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Twitter Poll (September 9, 2021)

  Which of the following membranous antigens has been recently identified and associated with underlying malignancy? A) NELL1 B) PLA2R C) EXT1/2 D) THSD7A   Answer: A) NELL1 NELL1, or neural epidermal growth factor-like 1 protein is a recently identified target antigen that has been associated with underlying malignancy in a subset of patients with membranous glomerulopathy. For further information, see references below. References: Caza T, Hassen S, Dvanajscak Z, Kuperman M, et al. NELL1 is a target antigen in malignancy-associated membranous nephropathy. Kidney Int 2020 Aug 20:S0085-2538(20)30956-X. Sethi S, Debiec H, Madden B, Charlesworth MC, et al. Neural epidermal...

Twitter Poll (July 21, 2021)

Cortex and Medulla, Banff criteria, renal transplant Banff classifications
  Which of the following is not a part of the Banff adequacy criteria for the evaluation of acute rejection in a kidney biopsy? A) At least 10 glomeruli B) Minimum 7 glomeruli C) At least 2 Arteries D) Cortex and medulla   Answer: D) Cortex and medulla Per the 2018 Banff reference guide for the evaluation of transplant biopsies, an adequate specimen is one that contains at least 10 glomeruli and at least 2 arteries. Additionally, the guidelines stipulate that there should be at least two cores or two separate areas of cortex in the same core in order...

Twitter Poll (July 7, 2021)

ALECT2 amyloidosis, or leukocyte chemotactic factor 2 amyloidosis makes up less than 10% of all cases of renal amyloidosis
Which of the following types of amyloid is classically associated with Hispanic heritage and is characteristically found within the cortical interstitium with medullary sparing? A) ATTR B) AL-type C) AA D) ALECT2   Answer: D) ALEC2 ALECT2 amyloidosis, or leukocyte chemotactic factor 2 amyloidosis makes up less than 10% of all cases of renal amyloidosis. This form of amyloidosis is classically seen in older individuals (~60 yrs.) and primarily affects individuals of Hispanic ancestry. Interestingly, while this form can be seen within glomeruli and vessels, it tends to have a propensity for interstitial deposition predominately within the cortex with sparing of...

Twitter Poll (June 23, 2021)

Large subepithelial hump-like deposits by electron microscopy are classically concerning for what? A) TMA B) Infection C) MGRS D) Minimal Change Answer: B) Infection The finding of large hump-like subepithelial deposits by electron microscopy should raise concern for a post-infectious/infection-associated glomerulonephritis and clinical correlation to identify a possible infection is warranted. 

Twitter Poll (June 9, 2021)

Which of the following is considered a primary podocytopathy and classically shows an excellent response to steroids? A) Minimal Change B) HSP C) Post-strep GN D) C3 GN Answer: A) Minimal change disease Minimal change disease is classically seen in young children and usually is identified by a sudden onset of nephrotic syndrome characterized by proteinuria > 3.5 g/24 hr, hypoalbuminemia, and edema. Histologically, the biopsy demonstrates minimal to no significant glomerular changes while proximal tubules show increased protein resorption droplets. The major finding however is seen by electron microscopy which demonstrates widespread (complete) podocyte foot process effacement by electron...

Twitter Poll (May 27, 2021)

  Answer: PAS-positive The typical histologic features of casts seen in cases of light chain cast nephropathy show light chain restriction by immunofluorescence, are typically PAS-weak or negative in their staining, show fracturing, and will classically show an associated intratubular cellular reaction. Typically these casts will involve the distal tubules and collecting ducts and occasionally, crystal formation can occur.          

Twitter Poll (May 13, 2021)

2,8-dihydroxyadeninuria (2,8-DHA) is caused by an autosomal recessive deficiency in the adenine phosphoribosyltransferase (APRT)
  Answer: 2,8-Dihydroxyadeninuria   2,8-dihydroxyadeninuria (2,8-DHA) is caused by an autosomal recessive deficiency in the adenine phosphoribosyltransferase (APRT). The gene is located on chromosome 16q24 of which greater than forty different mutations have been identified which include missense, nonsense, insertion, and deletion mutations. APRT is a purine salvage enzyme which in disease states leads to the absence of recycling adenine. Instead, adenine is eventually catabolized to 2,8-DHA which, in the kidney, leads to crystalline and stone formation due to its poor solubility in the urine. By light microscopy, these crystals are red to brown and birefringent on H&E and PAS...

Twitter Poll (April 28, 2021)

Linear GBM Poll
  Answer: Linear GBM   Anti-GBM disease is classically characterized by bright linear staining with IgG by immunofluorescence. By light microscopy, anti-GBM disease typically demonstrates a diffuse necrotizing, crescentic glomerulonephritis. Occasionally, multinucleated giant cells may be seen within the glomerular crescents as well as periglomerular areas. The pathophysiology of the disease is most often due to an autoantibody to the noncollagenous 1 (NC1) domain of the alpha 3 chain of collagen IV, however occasionally antibodies to the NC1 domain of the alpha 5 chain may also be present. Of note, a major prognostic factor at the time of biopsy is...

Diagnose This (April 19, 2021)

AA Amyloid Diagnosis in Renal Biopsy
What is your diagnosis in a 35 y/o male with paraplegia and chronic osteomyelitis who presents with nephrotic syndrome? Bonus: What subtype would you suspect based on the clinical history?     ​ ​   ​   ​ ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​  ...

Twitter Poll (April 14, 2021)

sickle cell nephropathy, Crescents
Answer: Crescents   Sickle cell disease is an autosomal recessive disorder classically seen in African-Americans which is caused by a single nucleotide change on chromosome 11p15.5 resulting in an amino acid change from glutamic acid to valine. In the kidney, the disease manifests as sickle cell nephropathy. Histologic features seen in this disease include focal segmental glomerulosclerosis, glomerular enlargement, double contour formation, and hemosiderin deposition within tubular epithelial cells to name a few. Crescent formation is not typically seen in sickle cell nephropathy and if seen would be worrisome for a concomitant process (i.e. ANCA-associated glomerulonephritis).