Tubular And Interstitial Diseases Flashcards
(28 cards)
What are the two causes of acute tubular necrosis?
Ischemia and toxins
What are seen in the urine as a tip off for acute tubular necrosis?
Dirty brown casts
What are areas are most affected in toxic acute tubular necrosis?
Proximal convoluted tubules.
What are the most commonly damaged structures in ischemic acute tubular necrosis?
The renal tubules are sensitive to ischemia.
What are the clinical features of acute tubular necrosis?
- Decreased GFR
- Oliguria with brown dirty casts
- Increased BUN:Creatinine
- Hyperkalemia with metabolic acidosis
What are the characteristics of acute tubulointerstitial nephritis?
Histologically is characterized by interstitial edema, leukocytic infiltration of the interstitium and tubules, and tubular injury.
- eosinophils in the urine*
What is a common cause of acute tubulointerstitial nephritis?
Immune mediated reaction to drugs.
What are the characteristic findings in chronic tubulointerstitial nephritis?
Infiltration with mononuclear leukocytes, interstitial fibrosis, and tubular atrophy.
What are the characteristic findings in acute pyelonephritis?
Hallmark–> patchy interstitial supparative inflammation, intratubular aggregates of neutrophils, tubular necrosis.
WBC casts on UA
What is the most common cause of clinical pyelonephritis?
Ascending infection.
What is always seen in the aftermath of pyelonephritis?
Fibrosis of the underlying renal pelvis and calyces
What are the symptoms that a patient will present with in pyelonephritis?
Fever, flank pain, WBC casts, and leukocytosis.
What allows bacteria to ascend the ureter into the renal pelvis?
Impotence of the vesiculoreteral valve.
What are the characteristic findings in chronic pyelonephritis?
Interstitial fibrosis and atrophy of tubules due to multiple bouts of acute pyelonephritis.
What findings in the kidney will chronic pyelonephritis lead to?
- Lumpy-bumpy scaring of calyces and pelvis, dilated blunted calyces, dilated calyces and pelvis.
- Corticomedullary scaring.
What symptoms will a patient present with in Tubulointerstitial nephritis that is caused by drugs?
Fever, rash, eosinophilia, and acute renal failure.
What are three potential complications that can arise from acute pyelonephritis?
Papillary necrosis–> diabetics, sickel-cell patients.
Pyonephrosis–> seen in total or almost total obstruction in the urinary tract.
Perinephric abscess–>extension of the suppurative inflammation through the renal capsule into the perinephric tissue.
What are the characteristic findings in analgesic nephropathy?
- papillary necrosis.
- edema and infiltration by mononuclear cells.
- interstitial fibrosis can be seen in the medulla.
Why are NSAIDS of concern in analgesic nephropathy?
The kidney expresses COX-2 and inhibition of this can lead to vasoconstriction and ischemia.
What are the 3 phases of ATN and what are the findings in each phase?
1) initiation- slight raise in BUN, oliguria may be present
2) maintenance - decreased urine output, NaCl and H2O overload, increased BUN, HyperK, metabolic acidosis
3) recovery- steady increase in urine volume with HypoK, slow return to normal with an increased susceptibility to infection
What are the findings that differentiate Tubulointerstitial nephritis from other glomerular diseases?
- absence of nephrotic/ nephritic syndromes
- presence of defects in tubular function-saltwasting, metabolic acidosis etc.
What are the organisms that are commonly responsible for pyelonephritis?
E. Coli, proteus, klebseilla, enterobacter from fecal flora.
What is the diagnostic clue into chronic pyelonephritis and analgesic nephropathy?
Involvement of the calyces
What is the cause of light chain cast nephropathy?
Accumulation of immunoglobin light chains (Bence-jones proteins). This can lead to renal dysfunction and CRF
