Peritoneal dialysis for management of pediatric acute renal failure.

BACKGROUND: While the use of continuous renal replacement therapies in the management of children with acute renal failure (ARF) has increased, the role of peritoneal dialysis (PD) in the treatment of pediatric ARF has received less attention. DESIGN: Retrospective database review of children requiring PD for ARF over a 10-year period. SETTING: Pediatric intensive care unit at a tertiary-care referral center. PATIENTS: Sixty-three children without previously known underlying renal disease who required PD for treatment of ARF. RESULTS: Causes of ARF were congestive heart failure (27), hemolytic-uremic syndrome (13), sepsis (10), nonrenal organ transplant (7), malignancy (3), and other (3). Mean duration of PD was 11 +/- 13 days. Children with ARF were younger (30 +/- 48 months vs 88 +/- 68 months old, p < 0.0001) and smaller (11.9 +/- 15.9 kg vs 28 +/- 22 kg, p < 0.0001) than children with known underlying renal disease who began PD during the same time period. Percutaneously placed PD catheters were used in 62% of children with ARF, compared to 4% of children with known renal disease (p < 0.0001). Hypotension was common in patients with ARF (46%), which correlated with a high frequency of vasopressor use (78%) at the time of initiation of PD. Complications of PD occurred in 25% of patients, the most common being catheter malfunction. Recovery of renal function occurred in 38% of patients; patient survival was 51%. CONCLUSIONS: Peritoneal dialysis remains an appropriate therapy for pediatric ARF from many causes, even in severely ill children requiring vasopressor support. Such children can be cared for without the use of more expensive and technology-dependent forms of renal replacement therapies.

Intravenous nicardipine for treatment of severe hypertension in children.

OBJECTIVE: To examine the effect of intravenous nicardipine in the treatment of children with severe hypertension. METHODS: The medical records of 29 children (mean age 94 months) treated with intravenous nicardipine were retrospectively reviewed. The mean duration of severe hypertension before nicardipine use was 12.5 hours. Most (74%) patients were receiving other antihypertensive agents before nicardipine. RESULTS: The initial nicardipine dose was 0.8 +/- 0.3 microg/kg/min (mean +/- SD). The mean effective dose was 1.8 +/- 1.0 microg/kg/min (range, 0.3 to 4.0). Blood pressure control was achieved within 2.7 +/- 2.1 hours after nicardipine was started. Nicardipine treatment produced a 16% reduction in systolic blood pressure, a 23% reduction in diastolic blood pressure, and a 7% increase in heart rate. Nicardipine was effective as a single agent on 26 (84%) of 31 occasions. Adverse effects included tachycardia, flushing, palpitations, and hypotension. CONCLUSIONS: When administered in the intensive care unit setting with close patient monitoring, intravenous nicardipine effectively lowered blood pressure in children with severe hypertension. Larger prospective studies should be conducted to confirm these findings.

Anuria, omphalocele, and perinatal lethality in mice lacking the CD34-related protein podocalyxin.

Podocalyxin is a CD34-related sialomucin that is expressed at high levels by podocytes, and also by mesothelial cells, vascular endothelia, platelets, and hematopoietic stem cells. To elucidate the function of podocalyxin, we generated podocalyxin-deficient (podxl(-/)-) mice by homologous recombination. Null mice exhibit profound defects in kidney development and die within 24 hours of birth with anuric renal failure. Although podocytes are present in the glomeruli of the podxl(-/)- mice, they fail to form foot processes and slit diaphragms and instead exhibit cell--cell junctional complexes (tight and adherens junctions). The corresponding reduction in permeable, glomerular filtration surface area presumably leads to the observed block in urine production. In addition, podxl(-/)- mice frequently display herniation of the gut (omphalocele), suggesting that podocalyxin may be required for retraction of the gut from the umbilical cord during development. Hematopoietic and vascular endothelial cells develop normally in the podocalyxin-deficient mice, possibly through functional compensation by other sialomucins (such as CD34). Our results provide the first example of an essential role for a sialomucin in development and suggest that defects in podocalyxin could play a role in podocyte dysfunction in renal failure and omphalocele in humans.

Treatment of Henoch-Schönlein Purpura glomerulonephritis in children with high-dose corticosteroids plus oral cyclophosphamide.

BACKGROUND: Henoch-Schönlein Purpura (HSP) is a common childhood vasculitis with manifestations in numerous organ systems, including glomerulonephritis. Patients with more severe HSP-associated glomerulonephritis may develop chronic renal failure. Currently, no widely accepted treatment protocols exist for patients with significant renal involvement. METHODS: We retrospectively reviewed the clinical courses of 12 children (mean age 9 years) with HSP glomerulonephritis treated with high-dose corticosteroids plus oral cyclophosphamide. All patients had nephrotic-range proteinuria, and all had significant histopathologic changes on biopsy, including crescentic nephritis in 10 patients. Treatment consisted of either intravenous pulse methylprednisolone or oral prednisone followed by oral cyclophosphamide (2 mg/kg/day) for 12 weeks, along with either daily or alternate-day oral prednisone. Prednisone was tapered following completion of cyclophsophamide. RESULTS: Serum albumin rose significantly after treatment from 2.8 +/- (SD) 0.5 to 3.7 +/- 0.4 g/dl (p < 0.001), and there was a concurrent reduction in proteinuria, as reflected by decreasing serial protein-to-creatinine ratios: from 6.3 +/- 4.4 to 0.8 +/- 0.8 (p = 0.002). Renal function remained normal in all patients. Hypertension developed during treatment in 10 patients, all but 1 of whom were normotensive at last follow-up, 35 +/- 17 months following biopsy. CONCLUSIONS: We conclude that treatment of children with HSP nephritis with high-dose corticosteroids plus oral cyclophosphamide is safe and, as in nephrotic syndrome, appears to significantly reduce proteinuria which is a known risk factor for the development of renal insufficiency in HSP. Further studies with larger numbers of patients should be conducted to confirm this finding.

Hemodialysis followed by continuous hemofiltration for treatment of lithium intoxication in children.

Hemodialysis is the usual recommended treatment for severe lithium intoxication; however, rebound of lithium levels may require repeated hemodialysis treatments. We proposed that the addition of continuous hemofiltration after hemodialysis would prevent rebound by providing ongoing clearance of lithium. We report two pediatric patients with lithium intoxication treated by hemodialysis followed by continuous venovenous hemofiltration with dialysis (CVVHD). Both patients were symptomatic at presentation and had initial lithium levels more than three times the usual therapeutic range. Hemodialysis followed by CVVHD resulted in rapid resolution of symptoms, followed by continuous clearance of lithium without requiring repeated hemodialysis sessions. Both patients had return of normal mental status during CVVHD treatment, and neither patient experienced complications of hemodialysis or CVVHD. Total duration of treatment with hemodialysis followed by CVVHD was 34.5 hours for the first patient and 26 hours for the second patient. We conclude that hemodialysis followed by CVVHD is a safe and effective approach to the management of lithium intoxication in children.

Altered podocyte structure in GLEPP1 (Ptpro)-deficient mice associated with hypertension and low glomerular filtration rate.

Glomerular epithelial protein 1 (GLEPP1) is a receptor tyrosine phosphatase present on the apical cell surface of the glomerular podocyte. The GLEPP1 gene (PTPRO:) was disrupted at an exon coding for the NH(2)-terminal region by gene targeting in embryonic stem cells. Heterozygote mating produced the expected genotypic ratio of 1:2:1, indicating that the Ptpro(-/-) genotype does not lead to embryonic or neonatal lethality. Kidney and glomerular structure was normal at the gross and light microscopic levels. Scanning and transmission electron microscopy showed that Ptpro(-/-) mice had an amoeboid rather than the typical octopoid structure seen in the wild-type mouse podocyte and that there were blunting and widening of the minor (foot) processes in association with altered distribution of the podocyte intermediate cytoskeletal protein vimentin. Reduced filtration surface area in association with these structural changes was confirmed by finding reduced glomerular nephrin content and reduced glomerular filtration rate in Ptpro(-/-) mice. There was no detectable increase in the urine albumin excretion of Ptpro(-/-) mice. After removal of one or more kidneys, Ptpro(-/-) mice had higher blood pressure than did their wild-type littermates. These data support the conclusion that the GLEPP1 (Ptpro) receptor plays a role in regulating the glomerular pressure/filtration rate relationship through an effect on podocyte structure and function.

Response to early measles-mumps-rubella vaccination in infants with chronic renal failure and/or receiving peritoneal dialysis.

Achieving immunity to childhood viral infections before renal transplantation is crucial. However, children with chronic renal failure (CRF) may respond poorly to vaccination, making it difficult to achieve immunity before transplantation, particularly if they will require transplantation at a young age. To address this problem, we developed a protocol of early measles-mumps-rubella (MMR) vaccination in infants with CRF. Nine infants received MMR vaccine at a mean age of 11.6 +/- 2.5 months. When vaccinated, 6 of the children (67%) were on peritoneal dialysis, and 3 (33%) had CRF [glomerular filtration rate (GFR) < 30 mL/min/1.73 m2]. Eight patients were later transplanted at a mean age of 16.8 +/- 4.8 months. Titers were measured before transplantation in all patients. Response to vaccination was excellent, with 89% developing immunity to measles, 88% developing immunity to mumps, 100% developing immunity to rubella, and 88% developing immunity to all three components of the vaccine. These response rates were equivalent to, or slightly better than, those previously reported by Schulman for older children (19 +/- 6 months) on dialysis: 80% for measles, 50% for mumps, 100% for rubella, and 30% for all three components. We conclude that early MMR vaccination induces immunity in most infants with CRF, even those on peritoneal dialysis. Response rates are similar to those previously reported in older children. This approach may help to facilitate transplantation in young infants by achieving immunity earlier than traditional vaccination schedules.

Identification of podocalyxin-like protein as a high endothelial venule ligand for L-selectin: parallels to CD34.

The leukocyte adhesion molecule, L-selectin, mediates the recruitment of lymphocytes to secondary lymphoid organs via interactions with specific ligands presented on high endothelial venules (HEV). Although the HEV-derived ligands for L-selectin are still incompletely defined, they share a common sialomucin-like structure which is thought to present clustered oligosaccharides to the lectin domain of L-selectin. Podocalyxin-like protein (PCLP) is a transmembrane sialomucin that is similar in structure to the well-characterized L-selectin ligand CD34. PCLP has been shown previously to be expressed on the foot processes of podocytes in the kidney glomerulus as well as on vascular endothelium at some sites. We have determined that PCLP is present on HEV, where it binds to both recombinant L-selectin and the HEV-specific monoclonal antibody MECA-79. Furthermore, purified HEV-derived PCLP is able to support the tethering and rolling of lymphocytes under physiological flow conditions in vitro. These results suggest a novel function for PCLP as an adhesion molecule and allow the definition of conserved structural features in PCLP and CD34, which may be important for L-selectin ligand function.

Neoral induction in pediatric renal transplantation.

Neoral was instituted in pediatric renal transplant patients with the hypothesis it would have more predictable kinetics than Sandimmun. However, significant questions have arisen concerning potential toxicity and dosing interval related to its rapid absorption with subsequent high initial peak. This is compounded by the fact that children appear to metabolize cyclosporine at a greater rate than adults. This combination of a rapid peak and rapid absorption may then result in lower trough levels at 12 h. We compared the trough cyclosporine levels of nine children who received Neoral with nine who received Sandimmun at the time of initial transplantation. More frequent dosing (every 8 h) was required in the Neoral population compared with the Sandimmun population for the 1st month in order to obtain comparable trough levels. Beyond the initial 4-6 weeks, trough levels were similar for Neoral and Sandimmun. Whereas 1-month creatinine levels and blood pressures were similar, the number of blood pressure medications was significantly higher in the Neoral group. At 5.5 +/- 1.1 months' followup, a single patient in the current Neoral group and in the retrospective Sandimmun group each experienced a single OKT3 allograft-treated rejection. We suggest that the area under the curve is different in Neoral than Sandimmun, and the initial dosing frequency may need to be adjusted accordingly.

Outcome of antineutrophil cytoplasmic autoantibodies-positive glomerulonephritis and vasculitis in children: a single-center experience.

Vasculitis associated with antineutrophil cytoplasmic autoantibodies (ANCA) can be accompanied by a focal and necrotizing glomerulonephritis that carries a high morbidity. As many as 60% of reported children with ANCA-associated glomerulonephritis progress to end-stage renal disease. Seven children (13.0+/-0.89 years, mean age +/- SEM) with both a focal and necrotizing glomerulonephritis and a positive ANCA titer are described. Presenting symptoms were constitutional (100%) and sinopulmonary (71%); additional renal features included microscopic hematuria (100%), proteinuria (71%), and renal insufficiency (71%). Acute therapy (0 to 2 weeks from diagnosis) included intravenous corticosteroids and intravenous cyclophosphamide for all patients. Induction therapy (2 weeks to 6 months from diagnosis) consisted of cyclophosphamide (100%) and daily corticosteroids (86%) for a minimum of 6 months. Maintenance therapy that followed 6 months of induction therapy consisted of alternate day steroids (100%) combined with either oral azathioprine (50%) or oral cyclophosphamide (50%). Long-term follow-up for 48+/-12 months in all seven patients revealed that only one (14%) patient had end-stage renal disease, whereas the remaining patients had microscopic hematuria (100%), proteinuria (50%), and renal insufficiency (33%). These findings suggest that early recognition and aggressive treatment of children with ANCA-associated glomerulonephritis and vasculitis may result in an improved renal outcome compared with previous reports.

Improvement of glycemic control by CAPD with intraperitoneal insulin in a child with IDDM and ESRD.

Use of intraperitoneal insulin in diabetic end-stage renal disease (ESRD) patients receiving continuous ambulatory peritoneal dialysis (CAPD) is known to result in improved glycemic control. This route of insulin administration, although standard in adult diabetic CAPD patients, has not previously been reported in children. A 12-year old boy with ESRD from renal dysplasia who also had insulin-dependent diabetes mellitus (IDDM) was treated with CAPD and intraperitoneal insulin prior to renal transplantation. Diabetes and renal dysplasia were both diagnosed at 11 weeks of age. When he reached end-stage he was initially started on hemodialysis via a central line but was switched to CAPD because of recurrent line sepsis. His IDDM had been poorly controlled up to that time. CAPD was performed using 4 exchanges per day of 1.5% dialysate with a fixed dose of insulin added to each bag and with adjustments made based on blood glucose. His glycemic control markedly improved, with a fall in his glycosylated hemoglobin from 13.6% to 6%. CAPD was continued for 7 months until a living-related renal transplant was performed. Two episodes of peritonitis occurred while the patient received CAPD (1 episode/3.5 patient-months). We conclude that the use of intraperitoneal insulin in children with IDDM and ESRD leads to improved glycemic control. The rate of peritonitis, however, may be increased in these children.

Beneficial effect of Sandoglobulin upon allograft survival in the pediatric renal transplant recipient.

The use of pooled immunoglobulin (IgG) has been shown to decrease panel reactive antibodies (PRA) in highly sensitized patients awaiting transplantation. IgG infusions have also been found effective for CMV prophylaxis. Analysis of 52 non-highly sensitized children (ages 1-18) who received kidney transplants from May 1991 through January 1995 was undertaken to determine if the immunoglobulin administered for CMV prophylaxis effected allograft survival. Comparison of the "Sando Pos" group (those who received Sandoglobulin for CMV prophylaxis) to the "Sando Neg" group demonstrates a significantly improved allograft survival at 1, 2, and 3 yr post-transplantation. Despite the Sando Pos group being younger [7.3 +/- 1.3 yr vs. 10.7 +/- 0.9 yr; (mean +/- SEM) p < 0.05] allograft survival was 95%, 95% and 88% in the Sando Pos group vs. 88%, 79% and 79% in the Sando Neg group at 1, 2 and 3 yr, respectively (p < 0.01 at all three time points). It is concluded that the potential mechanism of the immunosuppressive benefit of Sandoglobulin is speculative but presumed to be upon inhibition of anti-HLA class I antibodies. We conclude that Sandoglobulin may not only be useful for CMV prophylaxis but also as an adjunct to routine immunosuppression.

Molecular cloning and characterization of human podocalyxin-like protein. Orthologous relationship to rabbit PCLP1 and rat podocalyxin.

Human renal cortex and heart cDNA libraries were screened for a human homolog of rabbit PCLP1 using the rabbit PCLP1 cDNA as a probe. Clones spanning 5869 base pairs with an open reading frame coding for a 528-amino acid peptide were obtained. The putative peptide contains a potential signal peptide and a single membrane-spanning region. The extracellular domain contains multiple potential sites for N- and O-linked glycosylation and 4 cysteines for potential disulfide bonding similar to rabbit PCLP1. On Northern blot a major transcript is seen at 5.9 kilobases. Antibodies to this protein show a doublet at 160/165 kDa on Western blots of human glomerular extract and a pattern of intense glomerular staining and vascular endothelial staining on immunofluorescence of human kidney sections. Comparison of the rabbit and human peptide sequences shows a high degree of identity in the transmembrane and intracellular domains (96%) with a lower degree of identity in the extracellular domain (36%). An antibody to the intracellular domain reacted across species (human, rabbit, and rat) and recognized both rabbit PCLP1 and rat podocalyxin. An interspecies Southern blot probed with a cDNA coding for the intracellular domain showed strong hybridization to all vertebrates tested in a pattern suggesting a single copy gene. We conclude that this cDNA and putative peptide represent the human homolog of rabbit PCLP1 and rat podocalyxin.

Long-term cyclosporine therapy for pediatric nephrotic syndrome: a clinical and histologic analysis.

Cyclosporine (CsA) is effective in treating steroid-dependent (SDNS) and steroid-resistant (SRNS) nephrotic syndrome (NS) in children, but because of the potential for chronic nephrotoxicity, its long-term use is controversial. This study reports the results of long-term CsA treatment in 22 children with idiopathic NS. Indications for treatment included SDNS (N = 7) and SRNS (N = 15) children. Pre-CsA histology showed minimal change disease in three patients, immunoglobulin M nephropathy (IgM) in 14 patients, and focal segmental glomerulosclerosis (FSGS) in five patients. All patients had normal initial serum creatinine values. CsA was added to prednisone at 6.3 +/- 0.4 mg/kg per day (mean +/- SE) and adjusted to maintain whole blood trough HPLC levels of 70 to 120 ng/mL for a period of 6 to 53 months (mean, 22 months). Analysis by clinical course revealed that 13 of 15 patients with SRNS (87%) entered remission after a mean duration of CsA treatment of 58 days, whereas seven of seven patients with SDNS were able to be weaned off of daily prednisone therapy. Histologic analysis showed that all five patients with FSGS and 13 of 14 patients with IgM nephropathy either entered remission or were weaned off of daily steroids. Ten of the 22 patients (45%) with complete remission required CsA plus low-dose alternate-day prednisone to maintain remission. Hypertension was seen in eight of 22 patients (36%). No patient had a significant increase in serum creatinine concentration. Renal biopsies performed in 12 patients after 12 to 41 months (mean, 21 months) of CsA therapy showed no nephrotoxicity or disease progression in ten patients. Progression of the previous interstitial fibrosis and tubular atrophy was noted in two patients, suggesting a 17% incidence of CsA nephrotoxicity. This analysis of the long-term risks and benefits of CsA for childhood NS has identified two important findings: (1) combined CsA and alternate-day steroids can be highly effective in inducing complete remission in patients with SRNS and biopsy-proven IgM nephropathy, and (2) long-term use of CsA in moderate doses with closely monitored levels can result in a relatively low incidence of nephrotoxicity.

Molecular cloning, expression, and characterization of podocalyxin-like protein 1 from rabbit as a transmembrane protein of glomerular podocytes and vascular endothelium.

Podocytes are responsible in part for maintaining the size and charge filtration characteristics of the glomerular filter. The major sialoprotein of the podocyte foot process glycocalyx is a 140-kDa sialoprotein named podocalyxin. Monoclonal antibodies raised against isolated rabbit glomeruli that recognized a podocalyxin-like protein base upon size, Alcian blue staining, wheat germ agglutinin binding, and distribution in renal cortex were used to expression clone cDNAs from a rabbit glomerular library. On Northern blot the cDNAs hybridized to a 5.5-kilobase pair transcript predominantly present in glomerulus. The overlapping cDNAs spanned 5,313 base pairs that contained an open reading frame of 1,653 base pairs and were not homologous with a previously described sequence. The deduced 551-amino acid protein contained a putative 21-residue N-terminal signal peptide and a 26-amino acid transmembrane region. The mature protein has a calculated molecular mass of 55 kDa, an extracellular domain that contains putative sites for N- and O-linked glycosylation, and a potential glycosaminoglycan attachment sites. The intracellular domain contains potential sites for phosphorylation. Processing of the full-length coding region in COS-7 cells resulted in a 140-kDa band, suggesting that the 55-kDa core protein undergoes extensive post-translational modification. The relationship between the cloned molecule and the monoclonal antibodies used for cloning was confirmed by making a fusion protein that inhibited binding of the monoclonal antibodies to renal cortical tissue sections and then raising polyclonal antibodies against the PCLP1 fusion protein that also recognized glomerular podocytes and endothelial cells in tissue sections in a similar distribution to the monoclonal antibodies. We conclude that we have cloned and sequenced a novel transmembrane core glycoprotein from rabbit glomerulus, which has many of the characteristics of podocalyxin. We have named this protein podocalyxin-like protein 1.

Recognition and management of angiotensin converting enzyme inhibitor fetopathy.

Angiotensin converting enzyme (ACE) inhibitors are extensively used for the treatment of hypertension, to decrease proteinuria, and to mitigate hyperfiltration. These drugs now have been shown to be fetotoxic causing profound fetal hypotension, renal tubular dysplasia, anuria-oligohydramnios, growth restriction, hypocalvaria, and death when used in the second and third trimesters of pregnancy. We recommend that ACE inhibitors not be used in pregnancy. However, if a child is born with ACE inhibitor fetopathy, aggressive therapy with dialysis to remove the inhibitor may mitigate the profound hypotensive effects. Therapy will depend on the specific ACE inhibitor, and care recommendations cannot be generalized for the entire class of drugs as their protein binding and volume of distribution differ substantially.

Continuous venovenous hemodiafiltration in infants and children.

Continuous venovenous hemodiafiltration (CVVHD) is not commonly used in pediatric intensive care units due to the lack of suitable equipment needed for this technique of renal replacement therapy (RRT). We have used an adapted hemodialysis machine that includes a blood pump controller, an air leak detector, and a venous pressure monitor over the past year in the pediatric intensive care unit. Blood lines available for hemodialysis were used for CVVHD, limiting the extracorporeal circuit volume to 38 mL, which allows for CVVHD capability in an infant as small as 4.5 kg without a blood-primed circuit. We have compared this experience to previous continuous arteriovenous hemodiafiltration (CAVHD) at our institution. The two groups (CVVHD and CAVHD) were similar in age, weight, blood pressure, and indication for RRT. There was significantly less number of hemofilters used, an improved number of hours per hemofilter, and a significantly less change of RRT modality due to ineffective dialysis (CVVHD 0% v CAVHD 32%) when using CVVHD. Furthermore, an average of 48% less heparin was used in the CVVHD population. We conclude that CVVHD can be safely and effectively carried out in infants and small children with less heparinization, no need for arterial access, and less risk of ineffective RRT.

Recurrent focal segmental glomerulosclerosis in pediatric renal transplant recipients: successful treatment with oral cyclophosphamide.

Focal segmental glomerulosclerosis (FSGS) is the most common glomerulopathy leading to end-stage renal disease in children and transplantation is complicated by recurrent disease in a significant percentage of children. Treatment of recurrent FSGS has included high-dose steroids, high-dose cyclosporine (CSA), plasmapheresis, and ACE inhibitors with mixed results. We have had a consistent approach using oral cyclophosphamide (CTX) to treat recurrent FSGS since 1982. Three patients with ESRD secondary to nephrotic syndrome had recurrent disease. Biopsies in all 3 were consistent with recurrent FSGS. Patients were begun on a 8-12 week course of 1-2 mg/kg/day of CTX and dosage was adjusted for WBC count. Azathioprine was with held during CTX. Patients' dosage at the end of 12 weeks ranged from 0.89-1.75 mg/kg/day. All patients tolerated CTX well. After 8-12 weeks of treatment, 2 patients with nephrotic syndrome normalized their serum albumin and had negative to trace protein on urinary dipstick. One patient with proteinuria decreased his protein excretion from 770 to 340 mg/m2/day. At follow-up at 8, 38, and 125 months post-transplant, these 3 patients have stable graft function and negative to trace protein on urinalysis. The patient followed for 125 months has had 2 additional relapses at 51 and 82 months post-transplant that were treated successfully with pulse intravenous steroids. Three pediatric patients with recurrent focal segmental glomerulosclerosis post-renal transplant were treated with oral CTX and had significant improvement in proteinuria and preservation of graft function. This suggests that oral CTX is a potentially effective and well-tolerated treatment for recurrent FSGS in children.