Renal focal tubulointerstitial fibrosis with short bowel syndrome: report of a case

We report a male patient with short bowel syndrome (SBS) and renal focal tubulointerstitial fibrosis (FTIF). Seven years after surgery, he was introduced to us due to severe undernutrition, an impairment of growth hormone (GH) secretion, and abnormally low levels of plasma citrulline and arginine at 11 years 7 months of age, just before nutritional support using total parenteral nutrition (TPN) was begun. Thereafter, the support was changed to home TPN with GH supplementation. After an improvement of the disorders, GH was stopped at 17 years 3 months of age. However, hyperuricemia appeared and a renal biopsy revealed FTIF at 20 years of age. Home TPN was continued twice a week because the plasma arginine level was still low. His follow-up biopsy at 23 years of age showed morphometric amelioration. Arginine deficiency following SBS may be associated with FTIF. The cause of hyperuricemia after SBS therefore needs to be investigated in detail.