Internal Medicine

0521779407-20 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:22

1464 Tubulointerstitial Renal Disease

non nephrotic proteinuria

inactive urine sediment

Imaging

■Acute TIN:

➣ultrasound: kidneys may be swollen and enlarged

➣may have increased cortical echo density

■Chronic TIN:

➣ultrasound: kidneys may be small, echo dense

➣blunted calyx with reflux

Renal Biopsy

■definitive diagnostic test

■not always necessary

■perform when history and evidence are not strong

■consider in patients with ARF, who are not prerenal, and not

obstructed by ultrasound

■perform biopsy when information obtained will alter therapy

➣Acute TIN:

increased interstitial volume and edema

focal infiltrates of mononuclear cells primarily peritubular

location with sparing of glomeruli and vessels

immunoglobulin deposits rarely seen by immunofluorescence

amount of fibrosis may aid in determining aggressiveness of

therapy

➣Chronic TIN:

increased interstitial volume-primary fibrosis and tubular

atrophy

extent of fibrosis has prognostic value

differential diagnosis

■Clinical entities which must be distinguished from TIN

➣Acute TIN: any cause of pre-renal, post renal or renal ARF

➣Chronic TIN: any cause of chronic renal failure

Causes of ATIN

■Common causes:

➣Drug induced (immune mediated)

➣Systemic disease

➣Infection (frequently immune mediated)

➣Idiopathic