Diseases of the Renal and Genitourinary system

Question 1

Acute Kidney Injury - Definition

Answer 1

A rapid decline in renal function, with an increase in serum creatinine level (A relative increase of 50% or an absolute increase of 0,5 to 1,0 mg/dL). The creatinine may be normal despite a markedly reduced GFR in the early stages, due to the time it takes for creatinine to accumulate in the body.

AKI may present with olguria, anuria or actully nonoliguric (Nonoliguric AKI)

Question 2

RIFLE Criteria

Answer 2

RIFLE criteria was proposed in order to define and stratify the severity of acute kidney injury (AKI).

a) RISK - 1.5-fold increase in the serum creatinine or GFR decrease by 25% or urine output <0,5 mL/kg/hr for 6 hours.
b) INJURY - twofold increase in the serum creatinine or GFR decrease by 50% or urine output <0,5mL/kg/hr for 24 hours, or anuria for 12 hours.
c) FAILURE: Threefold increase in the serum creatinine or GFR decrease by 75% or urine output of < 0,5 ml/kg/hr for 24 hours, or anuria for 12 hours.
d) LOSS. Complete loss of kidney function (i.e., requiring dialysis) for more than 4 weeks
e) ESRD: Complete loss of kidney function (i.e., requiring dialysis) for more than 3 months.

Question 3

Most common findings in patients with AKI

Answer 3

Weight gain and edema. This is due to a positive water and sodium (Na+) balance.

Question 4

AKI is characterized by Azotemia (elevated BUN and Cr). In which other diseases/situations can you also see this?

Answer 4

a) Elevated BUN is also seen with catabolic drugs (e.g steroids), GI/soft tissue bleeding, and dietary protein intake.
b) Elevated Cr is also seen with increased muscle breakdown and varius drugs. The baseline Cr level varies proportionately with muscle mass.

Question 5

Prognosis of AKI

Answer 5

a) More than 80% of patients in who AKI develops recover completely. However, prognosis varies depending on the severity of renal failure, age + comorbidities.
b) The most common cause of death is infection (75% of all deaths), followed by cardiorespiratory complications.

Question 6

Types of AKI

Answer 6

1. Prerenal AKI - decrease in renal blood flow (60-70% of cases) = Most common!
2. Intrinsic AKI - damage to renal parenchyma (25-40%
3. Postrenal AKI - Urinary tract obstruction (5-10%)

Question 7

Prerenal AKI - Causes

Answer 7

Decr. in systemic arterial blood bolume or renal perfusion.

1. Hypovolemia
   - Dehydration
   - Excessive diuretic use
   - Poor fluid intake
   - Vomiting
   - Diarrhea
   - Burns
   - Hemorrhage
2. CHF
3. Hypotension (syst. BP below 90 mm Hg)
   - Sepsis
   - Excessive antihypertensive meds
   - Bleeding
   - Dehydration
4. Renal arterial obstruction (kidneys are hypoperfused despite elevated blood pressure)
5. Cirrhosis, hepatorenal syndrome
6. In patients with decr.renal perfusion, NSAIDS (constrict afferent arteriole), ACE inhibitors(cause efferent arteriole vasodilation) and cyclosporin can precipitate prerenal failure

= Decr. renal blood flow -> lowers GFR -> decr. clearance of meatbolites (BUN, Cr, Uremic toxins)
However, tubular function is preserved (in early stages) and kidney tries to conserve as much sodium and water as possible.
- Reversible on restoration of blood flow, but if hypoperfusion persists -> ischemia -> acute tubular necrosis.

Question 8

Prerenal AKI - Clinical and labs

Answer 8

Clinical:
Signs of volume depletion
- Dry mucous membranes, hypotension, tachycardia, decr. tissue turgor, oliguria/anuria

Labs:
- Oliguria - ALWAYS found in prerenal failure
- Increased BUN-Cr ratio (>20:1 is classic ratio)
- Increased urine osmolality (> 500mOsm/kg H2O - because kidney can absorbe water)
- Decr. urine Na+ (<20mEq/L, with FENa <1%, because Na+ is avidly reabsorbed)
- Bland urine sediment
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Question 9

Intrinsic AKI - Causes

Answer 9

Kidney tissue is damaged -> GFR and tubular function are significantly impaired. Kidneys are unable to concentrate urine effectively.

1. Tubular disease (ATN) - ischemia(= most common), but also nephrotoxins
2. Glomerular disease (acute glomerulonephritis, f.eks Goodpasture syndrome, Wegener granulomatosis, posttrep. GN, lupus)
3. Vascular disease - eks, renal artery occlusion, TTP, HUS
4. Interstitial disease (e.g allergic interstitial nephritis, often due to hypersensitivity rxn to medication)

Question 10

Intrinsik AKI - Clinical and labs

Answer 10

Clinical features depend on the cause. Edema is usually present. Recovery often takes longer than w prerenal failure

Labs:

• Decr. BUN-Cr ratio (<20:1, often 10:1). Both BUN and Cr are still elevated, but less urea is reabsorbed than in prerenal failure.
• Incr. urine Na+ (>40mEq/L, Fith FENa > 2-3%), because Na+ is poorly reabsorbed.
• Decr. urine osmolality (<350 mOsm/kg H20) - bcause renal water reabsorption is impaired
• Decr. urine- Cr ratio (<20:1) - because filtrate cannot be reabsorbed)

Question 11

Postrenal AKI - Causes

Answer 11

Least common cause of AKI

1. Obstruction of any segment of the urinary tract (with intact kidney), causes incr. tubular pressure, which leads to decr. GFR. Both kidneys has to be obstructed for creatinine to rise.
2. Urethral obstruction secondary to enlarger prostate = Most common!
3. Obstruction of solitary kidney
4. Nephrolithiasis
5. Obstructing neoplasm (bladder, cervix, prostate, etc)
6. Retroperitoneal fibrosis
7. Uretral obstruction is an uncommon cause because obstruction must be bilateral to cause renal failure.

Question 12

Diagnosis of AKI

Answer 12

1. Blood tests
   a) Elevation in BUN and Cr levels
   b) Electrolytes (K+, Ca20, Po43-), albumin levels, CBC with differential.
2. Urinalysis
   a) A dipstick test positive for protein (3+, 4+), suggest intrinsic renal failure due to glomerular insult.
3. Microscopic examination of the urine sediment:
   - Hyaline casts are devoid of contents(seen in prerenal failure)
   - RBC casts - indicate glomerular disease
   - WBC casts - indicate renal parenchymal inflammation
   - Fatty casts - indicate nephrotic syndrome
4. Urinary chemistry - to distinguish between different forms of AKI
   a) Urine Na+, Cr, and osmolality: Urine Na+ dependson dietary intake.
   b) FENa: collect urine and plasmaelectrolytes simultaneously.
   - (Values below 1% suggest prerenal failure)
   - (Values above 2-3% suggest ATN)
   - FENa is most useful if oliguria is present
5. Urine culture and sensitivities - if infection is suspected.
6. Renal USG
   - Useful for evaluating kidney size and for excluding UT-obstruction (postrenal failure)
   - Order for most patients with AKI
7. CT scan (if USG shows abnormalities such as hydronephrosis)
8. Renal biopsy
9. Renal arteriography - to evaluate renal artery occlusion.

Question 13

What is urine osmolality?

Answer 13

A measure of urine concentration. The higher the osmolality, the more concentrated the urine. Dehydration in a healthy person leads to increase in urine concentrations as follows: dehydration causes low intravascular volume, which triggers ADH release, which stimulates reabsorption of water from kidney to fill the vasculature, increased water reabsorption leadstomore concentrated urine.

Question 14

AKI - Cx

Answer 14

1. ECF volume expansion and resulting pulm edema - treat with furosemide.
2. Metabolic
   - Hyperkalemia (decr. excretion of K+ -> ICF -> ECF)
   - Metabolic acidosis (with increased anion gap) - due to decr. excretion of hydrogen ions, if severe, correct with sodium bicarbonate.
   - Hypocalcemia - loss of ability to form active vit Dand rapid development of PTH resistance.
   - Hyponatremia may occur if water intake is greater than body losses, or if a volume depleted patient consumes excessive hypotonic solutions.
   - Hyperphosphatemia
   - Hyperuricemia
3. Uremia - toxic end products of metabolism accumulate
4. Infection
   - a common and serious complication of AKI (occurs in 50-60% of cases)

Question 15

AKI - Tx - General

Answer 15

1. General measures
   a) Avoid meds that decrease renal blood flow (NSAIDS) and or nephrotoxic.
   b) Adjust med-dosages for level of renal function
   c) Correct fluid imbalance
   - IV volume depleted, give IV fluids. However, many patients with AKI are volume overloaded (espec. if they are oliguric or anuric), so diuresis may be necessary.
   - Monitor fluid balance by daily weight measurements (most accurateestimate)
   d) Correct electrolyte disturbances if present
   e) Optimize cardiac output, BP should be 120 to 140/80 to 90.
   f) Order dialysis if symptomatic uremia, intractable acidemia, hyperkalemia or volume overload develop.

Question 16

AKI - Tx - Prerenal

Answer 16

2. Prerenal
   - Treat underlying disorder
   - Give NS to maintain euvolemia and restore bloodpressure - do not give to pts. with edema and ascites.
   - Eliminate any offending agents (ACE inhibitors, NSAIDS)
   - If patient is unstable, Swan-Ganz monitoring for accurate assessmentof intravascular volume.

Question 17

AKI - Tx - Intrinsic

Answer 17

a) Once ATN develops, therapy is supportive. Eliminate the cause/offending agents
b) If oliguric, a trial of furosemide may help to increase urine flow. This improves fluid balance

Question 18

AKI - Tx - Postrenal

Answer 18

A bladder catheter may be inserted to decompress the urinary tract. Consider urology consultation.

Question 19

Chronic Kidney Disease - General

Answer 19

Defined as either decreased kidney function (GFR < 60 mL/min) or kidney damage (structural or functional abnormalities) for at least 3 months, regardless of cause.

Plasma Cr varies inversely with GFR
Cr Clearance is the most common clinical measure of GFR.
An increase in plasma Cr indicates disease progression, whereas a decrease suggests recovery of renal function.

Question 20

Chronic Kidney Disease - Causes

Answer 20

Diabetes is the most common cause (30% of cases)
HTN is responsible for 25%of cases
Chronic GN accounts for 15% of cases.
Interstitial nephritis, polycystic kidney disease, obstructive uropathy.
Any of the causes of AKI may lead to CKD if prolonged and/or if treatment delayed.

Question 21

CKD - Clinical (Cardiovascular)

Answer 21

• HTN (secondary to salt and water retention - decreased GFR stimulates RAS which leads to an increase in BP)
• CHF - due to volume overload, HTN and anemia
• Pericarditis (uremic)

Question 22

CKD - Clinical (GI)

Answer 22

Usually due to uremia

• Nausea, vomiting
• Loss of appetite (anorexia)

Question 23

CKD - Clinical (Neurologic)

Answer 23

-Lethargy, somnolence, confusion, peripheral neuropathy, uremic seizures

Question 24

CKD - Clinical (Hematologic)

Answer 24

• Normocytic, normochromic anemia (secondary to deficiency of erythropoietin)
• Bleeding secondary to platelet dysfunction (due to uremia)

Question 25

CKD - Clinical (Endocrine/metabolic)

Answer 25

a) Calcium-phosphorus disturbances
- Decr. renal clearance of phosphate leads to hyperphosphatemia, which results in decreased renal production of 1,25 dihydroxy vitamin D. This leads to hypocalcemia, which causes secondary hyperparathyroidism.
- So, hypocalcemia and hyperphosphatemia are usually seen, but long-standing secondary hyperparathyroidism and calcium-based phosphate binders may sometimes cause hypercalcemia.
- Secondary hyperparathyroidism causes renal osteodystrophy, which causes weakening of bones and possibly fractures.
- Hyperphosphatemia may cause calcium and phosphate to precipitate, which causes vascular calcifications that may result in necrotic skin lesions. This is called calciphylaxis.

b) Sexual/reproductive symptoms due to hypothalamic-pituitary disturbances and gonadal response to sex hormones: in men, decr. testo, in women, amenorrhea, infertility and hyperprolactinemia.
c) Pruritus - common and difficult to treat. Dialysisand UV light

Question 26

CKD - Clinical (Fluid and electrolyte problems)

Answer 26

a) Volume overload - watch for pulm. edema
b) Hyperkalemia - due to decr. urinary secretion.
c) Hypermagnesemia - secondary to reduced. urinary loss
d) Hyperphosphatemia
e) Metabolic acidosis - due to loss of renal mass and the kidney’s inability to excrete H+

Question 27

CKD - Clinical (Immunologic)

Answer 27

Uremia inhibits cellular and humoral immunity.

Question 28

CKD - Diagnosis

Answer 28

1. Urinalysis - examine sediment
2. Measure Cr clearance to estimate GFR
3. CBC (anemia, thrombocytopenia)
4. Serum electrolytes (e.g. K+, Ca2+, Po43-, serum protein)
5. Renal ultrasound - evaluate size of kidneys/rule out obstruction
   - Small kidneys are suggestive of chronic renal insufficiency with little chance of recovery.
   - Presence of normal-sized or large kidneys does not exclude CKD
   - Renal biopsy - in select cases to determine specific etiology

Question 29

CKD - Treatment

Answer 29

1. Diet
   a) Low protein - to 0.7 to 0.8 g/kg body weight per day
   b) Low salt diet if HTN, CHF, oliguria
   c) Restrict potassium, phosphate, magnesium intake
2. ACE-inhibitor - dilate efferent arteriole of glomerulus
   - use with caution - can cause hyperkalemia
3. BP control
   - Ace inhibitor first choice
4. Glycemic control prevents worsening(if diabetic)
5. Smoking cessation
6. Correction of electrolyte abnormalities
   - Correct hyperphosphatemia with calcium citrate
   - Give oral vit. D in an effort to prevent secondary hyperparathyroidism and uremic osteodystrophy
   - Acidosis - treat underlying cause (renal failure). Patients may require oral bicarbonate replacement.
7. Anemia - tx with erytropoietin
8. Pulm.edema, arrange for dialysis if the condition is unresponsive to diuretics
9. Pruritus- capsaicin cream
10. Dialysis
11. Transplantation is only cure

Question 30

Dialysis - General

Answer 30

Artificial mechanism where fluid and toxic solutes are removed from the circulation, when the kidneys cannot do so.
The two major methods of dialyzing a patient are 1) Hemodialysis and 2) Peritoneal dialysis

Settings in which dialysis is considered:

1. CKD - dialysis serves as a bridge to renal transplantation or as a permanent treatment if transplant is not happening.
2. AKI - dialysis is often required as a temporary measure until the patient’s renal function improves.
3. Overdose of medications or ingestions of substances cleared by the kidneys - some, but not all meds and toxins can be dialyzed.

Question 31

Dialysis - specific indications

Answer 31

1. Nonemergent:
   - Cr and BUN levels are not absolute indications for dialysis
   - Symptoms of uremia: Nausea, vomiting, lethargy, deterioration in mental status, encephalopathy, seizures, pericarditis.
2. Emergent indications (usually in setting of renal failure=
   - Life-threatening manifestations of volume overload
   e. g pulm edema, hypertensive emergency
   - Severe, refractory electrolyte disturbances, f.eks hyperkalemia, hypermagnesemia
3. Severe metabolic acidosis
4. Drug toxicity/ingestions; methanol, ethylene glycol, lithium, aspirin (espec. in those with renal problems)

Question 32

Hemodialysis

Answer 32

The patients blood must be heparinized to prevent clotting in the dialyzer. Use the central catheter placed either in subclavian or jugular vein. If permanent dialysis acess - ateriovenous fistula

Advantages of traditional hemodialysis:
- It is more efficient than peritoneal dialysis. High flow rates and efficient dialyzers shorten the period of time required for dialysis. It can also be initiated more quickly than peritoneal dialysis, using temporary vascular access in the emergent setting.

Disadvantages:

• Hypotension due to rapid removal of Intravascular volume, leadingto rapid fluid shifts from extravascular space into cells.
• Hypo-osmolality due to solute removal.

Question 33

Peritoneal dialysis

Answer 33

Dialysate fluid is infused into the peritoneal cavity, then fluids and solutes from the peritoneal capillaries diffuse into the dialysate fluid, which is drained from the abdomen.
- A hyperosmolar solution is used, and water is removed from the blood via osmosis.

Advantages:

• The patient can learn to perform dialysis on his or her own.
• It mimics the physiology of normal kidney function more closely than hemodialysis in that it is more continuos.

Disadvantages:

• High glucose load may lead to hyperglycemia and hypertriglyceridemia
• Peritonitis is a significant potential complication
• The patients must be highly motivated to self-administer
• Cosmetic- increased abdominal girth due to dialysate fluid.

Question 34

Proteinuria - General

Answer 34

Urinary excretion of > 150mg protein/24h

Classification:

1. Glomerular
   - Due to increased glomerular permeability to proteins
   - Can lead to nephrotic syndrome
   - May be seen in all types of GN
   - Protein loss tend to be more severe than in nonglomerular causes
2. Tubular
   - Small proteins normally filtered at the glomerulus, then reabsorbed by the tubules appear in the urine because of abnormal tubules (i.e due to decreased tubular reabsorption).
   - Proteinuria tends to be less severe
   - Causes include sickle cell disease, UT-obstruction, interstitial nephritis
3. Overflow proteinuria - increased production of small proteins overwhelms the tubules’ ability to reabsorb them.
4. Other causes:
   - UTI
   - Fever, heavy exertion/stress, CHF
   - Pregnancy
   - Orthostatic proteinuria - occurs when the patient is standing but not when recumbent; self-limited and benign

Question 35

Nephrotic syndrome - General

Answer 35

• Urine protein excretion rate > 3,5 g/24h
• Hypoalbuminemia - hepatic albumin synthesis cannot keep up with these urinary protein losses. The result is decr. plasma oncotic pressure, which leads to edema.
• Edema - results from hypoalbuminemia
• Hyperlipidemia and lipiduria - incr. hepatic synthesis ofLDL and VLDL(liver is revving up albumin synthesis)
• Hypercoagulable state (loss of certain anticoagulants in the urine) - incr. risk of thromboembolic events.
• Incr. incidence of infection - loss of immunoglobulins in urine.

Question 36

Nephrotic syndrome - Causes

Answer 36

1. Primary glomerular disease (50-75% of cases)
   - Membranous nephropathy in adults (40%)
   - Focal segmental glomerulosclerosis (FSGS) (35%)
   - Membranoproliferative GN (15%)
   - Minimal change disease is most common in children (75%)
2. Systemic disease
   - Diabetes
   - Collagen vascular disease
   - SLE
   - RA
   - Henoch Schønlein Purpura
   - Polyarteritis nodosa
   - Wegener granulomatosis
3. Amyloidosis, cryoglobulinemia
4. Drug/toxins
5. Infection - bacterial, viral, protozoal
6. Multiple myeloma, malignant HTN, transplant rejection

Question 37

Nephrotic syndrome - Diagnosis

Answer 37

1. Urine dipstic test
   - Specific for albumin
   - Graded 0, trace, 1+ (15-30mg/dL) through 4+ (> 500mg)
2. Urinalysis
   - Initial test once urine dipstic is positive
   - Examination of urine sediment is important
   (- RBC castsuggest GN)
   (- WBC casts suggest pyelonephritis and interstitial nephritis)
   (Fatty casts suggest nephrotic syndrome (lipiduria))
   - If urinalysis confirms the presence of protein, a 24-h urine collection(for albumin and Cr) is appropriate to establish the presence of significant proteinuria.
3. Test for microalbuminuria
   a) Corresponds to albumin secretion of 30-300mg/day
   b) Can be an early sign of diabetic nephropathy
   c) If positive, perform a radioimmunoassay
4. Other tests:
   a) Cr-clearance - best test of renal function
   b) Serum BUN and Cr
   c) CBC - to detect anemia due to renal failure
   d) Serum albumin level
   e) Renal usg
   f) Intravenous pyelogram
   g) ANA levels (lupus)
   h) Serum and urine electrophoresis
   i) Renal biopsy

Question 38

Nephrotic Syndrome - Treatment (Asymptomatic vs Symptomatic)

Answer 38

Asymptomatic:

a) Transient - no further workup or tx
b) Persistent - Further testing is indicated. Check BP and urine sediment. Treat underlying condition + assoc. problems.

Symptomatic:

a) Treat underlying disease (DM, multiple myeloma, SLE, minimal change disease)
b) ACE-inhibitors - decrease urinary albumin loss. Essential part of tx for diabetics with HTN, should be started before fixed albuminuria is present.
c) Diuretics - if edema
d) Limit dietary protein and sodium
e) Treat hypercholesterolemia
f) Vaccinate- increased risk of inf. in these patients.

Question 39

Hematuria - General

Answer 39

Defined as > 3 erythrocytes/HPF on urinalysis.

Microscopic hematuria = more commonly glomerular in origin.
Gross hematuria = more commonly nonglomerular or urologic in origin.

! Consider gross, painless hematuria to be a sign of bladder or kidney cancer until proven otherwise!

Question 40

Hematuria - Causes

Answer 40

1. Kidney stones
2. Infection (UTI, urethritis, pyelonephritis)
3. Bladder or kidney cancer
4. Glomerular disease, immunoglobulin A nephropathy
5. Trauma (Foley catheter, invasive procedures)
6. Strenous excercise
7. Systemic diseases
8. Bleeding disorders
9. Medications (cyclophosphamide, anticoag, sulfonamide)
10. Sickle cell disease
11. Analgesic nephropathy
12. Polycystic kidney disease, simple cysts
13. BPH - rarely causes isolated hematuria

Question 41

Hematuria - Diagnosis

Answer 41

1. Urine dipstick
2. Urine analysis - crucial in evaluation
   - urine sediment
   - if RBC cast and proteinuria are present, a glomerlar cause is almost always present (usually GN)
   - If pyuria is present, send for urine culture
   - If dipstick is pos for blood, but urinalysis does not reveal microscopic hematuria, hemoglobinuria or myoglobinuria is likely present.
3. Urine specimen
   - To detect cancers
   - If susp. for malignancy is high, perform a cystoscopy to evaluate the bladder regardless of cytology.
4. 24 urine - test for Cr and protein to assess renal function.
5. Blood test - coag.study, CBC, BUN/Cr
6. IVP, CT scan, USG
7. Renal biopsy - if suspicion of glomerular disease

Question 42

Glomerular disease (Glomerulonephropathies) - General

Answer 42

Can be primary (intrinsic renal pathology) or secondary (due to systemic disease).

Either Nephrotic syndrome or Nephritic syndrome - or both.

Question 43

Glomerular disease (Glomerulonephropathies) - Diagnosis and Tx

Answer 43

1. Urinalysis (hematuria, proteinuria, RBC casts)
2. Blood test (renal function test)
3. Needle biopsy of the kidney

Tx:
Depends on the disease, but often involves steroids and cytotoxic agents.

Question 44

Nephritic syndrome vs Nephrotic syndrome - Pathogenesis and causes

Answer 44

Nephritic S:
Inflammation of glomeruli due to any of these causes of glomerulonephritis:
- Post.strep glomerulonephritis (most common)

Nephrotic S:
Abnormal glumerular permeability due to a number of conditions.
- Membranous glomerulonephritis (most common in adults)
- Minimal change disease (most common in children)
- Diabetes
- SLE
- Drugs
- Infections
- Glomerulonephritis

Question 45

Nephritic syndrome vs Nephrotic syndrome - Lab findings

Answer 45

Nephritic S:

• Hematuria
• AKI (azotemia, oliguria)
• Proteinuria, if present, mild and not in nephrotic range

Nephrotic S:

• Urine protein excretion rate > 3,5g/24h
• Hypoalbuminemia
• Hyperlipidemia, fatty casts in urine

Question 46

Nephritic syndrome vs Nephrotic syndrome - Clinical findings

Answer 46

Nephritic S:

• HTN
• Edema

Nephrotic S:

• Edema
• Hypercoagulable state
• Incr. risk of infection

Question 47

Primary Glomerular disorders - Minimal change disease:

Answer 47

1. Nephrotic syndrome most common presentation
2. Most common in children - Hodgkins disease and Non-Hodgkins lymphoma have been assoc. with it.
3. Fusion of foot processes on electron microscopy.
4. Excellent prognosis; responsive to steroid therapy.
5. Current evidence points to systemic T-cell dysfunction as most likely root of MCD.

Question 48

Focal segmental glomerulosclerosis

Answer 48

= 25% of cases of nephrotic syndrome in adults.

• Hematuria and HTN are often present
• Fair to poor prognosis - generally resistant to steroids, course is progressive
• Tx is controversial, but usually cytotoxic agents, steroids, immunosupressive agents, ACE/ARBS common.

Question 49

Membranous glomerulonephritis

Answer 49

• Usually presents with nephrotic syndrome; glomerular capillary walls are thickened.
• Primary disease is idiopathic. The secondary form is due to infection.
• Prognosis is fair to good, remission is common. Steroids to not change survival rate.

Question 50

IgA nephropathy (Berger disease)

Answer 50

= Asymptomatic recurrent hematuria/mild protein is common. This is the most common cause of glomerular hematuria. Gross hematuria after an URI is common.

• Renal function usually normal
• Mesangial deposition of IgA and C3 are seen on microscopy.
• Some advocate steroids for unstable disease, but no therapy has been proven to be effective.

Question 51

Hereditary nephritis (Alport syndrome)

Answer 51

X-linked or autosomal dominant inheritance.

• Hematuria, pyuria, proteinuria, high-frequency hearing loss without deafness, progressive renal failure.
• No effective treatment

Question 52

Most common cause of Membranoproliferative GN, and association

Answer 52

Usually due to hepatitis C infection, other causes include hep. B, syphilis and lupus.
Common assoc. with cryoglobulinemia

Question 53

Poststreptococcal GN

Answer 53

= Most common cause of nephritic syndrome

1. Occurs after infection with group A B-hemolytic strep infection of the URT(or skin). The GN develops 10-14d after infection. Primarily affects children.
2. Features: hematuria, edema, HTN, low complement levels and proteinuria
3. Antistreptolysin-O may be elevated
4. Self limited, usually resolves in weeks to months.
5. Tx: supportive: antihypertensives, loop diuretics for edema, steroids in severe cases.

Question 54

Goodpasture syndrome

Answer 54

= Classic triad of proliferative GN, pulmonary hemorrhage and igG antiglomerular basement membrane antibody.

2. Clinical: rapidly progressive renal failure, hemoptysis, cough and dyspnea.
3. Lung disease precedes kidney disease by days to weeks
4. Renal biopsy shows linear immunoflourescence pattern.
5. Tx: Plasmapheresis to remove circulating anti-igG antibodies.Cyclophosphamide and steroids can decr. the formation of new antibodies.