Introduction: While impaired renal function has been reported among adult patients with intestinal failure (IF), the data on children is scarce. We assessed renal function in pediatric-onset IF.

Methods: Medical records of 80 patients (45 boys) with pediatric onset IF either due to short bowel syndrome (SBS, n=62) or primary motility disorder (n=18), and a history of parenteral nutrition (PN) dependency at least for one month were reviewed. Renal function at the most recent follow-up was evaluated using plasma creatinine, cystatin C and urea concentrations and estimated glomerular filtration rate (eGFR) calculated with the CKID Schwartz (utilizing cystatin C) equation^[1] or, if age > 18, the CKD-EPI Creatinine-Cystatin equation. Renal function was classified as normal when eGFR was above age-appropriate limits^[2].

Results: Twenty-one (26%) patients had decreased eGFR (Table).  At last follow-up, their median age was 4.7 years and PN duration 3 years. Of them, 12 (57%) had been weaned off PN at the time. They had higher cystatin C (p<0.001), creatinine (p=0.04) and urea concentrations (p<0.001) than those with preserved eGFR. None of the patients with decreased eGFR had signs of structural abnormalities, nephrocalcinosis or increased echogenicity in renal ultrasound. Patients with decreased renal function had significantly longer total duration of PN (36 months versus 10 months, p=0.045) and shorter percentage of the age-adjusted small bowel length remaining (23% versus 35%, p=0.032) when compared to patients with preserved renal function. No other predisposing factors for decreased eGFR were identified. Of the eight patients having received (n=5) or being listed (n=3) for intestinal transplant, five had decreased eGFR at listing.

Conclusions: Patients with pediatric onset IF are at significant risk of impaired renal function, which associates with PN duration and SB anatomy. Even after weaning off PN, patients with long-lasting PN and ultra-short SB should be routinely screened for decreased renal function.  

[1] Schwartz GJ, Schneider MF, Maier PS, et al. Improved equations estimating GFR in children with chronic kidney disease using an immunonephelometric determination of cystatin C. Kidney Int. 2012;82:445-453
[2] Schwartz GJ, Munoz A, Schneider MF, et al. New equations to estimate GFR in children with CKD. J Am Soc Nephrol. 2009;20:629-637