2012 USCAP Pathologist in Training Award Winner

M Kamran Mizra, MD, PhDM. Kamran Mizra, MD, PhD
The University of Chicago Medical Center
Chicago, Illinois

Abstract

Preexisting Membranous Nephropathy in the Cadaveric Donor Kidney: Report of a Case (Ultrastructural Section - USCAP Abstract #2175).

M. Kamran Mirza, Kammi Henriksen, Anthony Chang, Shane M Meehan. The University of Chicago Medical Center, Chicago, IL

Background: Reports of transplanted donor primary glomerular immune complex mediated disease are uncommon. IgA nephropathy is the most commonly reported transplanted immune complex mediated disease with a frequency of 9-24% in donor biopsy specimens. Membranous nephropathy (MN) is rarely described with very few reports in the literature. The disease appears to resolve with little impact on graft function. We report a case of transplanted MN identified at the time of donor biopsy.
Design: Retrospective analysis of pathologic and clinical data of a case of transplanted MN was performed. Tissue sections were evaluated using H&E and PAS stains. Immunofluorescence microscopy was used to evaluate IgG, IgM, IgA, C3, C1q, fibrinogen and albumin. Electron microscopy was performed and Ehrenreich and Churg staging was used to assess lesions of MN.

Results: The donor was a 36 year old female with a history of hypertension, who died of a subarachnoid hemorrhage. She did not have detectable proteinuria. The recipient was a 61 year old male who underwent renal transplantation due to chronic renal failure (GFR 28 ml/min) and had concomitant heart transplantation due to long term diabetes mellitus complicated by severe coronary atherosclerosis and cardiac failure. Renal biopsy had never been performed. After transplantation, renal biopsies were obtained for increasing serum creatinine at days 17, 150, 225 and 825. PAS staining on all biopsies revealed basement membrane thickening with segmental 'spike' formation and vacuolization. Clinical and pathologic findings are summarized in Table 1.

Table 1.

 

Pre-implantation

Day 17

Day 150

Day 225

Day 825

Cr (mg/dl)

N/A

1.9

1.7

1.3

1.4

Proteinurea

Nil

Nil

Trace

Nil

Trace

IF: IgG

3+

3+

3+

1-2+

trace - 1+

IF: C3

N/A

1-2+

1+

trace

trace

EM: Stage IV lesions

20-30%

40-50%

>90%

No EM

>95%

EM: Podocytes

FP preserved

FP preserved

FP preserved

No EM

FP preserved

IF: immunofluorescence microscopy, EM: electron microscopy, FP: Foot processes.

Conclusions: Despite well developed lesions of MN, there was no correlation with podocyte foot process effacement or proteinuria in this patient. In the present instance there was a slow, but gradual resolution of lesions despite removal of the pathogenic environment. These observations suggest that a recipient environment that is non-immunogenic for MN, and perhaps immunosuppressive therapy, together facilitate resolution of immune complex deposits in transplanted MN.