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Perifascicular Atrophy in Dermatomyositis

Perifascicular Atrophy, neuro notes, Arkana Laboratories, muscle biopsy
What histologic finding is observed in this case?     Answer:  Perifascicular Atrophy in Dermatomyositis   This case shows an acquired inflammatory myopathy with well-developed perifascicular atrophy.  Generally speaking, acquired inflammatory myopathies may be morphologically grouped into three categories: Polymyositis, Dermatomyositis, and Inclusion Body Myositis.  The classification of acquired inflammatory myopathies has undergone recent refinement, and additional entities show characteristic morphologic and clinical features (see Pestronk reference).  In the realm of acquired inflammatory myopathies, perifascicular atrophy is characteristic of dermatomyositis. The finding of skin rash in a characteristic distribution on physical exam is helpful, but is not always present (i.e. involvement...

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...

New Neuropathology Series: Neuro Notes

neuro notes, neuropathology, arkana laboratories
Introducing Neuro Notes!🚨   This new series by our neuropathologists, Dr. Wilson and Dr. Mrachek, will be highlighting cases, diagnosing neuropathological diseases, and making other observations in their unique neuropathology practice.   Below are ATPase enzyme histochemical stains from a skeletal muscle biopsy:   Image 1- pH 9.6 (Type II dark, Type I pale) Image 2- pH 4.6 (Type I dark, Type 2A pale, Type 2B intermediate) Image 3- pH 4.3 (Type I dark, Type II pale).  

Our Friend and Colleague: Robin Ollis

Robin Ollis, Arkana Employee, Arkana Laboratories
We lost a dear friend and colleague this week. Yesterday we said goodbye to Robin Ollis, our Assistant Lead for Electron Microscopy. Robin joined Arkana in 2011 and since then, he has not only served thousands of patients, but he also has trained, coached, and championed dozens of teammates. He was incredibly kind and such a joyful person to work with and we are honored to have been able to call him "one of us" for as long as we did. He will be incredibly missed. 

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...

A Big MYMP Landing!

Dr. Sharma, Dr. Larsen, Dr. Caza, NELL1, renal research
After several weeks of flying around our office, the MYMP landed and was caught by Dr. Caza, Dr. Larsen, and Dr. Sharma! Their newest paper discusses NELL1 and how it is a target antigen in malignancy-associated membranous nephropathy. Read the paper: NELL1 is a target antigen in malignancy-associated membranous nephropathy Who will catch the MYMP next?

Road To Renal with Dr. May

Dr. Murphy, Road to Renal, Dr. May, Arkana Podcasts
Our new fellow, Dr. May, began recording her new podcast this morning and her first guest was Dr. Murphy. He wanted to "dress up" for the occasion. Stay tuned for the first episode of Road to Renal with Dr. Rebecca May!  

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...

Back To School Donations

donations, Arkana Labs, giving back, Martin Luther King Jr. Elementary
Jack and JP (along with their Aunt Denise) stopped by this morning to help pack up school donations that Arkana has collected over the past few weeks. All donations are being given to the Martin Luther King Jr. Elementary School.  To make a contribution, visit the Little Rock School District's official website.

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...