Renal Pathology- Warren Flashcards
What nephrotoxic cause of ATN will you see oxalate crystals?
Ethylene Glycol
What are 2 types of ATN?
Ischemic
Nephrotoxic
What are causes of nephrotoxic ATN?
Crush injury (myoglobin) Urate (from tumor lysis syndrome) Aminoglycosides Heavy metals ethylene glycol Radiocontrast dye
Normal BUN: Cr ratio?
15:1
What kind of casts do you see in ATN?
Brown, granular casts
What kind of nephritis do NSAIDs, penicillin, and diuretics cause?
Acute Interstitial Nephritis (connective tissue between tubules)
What is found in the urine in Acute Interstitial Nephritis?
Eosinophils! High yield
Name one pharmacological cause of renal papillary necrosis.
Chronic analgesic abuse
What major protein is lost in nephrotic syndrome?
Albumin
Why do patients with nephrotic syndrome develop a hypercoaguable state?
They lose Antithrombin III
Why do patients with nephrotic syndrome get hyperlipidemia and hypercholesteremia?
Liver reacts by throwing excess fat into the blood because the blood gets “thin”
What is the most common cause of nephrotic syndrome in kids?
Minimal change disease
What can Minimal change disease be associated with?
Hodgkin Lymphoma (massive overproduction of cytokines from Reed Sternberg cells)
What do you lose in MCD?
Why?
Foot processes flatten/efface because of cytokine production
What histology hallmark is present in MCD?
NORMAL Glomeruli on H&E stain
EFFACEMENT of foot processes on EM
What is the only protein lost in MCD?
Albumin
don’t lose immunoglobulin
What holds together lobules of the glomerulus?
Mesangial cells!
What is the most common cause of Nephrotic syndrome in Hispanics and African Americans?
FSGS: Focal Segmental Glomerular Sclerosis
What can FSGS be associated with?
Heroin Use
HIV
Sicke Cell Disease
(or Idiopathic)
What does “segmental” mean in FSGS?
Only a single part of the glomerulus will be involved
What does “focal” mean in FSGS?
Only some of the glomeruli in the kidney will be involved
FSGS is the progression of what disease if it doesn’t respond to steroids?
Minimal Change Disease
Does FSGS respond to steroids?
No…progreses to Chronic renal failure
Most common cause of nephrotic syndrome in caucasian adults?
Membranous Nephropathy
Causes of Membranous Nephropathy?
Usually Idiopathic Hepatitis B/C SLE-->most common cause of death is renal failure! Solid Tumors Drugs
Usually patients with SLE don’t present with nephrotic syndrome, but if they do, what is it?
Membranous Nephropathy
What is happening in Membranous Nephropathy histologically?
Glomerular basement membrane becomes really thick!
Why does the membrane become thick in Membranous Nephropathy?
Immune complex deposition
Where is the immune complex deposition in Membranous Nephropathy?
Right under the podocytes (epithelial cells)
How do podocytes respond to immune complex deposition?
Try to lay down more basement membrane!
What is the EM description of membranous nephropathy?
Spike and dome subepithelial deposits
What do you see in Membranoproliferative Glomerulonephritis?
Thick capillary membranes on H and E with “tram track appearance” due to Immune complex deposition
What are the 2 types of Membranoproliferative glomerulonephritis based upon?
Location of deposits
What are the 2 types of Membranoproliferative glomerulonephritis?
I: subendothelial
II: Intramembranous
Why are there neutrophils in nephritic syndrome?
Inflammation is driven by immune complexes which activate complement. A byproduct of this is C5a–these attract neutrophils which mediate damage.
What are RBC casts a sign of?
glomerular bleeding
What virulence factor of some Group A Beta hemolytic streps increase the changes of PSGN?
M protein! This defines nephritogenic strains
When does PSGN usually occur?
2-3 weeks post infection
Is PSGN nephritic or nephrotic?
Nephritic
What do you see on EM in PSGN?
subepithelial humps
What is RPGN histology?
Crescents! Made of Fibrin and macrophages –Inflammatory Debris
What disease have positive p-ANCA?
Microscopic polyangiitis
Churg Strauss
Most common nephropathy worldwide?
IgA nephropathy
Where do IgA complexes like to deposit?
Mesangium
What is Alport Syndrome?
Inherited Defect in Type IV collagen that results in thinning and splitting of GBM
What is the genetics of Alport Syndrome?
X-linked
What does Alport syndrome present as?
Isolated hematuria
Sensory hearing loss
Ocular disturbances
How is polycystic kidney disease inherited?
Infant from - autosomal recessive
Adult form - autosomal dominant
What are two things associated with the autosomal recessive form of polycystic kidney disease?
Congenital hepatic fibrosis
Hepatic cysts
What three things are associated with the autosomal DOMINANT form of polycystic kidney disease? (adult form)
BERRY ANEURYSM
hepatic cysts
mitral valve prolapse
What genes are mutated in adult PKD? what do they code for?
**autosomal dominant
APKD1 = encodes polycystin 1 = integral membrane protein
APKD2 = encodes polycystin 2 = Ca+ channel
What is medullary cystic kidney disease? (aka medullary sponge kidney)
Autosomal dominant
Cysts in the MEDULLARY COLLECTING DUCTS
What is a gross feature that would distinguish PKD from medullary cystic kidney disease?
In PKD kidneys appear enlarged
In medullary the kidneys appear shrunken
What are the hallmarks of acute renal failure?
Severe decrease in renal function with in days
AZOTEMIA (increased BUN and creatinine)
Oliguira
How do you distinguish pre-renal azotemia and intrarenal azotemia?
Pre-renal will have BUN:Cr>15 (more BUN is getting reabsorbed)
Intra-renal will have BUN:Cr
What will you see in acute tubular necrosis?
BROWN granular casts
BUN:Cr 2%
Inability to concentrate urine (urine osm
What cancer can minimal change disease be associated with?
Hodgkin Lymphoma
Normal glomeruli
Effacement of foot processes on EM
Selective loss of Albumin
Associated w/ Hodgkin’s lymphoma
Minimal Change Disease