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Twitter Poll (September 16, 2020)

Fibrillary glomerulonephritis, arkana laboratories, twitter poll
Answer: C Fibrillary glomerulonephritis is a rare disease affecting less than 1% of all native kidney biopsies and is due to fibrillary deposits of immunoglobulin that by electron microscopy are randomly arranged fibrils of approximately 18-20 nm in diameter. Clinically patients will present with proteinuria and hematuria. Histologically it can show several patterns within glomeruli including mesangial proliferative, membranoproliferative, or even a crescentic pattern of glomerular injury. Positive staining with the DNAJB9 stain is extremely useful in identifying this disease as it is around 98% sensitive and 99% specific for Fibrillary GN. Associations with Fibrillary GN include autoimmune disease, infection...

Diagnose This (August 31 ,2020)

Alport Syndrome, COL4A5, COL4A3, COL4A4, Alport, X-linked, Hearing loss, GBM multilamellation
Q: What is your diagnosis based on this IF staining pattern in a patient with hematuria and proteinuria?   The immunofluorescence image is that of an Alport panel. The red staining highlights the alpha 2 subunit of collagen type IV while the green staining is that of the alpha 5 subunit of collagen type IV. The image shows segmental loss of the alpha 5 staining of type IV collagen along the glomerular basement membranes compatible with Alport syndrome. Alport syndrome is an inherited disease secondary to mutations in the alpha 3, 4, and 5 subunits of type IV collagen. The...

Twitter Poll (August 19, 2020)

collapsing FSGS, twitter poll, Arkana Laboratories
Answer: A, Collapsing FSGS   HIV-associated nephropathy classically demonstrates collapsing FSGS. Other features include increased proximal tubule protein resorption droplets, and microcystic tubular dilatation. While this disease has markedly diminished in the presence of highly active antiretroviral therapy (HAART), the rate is still high in areas of sub-Saharan Africa. Within the United States, approximately 90% of cases occur in African Americans and are associated with genetic mutations in the APOL1 gene (G1/G2 alleles). The typical presentation is that of nephrotic syndrome secondary to widespread foot process effacement seen by electron microscopy. Interestingly, the CD4 count has not shown to be...

Diagnose This (August 17 ,2020)

Membranous Glomerulopathy, PLA2R, Diagnose This, renal pathology, Arkana Laboratories
Q: What is your diagnosis for this patient with nephrotic syndrome?   The electron photomicrograph demonstrates numerous subepithelial deposits along the glomerular basement membrane characteristic of a Membranous Glomerulopathy. Subsequent staining with an immunoperoxidase stain for Phospholipase A2 receptor (PLA2R) was strongly and diffusely positive in this case consistent with a primary Membranous GN. By light microscopy, the classic findings include thickened glomerular basement membranes and pinholes (or bubbles) and spikes that can be seen along the capillary loops with the Jones silver stain. However, it should be noted that the degree, or severity, of these findings can be extremely...

Diagnose This (August 10 ,2020)

Tags: Collapsing GN, Nephrotic syndrome, APOL1, G1/G2, transplant, COVID-19, Diagnose This
Q: What is your diagnosis?   The light microscopic image depicts a glomerulus with collapse of the capillary loops on the Jones methenamine silver stain. This lesion is identified by its prominent capillary loop collapse with overlying epithelial cell hyperplasia and hypertrophy, with associated protein resorption droplets. It is important to look at the background tubulointerstitium for findings that can be seen in association with this lesion such as increased proximal tubular resorption droplets, tubular microcystic tubular dilatation, and interstitial inflammation, as this lesion can be easily mistaken for crescent formation. Collapsing glomerulopathy can be seen as a primary (idiopathic)...

Twitter Poll (August 5, 2020)

Nail-Patella syndrome, Twitter Poll, Arkana Laboratories
Answer: A, Autosomal recessive inheritance Nail-Patella syndrome is a rare autosomal dominant disease with an incidence of approximately 1/50,000. The majority of cases are due to a mutation in LMX1B located at chromosome 9q34.1. The gene is important in development as it encodes a transcription factor important in dorsoventral pattern limb development, proper development of the anterior eye, neuron development within the CNS, and podocyte differentiation and maintenance. The kidney pathology is rather non-specific and can show minimal glomerular changes to variable degrees of FSGS with thickened capillary loops. By EM, the classic finding is that of "Moth-eaten" glomerular basement...

Diagnose This (August 3 ,2020)

Fibrillary Glomerulopathy, Diagnose This!, Arkana Laboratories, pathology, nephropathology, renal pathology
Q: What is your leading diagnosis when seeing this interesting IgG staining pattern by IF?   The immunofluorescence shows a glomerulus with a very characteristic "smudgy" pattern of staining with IgG within the mesangium and along the capillary loops characteristic of Fibrillary Glomerulopathy. Fibrillary GN is an extremely rare disease, seen in <1% of native kidney biopsies and is caused by the deposition of fibrillar deposits of immunoglobulin within the mesangium with extension into the glomerular capillary loops. By electron microscopy, the fibrils are characterized as non-branching, randomly arranged, and have an average diameter of approximately 20 nm (range: 10-30...

Twitter Poll (July 22, 2020)

Polyomavirus Nephropathy, Banff Class 3, Twitter Poll, Arkana Laboratories
ANSWER: C The answer is C, Polyomavirus Nephropathy, Banff Class 3. The Banff Working Group Classification was created by Nickeleit et al. to provide a classification scheme to aid communication, better standardize reporting of polyomavirus nephropathy, and provide a way for better comparative analysis of cases going forward. The classification is broken into three classes, Banff Class 1-3. This case highlights an example of a Polyomavirus Nephropathy, Banff Class 3 with a pvl score of 3 and ci (fibrosis) score of 2. Based on this score, the findings of the Banff working group showed that approximately 50% of these patients...

Diagnose This (July 13,2020)

Fabry's disease, myelosomes, zebra bodies, X linked disease
What is your diagnosis?   The electron microscopic image depicts a podocyte with numerous myeloid bodies, myelinosomes, or "zebra" bodies as they are also known. This finding, taken in concert with the patient's clinical history was compatible with Fabry's disease. By light microscopy, a characteristic finding is the lacy, or foamy cytoplasm of the podocytes due to the lipid inclusions composed of globotriaosylceramide. Additionally, toluidine blue sections can be extremely helpful in identifying these inclusions. Fabry's disease is classified as a lysosomal storage disease caused by a deficiency in the alpha-galactosidase, an enzyme leading to the accumulation of globotriaosylceramide (GL3)...

Twitter Poll (July 8, 2020)

Twitter Poll, Deficiency of adenine phosphoribosyltransferase , APRT, Arkana Laboratories
ANSWER: D Renal oxalosis is a progressive tubulointerstitial disease which can be primary or secondary in nature. Specifically, secondary causes can be due to increased ingestion or absorption of sources of oxalate, decreased excretion, and certain vitamin imbalances. Oxalosis secondary to ingestion can occur with ingestion of oxalate containing foods such as rhubarb, spinach, peanuts, tea, starfruit, and ethylene glycol poisoning, among others. Increased absorption of oxalate containing substances occurs in maladaptive states such as after gastric/intestinal bypass surgery, prolonged antibiotic use, Crohn's disease, pancreatic insufficiency, and in short bowel syndrome. Other causes of oxalosis would include hypervitaminosis C, vitamin...