Kidney Pathology Education for Nephrology Fellows: Past, Present, and Future.

Kidney pathology education is a critical component in training of nephrology fellows, as well as for continuing medical education for practicing nephrologists. Kidney pathology images are included on nephrology fellow board exams, and clinicopathologic correlation of kidney biopsy findings is critical in everyday clinical practice. Nephropathology training is a requirement by the American College of Graduate Medical Education within nephrology fellowship curricula. However, greater than one-third of fellowship program directors believe that nephropathology training for their fellows is not sufficient. During the Coronavirus Disease-19 pandemic, the use of digital learning has become commonplace with virtual conferences (local, national, and international) and online meetings becoming the norm for education. Nephrology has become a leader in free open-access online medical education, both prior to and, to even a greater extent, during the pandemic. Here, we review available resources to nephrology fellows and other learners to supplement nephropathology training, which includes medical blogs, journal clubs, interactive quizzes and games, online conferences, podcasts, and mentorship opportunities. These resources are archived and provide durable content to learners of all stages of training, even beyond the pandemic.

A multi-center retrospective cohort study defines the spectrum of kidney pathology in Coronavirus 2019 Disease (COVID-19).

Kidney failure is common in patients with Coronavirus Disease-19 (COVID-19), resulting in increased morbidity and mortality. In an international collaboration, 284 kidney biopsies were evaluated to improve understanding of kidney disease in COVID-19. Diagnoses were compared to five years of 63,575 native biopsies prior to the pandemic and 13,955 allograft biopsies to identify diseases that have increased in patients with COVID-19. Genotyping for APOL1 G1 and G2 alleles was performed in 107 African American and Hispanic patients. Immunohistochemistry for SARS-CoV-2 was utilized to assess direct viral infection in 273 cases along with clinical information at the time of biopsy. The leading indication for native biopsy was acute kidney injury (45.4%), followed by proteinuria with or without concurrent acute kidney injury (42.6%). There were more African American patients (44.6%) than patients of other ethnicities. The most common diagnosis in native biopsies was collapsing glomerulopathy (25.8%), which was associated with high-risk APOL1 genotypes in 91.7% of cases. Compared to the five-year biopsy database, the frequency of myoglobin cast nephropathy and proliferative glomerulonephritis with monoclonal IgG deposits was also increased in patients with COVID-19 (3.3% and 1.7%, respectively), while there was a reduced frequency of chronic conditions (including diabetes mellitus, IgA nephropathy, and arterionephrosclerosis) as the primary diagnosis. In transplants, the leading indication was acute kidney injury (86.4%), for which rejection was the predominant diagnosis (61.4%). Direct SARS-CoV-2 viral infection was not identified. Thus, our multi-center large case series identified kidney diseases that disproportionately affect patients with COVID-19 and demonstrated a high frequency of APOL1 high-risk genotypes within this group, with no evidence of direct viral infection within the kidney.

Detection of SARS-CoV-2 in formalin-fixed paraffin-embedded tissue sections using commercially available reagents.

Coronavirus Disease-19 (COVID-19), caused by the coronavirus SARS-CoV-2, was initially recognized in Wuhan, China and subsequently spread to all continents. The disease primarily affects the lower respiratory system, but may involve other organs and systems. Histopathologic evaluation of tissue from affected patients is crucial for diagnostic purposes, but also for advancing our understanding of the disease. For that reason, we developed immunohistochemical (IHC) and in situ hybridization (ISH) assays for detection of the. virus. A total of eight autopsy lungs, one placenta, and ten kidney biopsies from COVID-19 patients were stained with a panel of commercially available antibodies for IHC and commercially available RNA probes for ISH. Similarly, autopsy lungs, placentas and renal biopsies from non-COVID-19 patients were stained with the same antibodies and probes. All eight lungs and the placenta from COVID-19 patients stained positive by IHC and ISH, while the kidney biopsies stained negative by both methodologies. As expected, all specimens from non-COVID-19 patients were IHC and ISH negative. These two assays represent a sensitive and specific method for detecting the virus in tissue samples. We provide the protocols and the list of commercially available antibodies and probes for these assays, so they can be readily implemented in pathology laboratories and medical examiner offices for diagnostic and research purposes.