Abstract
The residual renal function is often discussed in patients with a solitary kidney, such as those with a multicystic dysplastic kidney or after nephrectomy. We analyzed the changes in the serum creatinine (sCr) and serum cystatin C (sCysC) levels in six patients (four males and two females) who were receiving follow-up for a solitary kidney, and examined their renal function. As a result, the sCysC level was found to be higher than normal, while the sCr was within the normal range. Furthermore, we found a difference in the estimated glomerular filtration rate (eGFR), as well as a declining trend in the eGFR obtained from sCysC, especially beginning around the time of puberty. For the follow-up of a pediatric patient with a solitary kidney, we believe that a more accurate evaluation of the renal function will be possible by using a combination of the commonly-used sCr and sCysC values, which are less susceptible to changes resulting from the age and body type of the patient.
