Nephron number and primary hypertension.
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Child↗
Biomedical subjects
Patrick Niaudet
Publications and source records attributed to Patrick Niaudet.
Intravenous cyclosporine therapy in recurrent nephrotic syndrome after renal transplantation in children.
BACKGROUND: Early recurrence of massive proteinuria after renal transplantation occurs in 20% to 30% of patients with steroid-resistant idiopathic nephrotic syndrome and is responsible for graft failure in approximately half of cases. We report our experience with the use of intravenous (IV) cyclosporine (CsA) in children with recurrent proteinuria after renal transplantation. METHODS: Between March 1991 and August 2001, 36 renal transplantations were performed in 35 patients with steroid-resistant idiopathic nephrotic syndrome in our institution. Recurrence, defined by proteinuria higher than 50 mg/kg per day in the absence of acute rejection or urinary tract infection, was observed in 17 grafts performed in 16 patients. In patients with recurrence, CsA was administered IV, at an initial dose of 3 mg/kg per day, which was afterward adapted to maintain whole-blood levels between 250 and 350 ng/mL. RESULTS: In 14 of 17 cases (82%) with recurrence, proteinuria completely disappeared after 20.8+/-8.4 (range 12-40) days. The treatment was ineffective in the remaining three patients with persistent proteinuria at the end of the second month posttransplantation. Plasma exchanges were performed in four patients during the first 2 months, and proteinuria regressed in three cases and persisted in one. Persistent remission was observed in 11 patients with a follow-up of 3.7+/-3 (range 0.3-9) years. Actuarial graft survival was 92% and 70% at 1 and 5 years. CONCLUSION: IV CsA is a safe and effective treatment in children with recurrent nephrotic syndrome after renal transplantation.
Adolescent↗
Steroid-sensitive nephrotic syndrome: from childhood to adulthood.
BACKGROUND: The clinical presentation, treatment, and outcome of steroid-sensitive nephrotic syndrome (SSNS) during childhood have been extensively studied. Conversely, few data regarding the outcome in adulthood of childhood SSNS have been published previously. We undertook to conduct a retrospective study of the outcome in adulthood of a large cohort of patients diagnosed with an SSNS during childhood. METHODS: We identified all children born between 1970 and 1975 who had been admitted to our institution for an SSNS. Data regarding the outcome in adulthood of these patients were obtained through mailed questionnaires or phone calls to patients and/or their parents or through attending physicians. RESULTS: One hundred seventeen patients were identified. Data regarding the outcome of SSNS in adulthood were available for 102 patients (87.2%). Forty-three patients (42.2%) experienced at least one relapse of nephrotic syndrome in adulthood. By univariate analysis, young age at onset (<6 years) and more severe disease in childhood, indicated by a greater number of relapses (12.9 for adulthood relapsers versus 5.4 for adulthood nonrelapsers; P < 0.0001) and more frequent use of immunosuppressors (74.4% versus 31.6%; P < 0.0001) or cyclosporine (42.9% versus 7.3%; P < 0.0001) were predictive of the occurrence of SSNS relapse in adulthood. Conversely, relapse rate in the first 6 months of disease was not predictive of further relapses in adulthood. By multivariate analysis, only number of relapses during childhood was predictive of adulthood relapses (P < 0.0058). Long-term side effects of steroids were found in 44.2% of adulthood relapsers; the most frequent were osteoporosis and excess weight. CONCLUSION: The incidence of childhood SSNS relapses in adulthood was relatively high in our study. Further studies are required to assess long-term complications in adults with relapses and a history of prolonged steroid and immunosuppressor use.
Adolescent↗
Different inactivating mutations of the mineralocorticoid receptor in fourteen families affected by type I pseudohypoaldosteronism.
We have analyzed the human mineralocorticoid receptor (hMR) gene in 14 families with autosomal dominant or sporadic pseudohypoaldosteronism (PHA1), a rare form of mineralocorticoid resistance characterized by neonatal renal salt wasting and failure to thrive. Six heterozygous mutations were detected. Two frameshift mutations in exon 2 (insT1354, del8bp537) and one nonsense mutation in exon 4 (C2157A, Cys645stop) generate truncated proteins due to premature stop codons. Three missense mutations (G633R, Q776R, L979P) differently affect hMR function. The DNA binding domain mutant R633 exhibits reduced maximal transactivation, although its binding characteristics and ED(50) of transactivation are comparable with wild-type hMR. Ligand binding domain mutants R776 and P979 present reduced or absent aldosterone binding, respectively, which is associated with reduced or absent ligand-dependent transactivation capacity. Finally, P979 possesses a transdominant negative effect on wild-type hMR activity, whereas mutations G633R and Q776R probably result in haploinsufficiency in PHA1 patients. We conclude that hMR mutations are a common feature of autosomal dominant PHA1, being found in 70% of our familial cases. Their absence in some families underscores the importance of an extensive investigation of the hMR gene and the role of precise diagnostic procedures to allow for identification of other genes potentially involved in the disease.
Cohort Studies↗
A multicenter, open-label, pharmacokinetic/pharmacodynamic safety, and tolerability study of basiliximab (Simulect) in pediatric de novo renal transplant recipients.
BACKGROUND: Basiliximab (Simulect) has been shown to be safe and effective in adult renal transplant recipients, when used in combination with cyclosporine (Neoral) and corticosteroids. We report on the safety and preliminary efficacy of basiliximab in pediatric de novo renal transplant recipients. METHODS: This was an open-label, 12-month study of basiliximab in 41 patients (2 cohorts: <9 and 9 to <16 years). In phase 1, two intravenous (IV) bolus injections of basiliximab (12 mg/m ) were administered (before and 4 days postsurgery). In phase 2, two injections (<40 kg, 10 mg and > or =40 kg, 20 mg) were administered at the same time points. Most patients (26/41 [63%]) received cadaveric kidneys. Almost half of the patients had three human leukocyte antigen mismatches with the organ donors. Concurrent immunosuppression included Neoral and corticosteroids. Azathioprine was allowed after 28 days. RESULTS: All patients completed the 1-year study. The acute tolerability of basiliximab via IV bolus injection was good, without evidence of cytokine-release syndrome or acute local reactions. All patients experienced adverse events, but most (71%) were mild or asymptomatic. No deaths or malignancies occurred. The incidence and types of serious adverse events (59%) and serious infections (44%) were as expected in this patient population, and few were drug-related (7% and 5%, respectively). Thirty-eight patients (93%) had infections, mostly urinary tract infections, as expected for renal transplant patients. Six patients (15%) had drug-related adverse events. Biopsy-confirmed acute rejection episodes occurred in 6/41 (15%) of patients during the first 6 months posttransplantation and in 9/41 (22%) patients during the first 12 months. Five patients (12%) experienced graft loss, none of which were preceded by acute rejection episodes. CONCLUSIONS: Basiliximab is safe and well tolerated when administered by IV bolus injection in de novo pediatric renal transplant recipients. These preliminary data suggest that basiliximab, given in combination with cyclosporine and corticosteroids, is an effective immunosuppressive regimen for the prevention of acute rejection in pediatric renal transplantation.
Adolescent↗
A rational dosing algorithm for basiliximab (Simulect) in pediatric renal transplantation based on pharmacokinetic-dynamic evaluations.
BACKGROUND: The pharmacokinetics and immunodynamics of basiliximab were assessed in 39 pediatric de novo kidney allograft recipients to rationally chose a dose regimen for this age group. METHODS: In study part 1, patients were given 12 mg/m(2) of basiliximab by bolus intravenous injection before surgery and on day 4. An interim pharmacokinetic evaluation supported a fixed-dose approach for study part 2 in which infants and children received two 10-mg doses and adolescents received two 20-mg doses. Blood samples were collected over a 12-week period for analysis of basiliximab and soluble interleukin-2 receptor concentrations, flow cytometry, and screening for anti-idiotype antibodies. RESULTS: Basiliximab clearance in infants and children (n=25) was reduced by approximately half compared with adults from a previous study and was independent of age (1-11 years), weight (9-37 kg), and body surface area (0.44-1.20 m(2) ). Clearance in adolescents (12-16 years, n=14) approached or reached adult values. CD25-saturating basiliximab concentrations were maintained for 31+/-12 days in study part 1 with mg/m(2) dosing and for 36+/-14 days in study part 2 based on the fixed-dose regimen ( P=0.31). A single patient experienced a rejection episode during CD25 saturation. The duration of CD25 saturation in patients who experienced a rejection episode after desaturation did not differ from those who remained rejection-free for the full 6-month period: 34+/-6 days (n=6) vs. 35+/-14 days (n=33 patients); P=0.74. Anti-idiotype antibodies were detected in two patients; however, this did not influence the clearance of basiliximab or the duration of CD25 saturation. CONCLUSIONS: To achieve similar basiliximab exposure as is efficacious in adults, pediatric patients <35 kg should receive two 10-mg doses and those > or =35 kg should receive two 20-mg doses of basiliximab by intravenous infusion or bolus injection. The first dose is given before surgery and the second on day 4 after transplantation.
Algorithms↗
Transcriptional and post-transcriptional alterations of IkappaBalpha in active minimal-change nephrotic syndrome.
Minimal-change nephrotic syndrome (MCNS) is a renal disease characterized by heavy glomerular proteinuria and increased production of cytokines by immune cells. Because of the central role of nuclear factor-kappaB (NF-kappaB) in the regulation of cytokine expression, its activity during the relapse and remission phases of steroid-sensitive MCNS was analyzed. During relapse, nuclear extracts from peripheral blood mononuclear cells displayed high levels of NF-kappaB DNA-binding activity, consisting primarily of p50/RelA (p65) complexes. NF-kappaB p65 and IkappaBalpha proteins were barely detected or not detected in cytosolic fractions during relapse, in contrast to remission. The lack of expression of IkappaBalpha protein was associated with downregulation of IkappaBalpha mRNA and increases in the levels of the mRNA encoding the proteasome alpha2 subunit proteolytic pathway. In addition, inhibition of proteasome activity induced cytosolic accumulation of phosphorylated IkappaBalpha and significant reductions in the NF-kappaB binding activity in nuclear extracts from peripheral blood mononuclear cells from patients experiencing relapses. These results suggest that alterations in the NF-kappaB/IkappaBalpha regulatory feedback loop may contribute to the immunologic abnormalities that occur in steroidsensitive MCNS.
Adolescent↗