Serial estimation of glomerular filtration rate in children after renal transplant

Evaluation of serial monthly estimated glomerular filtration rate (eGFR) ma y be useful for studying pediatric renal allograft outcome. To determine th e validity of this approach, we reviewed our single-center experience in pe diatric renal transplant recipients to determine the effect of risk factors for renal allograft failure on eGFR. Clinical parameters recorded monthly through 5 years post transplant allowed serial assessment of eGFR. Monthly clinical data included height, weight, serum creatinine, cumulative number of acute rejection episodes, cyclosporine dose, and cyclosporine trough lev els. From these data, eGFR was calculated monthly for each patient using th e Schwartz formula. Time post transplant was grouped in 6-month intervals a nd plotted against mean eGFR to compare eGFR in patients grouped by demogra phic and clinical factors; 1,786 monthly data sets from 6 months post trans plant (n=76 patients) to 5 years post transplant (n=25 patients) were analy zed. Overall mean eGFR from 6 months to 1 year was 75 ml/min per 1.73 m(2) and from 4.5 to 5 years 46 ml/min per 1.73 m(2), eGFR was lower at all time intervals for recipients of cadaver versus living-related donor grafts, an d patients with greater than or equal to 1 versus 0 acute rejections (P<0.0 1). After 1 year, eGFR was lower in black patients compared with white or H ispanic patients (P<0.01). Cy closporine dose greater than 5 mg/kg per day was associated with better early and worse late graft function. These resul ts are similar to those reported in multi-center studies using the outcome variable of graft failure and suggest that serial eGFR may be valid as an o utcome variable to study chronic renal allograft dysfunction in children.