Diffuse glomerular basement membrane lamellation in renal allografts from pediatric donors to adult recipients

The transplantation of kidneys from pediatric cadaveric donors into adult r ecipients is performed in many centers. However, some studies indicate that the outcome of such renal transplants may be inferior compared with that o f adult donors, particularly if the donor is an infant. Morphologic studies of failed pediatric donor kidneys in adult recipients describe various deg rees of segmental or global glomerular sclerosis. The authors have performe d ultrastructural examinations on such transplants and have identified six cases with diffuse irregular lamellation of the glomerular basement membran e (GBM), a change that may develop as early as 10 weeks after transplantati on. The age of all donors was less than or equal to 6 years; three were inf ants. The incidence of the lesion was 9% at our institution in renal transp lant patients who received a graft from donors <10 years old. Diffuse GEM l amellation has not been found in renal transplants from adult donors. Light microscopy showed various degrees of diffuse mesangial expansion, usually with segmental glomerular sclerosis. The patients had severe proteinuria. W hile recurrent focal segmental glomerular sclerosis (FSGS) has to be exclud ed, such diffuse GEM lamellation is generally not seen in recurrent FSCS ca ses. The pathogenesis of the lesion is most likely related to hyperperfusio n injury of small pediatric donor kidneys grafted into adult recipients.