Tubules- Pathology Flashcards
(107 cards)
This is the most common cause of acute renal failure where there is an acute decline in renal fxn often with morphologic evidence of tubular injury.
Acute Kindey Injury (AKI)
What are the 4 causes of AKI?
- Ischemia
- Direct toxic injury
- Acute tubulointerstitial nephritits
- Urinary obstruction
What do u see in the urine in AKI?
Dirty brown granular casts
What happens to the GFR in AKI?
↓ because of an ↑ backpressure from the plug
What 2 segments of the nephron are susceptible to ischemic AKI?
PCT and medullary segment of thick ascending limb.
In ischemic AKI, waht protein is seen in the eosinophilic hyaline casts?
Tamm-Horsfall protein
What area is susceptible to toxic AKI?
PCT
What causes nephrotoxic AKI?
Aminoglycosides, heavy metal (lead, Slayer), myoglobinuria (crush injury), ethylene glycol, radioconstrast, urate (tumor lysis syndrome)
What are the names of the 3 stages for AKI?
Initiation, Maintenance, and recovery
In the initiation phase, what happens the BUN in addition to the slight decline in urine output?
↑ BUN (azotemia)
In the maintenance phase of AKI, there are sustained decreases in urine output, salt and water overload, rising BUN, and what changes in [K] and [H]?
hyperkalemia
metabolic acidosis
What happens to [K] in the recovery phase?
hypokalemia
What is the Tx to AKI?
Dialysis
This is a drug-induced hypersensitivity rxn of the interstitum and tubules, leading to ARF.
Acute interstitial nephritits (AIN)
What are the Sx to AIN?
fever, eosinophilic, rash, renal abnormalities, azotemia
What are the 3 drug classes to cause AIN?
NSAIDs
PCN
Diuretics
Which WBC do u see in the urine in AIN?
Eosinophils
What type of hypersensitivity rxn is AIN?
Type I
Case: pt presents with headache, anemia, GI Sx and HTN. Biopsy shows chronic tubulointerstitial nephritis and renal papillary necrosis. What has this pt been doing to cuase this?
Taking a ton of analgesics
Renal papillary necrosis is a result of what 4 things?
chronic analgesic abuse (phenacetin or ASA use), diabetes mellitus, sickle cell trait or disease, severe acute pyelonephritis
What are the 4 forms of renal injury from NSAID use?
1 hemodynamically induced ARF (↓ prostaglandins)
- acute hypersensitivity interstitial nephritis
- acute interstitial nephritis and minimal-change disease.
- membranous nephropathy
Who is susceptible to acute uric acid nephropathy?
Chemo pts
Who is susceptible to chronic urate nephropathy?
gout pts
What forms in the kidney in chronic urate nephroapthy?
monosodium urate crystals which form a tophus with giant cells and a fibrotic rxn