Sketchy Path: Tubulointerstitial Nephritis

Question 1

Acute interstitial nephritis usually spares the ______________.

Answer 1

vasculature and glomerulus (like how the fire is targeting the center of the kidney ferris wheel, not the periphery)

Question 2

What can cause AIN?

Answer 2

Virtually any drug, but here are some common ones:
• NSAIDs (like the guy with the NSAID backpack)
• Furosemide (guy furious at his friend)
• Penicillin (purple pencils holding up ferris wheel)
• Bactrim (kid throwing eggs at stand)

Question 3

What immune response usually occurs in AIN?

Answer 3

It’s a mixture of type I (the beehive on the light pole) and type IV (the squire who knocked down the cage).

Question 4

What will histologic exam of the kidney show in AIN?

Answer 4

Inflammatory cells in the interstitium (like the blue lights on the ferris wheel) and eosinophils (like the girl shooting her slingshot).

Question 5

____________ can sometimes appear in the urine of those with AIN.

Answer 5

Eosinophils (like the pink granules in the puddle) and WBC casts (like the T knight puppets falling into the puddle)

Question 6

What are signs and symptoms of AIN?

Answer 6

• Azotemia (BUN and credit card on the floor)
• Oliguria (empty soda on the floor)

It’s an AKI.

• Fever (clown with head on fire)
• Rash (clown’s spotted suit)

Question 7

How soon do the symptoms of AIN manifest following exposure to the drug?

Answer 7

1-2 weeks (like the “This site will be demolished in 2 weeks” sign near the macrophage cage)

Question 8

What causes chronic tubulointerstitial nephritis (TIN)?

Answer 8

Most often, TIN is caused by prolonged use of NSAIDs (like the little kid with the NSAID backpack getting kicked in the back).

Question 9

NSAIDs accumulate in the _____________.

Answer 9

renal papillae – the tips of the pyramids (like the pyramid design on the kidney that the TIN kid is walking into with his NSAID backpack)

Question 10

NSAID accumulation in the papillae leads to _______________.

Answer 10

oxidative molecule generation: glutathione depletion, uncoupling of oxidative phosphorylation (like the sparks from the lamp)

This leads to inflammatory infiltration (like the blue dots in the cave).

Question 11

What gross features will NSAID-induced TIN show?

Answer 11

• Calcification (like the chunks of white on the cave door)
• Patchy interstitial fibrosis (like the overgrown bushes)

Question 12

Ultimately, TIN leads to ____________ necrosis.

Answer 12

papillary (like the cracking tips of the pyramids)

This occurs from obliterated blood flow.

Question 13

The kidneys of someone with chronic TIN will be _________.

Answer 13

shrunken (like the tiny kidneys dangling from the grandfather clock)

Question 14

Although much less common than NSAIDs, __________ can both also cause chronic TIN.

Answer 14

chronic lead exposure (like the lead paint cans) and chronic lithium use (like the old liftium sign)

Question 15

Chronic TIN is the most common renal manifestation of which autoimmune disorder?

Answer 15

Sjogren’s (like the antibodies on the TIN cave)