Pathology of Glomerular Disease Part III

Question 1

What can a urinary tract infection infect (UTI)?

Answer 1

urethra, bladder, or kidneys

*usually ascending, starting in urethra and more common in women.

Question 2

What are the risk factors for UTI?

Answer 2

sexual intercourse, urinary stasis, and catheters

Question 3

What is cystitis?

Answer 3

inflammation of the bladder, presenting with dysuria (pain with urination), urinary frequency, urgency, and suprapubic pain.

Question 4

Do you normally see systemic signs with UTI?

Answer 4

NO (i.e. no fever).

Question 5

What are the lab findings for cystitis?

Answer 5

• urinalysis= cloudy urine with >10 WBCs/high power field.
• dipstick= + leukocyte esterase (due to pyuria) and nitrites (bacteria convert nitrates to nitrites).
• culture= > 100,000 colony forming units (gold standard).

Question 6

What are the 5 common etiologies?

Answer 6

1. E. coli (80%)
2. Stpahylococcus saprophyticus= increased incidence in young, sexually active women.
3. Kelbsiella pneumoniae
4. Proteus mirabilis= alkaline urine with ammonia scent.
5. Enterococcus faecalis

Question 7

What is sterile pyuria and what does it suggest?

Answer 7

pyuria (>10 WBCs/hpf and leukocyte esterase) with a negative urine culture, which suggests urethritis due to Chlamydia trachomatis or Neisseria gonorrhoeae.

Question 8

**What is pyelonephritis?

Answer 8

infection of the kidney, usually due to ascending infection. There will be an increased risk with vesicoureteral reflux.

• acute= bacterial
• chronic= infections, reflux, and/or obstruction

Question 9

Do patients with pyelonephritis present with systemic signs?

Answer 9

YES. Fever, flank pain, WBC casts, and leukocytes in addition to symptoms of cystitis.

Question 10

What are the 3 most common pathogens for pyelonephritis?

Answer 10

1. E. coli (90%)
2. Enterococcus faecalis
3. Klebsiella

Question 11

**What is chronic pyelonephritis?

Answer 11

interstitial fibrosis and atrophy of tubules due to multiple bouts of acute pyelonephritis. This is classically seen in CHILDREN due to vesicoureteral reflux, or may be due to obstruction (BPH or cervical carcinoma). This leads to cortical scarring with blunted calyces; scarring at upper and lower poles is characteristic of vesicoureteral reflux.

Question 12

What will the histology of chronic pyelonephritis show?

Answer 12

• atrophic tubules containing EOSINOPHILIC proteinaceous material, resembling thyroid follicles (THYROIDIZATION of the kidney). Waxy casts may be seen in urine.

Question 13

What is nephrolithiasis?

Answer 13

precipitation of a urinary solute as a stone.

*Risk factors= high concentration of solute in the urinary filtrate and low urine volume.

Question 14

How does nephrolithiasis present?

Answer 14

colicky pain with hematuria and unilateral flank tenderness. Stone is usually passed within hours. If not, surgical intervention may be required.

Question 15

What is the most common type of stone seen in adults?

Answer 15

calcium oxalate and/or calcium phosphate stone due to idiopathic hypercalciuria (but not hypercalcemia, bc the blood levels are fine). Treat with hydrochlorothiazide (Ca2+ sparing diuretic).

Question 16

What type of renal stone results in a staghorn calculi in the renal calyces?

Answer 16

• adults= ammonium magnesium phosphate stone

- children= cystine (RARE)

Question 17

What is the 3rd most common stone that will not be seen on x-ray (radiolucent)?

Answer 17

uric acid stone (seen with gout).

Question 18

**What is chronic renal failure?

Answer 18

end-stage kidney failure resulting from glomerular, tubular, inflammatory, or vascular insults.

Question 19

What are the 3 most common causes of chronic renal failure?

Answer 19

1. DM
2. HTN
3. glomerular disease

Question 20

**What are the clinical features of chronic renal failure?

Answer 20

1. UREMIA= increased nitrogenous waste products in BLOOD (azotemia). Pts may develop nauseas, anorexia, pericarditis, platelet dysfunction, encephalopahty with asterixis, and deposition of urea crystals in skin.
2. salt and water retention= HTN
3. HYPERKALEMIA with metabolic acidosis
4. anemia due to decreased erythropoietin production by RENAL PERITUBULAR INTERSTITIAL CELLS.
5. HYPOCALCEMIA due to decreased 1-alpha-hydroxylation of vitamin D1 by proximal renal tubule cells and HYPERPHOSPHATEMIA.
6. renal OSTEODYSTROPHY= damage to the bone due to renal failure. This results from secondary hyperparathyroidism (due to decreased Ca2+), osteomalacia (cannot mineralize the osteoid made by the osteoblasts), and osteoporosis.

Question 21

What is the treatment for chronic renal failure?

Answer 21

dialysis or renal transplant. Cysts often develop within shrunken end-stage kidneys during dialysis, increasing risk for renal cell carcinoma.

Question 22

***Can acute pyelonephritis cause papillary necrosis?

McDonald said to remember this

Answer 22

YES. This is necrosis of the apical 2/3 of the renal pyramids, usually associated with ANALGESIC abuse, which inhibits prostaglandins and cause ischemia of renal medulla.

Question 23

What is benign nephrosclerosis?

Answer 23

renal changes (hyaline arteriosclerosis; pink thickening of the vessel, decreased blood flow, and granular cortical surface) most commonly occurring in association with long-standing hypertension. It is termed benign because it rarely progresses to clinically significant renal insufficiency or renal failure.