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Primary hyperoxaluria type I (PH I) is a congenital error of metabolism that can be manifested by an increased oxalate production, and ultimately result in kidney failure. After a combined liver/kidney transplantation, children with PH I have persistent excretion of oxalate that causes crystal formation in the urinary tract, and could result in systemic oxalosis and eventual graft failure. We speculated that crystalluria may be predictive of this nephrolithogenic tendency and thus investigated the effect of an intensive therapeutic strategy to prevent crystal formation in 13 children at our hospital. Oxalate crystal volume (OCV) measurements were performed at regular intervals for 36 months, and compared with urine supersaturation measurements. We found that crystalluria with the OCV measurement is non-invasive, easily performed, and gives feedback on the efficacy of PH I therapy within one hour. Further study is needed to determine whether this method is a better predictor of nephrocalcinosis than is supersaturation alone.

The objective of this study was to quantify the deposition in the lung of a Colistine aerosol generated using a pneumatic nebuliser (Pari LL(R) equipped with a Pari Master, Pari, Germany) and to compare this with the results obtained with an ultrasonic nebuliser (DP100, DP Medical, France) in four subjects suffering from cystic fibrosis being colonised with Pseudomonas aeruginosa. To quantify the pulmonary deposition of the aerosols we have used an indirect isotopic method which consists in assimilating the kinetics of the molecules studied with a serum albumin tagged with Technetium 99m (Tc99mm) and added to a preparation of Colistine. We have previously verified that the addition of a radioactive tracer does not change the normal distribution or dynamics of the medication within the aerosol and the radioactive counter linked to the tracer reflects the mass of the medicament. The pulmonary deposition was expressed as a percentage of the nebuliser dose. A regional analysis of the deposition (central, peripheral, superior and inferior) was carried out and in central deposition compared to the periphery (C/P) and superior compared to inferior (S/I) were calculated. With the DP100 nebuliser the pulmonary deposition of the aerosol was very reproducible from one patient to another, varying only between 9.5 to 14 percent of the nebuliser dose. With the Pari LL the fraction deposited varied more from one patient to another from 5.6 to 27% of the nebuliser dose. In three of four patients, the pulmonary deposition was superior or equal to that obtained with the ultrasonic nebuliser. The patients whose pulmonary deposition was inferior, using the pneumatic nebuliser, was the youngest in the group and co-ordinately poorly the triggering of the nebuliser with the beginning of inspiration. With the two nebulisers, the pulmonary deposition of Colisitine was very heterogeneous throughout the pulmonary parenchyma. The mean of the ratio C/P and S/I obtained in all four patients was identical (1.35 an 0.86 respectively), indicating a deposition of the aerosol which was predominantly central and inferior but was distributed equally in the peripheral parts of the lung. Pneumatic nebulisers offer a reliable alternative notably for domiciliary treatment for Colistine aerosols in patients suffering from cystic fibrosis. In younger patients who have not yet acquired good motor co-ordination, nebulisers which function continuously or are triggered by inspiration seem to be the preferred choice.

In a series of 715 renal transplantations performed between 1973 and 1989, 72 cases of renal artery stenosis (RAS) in 69 children (9.7%) were managed at Hôpital Necker Enfants Malades. Forty cases of RAS were treated exclusively by antihypertensive drugs. A good result was obtained in 82.5% of cases. Thirty three transluminal angioplasties (TLA) were performed in 23 children with 26 RAS. A good clinical result was obtained in 15 children with a total of 17 stenoses, corresponding to a success rate of 65%. Transluminal dilatation of anastomotic stenoses always failed. There were no cases of transplant thrombosis. Eleven RAS were operated, including 5 after failure of TLA. Eight patients (73%) obtained a clinical improvement. There were 2 postoperative thromboses. Antihypertensive treatment must be administered in every case. If medical treatment fails, and with the exception of anastomotic stenoses, TLA should be the first-line procedure, while surgery is reserved for failures of TLA and for anastomotic stenoses.

In a series of 859 transplantations performed in children and adolescents from January 1973 to December 1992, vascular thrombosis accounted for 18% of all graft losses (2nd cause of graft failure), and 57% of early failures (within 2 months). Renal veins and arteries were equally affected. The young age of the donors and recipients constituted the main risk factor, thrombosis accounting for 40 and 37% respectively of all graft losses in donors and recipients5 years old. This explained the lower survival rate of these age groups after grafting, as reported in most published pediatric series. The prophylactic use of a low molecular weight heparin in high-risk grafts may help to decrease its incidence. A renal artery stenosis, located a few cm beyond the anastomosis in 2/3 of cases, was observed in 10% of grafts. Often severe hypertension (HBP) with cerebral complications, responsible for permanent sequelae in some cases, was the prominent symptom. Anti-hypertensive drug therapy was sufficient to control HBP in 40 cases out of 72, and in 10 of these, a spontaneous regression of the stenosis was remarked within a few months after repeated angiography. Transluminal angioplasty was used on 26 stenosis and was effective in 2/3 of cases; the recurrence rate, however, was 27%.

Intravenous recombinant human erythropoietin (Eprex Cilag) was used in 28 hemodialyzed children, treated in 3 French paediatric centers, from November 1989 to November 1990. Transfusion dependency disappeared in all cases: the number of transfusions decreased from 7.3 unit/patient/year to 0.6 unit/pt/year. The mean haemoglobin concentration for the whole group increased from 6.6 +/- 0.8 g/dl, to 9.2 +/- 1.2 at 6 months and 9.7 +/- 0.7 g/dl at 1 year. Twenty-two out of 28 children reached the target haemoglobin value of 9.6 g/dl (6 mmol/dL) within a mean time of 16.5 weeks. Poor responses were due to either a premature withdrawal of treatment because of renal transplantation, or too low a dosage for the age. The study showed indeed that the dose requirement was significantly dependent on physical development: the mean dosage required to maintain haemoglobin concentration at the target value was 300 U/kg/week in children weighing less than 20 kg, 222 U/kg/week in 20-30 kg children, and 135 U/kg/week in those weighing more than 30 kg (p = 0.02). The only complication was an increase in blood pressure, observed in 43% of cases. The increase of anti-hypertensive medication was always successful in controlling blood pressure, and hospitalization was required in only one case. The improvement in general condition was obvious, and in several cases, the cognitive abilities seemed to improve. The growth deficit remained unchanged.

The renal ultrasonography (US) scans of 23 children who had recently undergone kidney transplantation were reviewed; the studies included Doppler US scanning of the arterial vessels at several levels. There were 43 studies for children whose postoperative course was normal; 16 studies were obtained during episodes of acute tubular necrosis and 21 during episodes of acute rejection. The upper limit of normal for the resistive index (RI) at the arcuate artery is higher (up to 0.79) for a pediatric renal transplant patient than for adults with normal kidneys, regardless of the age of the kidney donor. Therefore, elevation of the RI to 0.80 or higher or complete loss of diastolic flow always indicates a complication of transplantation. Abnormally high RI values were seen in patients with both acute tubular necrosis and acute rejection; however, the RI value as determined by US did not distinguish these two entities. In addition, in 7 cases of acute tubular necrosis and 12 of acute rejection the RI was normal (0.58 to 0.79).

Twenty-four ultrasonography (US) studies of 21 renal transplants that had been in place for 1 to 19 (median 3) years were evaluated. The absolute resistive indices (RIs) determined during Doppler US at various arterial levels and the differences in RI between the levels did not correlate with the clinical diagnosis of chronic rejection. This study suggests that measuring RI values with Doppler US in people who received renal grafts as children does not currently contribute additional information for diagnosis or management.

From 1976 through 1991, 50 renal transplants (with 7 kidneys from living related donors and 43 cadaver kidneys) were performed in 47 children under five years of age (range 11 to 59 months) at the Enfants-Malades Hospital, Paris, France. Donor age ranged from 3 months to 53 years. Six of the seven kidneys from living related donors are currently functioning after a follow-up of 6 months to 8 years, whereas actuarial survival of cadaver kidneys was 70% at one year and 66% at five years. The main cause of graft loss was vascular thrombosis (40% of lost kidneys). In the most recent years of the study period, graft survival was substantially improved by routine prophylactic anticoagulant therapy with low-molecular weight heparin: one-year graft survival rate was 83% in the 23 children grafted between 1989 and 1991. Posttransplantation growth was closely related to quality of graft function: among the 29 children with sufficiently long follow-up the 19 patients with normal renal function exhibited normal or catch-up growth, whereas the ten patients with chronic renal failure or recent rejection had poor growth. Complications were uncommon with the exception of hypertension. Mortality rate was 12%, i.e., only slightly higher than in older pediatric kidney recipients. Achievement at school was normal in most cases (with a lag in only five patients). Provided effective therapy is given to prevent the main adverse outcome (i.e., vascular thrombosis), renal transplantation does not involve excessive risks even in infants as young as one year of age.

Among 149 kidneys transplanted in 141 children and teenagers aged 4 1/2 to 20 years, from November 1972 through December 1979, 70 (47%) were still functioning after ten years (67/145 cadaver donor grafts and 3/4 living related donor grafts). Medical and social status at the last follow-up visit (10 to 16 1/2 years after transplantation; m = 12 years) was analyzed. Patients were divided into five groups on the basis of glomerular filtration rate (GFR; ml/min/1.73 m2) and blood pressure (BP): 1) GFR greater than 80 ml and normal BP: 23 patients (33%); 2) GFR in the 60-80 ml range and/or high BP: 24 patients (34%/3) GFR in the 40-60 range: 6 patients; 4) GFR in the 15-40 range: 7 patients; and 5) hemodialysis restarted 10 1/2 to 13 years after transplantation. Mean adult stature was 155.7 +/- 10.4 cm in males and 149.8 +/- 10 cm in females. Osteoporosis was found in 88% of patients who underwent bone density quantitation. Twenty-four per cent of patients had aseptic osteonecrosis with variable degrees of impairment as a result. Chronic HBsAg carrier status was found in 37% of patients and was accompanied with persistent cytolysis in half the cases. Only one malignancy was seen (carcinoma of the urinary bladder in a child under cyclophosphamide). Six deaths were recorded between 10 and 13 years after transplantation; causes included septicemia (2 cases), cancer (1 case), hepatitis B (1 case), cerebral cystinosis (1 case), and unexplained sudden death (1 case).(ABSTRACT TRUNCATED AT 250 WORDS)

Vascular thrombosis is one of the main causes of early transplant failure in pediatric patients. This paper reports the results of an open trial of the low molecular weight heparin (Enoxaparine) used to prevent renal graft thrombosis in pediatric recipients with risk factors including donor or recipient age under 5 years, multiple arteries supplying the transplant, and positive history for recurrent thrombosis. During 1989, 42 of 67 children given a renal transplant were prophylactically treated with Enoxaparin. Only one transplant was lost to thrombosis among treated patients (1.5%), versus 9 transplants among 73 (12%) children who received their kidney in 1988 without prophylactic Enoxaparin. Risk factors were comparable in both groups of recipients. Enoxaparine therapy was associated with an increased rate of bleeding (12/42) without severe consequences. In conclusion, Enoxaparin is effective in preventing renal graft thrombosis. Availability of this prophylactic therapy makes it possible to use transplants removed from the youngest donors considered as inadequate by some groups.

A clinicopathologic study of 41 biopsy specimens from renal grafts transplanted at least ten years earlier showed normal findings or only mild tubulointerstitial lesions in 63% of cases. Results confirmed the good prognostic value of renal graft biopsy performed ten years after transplantation. A very close correlation was demonstrated between histologic evidence of chronic rejection (interstitial fibrosis, tubular atrophy, and fibrous endarteritis) and long-term graft outcome. Severity of interstitial fibrosis was apparently a more reliable indicator of prognosis than severity of fibrous endarteritis. Among 16 patients with a history of acute rejection, none had residual parenchymatous lesions. In contrast, among patients with major tubulointerstitial and/or vascular lesions, most had previously experienced one or several episodes of acute rejection. Evidence of allograft glomerulopathy was seen in approximately one case in four (11 patients). Among these patients, only eight had proteinuria and only four lost their graft. Among the four patients who developed recurrent membranoproliferative glomerulonephritis (type I in three cases and type II in one case), three lost the deposits previously detected by immunofluorescence, probably as a result of immunosuppressive therapy.

We report our experience with endoluminal angioplasty for the treatment of arterial stenosis involving transplanted kidneys in children. Four anatomic groups were individualized: stenosis of the iliac artery proximal to or at the level ot the anastomosis, single stenosis of the main renal artery, double stenosis of the main renal artery and/or a branch of the renal artery, and multiple arterial lesions. Angioplasty is performed under general anesthesia using balloon catheters appropriate for pediatric patients. Prevention of spasm and heparin therapy are essential. Results depended on the distal vascular bed. Good results were achieved in those patients with a dilatation distal to the stenosis and no multiple arterial lesions (type IV) that actually reflect vascular rejection. The overall success rate was estimated at 66% and the recurrence rate at 22%.

To study the accuracy of renal function quantification with 99Tcm-DMSA we compared DMSA renal uptake and creatinine clearance in 16 cases of children with single kidney. The age of the patients ranged from two months to fourteen years. Creatinine clearance was normalized to 1.73 m2. DMSA uptake was measured 7 h after intravenous injection. Background subtraction was used and soft tissue attenuation was taken into account. The uptake was normalized in percentage of the injected activity. A significant correlation was found between creatinine clearance and DMSA uptake (rt = 0.866, p less than 0.01). Normal creatinine clearance range in children (80 to 120 ml min-1/1.73 m2) allowed determination of normal uptake range (36 to 60%). This study indicates that in case of asymmetrical renal impairment renal uptake will reflect split renal creatinine clearance. Since the former is much easier to measure, DMSA should play an important role in the evaluation of differential renal function.

Infantile cystinosis is an autosomal recessive lysosomal disorder of aminoacid metabolism leading to a storage of cystine crystals in the cells of many tissues, but mainly in the kidney and the eye. The ocular symptoms and long term evolution were studied in a series of 25 patients at the Enfants Malades Hospital. The follow-up over 26 years demonstrated that infantile cystinosis affected mainly corneal and retinal epithelium just as it affected the kidney epithelium. Corneal involvement was a constant finding after one year of age. It induced photophobia, which appeared between three and four years when a superficial punctate keratopathy appeared. A characteristic retinopathy was observed as early as three years of age. It was constantly present at seven years of age and caused loss of vision. When ERG results were compared to the most recent measurement of visual acuity, a correlation was observed between retinopathy and visual defect. For this reason, no corneal grafts were performed. The use of topic cysteamine appeared promising but no definitive conclusions could be made.

In a 7 year-old girl presenting with nephrotic syndrome and repeated episodes of thrombosis, a decrease in antithrombin III and in vitro inactivity of heparin were observed. Treatment by vitamin K antagonists prevented further thromboembolic episodes.

Polycystic renal diseases in children include 2 pathologically and genetically distinct diseases: autosomal recessive polycystic kidney disease (ARPKD), incorrectly called the "infantile form", characterized by a constant hepato-renal involvement, and autosomal dominant polycystic kidney disease, often termed the "adult form", which is more and more frequently detected in children as a result of advances in renal imaging techniques. The differential diagnosis is not based on age at discovery, clinical symptoms or renal imaging, which may all be similar in the 2 diseases, but on the presence, detected by either pathology or ultrasonography, of the biliary dysgenesis specific to ARPKD, and mainly on the mode of inheritance, confirmed by the results of ultrasonography in parents and grandparents.

This study reports the results of 310 cadaver kidney transplantations in 295 children and adolescents performed from 1973 to 1983. The actuarial survival of patients was 97% at one year and 92% at 5 years; that of grafts was 79% at 1 year and 65% at 5 years, these rates having improved during the last years. Results were similar and even better for the 18 second transplantations. Among the causes of failure, rejection comes first (65%), then thromboses of renal artery (13%) and relapses of oxalosis or steroid resistant nephrosis (12%). Patients with cytotoxic antibodies have a less good survival of grafts, especially after 5 years. HLA A and B compatibility is a factor of success. Among complications hypertension is frequent, 53% of patients receiving antihypertensive treatment after 1 year. It is sometimes severe and was responsible for death in 5 cases. Growth was variable after transplantation: 25% of children before puberty had a catch-up curve, 25% had an unchanged growth and 50% an increased retardation. The average standard deviation was near zero but it was -0.49 SD/year in patients with creatinine level greater than or equal to 150 mumol and +0.24 SD in children under alternate day steroid therapy. Rehabilitation was excellent, less than 3% of patients not being engaged in any activity 1 year after transplantation.

Eighteen children who have received kidney transplants within the last three years at the Hopital des Enfants Malades in Paris provide material for this survey. We try to find out how these transplants effect the way the children live, and the main psychological problems that they create. This new way of life is characterized by an explosion of vitality, a certain liberation from prior restraint and the possibility of activities which up to then had been difficult or forbidden. However, the necessity for the child to be watched regularly, to attend the hospital for examination, to follow a special diet, to take immunodepressive drugs remind him that he is not cured. Consequences of corticotherapy and the growth retardation remain essential problems for some of them. The child will have to cope with this complex situation which also creates difficulties to acquire independence.

We studied the occurrence of diabetes mellitus in 6 children receiving corticosteroid therapy after renal transplantation. The first hyperglycemic episode occurred in all cases before the fortieth day of treatment but other episodes were observed thereafter. All children were glycosuric, without ketonuria. The diabetes has always been transient, and easily managed with insulin treatment and usual diabetic diet. A glucose tolerance test was performed 3 to 6 months after these episodes; glycemic response to glucose was abnormal in 2 of 6 children; in all cases, the insulin response to the glucose load was inadequate. In 2 children, the fasting blood glucose is still abnormal after a follow-up of 3 years. The other patients have recovered despite sustained corticotherapy. No specific background (genetics, HLA groups) or specific circumstances of treatment were identified. Therefore, we recommend to follow closely glycemia in children after renal transplantation, with a daily glycemic determination especially during the first 3 weeks.

Seventy patients (55 infants and 15 children) with the hemolytic uremic syndrome (HUS) were reviewed to evaluate the incidence of hypertension in HUS. Refractory hypertension was only observed in 5 infants (3 at onset and 2 after several months), whereas it was present in 9 children (4 at onset and 5 in the course of the disease). Controllable hypertension was present in 10 patients (8 infants and 2 children). Histopathological examination of renal specimens in 52 patients showed 3 patterns: cortical necrosis in 10, Thrombotic microangiopathy (TMA) with predominant glomerular involvement in 29 and TMA with predominant arterial involvement in 13. Clinicopathologic correlations showed that severe hypertension was almost exclusively observed in the patients with "vascular TMA". Bilateral nephrectomy performed in 8 patients led to the rapid disappearance of hypertension, thus demonstrating the role of hyperreninaemia in the development of hypertension in the HUS.

Thirteen children, 6 females, 7 males, aged 2 to 13 years were studied. At the time of study they were on continuous ambulatory peritoneal dialysis (CAPD) for 1 to 22 months. 25-(OH)D loss in daily dialysate fluids represented 2 to 22 micrograms/day. A significant correlation was found between 25-(OH)D plasma concentration and 25-(OH)D dialysate concentration. 25-(OH)D clearance was correlated to 25-(OH)D binding protein clearance (p less than 0.001). These findings of important 25-(OH)D losses in the dialysate fluid of children on CAPD demonstrate the necessity of carefully adapted vitamin D intakes with such a treatment.

Systemic hypertension after renal transplantation in children is frequent, occurring in 85% of the cases and may be the cause of severe neurologic complications. This can be due to multiple factors such as: rejection, recurrence of initial disease, steroid, etc. ... Among those factors, renal transplant artery stenosis (RTAS) must be identified as it may be cured by angioplasty. We report our experience in 18 children who had undergone angioplasty for RTAS. Angioplasty was performed under general anesthesia with 3F, 4F or 5F balloon catheters. Angioplasty was successful in 14 cases (77%) immediately (10 cases), progressively (2 cases) or after a successfully redilated recurrence (2 cases). Two of the 4 failures were due to technical problems, a successful surgical treatment was then performed. The 2 others failures were explained by a severe transplant rejection. The complications were rare: 1 femoral artery thrombosis and spasms of the intra renal arteries but without repercussion on the renal function. In our experience, angioplasty seems to be the treatment of choice in RTAS in children. However the indications must be carefully established taking in account other possible causes of hypertension in such patients.

Renal cysts are present in a wide variety of renal diseases, including those having a dysplastic nature and those of genetic origin. Genetic counseling requires clear differentiation between these types of cysts. This concept has made the classification of Potter useless because of the confusion it introduces between inherited diseases and developmental abnormalities. According to this classification, type I corresponds to autosomal recessive polycystic kidney disease (RPKD), type II to multicystic dysplasia, type III to autosomal dominant polycystic kidney disease (DPKD), and type IV to cystic dysplasia associated with urethral obstruction. The term "polycystic kidney disease" should be reserved for two hereditary cystic diseases, RPKD and DPKD, which are clearly distinct both by their modes of inheritance and by their pathologic characteristics. Both forms of polycystic disease may occur in children, but because the recessive form is much more prevalent, it is commonly called the "infantile form," whereas dominant polycystic disease is commonly known as the "adult form." The pediatric expression of these two forms and the problems of differential diagnosis will be examined.