Pathological evaluation of steroid withdrawal in pediatric renal transplant recipients

Protocol biopsies were performed to detect and treat subclinical rejection in eight living related pediatric renal transplant recipients who had been withdrawn from steroids. Low-grade tubulitis (t1) and mononuclear cell interstitial inflammation (i1), typical of borderline rejection and low-grade interstitial fibrosis (ci1), and tubular atrophy (ct1), characteristic of chronic rejection, appeared frequently in protocol biopsies more than 3 yr after steroid withdrawal. In contrast, early-type glomerulitis (g), allograft glomerulopathy (cg), arteriolar hyaline thickening (ah), intimal arteritis (v), and fibrous intimal thickening (cv) were not observed in protocol biopsies after steroid withdrawal. Low-dose pulse therapy (methylprednisolone (MP) 250 or 500 mg/d for 3 d) was administered to five patients for borderline and/or acute grade 1a rejection, as determined by protocol biopsies in the absence of clinical rejection. No oral steroids were administered. Renal function in all patients remained satisfactory, without proteinuria, in follow-up periods ranging from 22 to 68 months after steroid withdrawal. Of the eight patients, three grew to almost normal height (> mean -2SD) and four exhibited catch-up growth. Thus, steroid withdrawal can be safe and improves growth in pediatric renal transplant recipients if undertaken with careful clinical follow-up, including protocol biopsies.