Frequently relapsing nephrotic syndrome: treatment with mycophenolate mofetil

Long-term treatment with cyclosporin A (CyA) of children with frequently relapsing steroid-sensitive nephrotic syndrome (SSNS) carries the risk of nephrotoxicity. We have analyzed renal function in 23 children with SSNS during CyA therapy. Repeated measurements of glomerular filtration rate (single-shot ⁵¹Cr-EDTA clearance) showed a decline from 131±21 ml/min per 1.73 m² to 116±27 ml/min per 1.73 m² at last follow-up. Similarly, effective renal plasma flow (simultaneous ¹²³I-hippurate clearance) was correlated with duration of CyA treatment, and showed a decline from 980±318 ml/min per 1.73 m² to 724±242 ml/min per 1.73 m². In a pilot study we investigated the effect of mycofenolate mofetil (MMF) in 7 children with a median age of 12.7 years [6 with minimal change nephrotic syndrome (MCNS), 1 with focal segmental glomerulosclerosis (FSGS)] with signs of nephrotoxicity because of long-term CyA therapy. Only 1 patient with SSNS showed a relapse during MMF therapy. In the patient with FSGS, MMF was started in addition to CyA, resulting in complete remission for a follow-up of 28 months. This preliminary study demonstrates that children with MCNS treated with CyA may be successfully converted to MMF without major side effects. In all cases, including FSGS, MMF had a beneficial effect on renal function. These data should be confirmed by a prospective randomized clinical trial.     

Switch from cyclosporine A to mycophenolate mofetil in nephrotic children

Nephrotoxicity is a well-known adverse effect of cyclosporine A (CyA) treatment in children with steroid-dependent (SD) and steroid-resistant (SR) nephrotic syndrome (NS). We analyzed nine children (age: 3.3–15.7 years, two girls) with SD or SR NS who experienced a significant decrease in their GFR under CyA treatment as measured by inulin clearance (C_IN). Mycophenolate mofetil (MMF) was introduced progressively until doses of 1 g/1.73 m² twice daily were reached. CyA treatment was stopped after introduction of MMF and oral steroids were reduced if possible. After a median follow up of 261 days, no adverse effects of MMF such as diarrhea or hematological anomalies occurred in our patients. After switching from CyA to MMF, those children with SD NS remained in remission without proteinuria and those with SR NS did not show any significant changes in their residual proteinuria. The serum protein level did not change significantly in any of the children analyzed. GFR increased from a mean of 76.9±4.8 to 119.9±5.9 mL/1.73 m² per min (P<0.001). Oral steroid treatment could be reduced from a median [range] prednisone dose of 0.85 [0.26–2.94] mg/kg/d pre-MMF to 0.29 [0–1.1] mg/kg per day (P=0.026), and blood pressure decreased moderately after CyA withdrawal, but the difference did not reach statistical significance. We conclude that a switch from CyA to MMF seems to be safe for children with SDNS and SRNS in terms of side effects as well as disease control, at least in the short term. Interruption of CyA treatment lead to rapid amelioration of kidney function in these children, often associated with steroid sparing, which may lead to additional benefit for growth velocity, blood pressure and physical appearance.     

Cyclosporin A therapy for severe Henoch-Schönlein nephritis with nephrotic syndrome

To evaluate the efficacy of cyclosporin A (CyA) for treating severe Henoch-Schönlein nephritis (HSN), seven patients with nephrotic syndrome, aged 3.9–13.8 years (mean 6.5 years), were analyzed retrospectively. Mean follow-up times were 5.5 years (range 2–9 years). All underwent renal biopsy before treatment, and follow-up renal biopsy was performed in six of the seven patients. All patients improved, with 24-h protein declining from a mean of 9.2 g/m²/day (range 1.5–16 g/m²/day) to 0.3 g/m²/day (range 0.03–1.2 g/m²/day) (p=0.016) and serum albumin increasing from a mean of 2.1 g/dl (range 1.5–2.4 g/dl) to 4.6 g/dl (range 3.5–5.3 g/dl) (p=0.016) after CyA therapy. The activity index decreased significantly at the second renal biopsies obtained at a mean interval of 11.7 months after the first (6.4±3.3 vs 3.5±1.2, p=0.042, respectively), while the chronicity index and the tubulointerstitial scores did not change. On the immunofluorescent findings at the second biopsies, the degree of deposits of immunoglobulins such as IgA, IgM, C3, and fibrinogen decreased in five of the six patients. Although this case series is without controls, our study suggests that CyA may be beneficial to a subset of HSN patients with nephrotic syndrome.     

Cyclosporin in the treatment of idiopathic nephrotic syndrome in children

Thirty-five children (12 girls, 23 boys), aged from 1 year and 5 months to 14 years at the onset of idiopathic nephrotic syndrome, received cyclosporin A (CyA) because of steroid toxicity or failure to respond to steroids. The initial oral dose was 6 mg/kg per day and this was adjusted to obtain trough plasma levels of 50–150 ng/ml. The duration of treatment was between 2 and 8 months. In patients who responded to CyA treatment, the dosage was tapered off; treatment was stopped if found to be ineffective. Of the 35 children, 20 were frequent-relapsing steroid responders who suffered serious side-effects from steroid therapy. Seventeen of them either went into remission or did not relapse despite the withdrawal of prednisone. Prednisone doses could be lowered but not stopped in 1 patient and the remaining 2 patients relapsed when prednisone was tapered off. At the final examination, 10 of the 12 children in whom CyA was tapered off and who had initially responded to CyA had relapsed. A second course was given to these 10 patients and 3 failed to respond. Five children were partial steroid responders and CyA induced a remission in 1 and a partial remission in another. Among the 10 children who were steroid resistant, only 1 responded to CyA, 2 had a partial response and 7 failed to respond to CyA. A reduction of glomerular filtration rate occurred in 8 patients, 7 of whom had either persistent nephrotic syndrome or were in relapse, which suggests that factors other than CyA nephrotoxicity may have been operative. Complete reversal occurred in only 4 patients. Significant histological changes, likely to be related to CyA, were seen in 2 repeat renal biopsies out of the 11 performed.     

High-sensitivity C-reactive protein (hs-CRP) level in children with nephrotic syndrome

The aim of this study was to assess the serum concentration of high-sensitivity C-reactive protein (hs-CRP) in children with nephrotic syndrome (NS) treated with prednisone and cyclosporine A (CyA). Patients were divided into three groups: (I) 20 NS children (aged 4–14 years) in relapse and examined twice, (A) before treatment and (B) after proteinuria regression (a 3–4 week course of prednisone therapy); (II) 20 children with steroid-dependent or steroid-resistant NS, treated with CyA, also examined twice, (D) before treatment with CyA, (E) 6 months after therapy. A control group (C) consisted of 20 healthy children. Serum hs-CRP level was determined by a nephelometric method with a Behring Nephelometer 100 Analyzer, Dade Behring. The results showed that median hs-CRP concentration was the highest in children with relapsing steroid-sensitive NS before treatment (IA). After proteinuria regression (IB), the hs-CRP level had decreased and did not differ from that of healthy controls (C) (P > 0.05). In group II, before CyA administration (IID), the level of hs-CRP was normal, but it had increased after 6 months of treatment (IIE) up to a level six-times higher than that of the control group (P < 0.01). We concluded that, in children with steroid-sensitive nephrotic syndrome in relapse, the serum hs-CRP level is increased but returns to normal after 3–4 weeks of glucocorticoid treatment. In children chronically treated with CyA due to NS, serum hs-CRP level increases significantly during the therapy.     

Angiotensin converting enzyme inhibitors for reduction of proteinuria in children with steroid-resistant nephrotic syndrome

The effects of angiotensin converting enzyme inhibitors (ACEI) on proteinuria, renal function, and serum proteins were evaluated in six children with steroid-resistant nephrotic syndrome and proteinuria of 3–15 g/24h (277±47 mg/m² per hour). Following ACEI, proteinuria decreased from 7,408±2,385 (mean±SEM) to 3,746±1,395 mg/24 h (P<0.05). Creatinine clearance was 87.8±22.6 before and 96.4±23.6 ml/min per 1.73 m² after ACEI. In two patients, inulin and para-aminohippuric acid clearances were normal before and after ACEI, together with parallel reductions of urine protein of 50% and 46%. Clearance of total protein was reduced by 56% following ACEI, compared with reduction in the clearance of gamma globulin by 58% and albumin by 39.5%. No significant change was seen in blood pressure, serum albumin, or total protein following ACEI. After ACEI, diuretic doses were able to be reduced or eliminated in three patients. Reduction of proteinuria was sustained during a followup period of 11–20 months in three patients. ACEI may be of benefit in the clinical management of children with steroidresistant nephrotic syndromes, allowing reduction in diuretic requirements.     

Transforming growth factor-β1 in nephrotic syndrome treated with cyclosporine and ACE inhibitors

The aim of the study was to assess urinary transforming growth factor (TGF)-1 in children with steroid-dependent nephrotic syndrome (SDNS) treated with cyclosporine A (CyA) and ACE inhibitors (ACEI). The study involved 24 children (14 boys and 10 girls) with SDNS and signs of focal segmental glomerulosclerosis. The children were treated with prednisone, CyA, and ACEI. All children were examined four times: A during relapse of proteinuria, before treatment with CyA and ACEI, and B after 3 months, C 6 months, and D 12 months of treatment. The control group consisted of 20 healthy children of the same age. The urinary TGF-1 level was determined by ELISA (R and D Quantikine). The serum CyA level was measured by monoclonal antibody fluorescence polarization immunoassay. Prior to CyA treatment, the urinary TGF-1 level was the highest (135.61±38.31 pg/mg creatinine). During CyA treatment, TGF-1 was reduced to 117.96±81.57 after 3 months, to 80.26±49.52 after 6 months, and to 44.00±31.83 pg/mg creatinine after 12 months, but it was still higher than in the control group. At 3 months there was a positive linear correlation between urinary TGF-1 and proteinuria ( r =0.654, P <0.01). These results indicate that the urinary TGF-1 level increases in proportion to proteinuria during relapse of NS. Treatment with CyA and ACEI also influences urinary TGF-1, which is still higher after 12 months of treatment than in healthy children.     

Effect of Cyclosporine Therapy With Low Doses of Corticosteroids on Idiopathic Nephrotic Syndrome

Cyclosporine (CyA) has an immunosuppressive effect that might suggest a therapeutic role in idiopathic glomerular conditions. We focused on the optimization of CyA treatment control in patients with idiopathic nephrotic syndrome by using trough‐level CyA measurements (C0) and the 2‐h postdose levels (C2). Twenty‐two patients (14 male, 8 female) with idiopathic nephrotic syndrome and the mean age of 51 ± 18 months (mean [M] ± standard deviation [SD]) were enrolled in our study during a period of 10 months (range: 3–18 months). All of the patients received CyA (2–3 mg/kg) in combination with methylprednisolone. In the present study protocol CyA concentrations (C0, C2), renal function, lipid profile, and degree of proteinuria were determined. The mean proteinuria of our patients before treatment was 11 972 ± 7953 mg/24 H (±SD) and the mean creatinine level (Cr) was 0.99 ± 0.37 mg/dL (±SD). Proteinuria decreased significantly already from the first month of therapy with CyA to 3578 ± 2470 mg/24 H (M± SD), and during the whole study period this reduction was significant (0.56 ± 0.37 gr/24 H (M ± SD), P < 0.05). At the same time renal function preserved, 1.09 ± 0.48 mg/dL (M ± SD). The blood levels of C0 were 135.10 ± 97.36 ng/mL (M ± SD) and the blood levels of C2 were 725 ± 256 ng/mL (M ± SD) at the first month of therapy. At the same time renal function preserved, 1.09 ± 0.48 mg/dL (M ± SD). Total cholesterol levels reduced significantly during study period (276.89 ± 45.57 to 200.67 ± 40.27 mg/dL [M ± SD]). The mean number of antihypertensive medication remained the same. The whole therapeutic protocol did not provoke any kind of side effects and CyA was quite tolerated by our patients. Treatment of idiopathic nephrotic syndrome with low doses of CyA with methylprednisolone leads to remission of proteinuria without deterioration of renal function. Blood levels of C0 for monitoring and treatment of nephrotic syndrome agrees with recent literature, while our study focus on establishing the proper levels of C2 for the treatment of nephrotic syndrome. The efficacy of CyA is combined with safety and tolerance.     

Effect of cyclosporin a on proteinuria in patients with Alport's syndrome

Eight patients with Alport's syndrome and massive proteinuria (129±60.57 mg/m² per hour) were treated with cyclosporin A (CyA) for 8 months. The average dose of CyA administered to all patients was 4.21±0.26 mg/kg per day and blood CyA levels of 63.4±4.1 ng/ml were attained. In five patients, proteinuria abated during the 3rd week of treatment. In the remaining three, all of whom had low creatinine clearance (82.0, 46.0 and 43.2 ml/min per 1.73 m² respectively), proteinuria persisted but at levels lower than before treatment: 32.5±15.9 mg/m² per hour versus 183.3±29.7 mg/m² per hour. No permanent decrease in creatinine clearance was observed in any of these patients throughout treatment. In those patients in whom proteinuria abated, it reappeared 2 weeks after discontinuation of CyA treatment. We observed no significant increases in angiotensin II plasma levels in our patients during CyA administration. Although we have shown that CyA will reduce massive proteinuria in patients with Alport's syndrome, we cannot yet recommend its use as a therapeutic measure.     

Glycosaminoglycan excretion in children with nephrotic syndrome

Although most childhood nephrotic syndromes respond to steroid treatment, steroid resistant nephrotic syndrome (SRNS) is also common and is particularly difficult to treat. This study investigated the role of glycosaminoglycans (GAG) in the pathogenesis and clinical course of nephrotic syndrome in children. Thirty-four children (21 males and 13 females, mean age 3.7±1.6 years) with steroid-sensitive nephrotic syndrome and 20 children with steroid-resistant nephrotic syndrome (12 males and 8 females, mean age 10.9±3.8 years; of the twenty, four had primary SRNS (FSGS) and the others had secondary SRNS) were included the study. Mean urine levels of GAG relative to creatinine (U_GAG/U_Cr) in patients with SRNS (n=20, 113.01±78.46 mg g^–1 Cr) and in patients experiencing the nephrotic period of steroid-sensitive nephrotic syndrome (n=34, 132.15±101.55 mg g^–1 Cr) were both significantly higher than mean U_GAG/U_Cr for control subjects (n=30, 51.83±47.66 mg g^–1 Cr) (P<0.01 for both). Patients excreted significantly more GAG during the nephrotic period of steroid-sensitive nephrotic syndrome than during remission (132.15±101.55 vs 39.11±42.73 mg g^–1 Cr, respectively; P<0.01). There was, however, no significant difference between U_GAG/U_Cr for patients with steroid-resistant nephrotic syndrome and U_GAG/U_Cr in the nephrotic period of steroid-sensitive nephrotic syndrome. Urine GAG excretion correlated significantly with the severity of proteinuria. The results suggest that GAG play a significant role in the pathogenesis of nephrotic syndrome but that GAG excretion is not a marker for response to steroid treatment in pediatric patients with this condition.     

Long-term cyclosporine A treatment of steroid-resistant and steroid-dependent nephrotic syndrome

Eighteen patients with steroid-resistant nephrotic syndrome (SRNS) and steroid-dependent nephrotic syndrome (SDNS) were treated with cyclosporine A (CyA) (6 mg/kg/d) for 2 to 29 months. CyA levels were monitored monthly and plasma levels by Abbott TDX (Therapeutic Drug Analyzer System) fluorescence polarization immunoassay were maintained at 100 to 150 ng/mL. The corticosteroid dosage administered at the time CyA therapy was initiated was variable and was continued following CyA therapy. Six of these patients (all with SDNS and minimal change nephrotic syndrome [MCNS]) had been treated with one or more courses of cytotoxic drug therapy, and all had clinical evidence of corticosteroid toxicity after receiving corticosteroid therapy for 26 to 120 months. The corticosteroid dosage was reduced by slow tapering and was ultimately discontinued in six patients. These patients were maintained on CyA monotherapy for 7 to 21 months at a dose of 3.2 to 6.7 mg/kg/d. Following 11 to 29 months of CyA therapy, seven patients underwent an elective renal biopsy, which showed nephrotoxicity in all seven. This led to discontinuation of CyA in four patients. Following discontinuation of CyA monotherapy, all four patients relapsed within 2 to 4 months. CyA therapy did not achieve a remission in 10 patients with SRNS regardless of the presence of focal segmental glomerulosclerosis (FSGS) or MCNS on renal biopsy. In conclusion, CyA has limited effectiveness in patients with SDNS who manifest corticosteroid toxicity; however, CyA should be used cautiously because of the potential for CyA nephrotoxicity and the failure to obtain a sustained remission following discontinuation of CyA monotherapy. CyA dependence is substituted for corticosteroid dependence.     

Effect of acetylsalicylic acid and dipyridamole in primary membranoproliferative glomerulonephritis type I

Primary membranoproliferativeglomerulonephritis (MPGN) has a poor long-termprognosis, with 40 per cent of patientsreaching end-stage renal failure after 10 yearsof observation. Approximately 35 per cent ofpatients die due to complications of thenephrotic syndrome. This study investigates theeffect of acetylsalicylic acid (ASA) combinedwith dipyridamole on proteinuria and renalfunction in nephrotic MPGN patients withnormal/moderately reduced glomerular filtration rate(GFR). Fourteen patients with biopsy-proventype I MPGN received ASA (1000 mg/day) anddipyridamole (300 mg/day) for 24 months.Proteinuria was reduced from 6.8 ± 2.4 g/dayto 1.1 ± 0.6 g/day (p < 0.001). Serumalbumin levels increased from 2.2 ± 0.5 g/dLto 3.7 ± 0.4 g/dL (p < 0.001) duringthe study period after 24 months compared tobaseline. Serum creatinine and GFR did notsignificantly change in patients treated withacetylsaliclylic acid and dipyridamole duringthe observation period (p < 0.05). Ourstudy suggests that ASA combined withdipyridamole significantly reduces proteinuria without impairing renal function in patientswith MPGN.     

Bone histology in steroid-treated children with non-azotemic nephrotic syndrome

Patients with nephrotic syndrome (NS) and normal glomerular filtration rate (GFR) frequently exhibit abnormalities of calcium and vitamin D homeostasis, mainly hypocalcemia and reduced circulating vitamin D metabolites. These abnormalities have been linked to alterations of bone histology in adults with non-azotemic NS, particularly osteomalacia and excessive bone resorption. Whether similar abnormalities of bone histology occur in children and adolescents with NS, particularly in those requiring prolonged treatment with corticosteroids, remains largely unknown. Thus, bone histomorphometry and selected bone-modulating hormones were studied in eight children (aged 2–16 years) with normal GFR (range 85–169 ml/min per 1.73 m²) and NS. All patients received corticosteroids for at least 12 months prior to bone biopsy. At the time of bone biopsy, the urine protein/creatinine ratio was elevated (2.1±3.6), while the average concentrations of parathyroid hormone (36±13 pg/ml), 25-hydroxyvitamin D [25(OH) D] (22±14 ng/ml), and 1,25(OH)₂D (59±22 pg/ml) were normal. Bone histomorphometry displayed focal osteomalacia (OM) and mild increased bone resorption in most patients. The mineralization lag time, an indicator of the degree of osteomalacia, correlated with the time elapsed since the original diagnosis of NS (r=0.93, P<0.0005). Overt hyperparathyroidism was not evident, but increased eroded perimeter and elevated bone formation rate (BFR) were evident in two patients, suggesting high-turnover bone disease. The BFR was inversely correlated with the administered dose of prednisone at the time of biopsy (r=–0.78, P<0.05) and one patient exhibited low bone turnover changes. The growth velocity standard deviation score (SDS) at time of biopsy ranged from –1.6 to 3.2, resulting in a height SDS range of –1.9 to 0.6. The height SDS at time of bone biopsy correlated inversely with the dose of administered glucocorticoid (r=–0.71, P<0.05) and with the duration of the disease (r=–0.7, P=0.05). These data, albeit preliminary, demonstrate that children with NS treated with prolonged corticosteroid therapy exhibit bone histopathological changes without a concomitant impairment in GFR. While the OM appears to be related to the disease process, the alterations of bone formation and the adynamic changes are likely the result of the corticosteroid therapy. The potential consequences of these findings on adult bone mass and ultimate height deserve further studies.     

Renal function following kidney transplantation in children treated with cyclosporine

The study was performed to evaluate the longterm renal function of children treated with cyclosporine after kidney transplantation. Renal function was determined with clearances of inulin and aminohippurate sodium for evaluating glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Thirty-six children aged 0.4–16.2 (median 6.9) years at transplantation were examined within 5 months of transplantation and then yearly over 0.3–7.1 years. Twenty-five children and young adults, 1.5–20 (median 7.7) years of age, with solitary kidneys because of renal agenesis or nephrectomy, served as controls. The GFR and ERPF within 1 year of transplantation were significantly lower than those of controls (65±19 and 345±88 vs 96±12 and 474±91 ml/min per 1.73 m², respectively). GFR remained constant 4 years after transplantation, but ERPF decreased significantly. Significant inverse correlations were found between GFR within 5 months of transplantation and the mean cyclosporine concentration and the number of rejection episodes. The frequency of hypertension decreased from 82% within 5 months of transplantation to 0% after 4 years. The absolute GFR increased during follow-up. In conclusion, kidney transplantation results in a reduced renal function compared with that of solitary native kidneys. The reduction in renal function correlated with the number of rejection episodes and the cyclosporine load. The increase in absolute GFR during follow-up suggests a remaining capacity for growth and/or compensatory hypertrophy.     

Efficacy of mycophenolate mofetil in pediatric patients with steroid-dependent nephrotic syndrome

Most patients with minimal change nephrotic syndrome are steroid responsive and tolerate this medication. However, a substantial number of patients relapse frequently and become steroid dependent. These patients often require treatment with alternative immunosuppressive drugs to maintain remission and minimize steroid toxicity. Previous studies have suggested that mycophenolate mofetil is effective in treating these patients. However, there are limited data on the effectiveness of this agent in pediatric patients, specifically those with steroid-dependent nephrotic syndrome. The purpose of this study was to assess the efficacy and safety of mycophenolate mofetil therapy in children and adolescents with steroid-dependent nephrotic syndrome who failed other treatments. A retrospective chart review was performed on all patients with steroid-dependent nephrotic syndrome. Clinical characteristics, laboratory data and the relapse rate were assessed prior to and during mycophenolate mofetil treatment. Twenty-one patients, ages 2–17 years, with steroid-dependent nephrotic syndrome who were treated with mycophenolate mofetil between 2001–2005 were included in this review. The indication for mycophenolate mofetil use was steroid dependence in 17 and steroid toxicity in 4 patients. The mean duration of treatment was 1.0±0.5 years (range: 0.2–2.0 years). Patients treated with mycophenolate mofetil had a reduction in relapse rate from 0.80±0.41 to 0.47±0.43 relapses per month ( P <0.02). Side effects were mild and mostly gastrointestinal in nature. In 1 child, mycophenolate mofetil was discontinued due to varicella infection and not restarted. The findings indicate that mycophenolate mofetil is a useful adjunctive therapy in the treatment of patients with steroid-dependent nephrotic syndrome. It lowers the relapse rate by 40% and is well tolerated by patients with steroid-dependent nephrotic syndrome.     

Prophylactic calcium and vitamin D treatments in steroid-treated children with nephrotic syndrome

Steroid treatment has several side effects, including the deterioration of the bone and mineral metabolism in children with nephrotic syndrome. This randomized prospective study was conducted to determine the effects and prophylactic role of calcium plus vitamin D treatment on bone and mineral metabolism in children receiving prednisolone treatment. 40 children (27 boys and 13 girls) with NS (18 new onset and 22 relapsing) were included in the study. Their mean age was 4.6±1.8 years. All patients received prednisolone treatment (2 mg/kg/day for 4 weeks followed by alternate days at the same dose for 4 weeks). The patients were randomized into treatment (vitamin D 400 IU plus calcium 1 g daily) and non-treatment groups. Bone mineral density, serum Ca, P, alkaline phosphatase and urinary Ca and P excretions were analyzed at the beginning and 2 months after the treatment. The XR36 Norland device was used for bone mineral density analysis. Bone mineral density was significantly decreased in both the treatment (0.54±0.15 to 0.51±0.1 g/cm², P =0.001) and non-treatment (0.52±0.18 to 0.45±0.16 g/cm², P <0.001) group. But the percentage of bone mineral density decrease was found to be significantly lower in the treatment group than in the non-treatment group (4.6±2.1% vs. 13.0±4.0%, respectively; P <0.001). Serum calcium and urinary calcium excretion increased in the treatment group (8.0±1.0 to 10.0±0.5 mg/dl and 1.1±0.5 to 3.2±1.0 mg/kg/day) and non-treatment group (8.1±0.8 to 10.0±0.6 mg/dl and 1.4±0.9 to 3.8±3.3 mg/kg/day) after prednisolone treatment (P <0.001). Steroid treatment decreases bone mineral density in children with nephrotic syndrome. Vitamin D plus calcium therapy at the current doses reduces but does not completely prevent bone loss, with no additional adverse effects.     

Influence of serum albumin on renal function in nephrotic syndrome

 Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), determined by the clearances of inulin and para-aminohippuric acid, were evaluated in 119 children with different types of nephrotic syndrome and in different stages: the nephrotic stage (serum albumin <25 g/l), recovery stage (25–35 g/l), and remission (>35 g/l). GFR in the nephrotic stage was significantly lower than in remission and in controls, and was lowest at onset of the disease (84±6, 111±4, and 119±2 ml/min per 1.73 m²). ERPF was higher in the nephrotic stage than in recovery, especially in children with histological lesions. Thus the filtration fraction (FF) was greatly decreased in the nephrotic stage. In patients investigated both in the nephrotic and the remission phase, GFR and FF increased significantly. There was a direct correlation between the serum albumin concentration and FF and an inverse correlation between mean arterial pressure (MAP) and GFR and FF in all patients, a direct correlation between the serum albumin concentration and GFR in minimal change nephrotic syndrome patients, and an inverse correlation between ERPF and serum albumin in children with histological lesions. In conclusion, GFR and FF were decreased and ERPF increased in the nephrotic stage, normalizing in remission. The low GFR in the nephrotic stage was thus not dependent on hypoperfusion. We suggest that the low GFR is dependent on a very low ultrafiltration coefficient. The direct correlation between GFR and serum albumin and the indirect correlation between GFR and MAP suggest compensatory mechanisms that increase the ultrafiltration pressure to counteract the severely reduced ultrafiltration coefficient. Received: 19 November 1997 / Revised: 11 April 1998 / Accepted: 14 April 1998     

Growth hormone for children with chronic renal failure and on dialysis

We studied all children with CRF who received recombinant human growth hormone (rhGH) for more than a year (mean±SD duration of therapy 3.7±2.5 years) over an 11-year period. There were 32 children. Twenty-one children were conservatively managed, with a mean glomerular filtration rate (GFR) of 24±12 mL min^–1/1.73 m² at the start of rhGH. Their height standard deviation score improved from –2.5±1.4 to –2.1±0.7 at 1 year (P=0.3), –2.0±0.7 at 2 years (P=0.01), and –1.6±0.6 at 3 years (P=0.001). After that there was no improvement. Eleven children were on dialysis, six on haemodialysis (HD) and five on peritoneal (PD). Ht SDS improved from –2.7±0.5 to –2.3±0.5 at 1 year (P=0.02). Thereafter there was no further improvement. RhGH was stopped because of transplantation in 29 patients at a mean±SD age of 12.1±4.0 years. Mean Ht SDS was –1.8±0.8 at transplant and there was no change over the following 5 years. In conclusion, treatment with rhGH resulted in improvement in Ht SDS in conservatively managed CRF for up to 3.0 years and for 1 year in children on dialysis. Discontinuation of rhGH after transplantation resulted in little change in Ht SDS.     

Cyclosporine Inhibits Renal Uric Acid Transport in Renal Transplants not in Children Treated for Nephrotic Syndrome

Children with various grades of renal insufficiency (CON group) maintained uric acid excretion over a range of glomerular filtration rate (GFR) from 27 to 160 ml/min*l. 73m² despite a decreased filtered load which was paralleled by glomerular filtration of uric acid. This was achieved by a compensatory decrease of net uric acid reabsorption (Tua) and an increasing fractional excretion of uric acid (FEua) with decreasing GFR. Although there was a decreased GFR in the group of children after transplantation (NTx group) there was no difference in Tua and FEua between the NTx group and the CON group. Uric acid transport was not affected in children treated with Cyclosporine (CyA)for nephrotic syndrome (NEPH group) compared to the CON group. Decreased fractional phosphate reabsorption in the NTx group suggests proximal tubule damage associatedwith disturbed uric acid handling. Under conditions of water diuresis hyperuricemia seen in NTx may result from an indirect effect of renal ischemic damage due to the transplantation procedure causing disturbance of proximal tubular uric acid (active) secretionlreabsorption.