Renal Syndromes and Urinalysis Pt Deux Flashcards
what are the five criteria for nephrotic syndrome
- proteinuria>3.5 g/d
- edema
- hypoalbuminemia
- hyperlipidemia
- lipiduria
what is the pathophysiology of proteinuria? List 4
- loss of negative charge of the GBM
- Increase in pore size of the GBM
- loss of podocytes
- decreased synthesis of slit pore proteins
what are the slit pore proteins and what are their function
The slit pore proteins are nephrin, podocin, and actinin…function is to hold the integrity of the podocytes
What are the three diseases that present with proteinuria that were discussed in this lecture
- congenital nephrotic syndrome
- steroid-resistant nephrotic syndrome
- focal segmental glomerulosclerosis
what proteins are lost in each?
- congenital nephrotic syndrome-Nephrin
- steroid-resistant nephrotic syndrome-podocin protein
- focal segmental glomerulosclerosis-alpha-actinin-4 protein
explain the pathophysiology behind the edema in patients with nephrotic syndrome
- hypoalbunemia
- decrease in plasma volume and oncotic pressure
- stimulate the renin AN system, sympathetic flow, and ADH increase
- all of this cause Na retention and eventually fluid will move into the interstitium causing edema
hyperlipidemia pathophysiology in nephrotic syndrome
- increased hepatic synthesis of lipoproteins in nephrotic syndrome causing hyperlipidemia
- decreased catabolism of lipids also leads to nephrotic syndrome
what are the causes of nephrotic diseases
- systemic diseases
- infections
- drugs
- idiopathic
list some systemic diseases that can cause nephrotic disease
diabetes, lupus, cancer, amyloidosis
list some infections that can cause nephrotic disease
bacterial, viral, parasitic
-HIV, HCV, HBV, and streptococcus
what drugs can cause nephrotic disease
NSAIDs, COX-2 inhibitors, gold, penicillamine or bucillamine, heroin, pamidronate
idiopathic diseases in nephrotic syndrome include
the primary glomerular diseases
- minimal change disease
- focal segmental glomerulosclerosis
- membranous nephropathy
- membranoproliferative glomerulonephritis
serology and their indications:
- ASO
- ANA
- VDRL
- Hepatitis B, C
- HIV
- Complement
- Chest X-ray
- Renal ultrasound
- renal biopsy
Ans:
i. You should assess for antistreptolysin O to rule out postinfectious glomerulonephritis.
ii. You should also assess for antinuclear antibody (ANA) to rule out lupus as the cause of nephrotic syndrome.
iii. VDRL should be assessed for to rule out membrane nephropathy or minimal change disease. The nephrotic syndrome will disappear in this case if you give penicillin.
iv. Hepatitis B and C should be assessed for as well.
v. HIV should be assessed for in the serology if indicated.
What are the four possible causes of nephrotic syndrome is liver function tests are normal and the patient is experiencing hypocomplementemia
Complement should also be analyzed in serology. Patients with proteinuria and hypocomplementemia have a DDX of 4 diseases. Complement is synthesized in the liver. If liver function tests are normal, protein is in the urine, and complement levels are low, there are 4 possible causes.
- Patients with proteinuria and hypocomplementemia can have acute postinfectious glomerulonephritis.
- They can also have membranoproliferative glomerulonephritis.
- They may have mixed cryoglobulinemia.
- If the patient has hypocomplementemia and proteinuria, systemic lupus erythematosus is another possibility
what are the complications of nephrotic syndrome
- hypercoagulability and thromboembolism (leading to thrombosis everywhere)—loss of antithrombin III, protein S, and protein C
- Infections because of loss of gamma globulins or loss of function; malnutrition that is developed from the edema leads to increased risk of infections
- accelerated atherosclerosis due to hyperlipidemia
- Proteinuria leads to acute renal failure—must treat with ACE inhibitors and immunosuppresants
- Skeletal abnormalities due to loss of vitamin D and phosphate (mainly in children)