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Twitter Poll (January 9, 2019)

ANSWER: C DNAJB9 immunohistochemical (IHC) stain is a quick and inexpensive tool used to confirm the diagnosis of Fibrillary GN. DNAJB9 IHC has a sensitivity of 98% and >99% specificity.   In 2017, Dr. Nasr et al. discovered a novel proteomic biomarker for Fibrillary GN called DnaJ homolog subfamily B member 9 (DNAJB9), which is a member of the chaperone gene family. DNAJB9 immunohistochemical (IHC) stain is a quick and inexpensive tool used to confirm the diagnosis of Fibrillary GN. DNAJB9 IHC has a sensitivity of 98% and >99% specificity.   Reference: Nasr S, et al. DNAJB9 is a specific...

Twitter Poll (January 2, 2019)

ANSWER: B A reduced nephron number is associated with low birth weight, preterm birth, reduced kidney mass and size, short stature, maternal hyperglycemia, maternal protein malnutrition, and gene polymorphism for PAX2 and RET. References: Luyckx VA, Brenner BM. The clinical importance of nephron mass. J Am Soc Nephrolo 2010;21:898-910 Hughson M, Farris AB III, Douglas-Denton R, et al. Glomerular number and size in autopsy kidneys: the relationship to birth weight. Kidney Int 2003;63:2113

Twitter Poll (December 7, 2018)

ANSWER: D MGRS was introduced to acknowledge a clonal plasma cell or B lymphocyte proliferation causing a renal lesion in the absence of hematologic malignancy or other myeloma-defining events; the renal lesion is a consequence of the MIg, which carries major implications for management and prognosis, including the potential for progressive renal injury and ESRD. MGRS caused by PC is defined as <10% bone marrow plasma cells (BMPCs), <3 g/dl of M protein, and the presence of renal lesions without any other myeloma-defining events (CRAB features; clonal PC ≥60%; serum FLC ratio of ≥100; or >1 focal lesion on magnetic...

Twitter Poll (November 30, 2018)

ANSWER: D The cells of Goormaghtigh, AKA extraglomerular mesangial cells, lacis cells or Polkissen cells, are part of the juxtraglomerular apparatus. Ultrastructurally, these cells resemble mesangial cells. The lacis cells function as a physiologic liaison between the macula densa and arteriolar smooth muscle cells and the arteriolar granular myoepithelioid cells. They play an important role in renal autoregulation of blood flow to the kidney and regulation of systemic blood pressure through the renin-angiotensin system. References: Eknoyan G, Rubens R, Lameire R. The juxtaglomerular apparatus of Norbert Goormaghtigh – a critical appraisal. Nephrol Dial Transplant 2009; 24:3876-81. Christensen JA, Bohle A...

Twitter Poll (November 15, 2018)

ANSWER: A The number of nephrons in the normal kidney is important because they may play a role in the development of hypertension and progression of chronic renal disease. Nephron number is influenced by many factors that affect renal development. References: 1. Luyckx VA, Brenner BM. The clinical importance of nephron mass. J Am Soc Nephrolo 2010;21:898-910. 2. Bertram JF, Douglas-Denton R, et al. Human nephron

Twitter Poll (November 1, 2018)

ANSWER: D Drug-induced AIN may account for 60-70% of AIN cases. Some offending drugs include: antibiotics, proton pump inhibitors, NSAIDs, PD1-inhibitors, anti-convulsants, and diuretics, among others. References: Cortazar FB et al. Clinicopathological features of acute kidney injury associated with immune checkpoint inhibitors. Kidney Int 2016; 90: 638-47 Muriithi AK et al. Clinical characteristics, causes and outcomes of acute interstitial nephritis in the elderly. Kidney Int 2015; 87: 458-464. Muriithi AK et al. Biopsy-proven acute interstitial nephritis. Nat Rev Nephrol 2010; 6(8): 461-70 Praga M et al. Acute interstitial nephritis. Kidney Int 2010; 77(11): 956-61

Twitter Poll (September 26, 2018)

ANSWER: D Hall’s stain is used to confirm the presence of bile casts. This technique uses the oxidizing action of Fouchet’s reagent to convert the bile pigment (bilirubin) into an easily identifiable green color (biliverdin). Bile pigments appear green against a yellow background. The color ranges from olive green to emerald green, depending upon the concentration of bilirubin. REFERENCES: Hall MJ. A staining reaction for bilirubin in sections of tissue. Amer J Clin Path, 1960; 34:313-316. Luna LG. Manual of Histologic Staining Methods of the Armed Forces Institute of Pathology, 3rd ed., McGraw-Hill, N.Y., c. 1968, p.174. van Slambrouck CM,...

Twitter Poll (September 6, 2018)

ANSWER: A - Thick ascending limb of the loops of the Henle THP (aka uromodulin) is an 85 -kDa glycoprotein encoded by the UMOD gene in humans.  It’s involved in the pathogenesis of light chain cast nephropathy, urolithiasis, and tubulointerstitial nephritis, in urothelial cytoprotection against UTIs, and in mutations of the THP gene in FJHN and MCKD2. References: Micanovic R, et al. Tamm-Horsfall Protein Regulates Granulopoiesis and Systemic Neutrophil Homeostasis. J Am Soc Nephrol 2015; 26(9): 2172-2182. Serafini-Cessi F, et al. Tamm-Horsfall glycoprotein: biology and clinical relevance. Am J Kidney Dis 2003; 42: 658-676. Nasr SH, et al. Uromodulin storage...

Twitter Post (August 30, 2018)

ANSWER: B Type II (mixed) cryoglobulinemia is characterized by immune-complexes containing a monoclonal Ig (usually IgM) that have an RF activity and polyclonal Ig (usually IgG). It’s most commonly caused by HCV, with some cases caused by lymphoproliferative or autoimmune disorders. References: Zaidan M, et al. Spectrum and prognosis of noninfectious renal mixed cryoglobulinemic GN. J Am Soc Nephrol 2016; 27:1-12. Fabrizi F, et al. Hepatitis C virus infection, mixed cryoglobulinemia, and kidney disease. Am J Kidney Dis 2013; 61(4): 623-637.  

Twitter Poll (August 22, 2018)

ANSWER: D Anti-GBM disease is a rare small vessel vasculitis that affects glomerular and pulmonary capillaries. The majority of patients develop widespread glomerular crescent formation, presenting with features of rapidly progressive GN, and 40-60% will have concurrent alveolar hemorrhage