Tubulointerstitial diseases Flashcards
What are the causes of acute interstitial nephritis?
- Drugs (RSVP)
- infections
- autoimmune disorders
- acute obstructive disorders
RSVP
- Rifampin
- Sulpha drugs
- Proton pump inhibitors
- Pee pill (diuretics)
- Penicillins
- Pain killers (NSAIDs)
- Phenytoin
What is the pathophysiology or acute interstitial nephritis?
tissue edema, tubular cell injury, & compromised tubular flow caused by
- aggressive inflammatory infiltrates
- frank obstruction of the tubules with casts, cellular debris, or crystals
- drugs inducing type IV hypersensitivity reaction
What are the clinical features of acute interstitial nephritis?
- AKI
- eosinophilia
- rash
- fever
- pyuria & hematuria
What are the diagnostics & management for acute interstitial nephritis?
- elevated serum creatinine, eosinophilia
- eosinophiluria
- WBC cast, microscopic hematuria or mild proteinuria
stop offending drug & administer IV fluids
give glucocorticoids if function doesn’t improve
What are the causes of renal papillary necrosis?
POST CARDS
- Pyelonephritis
- Obstruction
- Sickle cell disease
- Tuberculosis
- Cirrhosis
- Analgesics (NSAIDs)
- Rejection of renal transplant
- Diabetes
- Systemic vasculitis
What is the pathophysiology & clinical features of renal papillary necrosis?
necrosis & sloughing of papillae -> ureteral obstruction -> scarring
- flank pain (colicky pain)
- hematuria
- proteinuria
- fever, chills
- AKI
How is renal papillary necrosis diagnosed & treated?
- CT urography will show bilateral calcifications (ring shadows)
treat underlying cause
What are the types of renal tubular acidosis?
TYPE I -> inability to secrete H at distal tubule
TYPE II -> inability to reabsorb HCO3 at proximal tubule
TYPE IV -> aldosterone deficiency or resistance in collecting duct & distal convoluted tubules
What are the causes & clinical features of RTA type I?
caused by
- congenital anomalies
- multiple myeloma
- nephrocalcinosis
- amphotrecin B toxicity
- autoimmune diseases
clinical features
- urine PH > 5.5 (n=4.5-4.7)
- hypokalemia & renal stones
How is RTA type I treated?
- alkalinization therapy with oral sodium bicarbonate
What are the causes & clinical features of RTA type II?
caused by
- Fanconi syndrome
- multiple myeloma
- carbonic anhydrase inhibitors
Clinical features
- hypokalemia & Vitamin D-resistant hypophosphatemic osteomalacia
- if serum HCO3 is higher than its reabsorption threshold pH >5.5
- if serum HCO3 if depleted pH <5.5
How is RTA type II treated?
alkali therapy with orally administered potassium citrate
What are the causes & clinical features of RTA type IV?
- increased aldosterone production -> DM, ACE-i, ARBs, adrenal insufficiency
- aldosterone resistance -> K sparing diuretics, nephropathy due to obstruction, TMP-SMX
clinical features
- urine pH <5.5
- hyperkalemia
- decreased urinary ammonium excretion
How is RTA type IV treated?
- furosemide
- mineralocorticoid replacement
- low-potassium diet
