Microalbuminuria and hyperfiltration in subjects with nephro-urological disorders.

BACKGROUND: Microalbuminuria (MA) has been shown to be an early biomarker of renal damage. It is postulated that MA is the early result of hyperfiltration, which could evolve into glomerular sclerosis and renal failure if hyperfiltration is left untreated. We hypothesized that MA is a good indicator of hyperfiltration in children with kidney disorders, obviating the need to calculate the filtration fraction (FF). METHODS: A total of 155 children or young adults were prospectively included [42 single kidney (SK), 61 vesico-ureteral reflux, 23 obstructive uropathies, 29 other kidney diseases]. We measured inulin, para-aminohippuric acid clearances, FF and MA. Prediction of hyperfiltration was explored by studying the association between the FF and other variables such as urinary albumin (Alb), urinary albumin-creatinine ratio (ACR) and creatinine clearance. RESULTS: A significant but weak association between urinary Alb or ACR and FF was found in subjects with an SK (Spearman correlation coefficients 0.32 and 0.19, respectively). Multivariate analysis also showed that urinary Alb and ACR significantly predict FF only in subjects with an SK (r(2) = 0.17, P = 0.01 and r(2) = 0.13, P = 0.02, respectively). This holds true only in subjects with an SK and inulin clearance >90 mL/min/1.73 m(2) (r(2) = 0.41, P < 0.001). There was no association between creatinine clearance and FF. CONCLUSIONS: MA is not associated with FF in our subjects with nephro-urological disorders, except in those with an SK, where the association is weak, indicating that MA is due to other mechanisms than high FF and cannot predict hyperfiltration in such groups.

[Pyelonephritis treatment in children in 2007: current literature review]. / Traitement de la pyélonéphrite chez l'enfant en 2007.

Four studies, including two being published as an abstract, have recently demonstrated the feasibility of oral treatment of pyelonephritis in children, with no increased risk of treatment failure, early urinary tract re-infection, or renal scars. To do so, the pediatrician must ensure that: (1) the patient does not appear toxic, has no vomiting; (2) there is no known severe obstructive or refluxing uropathy and (3) parents are deemed to be adherent to the treatment. If these criteria are fulfilled, the pediatrician can start an oral treatment with a 3rd generation cephalosporine for 10 to 14 days. Ambulatory follow-up is crucial, and persistance of fever after 3 days is a reason for a new outpatient visit, additional or supplementary imaging studies (renal ultrasonography) and eventually a switch to intravenous treatment.