SFP: tubulointerstitial diseases/UTI Flashcards
What does PAS stain highlight?
Proteoglycans (basement membrane)
What is acute pyelonephritis?
Bacterial infection of kidney and renal pelvis
What is chronic pyelonephritis?
Bacterial infection plus scarring
what can cause chronic pyelonephritis
reflux or obstruction
What can cause UTIs?
Cystitis (bladder infection), pyelonephritis, or both
What are ways pathogens can get into the kidney?
- Ascending infection 2. Through the filtered blood 3. Reflux
What are some main predisposing factors for pyelonephritis?
Pregnancy, catheters, diabetes, immunosuppression, BPH, young female
Which papillae are more affected by reflux?
Compound papillae
Reflux nephropathy impacts…
Upper and lower poles
When do we see white cell casts?
Acute pyelonephritis (usually neutrophilic)
Describe papillary necrosis.
Rare complication of pyelonephritis that causes ischemic and suppurative necrosis of the tips of renal pyramids
What are predisposing conditions for papillary necrosis?
Diabetes, urinary tract obstruction, sickle cell anemia
What is the clinical presentation of acute pyelonephritis?
Costovertebral angle pain, fever/chills/malaise, pyuria, dysuria, maybe papillary necrosis
What is glomerulosclerosis?
In chronic pyelonephritis can present with glomeruli scarring themselves off
What is thyroidization?
It occurs in chronic renal disease and shows up as little pink blobs
Focal segmental sclerosis is a complication of…
Reflux nephropathy
What is the clinical presentation of cystitis?
Acute/severe onset of urgency and burning, bacteriuria, hematuria, pain/tenderness
When is fever seen in cystitis?
If infection has spread to the kidney
What is the most common microorganism causing UTI?
UPEC (uropathogenic E. coli)
Which microorganism is only found in uncomplicated UTI?
Strep saprophyticus
What are virulence factors of uropathogens?
Adhesins!
Compare adhesins in uncomplicated vs complicated UTI.
In uncomplicated they cause pathogen binding directly to urothelium, while in complicated the pathogen is usually binding to urinary stones or catheters
Describe UPEC.
They are the most common cause of UTI, live intracellularly, and have FimH antigen that acts as an adhesin and P pili that facilitate kidney infection
Describe staph saprophyticus.
Part of normal GI flora, causes UTI in young women, and coagulase negative
Describe enterococcus and pseudomonas as causes of UTI.
Cause nosocomial UTI post-surgically or with catheters
Describe proteus mirabilis.
Has urease that raises pH, forms calcium crystals and magnesium ammonium phosphate precipitates. They also form crystalline biofilms on catheters
What is the pharmacologic treatment of uncomplicated UTI?
3 days of TMP/SMX or 5 days nitrofurantoin
What is the pharmacologic treatment in complicated cystitis?
Empiric fluoroquinolone for 7-14 days
Why can we not leave urine samples on the counter?
They can replicate and make an inaccurate sample
What may be the first sign of UTI in the elderly?
Delirium
What virus causes tubular interstitial injury in kidney transplant patients?
BK polyomavirus
What drug can be associated with drug induced interstitial nephritis?
NSAIDs
What is the most common cause of acute drug-induced interstitial nephritis?
PPIs
What is seen histologically in acute drug induced interstitial nephritis?
Looks allergic, eosinophils!
What labs would support tubulointerstitial disease diagnosis?
Increased creatinine/BUN, renal tubule acidosis, hyper or hypokalemia, proteinuria
What might be the clinical presentation of acute drug induced interstitial nephritis?
Fever and rash 15 days after medication use
What is analgesic nephropathy?
Caused by excessive intake of things like aspirin, coffee, caffeine, acetaminophen
What is the pathology of analgesic nephropathy?
Renal papillary necrosis and chronic interstitial nephritis
What is seen microscopically in analgesic nephropathy?
Coagulative necrosis of the medulla (no nuclei visible)
Which condition increases risk of urothelial cancer of renal pelvis?
Analgesic nephropathy
What conditions in the kidney are associated with NSAIDs?
Acute interstitial nephritis, minimal change disease, renal papillary necrosis
What does Balkan nephropathy lead to?
Tubulointerstitial and end stage renal diseases
Describe the presentation of acute phosphate nephropathy.
Renal insufficiency several weeks after exposure
Where does calcium phosphate deposit?
In the renal tubules
Describe lithium toxicity.
Can lead to mild-moderate tubulointerstitial disease and possibly end stage renal disease. Lithium drug and AKI may lead to this!
What is the earliest renal finding of sickle cell disease?
Loss of urine concentrating ability
Describe sickle cell in the kidney.
Low oxygen tension in the medulla leads to sickling and fibrosis
What can cause acute tubular injury?
Ischemia and toxins
