Renal UWorld 3

Question 0

Calcineurin inhibitors

Answer 0

Cyclosporine, tacrolimus. Immunosuppressants used for transplant rejection and prophylaxis. Cyclosporine used also for psoriasis and rheumatoid arthritis.

Toxicity = nephrotoxicity and diabetes. Cyclosporine also has hypertension, hirsutism, gingival hyperplasia

Question 1

Calcineurin

Answer 1

Intracellular messenger turned on by TCRs. Activates NFAT, a transcription factor that activates transcription of NF-kB and IL-2 -> promotes growth and differentiation of T-cells. Frequent target of immunosupression therapy.

Question 2

3 main therapeutic catagories for BPH tx

Answer 2

1) alpha-antagonists (terazosin, tamulosin): relaxes smooth muscle in bladder neck and prostate. Works within days/weeks. Can cause hypotension and dizziness.
2) 5-alpha reductase inhibitors (finasteride, dutasteride): inhibits testosterone conversion to DHP. Reduces prostate volume (“fixed” cause), works in 6-12 months. Decreased libido and ED.
3) Antimuscarinics (tolterodine): used for men with overactive bladder and incontinence.

Question 3

How is PAH excreted? Can this be saturated?

Answer 3

• Freely filtered –> cannot be saturated

- Secreted in PCT –> carriers CAN be saturated

Question 4

Treatment for minimal change disease

Answer 4

Corticosteroids (rapid response)

Question 5

Nephritic syndrome with enlarged and hypercellular glomeruli

Answer 5

Post strep glomerular nephritis

Question 6

Lab findings in post strep glomerulonephritis

Answer 6

high ASO and anti-DNase B titers, decreased C3 and complement, presence of cryoglobulines

Question 7

Units for filtration fraction, GFR, RPF, normal values

Answer 7

FF (unitless) = GFR (ml/min) / RPF (ml/min)

0.2 = 125 / 625

Question 8

What happens to filtration fraction in severe hypovolemia?

Answer 8

Increases. Both GFR and RPF decrease, but GFR decreases less because of angiotensin II

Question 9

Vasopressin: receptor, mechanism

Answer 9

V2 receptor, increases permeability to water and urea

Question 10

Gross painless hematuria in an older patient should be seen as a sign of:

Answer 10

Urothelial cancer until proven otherwise

Question 11

histology of renal cell carcinoma

Answer 11

“Clear cell carcinoma”. Originates from proximal tubule cells –> polygonal clear cells filled with lipids and carbohydrates

Question 12

Majority of free water reabsorption in nephron happens in

Answer 12

Proximal tubule, even if the pt is dehydrated

Question 13

Which diuretics cause hypercalcemia? Hypocalcemia?

Answer 13

Thiazides cause hypercalcemia - proximal and distal Ca reabsorption

Loops cause hypocalcemia - Ca wasting in loop

Question 14

In water deprivation, where is urine most dilute? Most concentrated?

Answer 14

Dilute = distal tubule, concentrated = collecting duct

Question 15

High Cl, low K, metabolic acidosis

Answer 15

Acetazolamide

Question 16

64 y/o man with persistent back pain, constipation, easy fatigability for several months. Low Hb, Cr = 2.9, biopsy shows atrophic tubules with large obstructing eosinophilic casts

Answer 16

Multiple myeloma

Question 17

4 symptoms in an elderly pt that make you think multiple myeloma

Answer 17

anemia, constipation (hypercalcemia), bone pain (back and ribs, due to osteoclast activation factor and bone lysis), renal failure

Question 18

Bence Jones proteinuria

Answer 18

light chains which can precipitate to for eosinophilic casts

Question 19

Muddy brown granular and epithelial cell casts with free tubular epithelial cells

Answer 19

Ischemic tubular necrosis

Question 20

Pyuria and white cell casts

Answer 20

acute pyelonephritis

Question 21

Bicarb in DKA

Answer 21

Serum bicarb is decreased, and acidosis increases H secretion –> bicarb reabsorption –> urinary bicarb is also low

Question 22

DKA: PaCO2

Answer 22

Because of the metabolic acidosis, it should be going down as compensation.

Question 23

Painless hematuria 2-3 days after URI, IgA deposits in mesangium on IF

Answer 23

IgA nephropathy

Question 24

IgA nephropathy, Abdominal pain, purpuric skin lesions

Answer 24

Henoch-Schonlein purpura

Question 25

Glomerulonephritis with crescents, no Ig or complement deposits

Answer 25

Type of RPGN, “pauci immune”, associated with granulomatosis with polyangiitis

Question 26

Most important prognostic factor in post-strep glomerulonephritis

Answer 26

Age. Kids do great, adults develop RPGN or chronic glomerulonephritis

Question 27

Most common cause of acute renal failure in kids

Answer 27

hemolytic uremic syndrome

Question 28

HUS triad, common cause

Answer 28

Microangiopathic hemolytic anemia, thrombocytopenia, acute renal failure. Usually due to bowel infection

Question 29

NSAID renal injury

Answer 29

Papillary necrosis and chronic interstitial nephritis

Question 30

How do thiazides cause hypercalcemia?

Answer 30

Block Na/Cl symporters. Reduced intracellular Na increases Na-Ca2+ basolateral exchanger. This reduces intracellular Ca, causing increased absorption in distal tubule. Also can be reabsorbed in proximal tubule secondary to volume depletion

Question 31

Phases of acute tubular necrosis

Answer 31

Inciting event
Maintenance (oliguric)
Recovery (polyuric, re-epithelialization of tubules)

Question 32

Renal/clear cell carcinoma is from what part of kidney?

Answer 32

Proximal tubules

Question 33

Pathogenesis of nephrotic syndrome

Answer 33

• Increased permeability of glomerular capillary wall, massive protein urine loss
• Albumin loss liver cannot completely compensate. Drop in colloid osmotic pressure, fluid moves into tissue, edema
• Decrease in vascular volume acivates RAAS, aldo retains water as does ADH, leads to worse edema
• Liver increases lipoprotein synthesis to compensate for low albumin, ends up making lots of cholesterol, triglycerides. Followed by lipiduria.

Question 34

What are crescents in RPGN made of?

Answer 34

Glomerular parietal cells, monocytes, macrophages, and abundant fibrin.

Question 35

Slow onset painless hematuria, normal creatinine, history of exposure to rubber

Answer 35

Bladder cancer (transitional cell carcinoma)

Question 36

Concentrations of each of these things increase or decrease along the tubule? Bicarb, creatinine, inulin, urea, glucose, PAH, amino acids

Answer 36

Conc. of PAH, creatinine, inulin, urea increase (not well absorbed, and water goes away)

Bicarb, glucose, amino acids decrease

Question 37

pH, bicarb, PaCO2 in dka

Answer 37

All 3 are low