ESPN 53rd Annual Meeting

ESPN 2021


 
The spectrum of kidney function alterations in adolescent with a solitary functioning kidney.
MATHILDE GRAPIN 1 NATHALIE BIEBUYCK 1 FRANÇOIS GAILLARD 2 MELISSA OULD-RABAH 4 CAROLE HENNEQUIN 1 ROMAIN BERTHAUD 3 GUILLAUME DORVAL 3 THOMAS BLANC 3 NICOLAS GARCELON 3 FRANK BIENAIMé 1 OLIVIA BOYER 1

1- SERVICE DE NéPHROLOGIE PéDIATRIQUE, CENTRE DE RéFéRENCE MARHEA, HôPITAL NECKER-ENFANTS MALADES, ASSISTANCE PUBLIQUE-HôPITAUX DE PARIS, PARIS FRANCE
2- UNIVERSITé DE PARIS, INSTITUT NECKER-ENFANTS MALADES INSERM U1151, PARIS, FRANCE
3- INSTITUT IMAGINE, INSERM U1163, UNIVERSITé DE PARIS, PARIS, FRANCE
4- SERVICE DE PHYSIOLOGIE , HôPITAL NECKER-ENFANTS MALADES, ASSISTANCE PUBLIQUE-HôPITAUX DE PARIS, PARIS, FRANCE
 
Introduction:

 A precise assessment of glomerular filtration rate is key to delineate the care of children with a solitary functioning kidney (SFK). Data regarding measured GFR (mGFR) in this population is restricted to a single study of 77 individuals, which suggested that a GFR estimation (eGFR) method based on creatinine and cystatin C (eGFR-CKiD2) performed better than Schwartz’s equation (eGFR-Schwartz).

Material and methods:

 We measured GFR in 210 consecutive adolescents (7 to 22 years old) with a SFK referred to our institution between 2014 and 2019 and in 43 young candidates to kidney donation (18 to 25 year old). We compared the distribution of mGFR in both groups and determined the factors associated with reduced mGFR in adolescent with a SFK.  We further compared different eGFR formulas with mGFR and assessed the association of mGFR and eGFRs with PTH and FGF23, two early indicators of GFR reduction.

Results:

 While adolescent with a SFK had a similar median mGFR than healthy controls (103±24ml vs 107±12 ml/min/min/1.73m2), the fraction of individuals with a mGFR below 90ml/min/1.73m2 was higher in patients with SFK (23% vs 5 % in controls; P=0.005). Multiple linear regression identified older age, ipsilateral abnormalities of the urinary tract, lack of compensatory hypertrophy and treated hypertension as independent factors associated with reduced mGFR. eGFR-Schwartz showed a smaller bias [95% confidence interval (95%CI): 3 to 7] than other eGFR. mGFR showed a stronger correlation with PTH (r=0.1 vs r=0.04) and FGF23 (r=0.05 vs r=0.03) than eGFR-Schwartz.

Conclusions:

SFK is not a benign condition, since 20% of the patients display altered renal function. Our results raise caution regarding the use of the cystatin-based equation. mGFR shows a better ability than eGFR-Schwartz to discriminate patients showing early homeostatic adaptation to GFR reduction.