Comparison of preemptive and non-preemptive kidney transplantation outcomes in children aged <6 years.

We aimed to compare the outcomes of pediatric kidney transplantation (KT) between preemptive KT (PEKT) and non-PEKT in children aged < 6 years. Seventy-four pediatric recipients aged < 6 years who underwent KT were divided into the PEKT and non-PEKT groups. They were retrospectively evaluated for patient and graft survival, graft function, growth, and cytomegalovirus (CMV) infection. Comparison of the groups (PEKT, n = 14; non-PEKT, n = 60) revealed no significant differences between them in terms of distribution of sex, age, weight, primary disease, or population of pre-transplant CMV immunoglobulin G-positive patients. The median estimated glomerular filtration rate before KT in the PEKT and non-PEKT groups was 11.4 and 7.3 (mL/min/1.73 m2) (P < .001), respectively, and the median duration of dialysis was 2.7 years in the non-PEKT group. Graft survival at 5 years was 100% and 95% in the PEKT and non-PEKT groups, respectively (P = .634). One patient in the non-PEKT group had vascular complications, with subsequent early graft loss. Incidence of CMV infection was significantly lower in the PEKT group (P = .044). There were no significant differences in post-transplant estimated glomerular filtration rate, acute rejection, or growth. The height standard deviation score showed catch-up growth after KT in both groups. There was no significant difference in transplant outcomes in recipients aged < 6 years, with or without pre-transplant dialysis, except for the incidence of CMV infection. Therefore, PEKT in younger children should be performed aggressively by experienced multi-disciplinary teams.

Subclinical C1q Nephropathy Combined with Possible Donor-Derived IgA Deposition in a 1-Year Kidney Allograft Biopsy: A Case Report.

Few previous studies have reported immune-complex nephropathy that has not been classified as a specific phenotype in kidney allografts. We report a case of a de novo subclinical "full-house" pattern of deposition in a pediatric transplantation recipient with possible donor-derived IgA deposition. A five-year-old boy underwent living kidney transplantation due to congenital kidney and urinary tract anomalies. A one-hour implantation biopsy revealed IgA deposition. A four-month protocol biopsy finding showed less intense IgA deposition, in contrast with the one-hour biopsy, and trace para-mesangial deposits. A one-year protocol biopsy demonstrated a full-house deposition pattern and massive electron-dense deposits with minor glomerular changes. At the time of the one-year biopsy, kidney function was stable, with no urinalysis abnormalities. No evidence of systemic lupus erythematosus was observed in clinical and serologic examinations. Mesangial IgG, IgM, C3, and C1q deposition was codominant, and IgA deposition was weaker. We diagnosed this case as C1q nephropathy combined with remaining donor-derived IgA deposition. Few studies have reported C1q nephropathy in kidney allograft; further accumulation of cases is required. To distinguish between donor-derived and de novo glomerular lesions, it is important to assess the serial histologic findings of immunofluorescence and electron microscopy. Here, we report a rare case of subclinical C1q nephropathy with possible donor-derived IgA nephropathy.