Tubulo-interstitial diseases Flashcards
what are the two broad groups of conditions
- acute tubular necrosis (ischaemic or toxic necrosis of tubular cells)
- tubulointerstitial nephritis (inflammatory reactions involving tubules)
ATN due to ischaemia
due to shock and reduction of intrarenal blood flow
ATN due to toxins
heavy metals organic solvents drugs iodinated contrast agents used for xrays pesticides glycols
ATN features
macro - pale swollen edematous kidney micro - focal tubular epithelial necrosis and apoptosis basement membrane rupture interstitial rupture epithelial regeneration
the 3 phases of ATN
- initial - increase in urine output and rise in serum urea
- oliguric - urine output is 400ml or less a day (water retention), rising urea, metabolic acidosis, danger of pulmonary edema
- diuretic - urine output more than normal (loss of water)
pathogenesis of 3 phases
initial - tubular cells begin to lose concentrating ability
oliguric - tubular epithelium lost, leading to reabsorption of most of glomerular filtrate
diuretic - regenerating epithelium can prevent reabsorption but cant concentrate
renal cortical necrosis
severe hypotension renal blood flow diverted to medullary vasa recta away from cortex
whole cortex becomes infarcted which is irreversible
tubulointerstitial nephritis types
primary - lacks significant glomerular or vascular injury
secondary - due to glomerular disease, systemic or vascular disorders
acute - interstitial edema, neutrophils, focal tubular necrosis
chronic - mononuclear inflammation, interstitial fibrosis, tubular atrophy
pathophysiology of acute drug induced
delayed type 4 hypersensitivity reaction due to drug effect which binds to tubular epithelium making it immunogenic
micro - edematous interstitium containing abundant eosinophils and neutrophils, lymphocytes, macrophages
other causes of papillary necrosis
diabetes mellitus
obstruction
sickle cell disease
complications of acute pyelonephritis
papillary necrosis
pyonephrosis
perinephric abscess
pathogenesis of chronic pyelonephritis
urine refluxes into ureter during micturition
common at renal poles
clinical course of chronic pyelonephritis
insiduos
acute recurrent pyelonephritis
hypertension
causes of obstructive uropathy
urethral strictures, meatal stenosis, bladder neck obstruction, uretopelvic junction narrowing, vesicoureteal reflux, stones, prostatic hypertrophy, inflammation, pregnancy,
what is hydronephrosis
cystic dilation of renal pelvis and calyces associated with progressive atrophy of kidney due to obstructive uropathy
