[Current definition of urinary tract infection in the child]

Apport du dosage de la procalcitonine pour le diagnostic de pyélonéphrite aiguë de l'enfant

BACKGROUND

Acute pyelonephritis can induce parenchymal scarring. The aim of this study was to evaluate the usefulness of procalcitonin (PCT) to predict renal involvement in febrile children with urinary tract infection (UTI).

METHODS

In a prospective study serum PCT was measured and compared with others commonly used inflammatory markers in children admitted to the emergency unit with acute pyelonephritis. Renal parenchymal involvement was assessed by a (99 m)Tc-labeled dimercaptosuccinic acid (DMSA) renal scar performed in the first 3 days after the admission.

RESULTS

Among 42 enrolled patients, 19 (45%) had acute renal involvement (Group A) ; 23 (55%) (Group B) had normal DMSA scan (n = 16), or old scarring (n = 4) or various anomalies related to uropathy (n = 3). In group A, the mean PCT level was significantly higher than in the group B (5.4 ng/ml, vs 0.4 ng /ml, p < 10(-5)). In these 2 groups, mean C reactive protein (CRP) levels were 99.1 mg/l and 44.6 mg/l respectively (p < 0.001). For a level of serum PCT > or = 0.5 ng/ml, the sensitivity and specificity to predict the renal involvement were 100% and 87% respectively; for a level> or= 20 mg/l CRP had a sensitivity of 94% but a specificity of 30%.

CONCLUSION

Serum PCT levels were significantly increased in febrile children with UTI when acute renal parenchymal involvement was present. PCT seems a better marker than CRP for the prediction of patients at risk of renal lesions.

[Antibiotic treatment of acute pyelonephritis in the child]

Antimicrobial therapy for pyelonephritis in children must quickly eradicate the bacterial infection and prevent scars in renal parenchyma. Escherichia coli (E Coli) is found in about 90% of cases of acute pyelonephritis in outpatients, 40% of E coli being ampicillin-resistant. The present effective antibiotics are: 3rd-generation cephalosporines, amoxicillin-clavulanic acid association, and aminoglycosides. In the literature therapeutical guides are divergent concerning the route of administration (oral or i.v.), mono or bitherapy, the duration of the treatment (usually for 10 days), and the need for hospitalisation. The criteria for choice are risk factors such as: very young age (< 6 months), fever with toxic symptoms, vomiting, dehydration, uropathy, and poor compliance. There are few long term studies which compare two, therapeutic regimens and no evaluation of the frequency of consequent chronic pyelonephritis in adult age has taken place. Recent data suggest that an oral sequential treatment may permit a shorter hospital stage. The trend is chiefly to do bona fide recommendations more than elaboration of a true consensus.