tubule-interstitial diseases of the kidney Flashcards
what kind of kidney injury are tubulointerstitial diseases?
intrinsic kidney injury
acute tubulointerstitial nephritis definition
an acute inflammation of the renal interstitial and tubules that causes a decline in renal function over days to weeks
acute interstitial nephritis urine findings
WBCs, eosinophils
WBC casts
acute tubular necrosis urine findings
muddy brown granular casts
renal tubular epithelial cells/casts
Acute tubular injury/necrosis pathophys
ischemic or toxic injury to tubular cells causes cells to swell and undergo apoptosis/necrosis
cell debris obstructs tubules leading to decreased GFR
ischemic causes of ATN
blood loss
hypotension
septic shock
aortic surgery
toxic causes of ATN
radiocontrast abx: aminoglycosides amphotericin B antivirals Chemo (cisplatin)
presentation of ischemic ATN
low BP
shock syndrome
blood loss signs
oliguria (<400ml/day)
toxic ATN clinical presentation
non-specific
tends to have non-oliguric urine flow because there is less tubular injury
get a good history to find out if a drug could be causing it
ATN lab findings
increased BUN and Cr hyperkalemia metabolic acidosis uremia granular cases and tubular casts in urine
granular casts usually indicate
acute tubular injury
difference in urination between toxic and ischemic ATN
toxic=non-oliguria
ischemic=oliguria
toxic ATI/ATN is very common among ___
ill hospitalized patients (10-20% of patients!)
acute interstitial nephritis pathophys
usually a drug allergy
acute attack on tubules by inflammatory (T) cells. T cells migrate into tubule lumens which become obstructed leading to kidney injury and GFR decline
AIN clinical presentation
often asymptomatic
fever, malaise, rash, arthralgia, flank pain
AIN etiology
inflammation due to:
allergic response
autoimmune response
infectious response
AIN diagnosis
clinical context (new drug, disease) WBCs/casts in urine kidney biopsy is definitive
AIN kidney biopsy findings
interstitial cellular infiltrate with T cells and tubulitis
chronic interstitial nephritis definition
chronic inflammation of the renal interstitial and tubules that usually progresses to tubular atrophy and interstitial fibrosis
causes of chronic interstitial nephritis
drugs chronic infection in the bladder autoimmune heavy metals infiltrative diseases metabolic diseases
chronic interstitial nephritis clinical features
asymptomatic,
fatigue, fever, nocturne, polyuria
chronic interstitial nephritis labs and imaging
BUN and Cr increase slowly
renal US shows small echogenic kidneys
chronic interstitial nephritis urinalysis
bland urine sediment
waxy or granular casts
+/- WBC cells/casts
renal sarcoidosis
granulomatous multi-system autoimmune disease that affects the kidneys
primary and enteric hyperoxaluria
elevated level of oxalic acid in urine leading to calcium oxalate crystal deposition in the kidneys
common in pts with gastric bypass or taking weight loss rx
autosomal dominant polycystic kidney disease
a common inherited kidney disease due to a mutation on either chromosome 16 or 4 that leads to the development of multiple cysts in the kidneys
PKD clinical presentation
usually asymptomatic until advanced
polyuria, hematuria, flank pain, HTN
PKD diagnosis
kidney ultrasound is most commonly used
CT scan or MRI
showing 2-3 cysts in both kidneys
PKD treatment
ACEi to lower BP
increase water intake
Tolvaptan to slow cyst growth
