U of U PA School Nephrotic Syndrome

What are the features of nephrotic syndrome? (5)

>3.5 g/24 hour proteinuria

Urine protein/creatinine ratio >3g/g

Hypoalbuminemia

Edema

Hyperlipidemia

What are the primary causes of nephrotic syndrome?

Minimal change disease

Membranous nephropathy

Focal segmental glomerulosclerosis (FSGS) - scar tissue in the glomeruli

What are the secondary causes of nephrotic syndrome?

Diabetic nephropathy

Lupus nephritis

Amyloidosis

What is the most common cause of nephrotic syndrome in children?

Minimal change disease

Why is it called minimal change disease?

Due to normal biopsy results

-Need electron microscopy to show changes

How is minimal change disease treated?

Steroids

What is membranous nephropathy?

Immune complex deposition in sub epithelial space of GBM

Damages podocyte foot processes and slit diaphragms

What are the classifications of membranous nephropathy?

Primary - autoantibodies in situ antigens on podocyte foot process or slit lamps

Secondary - autoantibodies to antigens outside kidney that deposit in sub epithelial space

-Lupus, Hep B, cancer antigens

How is membranous nephropathy diagnosed?

Biopsy

What is FSGS?

Scarring of segments of few glomeruli

Focal - <50% of glomeruli

Segmental <50% of each glomerulus

Tends to occur after initial podocytopathy

What are the classifications of FSGS? (6)

Primary/idiopathic

Genetic mutation

Viral - HIV, parvovirus, COVID-19

Drugs - pamidronate, interferons, lithium, sirolimus

Secondary to kidney tissue loss

Secondary to glomerular stress

What is the most common cause of nephrotic syndrome? What is it also the most common cause of?

Diabeic nephropathy - also most common cause of ESRD

How does diabetic nephroapthy progress?

Microalbuminuria -> overt proteinuria -> nephrotic syndrome -> ESRD

What GFR, uACR, urine dipstick, and BP indicate preclinical diabetic nephropathy?

GFR - Increased

uACR - <30

Urine dipstick - Negative

BP - Normal

What GFR, uACR, urine dipstick, and BP indicate incipient (5-15 years) diabetic nephropathy?

GFR - Normal

uACR - 30-300

Urine dipstick - Negative

BP - Begins rising

What GFR, uACR, urine dipstick, and BP indicate overt (15-20 years) diabetic nephropathy?

GFR - Decreased

uACR - >300

Urine dipstick - Positive

BP - Hypertensive

What GFR, uACR, urine dipstick, and BP indicate ESRD (20-25 years) diabetic nephropathy?

GFR - Severely decreased

uACR - Nephrotic

Urine dipstick - Positive

BP - Hypertensive

When is a biopsy not required for nephrotic syndrome?

Peds unless steroid resistant because most cases are minimal change disease

Diabetes if clinical cource fits pattern of diabetic nephropathy

What non specific treatment is done for nephrotic syndrome?

Hypertension and proteinuria control with ACEI/ARB

Cholesterol control with statiins

Anticoagulants as needed

What specific treatments is done for nephrotic syndrome?

Glucose control in diabetes

Prednisone in minimal change disease

Immunosuppression for lupus, FSGS, and membranous disease

How long does specific treatment for nephrotic syndrome last?

6-12 months or until syndrome resolved

-Whichever is longer

What complications can arise from nephrotic syndrome? (4)

Edema

Hyper-coagulability and thrombosis

Infections

Hyperlipidemia

What causes edema in nephrotic syndrome?

Hypoalbuminemia and increased renal sodium absorption

What is the treatment for nephrotic induced edema?

Sodium restriction

Diuretics

IV albumin

What causes hypercoagulability and thrombosis in nephrotic syndrome?

Loss of antithrombin proteins and membranous nephropathy

Risk increases if serum albumin <2.5 g/dl

What is the treatment for nephrotic-induced hypercoagulability and thrombosis?

Prophylaxis warfarin if serum albumin <2.5 + 1 of the following

-Proteinuria >10 g day

-BMI >35

-Genetic predisposition to thromboembolic events

-NYHA III/IV HF

-Recent surgery/prolonged immobilization

What causes nephrotic induced infections?

Urine loss of immunoglobulins

How should nephrotic induced infections be screened and treated?

All patients with glomerular disease screened for latent HBV, HCV, HIV, or TB

Use prophylatic TMP-SMZ if long term prednisone administered

If IgG<600 mg/dl, monthly IVIG may decrease infection risk

When should patients with nephrotic syndrome be referred?

All patients except a child who I have 100% confidence has minimal change disease