CNI onset, and last available follow-up. Pathogenicity of all reported variants was assessed by a dedicated geneticist according to the American College of Medical Genetics guidelines and only patients with a pathogenic genotype were included in the analysis1. Patients were classified according to their response to CNI as complete, partial or non-responders based on the IPNA Clinical Practice Recommendations for SRNS2.
Results
141 patients from 37 international paediatric nephrology centers were included in the study. At 6 months from CNI initiation and at last visit, 27.6% and 22.5%, respectively, demonstrated either complete or partial response (“at least partial response”). Median observation time between CNI initiation and last visit was 42.1 months (IQR 20.1–65.6) and was comparable between patients with no response and at least partial response (42.3 vs 41.6 months; P>0.05). No serious adverse effects mandating treatment discontinuation were reported. Children demonstrating at least partial response at 6 months had a lower risk of progression to kidney failure at last visit versus non-responders (hazard ratio 95%CI 0.25, 0.10–0.62; P = 0.003). Subgroup analysis of patients with a follow-up of at least 2 years revealed similar results with a hazard ratio of 0.35 (95%CI 0.14–0.91; P = 0.03). Of the various clinical, biochemical, genetic, histopathologic and treatment parameters tested in a multivariable logistic regression model only higher serum albumin at CNI onset was associated with higher likelihood of response at 6 months (odds ratio 95% CI 1.16, 1.08–1.24; P < 0.001).
Conclusion
Our findings suggest that CNI use could be considered in monogenic SRNS and that achievement of response in this setting can alter an otherwise dismal long-term kidney outcome.
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