20 Tubulointerstitial Disease

  • like heart attack

  • cat scan
  • multiple myeloma: bence jones protein

  • Rusty downspout draining muddy water: acute tubular necrosis (ATN)
  • muddy cast on urinalysis

  • epithelial cells squeeze through nephron and form casts

  • phase 1: clinically silent
  • maintenance: acute RF, a few days later
  • metabolic acidosis: can't excrete acids
  • phase 3: fast urine output, drop K with urine
  • know hyperkalemia in phase 2 and hypo in phase 3

AIN

Acute

  • Kidney bag with little blue candies: interstitial nephritis

  • Blue star clusters in kidney nebula: drug-induced interstitial nephritis

  • Baseball-filled kidney containers: NSAIDs can cause acute interstitial nephritis

  • Kidney filled with blue tickets: loop diuretics can cause interstitial nephritis (blue cells on histology )

  • Kidney sharps: IV acyclovir can cause interstitial nephritis or crystalline nephropathy

  • don't need to know individual bacteria

  • WBC casts: inflammation of nephron
  • no bladder symptoms (frequency, urgency, burning urination) association with pyelonephritis (ascending infection from bladder to kidney)
  • eosinophilia: allergic reaction

Chronic

  • longterm NSAIDS exposure

NSAIDS

  • Constricted proximal end of hose: NSAIDs cause afferent arteriole vasoconstriction, decreasing GFR
  • Bursting from high pressure: NSAIDs can increase blood pressure due to COX inhibition in the kidney, decreasing sodium excretion
  • Baseball-filled kidney containers: NSAIDs can cause acute interstitial nephritis
  • Sloughing off cleat spikes: NSAIDs can cause renal papillary necrosis (sloughing of renal papillae)
  • Elevated “lift-ium” balloons: NSAIDs can increase serum lithium concentrations
  • Depleted mineral mine: NSAIDs can cause hypoaldosteronism (decreased mineralocorticoids)
  • Big K: NSAID induced hypoaldosteronism can cause hyperkalemia. Type 4 RTA

Papillary Necrosis

  • Gray-white or yellow necrosis of the distal two-thirds of the renal pyramids is seen macroscopically and corresponds microscopically to coagulation necrosis with preserved tubule outlines; cortical surface scars can develop subsequently as inflammatory foci are replaced by fibrous depressions.
  • Symptoms are due to sloughed papillae (sometimes visible in urine as tissue flecks) and include dark or bloody urine and colicky flank pain (due to ureteral obstruction).

  • phenacetin: analgesic no longer used

  • Baseball-filled kidney containers: NSAIDs can cause acute interstitial nephritis

Cortical Necrosis

  • i in cortical stands for ICU and DIC: critically ill
  • caused by massive tissue destruction

  • kidney diseases as either glomerular diseases (biopsy) or tubulointerstitial diseases (clinical diagnosis)