Renal function before and long after liver transplantation in children

Background. Renal dysfunction occurs in children with liver diseases and re nal function is often further impaired after orthotopic liver transplantati on (OLT). Inaccurate methods of determining renal function are used in many cases. We studied renal function with accurate methods before and repeated ly after OLT to analyze the effect of the underlying diseases, hypertension , and the immunosuppressive agents. Methods. A total of 46 children were studied both before and annually after OLT with clearances of inulin and paraaminohippuric acid to determine the glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Th e clearance of inulin was also compared with the formula creatinine clearan ce. Results. GFR and ERPF decreased from before to after OLT and decreased furt her during the first years after OLT. Patients with extrahepatic biliary at resia and with tumours showed higher GFR 1 year after OLT than those with m etabolic and miscellaneous dis. orders. No significant change in GFR of ind ividual patients occurred from the first to the last values determined at a round 1 and 6 years after OLT. No difference in renal function was seen dur ing the first years between patients treated with cyclosporine as compared to those treated with tacrolimus, but 4 years after OLT, the GFR was higher in the tacrolimus-treated patients. Patients on antihypertensive agents ha d lower GFR than the normotensive ones. There was no agreement between GFR, determined by clearance of inulin, and that calculated on the basis of ser um creatinine and the height of the patients. Conclusions. Renal function is reduced by OLT and decreases further during the first years after OLT. Patients with metabolic disorders and those on a ntihypertensive treatment have the lowest GFR. Determination of GFR by the formula creatinine clearance is inaccurate in children after liver transpla ntation.