Prognostic value of urinary TGF-ß1 in hemolytic uremic syndrome: A pilot study.

BACKGROUND: Transforming growth factor ß1 (TGF-ß1) is the main profibrotic cytokine. Its urinary excretion reflects intrarenal production; thus, we conjectured that it is elevated during hemolytic uremic syndrome related to Shiga-toxin-producing Escherichia coli (STEC-HUS). In this pilot study, we explored the ability of baseline TGF-ß1 excretion (exposure variable) to predict renal prognosis at 6 months (outcome variable). In a secondary investigation, we compared changes in cytokine levels during the study period between patients with opposite renal outcomes. METHODS: Urinary TGF-ß1 concentrations were measured prospectively in 24 children with STEC-HUS on admission, and at 15, 30, 60, 90, and 180 days. Normal values were obtained from 20 healthy subjects. RESULTS: Baseline TGF-ß1 concentrations predicted renal outcomes with an area under the curve of 1 (95%CI 0.85-1; sensitivity 100%, specificity 100%) with the best cutoff level >293.7 pg/mg uCr. All patients with high TGF-ß1 levels developed persistent renal impairment, unlike none with low concentrations (4/4 vs. 20/0 respectively, P = 0.0001). The latter had higher cytokine levels (P < 0.05) at each time point without reaching normal concentrations (<45 pg/mg uCr). CONCLUSIONS: Baseline urinary TGF-ß1 levels accurately predicted short-term renal outcomes in STEC-HUS children, and cytokine excretion during the first 6 months after diagnosis was higher among those with worse evolution. Larger studies are needed to validate these findings.

Pre- and post-treatment urinary tract findings in children with nephrogenic diabetes insipidus.

BACKGROUND: Nephrogenic diabetes insipidus (NDI) is characterized by the kidney's inability to concentrate urine, which causes intense polyuria that may lead to urinary tract dilation. We report the morphological findings of the urinary tract in ten boys with NDI specifically addressing the presence and changes of urinary tract dilation during treatment. DIAGNOSIS/TREATMENT: Patients were diagnosed at a median age of 1.6 years (range, 0.16-6.33 years) and treated with a low osmotic diet, hydrochlorothiazide-amiloride and indomethacin, which decreased the diuresis from a median of 10.5 ml/kg/h to 4.4 ml/kg/h (p < 0.001). Three patients showed normal renal ultrasound before treatment until last control, while the remaining seven showed urinary tract dilation. In this second group, dilation was reduced with treatment in four patients and disappeared in the remaining three. Children without dilation or in whom the dilation disappeared were diagnosed and treated earlier than those with persistent dilation (median 1.66 versus 4.45 years, respectively). After a median of 10.4 (range, 2.3-20.3) years of follow-up, no patients showed urological complications. CONCLUSIONS: Medical treatment of the disease improved the dilation in all cases, preventing its potential complications. Regardless of the good outcome of our patients, periodic urologic follow-up is recommended in NDI patients.

Additive antiproteinuric effect of enalapril and losartan in children with hemolytic uremic syndrome.

BACKGROUND: Angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor blockers decrease postdiarrheal hemolytic uremic syndrome (D + HUS) sequelar proteinuria. However, proteinuria may persist in some patients. In nephropathies other than D + HUS, an additive antiproteinuric effect with coadministration of both drugs has been observed. METHODS: To assess such an effect in D + HUS, 17 proteinuric children were retrospectively studied. After a median period of 1 year post-acute stage (range 0.5-1.9) patients received enalapril alone for a median of 2.6 years (range 0.33-12.0) at a median dose of 0.4 mg/kg/day (range 0.2-0.56). As proteinuria persisted, losartan was added at a median dose of 1.0 mg/kg/day (range 0.5-1.5) during 2.1 years (range 0.5-5.0). RESULTS: The decrease in proteinuria with enalapril was 58.0 %, which was further reduced to 83.8 % from the initial value after losartan introduction. The percentage of reduction was significantly greater with the association of both drugs (p = 0.0006) compared with the effect of enalapril exclusively (p = 0.023). Serum potassium, glomerular filtration rate, and blood pressure remained unchanged. CONCLUSIONS: Our results suggest that adding losartan to persisting proteinuric D + HUS children already on enalapril is safe and reduces proteinuria more effectively. Whereas this effect is associated with long-term kidney protection, it should be determined by prospective controlled studies.

Effect of diet, enalapril, or losartan in post-diarrheal hemolytic uremic syndrome nephropathy.

Proteinuria is the main indicator of renal disease progression in many chronic conditions. There is currently little information available on the efficacy, safety, and individual tolerance of patients with post-diarrheal hemolytic uremic syndrome (D+ HUS) nephropathy to therapies involving diet, enalapril, or losartan. A multicenter, double-blind, randomized controlled trail was conducted to evaluate the effect of a normosodic-normoproteic diet (Phase I) and the effect of normosodic-normoproteic diet plus enalapril (0.18-0.27 mg/kg/day) or losartan (0.89-1.34 mg/kg/day) (Phase II) on children with D+ HUS, normal renal function, and persistent, mild (5.1-49.9 mg/kg/day) proteinuria. Dietary intervention reduced the mean protein intake from 3.4 to 2.2 mg/kg/day. Of 137 children, proteinuria normalized in 91 (66.4 %) within 23-45 days; the remaining 46 patients were randomized to diet plus placebo (group 1, n = 16), plus losartan (group 2, n = 16), or enalapril (group 3, n = 14). In groups 1, 2, and 3, proteinuria was reduced by 30.0, 82.0, and 66.3%, respectively, and normalized in six (37.5%), three (81.3%), and 11 (78.6%) patients, respectively (χ(2)= 8.9, p = 0.015). These results suggest that: (1) a normosodic-normoproteic diet can normalize proteinuria in the majority of children with D+ HUS with mild sequelae, (2) the addition of enalapril or losartan to such dietary restrictions of protein further reduces proteinuria, and (3) these therapeutic interventions are safe and well tolerated. Whether these short-term effects can be extended to the long-term remains to be demonstrated.

Levels of urinary transforming growth factor beta-1 in children with D+ hemolytic uremic syndrome.

About 25-50% of survivors of the acute phase of postdiarrheal hemolytic uremic syndrome (D+ HUS) develop chronic renal disease. Transforming growth factor beta-1 (TGFbeta-1) is the main fibrogenic growth factor in humans, and there is a significant correlation between its levels and the grade of interstitial fibrosis in chronic nephropathies. We hypothesized that increased urinary TGFbeta-1 may be an early indicator of sequelae in D+ HUS patients who show no sign of renal damage as determined by conventional diagnostic tests. We therefore compared the levels of TGFbeta-1 in urine collected from healthy controls (HC) (n = 18) with that from patients with a past history of D+ HUS (n = 39). We found that TGFbeta-1 excretion was significantly higher (p < 0.001) in the patient group (median level 73 pg/mg creatinine) than in the HC (median level 28 pg/mg creatinine). TGFbeta-1 excretion did not correlate with age, white blood cell count, length of oligoanuric period, maximum creatinine at the acute stage, or length of the follow-up. Since TGFbeta-1 excretion may reflect ongoing renal tissue damage, our results emphasize the need for the lifelong follow-up of patients with a past history of D+ HUS, even those showing apparent recovery. Long-term monitoring of this cohort is necessary to determine the clinical utility of our findings.

Long-term growth of children with nephrogenic diabetes insipidus.

Primary nephrogenic diabetes insipidus (NDI) is a genetic, chronic disease characterised by lack of distal renal tubule to antidiuretic hormone. The condition produces polyuria, polydipsia, and consequently, reduced caloric intake and growth failure. There is very scarce information on physical growth of affected children. The objective of the paper is to describe long-term growth of 14 patients from 11 families, studied retrospectively and followed for 3-16 years (median 11.6 years). Diagnosis was made on the basis of clinical and laboratory data and concentration test under pitressin. Patients were treated with indomethacin, thiazides, and amiloride. Weight and standing height was measured periodically at the Laboratory of Anthropometry, following standardised techniques. Information was obtained from clinical notes. The majority of children grew below the third centile of local standards, and many showed improvement of weight, height, and body mass index (BMI) over time. Mean height, weight, and BMI gain during follow-up was 1.72, 1.06, and 1.46 standard deviations (SDs), respectively. Three children who did not adhere to treatment showed growth delay. Height gain during the first 2 years of follow-up was inversely associated with height deficit at diagnosis. Further studies on growth at adolescence and in different mutations are recommended.

[Hemolytic uremic syndrome (HUS): medical and social costs of treatment]. / Evaluación de costos directos e indirectos del tratamiento del síndrome urémico hemolítico en sus distintas etapas evolutivas.

Hemolytic Uremic Syndrome (HUS) is the most frequent cause of renal failure in children, and the second cause of renal transplant. Argentina has the highest incidence of the world. Direct and indirect costs of HUS in its different clinical phases were studied. A retrospective review of all clinical notes of patients attending the hospital during the period 1987-2003 was carried out. Cost of every medical intervention, including diagnostic and therapeutic actions were calculated by the Hospital Department of Costs, according to two criteria: cost per process and cost per patient (considering total processes received each). Indirect costs were estimated according to guidelines established by the National Institute of Statistics and Census (INDEC): 1) family costs 2) social expenses afforded by the state, 3) cost of health services. Out of a total sample size of 525 patients, 231 clinical notes of children were selected and studied. The direct cost per patient in the acute period was US dollar 1 500, the total direct cost of care for each patient per year was US dollar 15 399,53; indirect costs per patient and for all year were US dollar 3 004,33 and US dollar 7 354,98 respectively. Total costs during 2005 per patient and per year was US dollar 17 553,39 and US dollar 2 170 477,37 respectively. Our study provides valuable information not only for purposes of health care planning, but also for helping authorities to set priorities in health, and to support the idea of developing preventive actions in a totally preventable condition in Argentina.

Two different therapeutic regimes in patients with sequelae of hemolytic-uremic syndrome.

Renal disease is the most important long-term complication of hemolytic-uremic syndrome (HUS). A comparative study of renal function was carried out in two groups of patients. Group 1 included 19 children followed for a median of 11 years, 1960-1980, with a low-sodium diet, antihypertensive drugs, and a restricted protein intake in the end stage of renal disease. Group 2 included 26 children treated for a median of 9 years, 1988-2002, on a low-sodium diet, early restriction of protein intake according to recommendations, and angiotensin converting enzyme inhibitors (ACEi). Long-term renal function was assessed by the inverse of the plasma creatinine concentration (1/[Cr]) over time. Linear regression lines were fitted to individual values of 1/[Cr] for each child. Regression coefficients of children in group 1 were all negative, ranging from -0.031 to -0.00043; 7 were significantly different from zero, indicating a linear fall in renal function over time. In contrast, children from group 2 had 11 negative slopes (only 1 significant) and 15 positive slopes, ranging from 0.17893 to -0.3899. Fisher's exact test showed that group 1 had significantly more children with negative slopes than group 2. This comparatively better long-term outcome of renal function in children under contemporary treatment was probably associated with early restriction of protein and use of ACEi.

Diálisis peritoneal en pediatría / Peritoneal dialysis in pediatric

Diálisis peritoneal: Desarrollo, Fundamentos, Utilidad clínica, Complicaciones y Técnica.- Efectividad del peritoneo como membrana dializante