Renal Disorders Flashcards
Nephrotic Syndrome
● Noninflammatory damage
to the glomerular capillary
wall
● Proteinuria – >3g/day
Essentials of Diagnosis of Nephrotic syndrome
○ Severe proteinuria (>3g/day)
○ Hypoalbuminemia
○ Edema (legs, lungs, abdomen)
○ Hyperlipidemia
Most common cause of nephrotic
syndrome in children
Minimal Change Disease
Nephrotic syndrome presentation
● Weight gain
● Fatigue
● SOB
● Edema
● Frothy urine
T/F Labs cannot be used to distinguish
between forms of nephrotic syndrome
T
Primary (Idiopathic) Minimal Change Disease
● Most common
● Not associated w/ underlying
disease
● ↑ glomerular capillary wall
permeability = foot process
effacement and proteinuria
Secondary etiology for Minimal Change Disease
● Drugs
○ NSAIDs, Lithium
○ Some antibiotics, including
cephalosporins
● Neoplasms
○ Hodgkin lymphoma
● Infections
○ Viral URI (especially in kids)
○ TB, syphilis, Hepatitis C, Lyme disease.
● Allergy
○ NSAIDs, bee stings
Minimal Change Disease - Presentation
● Sudden onset (compared to other causes of
nephrotic syndrome) over days to 1-2 weeks.
● Often following an upper respiratory or
systemic infection
● Microscopic hematuria and AKI (mostly adults)
● Elevated serum creatinine
Minimal Change Disease - Diagnostics
● Labs: CBC, CMP, lipid panel, UA, urine
microalbumin/creatinine ratio
○ Can’t be used to distinguish between
forms of nephrotic syndrome
● Kidney biopsy is required for diagnosis
in adults
Minimal Change Disease - Pathologic Findings
● Glomeruli appear normal
● No complement or immunoglobulin deposits
● Effacement of pedicles
○ They fuse and become short and wide
Minimal Change Disease - Management
● STEROIDS
○ 1st line is prednisone
○ Up to 16 weeks (and 2 weeks
after remission)
● Infection control
● Treat edema
○ Salt restriction, diuretics
● Prevent blood clots
○ Pt’s mobility should not be restricted
● Maintain adequate protein intake
Focal Segmental Glomerulosclerosis -
Epidemiology
● More common in adults
● Most common primary glomerular
disease identified in patients with
end-stage kidney disease in the USA
● Higher risk of ESKD in Blacks and males
● Incidence is rising
FSGS - Etiology/Presentation (Primary)
● Circulating permeability factor causes
podocyte dysfunction and pedicle
effacement
● Can also be caused by genetic mutations
● Acute onset nephrotic syndrome (80% of
children and 50% of adults)
Biopsy will show diffuse (≥80 percent)
podocyte foot process effacement with ____
Primary FSGS
FSGS - Etiology/Presentation (Secondary)
● Nephrotic syndrome is uncommon
in secondary FSGS (but can still
happen!)
● Slowly increasing proteinuria (often
in non-nephrotic range)
● Almost always serum albumin level
stays normal (no peripheral edema or
hypoalbuminemia)
● Proteinuria w/o hypoalbuminemia
Kidney biopsy will show segmental (<80 percent) podocyte foot process effacement with ______
FSGS - Secondary
FSGS - Diagnostics
● Labs (are these going to tell you the exact
diagnosis?)
● Genetic testing
● BIOPSY REQUIRED
FSGS - Management (Primary)
● Immunosuppressive medication
○ Corticosteroids, calcineurin inhibitors
○ Only use if nephrotic syndrome
FSGS - Management (Secondary)
● Treat or remove the underlying cause
FSGS - Management (General)
● Sodium and protein
restriction
● BP control
● Minimize proteinuria w/ ACE/ARB
● Statin for hyperlipidemia if needed
Membranous Nephropathy -
Epidemiology
● Most common cause of primary adult
nephrotic syndrome
● Primary MN is more common in White
males over the age of 40 years
● MN in young females should raise the
suspicion of systemic lupus
erythematosus
● Less common in children, but if present
is often associated w/ hepatitis B,
autoimmune, or thyroid disease
Membranous Nephropathy - Primary Etiology
● Autoantibodies against podocyte
antigens
○ phospholipase A2 receptor
PLA2R most common
○ THSD7A or NELL
Membranous Nephropathy - Presentation
● Most patients present w/ nephrotic
syndrome
● May just have asymptomatic proteinuria
● Signs of underlying infection or neoplasm
(secondary)
● Caused by gradual subepithelial deposits, so
symptoms develop more slowly than MCD or FSGS
● Proteinuria anywhere from <3.5 to over 20 g/day
● Severe hyperlipidemia (if nephrotic)
● Fatty casts in urine
Membranous Nephropathy - Diagnostics
● Labs: What do you want to order?
● Serologic testing for SLE, syphilis, anviral hepatitis
● Age- and risk-appropriate cancer screening
● PLA2R antibody titer
○ Diagnostic
○ May eliminate need for biopsy
● Kidney biopsy
Pathology of Membranous Nephropathy
● Thickened glomerular basement
membrane
● “Spike and Dome” pattern -
projections of excess GBM between
the subepithelial immune complex
deposits
Membranous Nephropathy - Management if high risk
- Serum creatinine ≥1.5 mg/dL
- Progressive decline in kidney function
- Severe, disabling, or life-threatening
nephrotic syndrome