Tubulointerstitial DIseases Flashcards Preview

IM_Renal and GU > Tubulointerstitial DIseases > Flashcards

Flashcards in Tubulointerstitial DIseases Deck (25):

MCC cause of acute interstitial nephritis

acute allergic reaction to medication (penicillin, cephalosporin, sulfa drugs, diuretics, anticoags, phenytoin, rifampin, PPI)


Other causes of AIN besides allergic rxn

infection (strep/legionella), collagen vascular disease, autoimmune disease (SLE, Sjrogens)


What to ask/look for when suspicious for AIN?

- recent infection?
- start a new med?
- fever, general aches/pains?
- signs of AKI?


Clinical features of AIN

- rash, fever, eosinophilia (CLASSIC FINDINGS)
- pyuria/hematuria may be present


Tests/findings to diagnose AIN

- renal function tests (azotemia, AKI)
- urinalysis (eosinophils are suggestive!, also may see proteinuria/microscopic hematuria
- renal biopsy to distinguish between ATN and AIN (not usually done)


Treatment for AIN

remove offending agent (usually does the most help)
steroids may help if that doesn't fully work
treat infection if present


Renal papillary necrosis can be seen in what conditions?

- analgesic nephropathy
- DM nephropathy
- sickle cell
- urinary tract obstruction
- chronic alcoholism
- renal transplant rejection


How to diagnose renal papillary necrosis

excretory urogram (changes in papilla/medulla)


What agents can cause analgesic nephropathy

phenacetin, acetaminophen, NSAIDs, aspirin
may lead to acute or chronic renal failure


Features generally common to all RTAs

non-anion gap hyperchloremic metabolic acidosis, with glomerfular function normal
decrease in H+ excreted in urine leading to acidemia and urine alkalosis


Type 1 and type 2 RTA (distal vs. proximal?)

type 1 - distal
type 2 - proximal


Inability to secrete H, urine pH > 6 (normal around 4.7), hypokalemic + hyperchloremic nonanion gap metabolic acidosis, nephrolithiasis and nephrocalcinosis

type 1 RTA


causes of type 1 RTA

congenital, multiple myeloma, nephrocalcinosis, nephrotoxicity (amphotericin B), autoimmune diseases (SLE, Sjrogens), medullary sponge kidney, analgesic nephropathy


Treatment for type 1 RTA

-correct acidosis (sodium bicarb), also helps prevent kidney stones
- phosphate salts (promotes excretion of acid)


inability to reabsorb HCO3
increased excretion of bicarb in urine
hypokalemic hyperchloremic nonanion gap metabolic acidosis
NO nephrolithiasis/nephrocalcinosis

type 2 RTA (proximal)


Treatment for type 2 rta

treat underlying cause
DO NOT GIVE BICARB to correct acidosis (it will just be excreted in urine)
sodium restrict (this leads to increased sodium reabsorption and thus bicarb reabsorption in proximal tubule)


Causes of type 2 RTA

fanconi syndrom (in children)
cystinosis, wilson's disease, lead toxicity, multiple myeloma, nephrotic snydorme, amyloidosis


What should be always be ruled out in type 2 RTA patient

multiple myeloma (excretion of monoclonal light chains)


FIndings in Type 4 RTA

- decreased NA absorptoin H and K secretion in distal tubule
- hyperkalemia and acidic urine
- rare to see nephrolithiasis and nephrocalcinosis
- nonanion gap metabolic acidosis still occurs


Autosomal recessive inheritance of defective amino acid transporter -> results in decreased intestinal and renal reabsorption of neutral amino acids such as tryptophan leading to nicotinamide deficiency

hartnup syndrome


How does hartnup syndrome present?

similar to pellagra: dermatitis, diarrhea, taxia, and psychiatric disturbances


How to treat hartnup syndrome

give supplemental nicotinamide if patient is symptomatic


Fanconi syndrome is a hereditary or acquired proximal tubule dysfuciton that leads to defective transport of what?

glucose, aminoa accids, sodium, K, phsophate, uric acid, and bicarp


What are some problems seen in Fanconi syndrome

- glucosuria
- phosphaturia (leads to rickets/impaired growth in children, osteomalacia, osteoporosis, fractures
- proteinuria
- polyuria
- dehydration
- type 2 RTA
- hypercalciuria


How to treat fanconi sydnrome

phsophate, K, alkali and salt supplementation, adequate hydration