Medical renal diseases are frequent but often unrecognized in adult autopsies

Abstract

Kidney diseases affect many hospitalized patients and contribute to morbidity and mortality. Therefore, kidney disease should be prevalent, but the frequency and spectrum of medical renal pathology in autopsy specimens has not been well documented. We sought to determine the spectrum of medical renal pathology in adult autopsy specimens and the frequency of overlooked diagnoses. We reviewed the hematoxylin- and eosin-stained kidney sections from 140 adult autopsies performed at a large teaching hospital over a 2-year period. Fifty-eight cases (41%) had findings warranting further analysis, including alterations in glomerular matrix and/or cellularity, atypical or pigmented casts, thrombi, tubulointerstitial or vascular inflammation, or deposition of amorphous material. After additional studies and clinical correlation, the pathologic changes in 43 cases (31%) were categorized as follows: diabetic nephropathy, bile cast nephropathy, thrombotic microangiopathy, infection-related glomerulonephritis, focal necrotizing/crescentic glomerulonephritis, oxalate nephropathy, light-chain cast nephropathy, amyloidosis, urate nephropathy, hemosiderosis, antineutrophil cytoplasmic antibody-associated vasculitis, polyoma virus nephropathy, atheroembolic disease, and nephrocalcinosis. These diagnoses were not reported in 26 (60%) cases during the initial autopsy evaluation. This study demonstrates that medical renal diseases are common in autopsy cases, but significant diagnoses can be easily overlooked. Autopsy kidney specimens are a rich source of renal pathology and their evaluation should be emphasized in anatomic pathology residency training. Ultimately, our understanding of how kidney disease contributes to morbidity and mortality will benefit from accurate recognition of renal pathology in autopsy specimens.

Paraffin Immunofluorescence: A Valuable Ancillary Technique in Renal Pathology

“…Because formalin fixation induces protein cross-linking, which generally blocks antigenicity, an antigen-retrieval step that allows for increased penetration of antibodies to the antigens “masked” by formalin fixation is required in IF-P. 5 , 6 This step involves incubating the paraffin sections with a proteolytic enzyme or heating the sections before incubation with fluorescein isothiocyanate–conjugated antibodies against Igs and complement components. Multiple proteolytic enzymes have been used in IF-P, including trypsin, 7 , 8 , 9 , 10 , 11 , 12 pronase E (protease XIV), 13 , 14 , 15 , 16 , 17 proteinase XXIV, 18 and proteinase K. 13 , 19 , 20 , 21 , 22 Successful results were also obtained by heat treatment with Tris or citrate buffers 15 and with dual microwave heating in EDTA antigen-retrieval solution. 23 In our laboratory, we use the pronase technique, which was originally described by Fogazzi et al.…”

“…IF-P is also useful to exclude immune complex–mediated glomerulopathies and monoclonal gammopathy-related kidney diseases on nephrectomy specimens done for tumor resection and on postmortem specimens, in which unfixed/frozen tissue is frequently not stored due to cost. 11 , 28 , 29 …”

Iloprost in Acute Post-kidney Transplant Atheroembolism: A Case Report of Two Successful Treatments

“…Since the damage caused by CE is patchy, it is well-known that histologic diagnosis is difficult and often underestimated; this also occurs in native kidneys (12,13). Moreover, cholesterol crystals are not always present in the sample, and the only lesions seen are ATN and inflammatory infiltrates (2).…”

“…Considering the increase in transplants from extended criteria donors (ECDs), from donation after circulatory death (DCD), and the tendency for recipients to be older, the possibility of embolization arising from either donor or recipient vessels is expected to increase (6)(7)(8)(9)(10). Moreover, since embolization leads to focal and patchy damage, diagnosis is difficult, and injury severity may be underestimated (2,(11)(12)(13).…”

Autopsy Kidneys: An Overlooked Resource

“…In addition to frequent findings of acute tubular injury and arterionephrosclerosis, we detected a wide variety of significant renal pathology in one-third of adult autopsies over a 2-year span. 3 Common lesions included diabetic nephropathy, thrombotic microangiopathy, glomerulonephritis (frequently infection-related), diseases related to underlying hematologic malignancies, and toxic/metabolic tubulointerstitial diseases. Review of the corresponding autopsy reports reveals that most of these lesions (60%) were not identified.…”