Renal Review - Lessons Flashcards
What is an important causative antibody target in Goodpasture syndrome?
Type IV collagen, α3 subchain
What is an important causative antibody target in membranous nephropathy?
Phospholipase A2 receptor
What is an important causative antibody target in Wegener polyangiitis?
Proteinase 3
(T/F) Deposits can be identified in cases of Goodpasture’s syndrome by both immunofluorescence and electron microscopy.
False. Only IF.
Which nephrotic syndrome causing disesae can also cause hematuria?
MPGN
What are the clinical features of amyloidosis? Which syndrome does it cause?
Macroglossia, heart failure, 10 nm glomerular fibrils on EM; Nephrotic
What is another common name for the Shiga-like toxin that can cause classical hemolytic-uremic syndrome?
Verocytotoxin
What is the main mechanism of Ca reabsorption in the nephron and how can it be pharmacologically inhibited?
Ca follows Na reabsorption especially in the PCT and the thick ascending limb. Loop diuretics can inhibit this, and can thus result in hypercalciuria.
What is the approach in a 5 yo child with foamy urine and facial edema?
The child almost certainly has MCD, so immediate steroid therapy is indicated.
What is the clinical presentation of tumor lysis syndrome (describe BP and potassium, phosphate, nitrogen, and creatinine levels)?
Hyperkalemia, hyperphosphatemia, acidosis, azotemia, hypertension, and high serum creatinine
How does 1/2 NS distribute upon IV administration?
Half goes to the ECF (3/4 IS and 1/4 plasma) and the other half distributes as free water (2/3 ICF and 1/3 ECF)
Are recurrence rates in low grade urinary papillary carcinomas high or low?
High
What is the blood supply to the medullary pyramid of the kidney lobe?
Vasa recta
Where are the arcuate vessels located?
Between the cortex and medulla
Where does vasa recta empty into?
Arcuate veins
What electrolyte abnormality can be caused by clay ingestion or amphotericin B toxicity?
Hypokalemia
What is a crucial histological finding in lupus nephritis?
Wire loop capillaries
What is “thyroidization” of the kidney?
Tubules are often dilated and filled with eosinophilic casts. Seen in chronic pyelonephritis.
What are some clinical features of nephrosclerosis?
Reduced size/mass (esp. cortex) and have increased peripelvic fat; very vulnerable to nephrotoxic drugs; usually don’t cause renal insufficiency but have low functional reserve so can fail in case of shock/trauma/etc.
What does the urine look like in a patient with prerenal azotemia?
Low urine Na concentration but high osmolarity because of ADH response from the low GFR
List 5 main treatments of hyperkalemia
Insulin and glucose (facilitates uptake), IV bicarb (alkalizes causes uptake), IV calcium chloride (prevents VT), beta-2 agonists (facilitates uptake), loop/thiazide diuretics (increases K excretion)
What cell/virus combo causes post-transplant lymphoproliferative disorder?
EBV-induced B cell proliferation
What are the most common causative organisms of acute pyelonephritis?
E. coli (70-80%) and Enterococcus (10%)
What is most likely to cause edema in a patient with CHF?
High venous pressure
What is the most common complication of CKD?
Cardiovascular disease (also causes hypocalcemia and hyperphosphatemia)
What is the main purpose of the medullary osmotic gradient?
To excrete hypertonic urine
What is the clinical picture of prerenal vs. intrarenal azotemia?
Prerenal has low urine Na (high ATII and aldosterone), low FENa, and negative urine cytology; intrarenal has high urine Na and high FENa (ATN)
What are the four main compartments of the kidney?
(1) glomerular, (2) vascular, (3) tubular, and (4) interstitial
Name three mechanisms that link hypokalemia and metabolic alkalosis.
(1) K+ extravasation during hypokalemia results in absorption of extracellular H+, (2) aldosterone causes both K+ and H+ excretion in the distal tubule and collecting duct, and during hypokalemia, H+ secretion in the DCT/CCD increases, (3) most common causes of metabolic alkaloses (vomiting, diarrhea) cause the loss of both H+ and K+
Which diuretics cause acidemia?
Carbonic anhydrase inhibitors and K+ sparing diuretics
Which diuretics cause alkalemia?
Loop and thiazide diuretics
What is the effect of loop and thiazide diuretics on serum Ca?
Loop diuretics can cause hypocalcemia and thiazide diuretics can cause hypercalcemia
What is the homeostatic response to increased serum osmolality with an unchanged effective arterial blood volume?
Increased ADH and thirst stimulus from the hypothalamus
In the empty bladder, the fully differentiated cells at the top of the urothelium are _____
Dome-shaped (umbrella cells)
On H&E, does the PCT or the DCT appear thicker?
PCT
How is K reabsorbed in the PCT?
Passive transport
Which disease causes full-house IF staining?
DPGN
Which disease is associated with IgA nephropathy?
Celiac disease
Is ATN reversible?
Yes
Where in the prostate does carcinoma generally develop?
Peripheral zone
White blood cell casts are most likely to be seen in which renal disease?
Acute pyelonephritis
Presbynephrosis has which main characteristic?
Shrunken kidneys with peripelvic fat
Ca and Mg are mostly absorbed along which nephron segment?
Thick ascending loop of Henle
What is the daily GFR in a normal 70 kg person?
150 L per day
In patients who already have renal insufficiency, what are the most serious side effects of ACE-inhibitors or angiotensin-receptor blockers?
Lower GFR, hyperkalemia (can also cause metabolic acidosis)
What are some causes of high anion gap metabolic acidosis?
Glycols (ethylene or propylene glycol), Oxyproline (derivative of acetaminophen), uremia, L-lactate, D-lactate, methanol, aspirin, renal failure, ketoacidosis
What group is affected by rhabdoid tumors and what is the prognosis?
Infants, and they are highly aggressive despite treatment
Which kidney cells produce EPO?
Peritubular interstitial cells
Describe the serum potassium and pH in a patient with significant hyperaldosteronism
Hypokalemia and high bicarb
Which type of kidney stone is radiolucuent?
Uric acid stones
What are the three main types of channels in the PCT?
Na+/H+ antiporter, simple Na+ channels, and Na+/organic solute cotransporters
What is the the most rapidly effective IV treatment for EKG changes caused by hyperkalemia?
IV calcium
Why does the plasma K+ concentration contributes to the resting membrane potential of cells?
The permeability across the membrane is higher for K+ than it is for Na+
What sort of depositions do we see in Henoch-Sch_nlein purpura?
IgA subendothelial deposits
What are some histological findings of acute tubular necrosis?
Swollen tubular epithelium, interstitial edema, dilated convoluted tubules
How is pH calculated from serum bicarb and PCO2?
pH = 6.1 + log [HCO3-] / 0.03 PCO2
How much K is in a standard 70 kg person?
4000 mEq
What is the best treatment for severe diarrhea hypotension in areas where there is no access to intravenous fluids?
Oral rehydration therapy of water with glucose, NaCl, bicarb, and KCl
How does clay ingestion cause hypokalemia?
It sticks to the gut wall and traps K+, preventing the ingestion of potassium.
Which three classes of drugs can really mess with glomerular filtration regulation?
NSAIDs, ACEIs, and ARBs
What are the three main causes of isotonic volume depletion?
Hemorrhage, sepsis, and CHF
What sort of urological cancer does schistomiasis predispose patients to?
Squamous cell carcinoma of the bladder
Is mesoblastic nephroma malignant or benign?
Benign
55-year-old man with blood in his urine. The light microscopy shows a total of 12 glomeruli of which four show global sclerosis and two contain cellular crescents. The remaining glomeruli appear normal. There is no staining by immunofluorescence. What is the best diagnosis?
Pauci-immune glomerulonephritis
What has been shown in clinical trials to reduce the progression of chronic renal failure?
ACE inhibitors to reduce proteinuria
What are some examples of factors leading to a complicated UTI?
Pregnancy, male sex, diabetes, urinary tract instrumentation, anatomic abnormalities, immunosuppression
What types of glomerulonephritidies present with low serum C3?
MN, PSGN, DPGN, cryoglobulinemia
With a substance that is freely filtered/secreted maximally, what will happen to its clearance as you raise the plasma concentration?
It will decrease and approach the clearance of inulin
Reasons for diuretic refractoriness
Low oncotic pressure, too much dietary salt, impaired kidney function, pre-renal azotemia
Adenocarcinoma of the bladder is associated with what?
Persistent urachus and exstrophy
What is the big pathogenic finding of diabetic nephropathy?
BM thickening and mesangial proliferation
Which nephropathy gives subepithelial “spike-and-dome” or “diffuse deposits”?
Membranous nephropathy
What causes intracapillary lipids with non-specific trapping of plasma proteins?
FSGS
What causes intramembranous deposition of C3?
Type II MPGN
What is suggested by the finding of hemosiderin laden macrophages?
Hemolysis
Carcinoma in situ of the bladder has which characteristics (cellular and nuclear morphology)?
Flat, non-invasive; high-grade nuclear atypia
What is the embryonal origin of podocytes?
Primitive renal tubule epithelium
What is a renal corpuscle?
The initial blood-filtering component of a nephron
Crescent formation is most typically associated with which finding?
RBC casts
What is the prognosis for patients with thin basement membrane disease?
Benign; they will likely maintain kidney function for their whole lives
What kidney issue can multiple myeloma cause?
Renal failure caused by tubulointerstitial nephritis
Which cancer can you treat with BCG?
Bladder carcinoma
What toxins can cause ATN?
Aminoglycosides, cisplatin, Hg, Pb, other heavy metals
What cells are in muddy brown casts?
Epithelial cells
Which kinds of bacteria almost never cause UTIs?
Staph
Which foods have the saltiest content?
Canned foods
Low magnesium causes what electrolyte abnormality?
Hypokalemia
What disease causes mesangial and endocapillary proliferation with lobular accentuation and double contoured capillary walls?
MPGN Type I
Name four causes of renal papillary necrosis
Sickle cell disease or trait, analgesic use, diabetes mellitus, and severe pyelonephritis
What finding is associated with thrombotic micropathy?
Thrombocytopenia
“Free access to water” means what about someone’s electrolyte levels?
They’ll normalize
What are the four signs of CKD?
Hematuria, proteinuria, low GFR, hypertension
