Biomedical subjects
Publications and source records attributed to P Cochat.
Beneath its apparent simplicity, the urinary dipstick is one of the most important advances in the current diagnosis procedure in pediatric nephro-urology. This test represents the best way to approach the most frequent conditions, i.e., urinary tract infection, hematuria and proteinuria. It therefore offers reliable information at a very low financial cost.
Renal scarring is the main long term complication of acute pyelonephritis in children. The prevalence rate is hazardous since data from the literature are confusing with respect to reflux nephropathy, chronic pyelonephritis and renal hypoplasia. The pathology of such lesions consists in focal interstitial fibrosis. When the first pyelonephritic attack occurs during infancy, renal growth may be compromised. The current approach of renal scar assessment is based on dimercaptosuccinic acid (DMSA) scan. Bilateral extensive lesions may be responsible for altered glomerular filtration rate (GFR) and/or arterial hypertension. The management of overt scarring is conservative and careful prevention must be based on early and aggressive treatment of acute pyelonephritis.
BACKGROUND: Since renal transplantation is known to be the best choice for the growing child with end-stage renal failure, we prospectively evaluated early and late graft function in transplanted children. POPULATION AND METHODS: The study included 78 children (32 girls, 46 boys) 10.4 +/- 0.6 years at the time of transplantation. Renal investigations were performed at 3, 6 and 12 months post-transplantation and yearly thereafter. Inulin clearance was used to evaluate the glomerular filtration rate (GFR), and the reabsorption rates of Na, P and Ca were measured concomitantly. RESULTS: The overall adjusted GFR was approximately 70 mL/min/1.73 m2 and remained unchanged during the first 5 years post-transplantation. In the mean time the absolute GFR increased significantly, suggesting a remaining capacity for compensatory hypertrophy of the transplanted kidney. Renal function was significantly influenced by the number of rejection episodes during the first 2 years post-transplantation but no correlation was found between GFR and the number of HLA mismatches or the use of preemptive transplantation.
BACKGROUND: Nephrogenic rests generally constitute precursor lesions of Wilms' tumor. We report a case of right nephroblastomatosis with dysmorphic features. CASE REPORT: An enlargement of the right kidney was incidentally discovered in a 1-year-old girl with dysmorphic features but normal psychomotor development. Combined ultrasonography and computerized tomography (CT) scan showed right cortical nephroblastomatosis. Chemotherapy using actinomycin D and vincristin was successful; however, an hyperechogenic nodule was subsequently found, necessitating a right nephrectomy. CONCLUSION: The relationship between nephroblastomatosis and Wilms' tumor is discussed. This case report reminds us of the importance of a long-term follow-up including echography and CT scan in cases of nephroblastomatosis.
BACKGROUND: Recombinant human growth hormone (rhGH) is an anabolic hormone promoting protein synthesis in various tissues. Therefore, changes in body composition may be expected during rhGH treatment. METHODS: We studied changes in body composition during two years of rhGH treatment in 21 children after at least one year with a functioning renal transplant. The mean +/- SD age was 12.9+/-2.5 years at the start of rhGH therapy. A whole body, dual energy X-ray absorptiometry (DEXA) exam was performed before the initiation of rhGH therapy (T0), and was repeated at one and two year intervals after initiation of the therapy (T1 and T2, respectively). RESULTS: Lean body mass increased by a median of 0.48 SDS during the first year of treatment (P = 0.022), and the median increase during two years of therapy was 0.36 SDS (P = 0.061). On the contrary, the median fat body mass decreased by 2.17 SDS during the T0 to T1 period (P = 0.04) and by 1.99 SDS during the T0 to T2 period (P = 0.055). The index for fat body mass/lean body mass (FBM/LBM) decreased by a median of 5.3% during T0 to T1 (P < 0.001), however, a slower but still significant decrease by a median of 4.2% was noted at T2 (P < 0.05). Bone mass content did not change significantly during rhGH treatment. The medians in caloric and protein intakes were stable during rhGH treatment. CONCLUSION: A significant increase of lean body mass and a decrease of fat body mass was noted during rhGH therapy in children after renal transplantation.
Autosomal recessive Alport syndrome is a progressive hematuric glomerulonephritis characterized by glomerular basement membrane abnormalities and associated with mutations in either the COL4A3 or the COL4A4 gene, which encode the alpha3 and alpha4 type IV collagen chains, respectively. To date, mutation screening in the two genes has been hampered by the lack of genomic structure information. We report here the complete characterization of the 48 exons of the COL4A4 gene, a comprehensive gene screen, and the subsequent detection of 10 novel mutations in eight patients diagnosed with autosomal recessive Alport syndrome. Furthermore, we identified a glycine to alanine substitution in the collagenous domain that is apparently silent in the heterozygous carriers, in 11.5% of all control individuals, and in one control individual homozygous for this glycine substitution. There has been no previous finding of a glycine substitution that is not associated with any obvious phenotype in homozygous individuals.
BACKGROUND: The donor, i.e. adult or paediatric, might influence the outcome of the graft function. METHODS: The glomerular filtration rate (GFR) of 120 transplanted children (47 girls) aged 10.4+/-4.6 years (0.7-17.2) was prospectively assessed over a 5-year period. The patients were divided into two groups according to the age of donor: adult (donor age > 18 years; n=33) and paediatric (donor age < 18 years; n=87). GFR was assessed by inulin clearance at 3, 6 and 12 months and yearly thereafter. RESULTS: The average GFR was stable in the range of 70 ml/min/1.73 m2 for the whole follow-up period. The adjusted GFR in adult graft recipients was significantly higher at 3 months post-transplantation: 80.6+/-36.9 vs 65.1+/-22.0, P=0.02. However, from the second year post-transplantation, the adjusted GFR in paediatric graft recipients became significantly higher than that of adult graft recipients. Such results could be due to an improvement in the absolute GFR (ml/min) of paediatric graft recipients with time (P=0.0001) whereas that of the adult graft recipients remained stable despite the children's growth. CONCLUSIONS: The adjusted GFR of adult graft recipients was significantly higher than that of paediatric graft recipients in the early post-transplant period. In the long-term, a progressive decrease in adjusted GFR was noted in adult graft recipients. On the one hand, this may be due to a functional adaptation and/or inadequate compensatory growth of the graft. On the other hand, the absolute GFR of paediatric graft recipients increased, suggesting an ongoing capacity for growth and/or compensatory hypertrophy after child-to-child renal transplantation.
Explore the source record for details and available documents.
Urolithiasis and/or nephrocalcinosis due to hereditary diseases are a rare event which must be kept in mind of physicians who take care of children (10 to 40% of all causes of lithiases) as well as of adults (less than 15% of all causes of lithiases) since a specific management is usually required. The most frequent inborn disorders are idiopathic hypercalciuria, distal tubular acidosis, cystinuria and hyperoxaluria. Stone formation is always secondary to an increased urine concentration of promotors, i.e. calcium, oxalate, phosphate, cystine, xanthine. One of the most informative diagnosis investigation is infrared spectrophotometry which can identify stone composition. When such a technique is not available, biochemical investigations should be adapted to both personal and family history. In addition to high fluid intake (2 to 3 L/m2/24 h) sometimes associated with alcalinisation, the management of hereditary stone disease requires specific procedure. In all cases, the long-term renal prognosis is related to both primary disease and therapeutic compliance.
The present study compares the outcome of 40 children (39%) transplanted without prior dialysis, i.e., preemptive transplantation (PET), with 63 children (61%) transplanted after a variable duration of dialysis, i.e., pretransplantation dialysis (PTD). The two groups were matched for recipient and donor age and for immunological risk factors. There was no statistical difference in the time to first acute rejection episode nor in the number of acute rejection episodes during the 1st year after renal transplantation. In the PET group, 78% of the recipients received blood transfusion versus 92.5% in the PTD group (P < 0.05), and the average number of blood units per patient was 3.2 and 7.8, respectively (P < 0.05). Arterial hypertension was found in 55% of the patients in the PET group versus 73% in the PTD group (P < 0.05). The number of functioning grafts at the end of the study period was 87.5% in the PET group and 73% in the PTD group (NS). The major cause of graft failure was vascular thrombosis in the PET group (3/5) and chronic allograft rejection in the PTD group (10/17). In the PET group, the actuarial graft survival rate was 100%, 84%, 81%, and 76% at 1, 3, 5, and 7 years, which was not statistically different from the PTD group at 1, 3, and 5 years (98%, 91%, and 73%, respectively) but there was a significantly lower graft survival (59%) after 7 years in the PTD (P < 0.05). The 7-year actuarial patient survival rate was 97% in the PET group and 90% in the PTD group (NS). In the PTD group, children on dialysis for less than 1 year (group 1, n = 25) were compared with those on dialysis for more than 1 year (group 2, n = 38). Arterial hypertension was noted in 40% of patients from group 1 and 65% from group 2 (P < 0.05); there was no significant difference in graft loss rate. In conclusion, these results confirm PET as the preferred approach rather than PTD in children who need renal replacement therapy.
A 16-day-old girl with Waardenburg syndrome type 1 presented with a right multicystic dysplastic kidney (MDK) and hydronephrosis in the left kidney. To our knowledge, such an association has not yet been reported and should be added to the list of MDK-associated genetic syndromes.
There are very few available child quality of life questionnaires. We describe here a French questionnaire (AUQUEI) which consists of a structured format scale (26 items). The first part of the questionnaire studies child satisfaction. Response levels are measured by checking faces expressing different emotional states. The validation is satisfactory, and the questionnaire is able to differentiate healthy children from sick children (HIV positive). A second part of the questionnaire focuses on the child's own quality of life, and is based upon open-ended questions. This second approach allows to broaden the structured format scale and improves the understanding of the child's quality of life. It constitutes a necessary complement to the first part as it avoids using mechanically adult-specific concepts for children. We also found it to be sensitive enough to distinguish sick children from healthy ones. The AUQUEI questionnaire with its two complementary parts appears to be a potentially valuable tool to better understand the experience of sick children, in the various aspects of their life, and to follow their evolution.
BACKGROUND: Most children with Wilms tumour recover after nephrectomy, chemotherapy and sometimes radiotherapy. It is therefore important to assess their long-term renal function. POPULATION AND METHODS: Thirty-three patients with Wilms tumour experienced unilateral nephrectomy between 1986 and 1993: three were excluded; 23 were staged as grade I, one at grade II, two at grade III and four at grade IV. They were treated with SIOP 6 and SIOP 9 protocols. The results were compared to five controls who underwent unilateral nephrectomy including three for renal trauma. The glomerular filtration rate (GFR) was measured by inulin clearance and the renal plasma flow (RPF) by para-amino-hippuric acid clearance. RESULTS: The mean age at nephrectomy was 3.4 +/- 2.5 years (median: 3, range: 0.2-10.6) and the duration of follow-up was 4.6 +/- 3.1 years (median: 4.5, range: 1-8.5), the GFR was 93 +/- 13 mL/min/1.73 m2 (median: 93, range: 73-130), the RPF was 441 +/- 85 mL/min/1.73 m2 (median: 453, range: 236-650) and the filtrated fraction (FF) was 0.21 +/- 0.03 (median: 0.20, range: 0.18-0.31). The difference in renal function between patients and controls was not significant (GRF: 86 +/- 12 mL/min/1.73 m2, RPF: 486 +/- 185 mL/min/1.73 m2, FF: 0.22 +/- 0.03). The electrolyte reabsorption rate was normal and none of the patients suffered from arterial hypertension. Fourteen children had urinary albumin: creatinine ratio > 2 g/mol. When comparing patients according to the duration of follow-up after nephrectomy (< 4 years vs > 4 years), the renal function was not statistically different. The age at nephrectomy (< 2 years vs > 2 years) did not increase the risk of renal impairment. CONCLUSION: Children with Wilms tumour who were treated with nephrectomy and non-nephrotoxic drugs (actinomycin, vincristine, epiadriamycin) have a good long-term renal outcome. It is speculated that systematic renal investigation should be limited to those children with increased microalbuminuria and/or elevated blood pressure.
Determination of serum oxalate concentration is important for the diagnosis and monitoring of hyperoxalurias, and extends to patients with all types of renal disease. Approximately 5 to 10 ml of blood is required for each test by conventional methods, and the test is not adapted for use in children. We developed a highly sensitive method that limits the volume of blood required for the test. This new and sensitive tool to detect H2O2 can be successfully substituted for the conventional, and expensive, colorimetric reaction to accurately analyze oxalate concentration.
Explore the source record for details and available documents.
BACKGROUND: The main causes of secondary hyperparathyroidism in end-stage renal disease are supposed to disappear after renal transplantation thanks to good graft function, but the regression of the glandular hyperfunction often takes a long time. The aim of the present work was to evaluate the possible role of the duration of dialysis in the outcome of parathyroid function after renal transplantation in children. METHODS AND RESULTS: The study was based on data from calcium-phosphate metabolism before and over a 90-day period after renal transplantation in 41 children. Patients were divided into: group I, pre-emptive transplantation (n = 17), and group II, dialysis prior to transplant (n = 24). Groups were matched for age, sex, causes of chronic renal failure, duration of ischaemia time and immunosuppressive treatment. No significant difference was noted with respect to all assessments of serum Ca, P, 25OHD and Mg between the two groups. On the other hand, PTH was statistically different both before and after renal transplantation, while glomerular filtration rate and tubular function tests were identical. CONCLUSION: It is therefore suggested that children submitted to pre-emptive transplantation achieve normal PTH levels sooner than dialysed children, which might denote an 'inappropriate PTH secretion' in the latter group. Skeletal resistance to PTH, low density of calcitriol receptor in parathyroid and/or nodular rather than diffuse hyperplasia of the gland could be speculated to explain such conclusions.
Body composition using standard anthropometric methods and dual-energy X-ray absorptiometry (DEXA) was determined in a cross-sectional study among 26 pediatric renal transplant recipients. At the same time, spiroergometry exam, pulmonary function tests, dynamometry and tremometry exams were performed in all patients. Fat body mass obtained by DEXA correlated inversely with maximal physical load during spiroergometry exam (r2 = 0.51, p = 0.0001). The study demonstrates good tolerance of increased physical load in children after renal transplantation. An inverse relationship was found between fat body mass and physical performance. Exercise training programs for children after renal transplantation are therefore suggested.
Hypomelanosis of Ito is a rare neuroectodermal syndrome characterized by specific cutaneous lesions and frequent musculoskeletal or visceral involvement. We report on a child with an original nephritis with major segmental abnormalities of the glomerular basement membrane. Such an association might not be fortuitous and glomerular involvement might be underestimated in hypomelanosis of Ito.