Tubulointerstital Diseases

Question 1

Two most common causes of acute tubular necrosis

Answer 1

Acute loss of Bloodflow (trauma, acute pancreatitis, shock, sepsis)
Nephrotoxic Agents

Question 2

Most commonly mentioned nephrotoxic agents that trigger acute tubular necrosis

Answer 2

Gentamicin/Other ABs
Contrast
Heavy Metal
Organic Solvents (Carbon Tetrachloride)

Question 3

Less common causes of acute tubular necrosis

Answer 3

Ethylene glycol/Methanol poisoning

Hemaglobinuria/Myoglobinuria (crush injury, OH binges)

Question 4

acute tubular necrosis casts are made primarily of

Answer 4

Tam Horsfall protein

Can also add globin + plasma proteins

Question 5

Describe the appearance of regenerating epithelial cells in acute tubular necrosis

Answer 5

Flattened
Hyperchromatic Nuclei
Mitotic Figures

Question 6

Carbon tetrachloride poisoning microscopic features

Answer 6

Neutral lipid accumulations

Question 7

Ethylene glycol poisoning microscopic features

Answer 7

Ballooning and hydrophobic or vacuolar degeneration with formation with formation of Ca Oxalate Crystals

Question 8

Describe the three clinical phases of acute tubular necrosis

Answer 8

1. Initiating - Slight decline in urine output + inc. BUN
2. Maintenance - Major drop in renal output, too much salt, water, BUN, K, and metabolic acidosis
3. Recovery - Steady increase in urine output, hypokalemia risk

Question 9

Describe the features of acute tubulointerstitial nephritis

Answer 9

• Interstitial edema, leukocytic infiltrates, focal tubular necrosis
• Caused by acute renal failure

Question 10

Describe the features of chronic tubulointerstitial nephritis

Answer 10

• Infiltration by mononuclear cells, interstitial fibrosis, and tubular atrophy
• Caused by slowly progressing toxic damage (analgesic abuse)
• Usually not recognized till late

Question 11

How is tubulointerstitial nephritis clinically distinguished from other renal diseases

Answer 11

ABSENCE of nephrotic/nephritic symptoms
Impaired concentrating ability
Salt Wasting
Metabolic Acidosis

Question 12

Drugs that cause Acute interstitial nephritis

Answer 12

• Sulfonamides, Synth. Penicillins, other synt. ABs (rifampin)
• Diuretics (esp. thiazides)
• NSAIDs (phenylbutazone)
• Pheniodine and cimetidine

Question 13

Clinical presentaiton of a hypersensitivity rxn triggered interstitial nephritis

Answer 13

2-6 weeks after drug exposure
Fever, Eosinophilia, Rash, Renal abnormalities
Acute renal failure in 50%

Question 14

Describe the process of developing chronic renal disease due to analgesic abuse

Answer 14

First – Papillary Necrosis, tubulointerstitial neph. is 2dary
NSAID covalently binds and oxidatively damages
Inhibit PGs –> No Vasodilation –> Papila ischemic

Question 15

Which analgesics are most prone to cause chronic renal disease due to analgesic abuse

Answer 15

Phenacetin

Aspirin, Caffeine, Acetaminophen, Codeine

Question 16

Clinical associations for interstitial nephritis from analgesics

Answer 16

• Look for women with chronic headaches, pains
• Early – cant concentrate urine, acidosis, stones
• UTI in about 50%

Question 17

Causes of papillary necrosis

Answer 17

Analgesic nephropathy
Diabetes
Urinary Tract Obstruction
Sickle Cell
Renal TB

Question 18

Cancer that chronic analgesic abuse is associated with

Answer 18

transitional papillary carcinoma of the renal pelvis

Question 19

NSAID drug nephropathy is associated with which glomerular disease

Answer 19

membranous glomerulonephritis

Question 20

Three forms of urate nephropathy

Answer 20

1. Acute Urate Nephropathy 2dary to uric acid crystals
2. Chronic urate nephropathy
3. Nephrolithiasis w/ uric acid stones

Question 21

Important details abut acute urate nephropathy secondary to precipitation of uric acid crystals

Answer 21

Obstructs nephrons/CDs
Can cause Acute Renal Failure
Assocaited with Leukemias and Lymphomas going thru chemo

Question 22

Disorders that cause hypercalcemia (4)

Answer 22

Hyperparathyroidism
Multiple Myeloma/Bone Cancer
Vitamin D intoxication
Taking in too much Ca

Question 23

What happens to the Bence Jones (light chain) proteins the kidney of a multiple myeloma patient

Answer 23

Proteinuria + Cast nephropathy
Light chains are toxic to epithelial cells
Combine with Tamm-Horsfall to make casts
Cause obstructions with peritubular inflammation**

Question 24

Other than the Myeloma kidney with peritubular inflammation, what are some other ways that multiple myeloma may affect kidney fxn

Answer 24

Amyoidosis
Light Chain Glomerulonephritis
UT obstruction with secondary pyelonephritis

Question 25

How to identify amyloid deposits in the glomerulus

Answer 25

Congo red positive fibrillary deposits of mesangium and subendothelium
Also hits BVs and kidney interstitium