[2176] Alport-Like Changes in Allograft Glomerular Basement Membranes: A Peculiar Manifestation Occurring in a Setting of Pediatric Donor-Adult Recipient Renal Transplantation

Manisha M Mishra, Conchitina MC Crisostomo, Joseph R Lee, Helen Liapis, George A Youngberg. East Tennessee State University, Johnson City, TN; Mountain States Health Alliance, Johnson City, TN; Washington University School of Medicine, St. Louis, MO

Background: We report a renal allograft with Alport-like electron microscopic (EM) changes and unique immunofluorescence (IF) findings. An adult with hypertensive nephropathy received an en-bloc transplant from a two year old male donor. The clinical course was complicated by proteinuria (2.5g/24hrs), first detected 2.5 years post-transplant. Two renal biopsies were obtained, with the second showing unusual EM findings.
Design: The biopsy was examined using a standard protocol. Because of the EM findings, COL4A3 and COL4A5 stains were obtained.
Results: EM identified foci of multi-lamellation (basket-weaving) of the glomerular basement membranes (GBMs) simulating Alport syndrome (AS).

An IF study for COL4A3 and COL4A5 showed segmental loss of GBM staining; there was no history of AS in the donor or his family. The differential diagnosis included mechanical (perhaps hyperperfusion) injury in an immature kidney allograft from a young child to an adult. This unusual GBM injury may affect COL4 isoform staining due to degeneration of the lamina densa. This is the tenth case in the literature of AS-like GBM changes on EM in a post-transplant biopsy with no known history of AS in the donor. Eight of these cases involved pediatric-donor adult-recipient allografts. Our case is important in two aspects. It is the first reported case showing abnormalities on IF staining for COL4A3 and COL4A5 along with the AS-like EM changes. Only one of the previous cases had IF for COL4A3 and COL4A5, and the results showed no abnormality. Our case is only the second reported case involving a pediatric en-bloc kidney transplant into an adult (all the remaining reported cases involved pediatric-donor single kidney transplants).
Conclusions: This peculiar glomerular pathology is little recognized. It emphasizes the importance of EM in the evaluation of renal allograft biopsies and provides further evidence that en-bloc transplantation does not prevent the development of this clinically important post-transplant glomerular complication.
Category: Ultrastructural

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 313, Wednesday Morning

 

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