1. ¹Service de Pédiatrie and Centre de Référence des Maladies Rénales Rares, Hospices Civils de Lyon and Université Lyon 1, Lyon, France
2. ²Service de Pédiatrie, Hôpital Pellegrin, Bordeaux, France
3. ³Service de Néphrologie Pédiatrique, Hôpital Necker Enfants-Malades, Paris, France
4. ⁴Service de Pédiatrie, Hôpital La Timone, Marseille, France
5. ⁵Service de Néphrologie Pédiatrique, Hôpital Universitaire des Enfants Reine Fabiola, Brussels, Belgium
6. ⁶Centre Perharidy, Roscoff, France
7. ⁷Service de Pédiatrie, Centre Hospitalier Universitaire Nord, Amiens, France
8. ⁸Service de Pédiatrie, Centre Hospitalier Universitaire, Angers, France
9. ⁹Clinique Pédiatrique, Centre Hospitalier Universitaire, Nantes, France
10. ¹⁰Service de Néphrologie Pédiatrique, Hôpital Robert Debré, Paris, France
11. ¹¹Service de Pédiatrie, Hôpital Gatien-de-Clocheville, Université François Rabelais, Tours, France
12. ¹²Service de Médecine de l'Enfant et de l'Adolescent, Hôpital Sud, Rennes, France
13. ¹³Laboratoire de Biochimie Pédiatrique, Centre de Biologie Est, Lyon, France

Correspondence: Pierre Cochat, Service de Pédiatrie, Centre de Référence des Maladies Rénales Rares, Hôpital Femme Mère Enfant, 59 boulevard Pinel, Bron cedex 69677, France. E-mail: pierre.cochat@chu-lyon.f

Received 6 March 2009; Revised 11 May 2009; Accepted 13 May 2009; Published online 1 July 2009.

Abstract

Primary hyperoxaluria type 1 results from alanine:glyoxylate aminotransferase deficiency. Due to genotype/phenotype heterogeneity in this autosomal recessive disorder, the renal outcome is difficult to predict in these patients and the long-term impact of conservative management in children is unknown. We report here a multicenter retrospective study on the renal outcome in 27 affected children whose biological diagnosis was based on either decreased enzyme activity or identification of mutations in the patient or his siblings. The median age at first symptoms was 2.4 years while that at initiation of conservative treatment was 4.1 years; 6 children were diagnosed upon family screening. The median follow-up was 8.7 years. At diagnosis, 15 patients had an estimated glomerular filtration rate (eGFR) below 90, and 7 children already had stage 2–3 chronic kidney disease. The median baseline eGFR was 74, which rose to 114 with management in the 22 patients who did not require renal replacement therapy. Overall, 20 patients had a stable eGFR, however, 7 exhibited a decline in eGFR of over 20 during the study period. In a Cox regression model, the only variable significantly associated with deterioration of renal function was therapeutic delay with a relative risk of 1.7 per year. Our study strongly suggests that early and aggressive conservative management may preserve renal function of compliant children with this disorder, thereby avoiding dialysis and postponing transplantation.