Proteinuria in pediatric renal transplant recipients during the first 60 post-transplant days

Abstract: Although normative values of post-transplant proteinuria have been reported in adults, data for pediatric renal transplant recipients have not been previously published. We hypothesized that pediatric renal transplant recipients achieve normal urinary protein to creatinine (UProt/UCr) ratios (<0.2) by 60 days post-transplant in the absence of early recurrent disease. Retrospective chart review of 108 consecutive pediatric renal transplant recipients at Stanford University was performed. Thirty-two (30%) patients who were eligible had ≥1 UProt/UCr ratio obtained during the first 60 post-transplant days. Mean age at transplant was 13.9 ± 4.2 yr. UProt/UCr ratios were grouped by week post-transplant for quantile analysis. Mean weekly UProt/UCr values were not lower than 0.2 until the ninth post-transplant week. No difference in post-transplant proteinuria existed between nephrectomized and non-nephrectomized transplant recipients. Experience with a single patient with proven focal segmental glomerulosclerosis (FSGS) recurrence suggests that normative UProt/UCr data may be useful in early identification of patients experiencing disease recurrence. Univariate correlations demonstrated that UProt/UCr negatively correlated with serum albumin levels (−0.415, p < 0.0001) and days post-transplant (−0.531, p < 0.0001). Independent of primary diagnosis, proteinuria persists throughout the first 60 days in most pediatric renal transplant patients, decreasing relative to time post-transplant.