TubuloInterstitial Disease and PCKD Flashcards
How does the protein loss associated with tubulointerstitial disease differ from the nephrotic protein loss?
TIN predominantly loses LMW proteins like B2-microglobulin instead of albumin
TIN can have isolated tubular defects and urinary concentrating defects. What would be the clinical presentations of those?
Tubular defects: glycosuria proteinuria aminoaciduria K wasting OR retention RTA
Urinary concentrating defects:
polyuria
nocturia
What is the effect of TIN on urinary Na, urine concentration and body volume?
It enhances Na wasting, the urine is dilute and the body volume is depleted
What metablic disorder is often associated with TIN?
NG metabolic acidosis due to defective ammoniagenesis in the tubules
You do a urinalysis and see RBC, RBC casts, proteinuria and granular casts. What is the likely cause of the disease : nephritic, nephrotic or interstitial?
Nephritic
You do urinalysis and see heavy proteinuria, fatty casts, oval bodies, and free fat droplets. Is this nephrotic, nephritic or interstitial?
Nephrotic
You do urinalysis and see WBC casts, sterile pyuria, eosinophiluria, low grade proteinuria, hematuria. Nephritic, nephrotic or interstitial?
Interstitial
Primary Na retention Low urinary Na hypertension CHF edema severe reduction in GFR
Nephritic, nephrotic, interstitial?
Nephritic
Secondary Na retention low urinary Na \+/- hypertension edema less severe reduction in GFR
Nephritic, nephrotic, interstitial?
nephrotic
impaired urine concentration
hyperkalemia
RTA (type IV)
Na wasting
Nephritic, Nephrotic, interstitial ?
Interstitial
What if Fanconi syndrome?
The clinical presentation of myeloma where there is disruption of the proximal tubule resulting in:
- RTA
- Glycosuria
- Phopsphate wasting, Uricosuria
What is the functional defect of a proximal tubule defect in Interstitial renal disease?
What is the syndrome?
Decreased reabsorption of HCO3, glucose, aminoacids, phosphate, uric acid
=
Fanconi syndrome
What are the functional defects of distal nephron interstitial renal disease?
decreased Na reabsorption, impaired K and H excretion –> RTA 4
What are the functional defects of the loop in interstitial renal disease?
- decreased Na reabsorption leading to salt wasting.
2. nephrogenic DI
What are the functional defects of the interstitium in TIN?
decreased epo—> anemia
decreased gradient so can’t concentrate urine
What is the most common cause of acute interstitial nephritis (non-infectious)?
How does it manifest?
Acute-Allergic drug reaction - a hypersensitivity reaction to a medication like antibiotic, NSAID, diuretic
The patient gets a rash, pruritis, eosinophilia and fever [ABSENT RESPONSE W NSAIDS]
What are indications for biopsy when acute allergic TIN is suspected?
- diagnostic uncertainty
- advanced kidney failure
- lack of spontaneous recovery after drug removal
How is acute allergic TIN treated?
- withdraw inciting medication
- corticosteroids if there is aggressive disease (worsening azotemia).
If biopsy shows acute inflammation in the absence of chronic damage, cortico will be more effective
What does the urinary sediment for acute allergic TIN show?
RBC, WBC, WBC casts
How does acute TIN from NSAIDs differ from TIN from antibiotics or diuretics?
NSAIDs will not have rash, fever etc but will have large amounts of proteinuria.
It looks like MCD with concurrent tubulointerstitial inflammation
What two renal syndromes are NSAIDs associated with?
- ATN when the patient has decreased EABV
2. TI renal disease with nephrotic proteinuria
What are clinical signs of chronic TIN?
What is seen in the urine?
It is a syndrome of CKD that progressed to ESKD where older women are at highest risk
- polyuria
- nocturia
Urine will have bland sediment, low urine protein (and the proteins will be LMW like b2 microglobulin, tamm-horsfall, and light chains)
What is seen on ultrasonography and biopsy for chronic TIN?
Ultrasonography- atrophic echogenic kidneys with CKD
Biopsy-
- lymphocytic infiltrate
- fibrosis in interstitium
- tubular atrophy
- arteriosclerosis
- global glomerulosclerosis
What drugs cause chronic TIN?
Chinese herbs, lithium, cyc A, ANALGESICS