Nephrotic Syndrome Flashcards
What is Nephrotic Syndrome?
This is a kidney disorder that is characterized by a set of symptoms that indicates kidney damage. It is characterized manly by proteinuria, hypoalbuminemia and edema. Nephrotic Syndrome is usually the result of 1 of several diseases.
List the clinical signs and symptoms of Nephrotic Syndrome
- Heavy proteinuria (>3.5gm/day)
- Hypoalbuminemia
- Edema
- Hyperlipidemia & lipiduria
- Normal complement levels
Describe the pathophysiology of Nephrotic Syndrome
List the renal diseases that cause Nephrotic Syndrome
Involves immunoglobulin deposition
- Membranous nephropathy
Does not involve immunoglobulin deposition
- Minimal change
- FSGS
- Diabetic Nephropathy
- Amyloidosis
Membranous Nephropathy (Clinical Relevance)
- Present with nephrotic syndrome, microscopic hematuria (50%), HTN, renal insufficiency (late), renal vein thrombosis
- Poor prognosis if: male, >50 years of age, >10 gm proteinuria
List the causes (antigens and disorders) associated with membranous nephropathy
Causes
Idiopathic
Endogenous Antigens (DNA, “SLE”/tumors)
Exogenous antigens:
- Hepatitis B
- Syphillis
- Malaria
- Captopril
- Mercury
- Gold
- Penicillamine
Membranous Nephropathy (Pathology)
LM: diffuse thickening of the glomerular basement membrane with little increase of cellularity
IF: Fine granular deposits of IgG, C3 along the basement membrane–subepithelial
EM: subepithelial immune complex deposits and proliferation and growth of new GBM “spikes” formation
Membranous Nephropathy (Pathogenesis)
Minimal Change Disease (Clinical Relevance)
- Most common disorder in children
- >90% of children have complete remission of proteinuria within 8 weeks of steroids
- Relapses are frequent after stopping steroids
- No tendency to progress to CRF/ESRD
- Renal failure and mortality rates are low but somewhat higher in adults than children
- Patients die of complications of NS or therapy
- Present in 15% of adult cases
Idiopathic - usually. May be seen in lymphoma, or renal cell carcinoma
Labs: - Serum: Low albumin, normal creatinine
- Urine: proteinuria, bland urine sediment
Physical Exam: - Normal BP, Edema (periorbital, pedal)
Minimal Change Disease (Pathology)
LM: normal (glomeruli, tubules, vessels)
IF: no immunoglobulin deposits
EM: fusion (blunting) of foot processes and effacement, detachment of basement membrane
Minimal Change Disease (Pathogenesis)
- This is unclear but may involve circulating “glomerular permeability factors”
- The primary target is the glomerular epithelial cells (podocyte).
- Injury results in increased glomerular permeability & subsequent massive proteinuria
- No immune-complex deposition or inflammatory injury
FSGS (Clinical Relevance)
FSGS (Pathology)
LM: FSGS
IF: negative/or non specific granular deposits of IgM
EM: patchy fusion of the foot processes & effacement
FSGS (Pathogenesis)
Diabetc Nephropathy (Clinical Relevance)
- Leading cause of end stage renal disease in the US (1/3 of all patients)
- Seen in 25-40% of type 1 and type 2 diabetics
Initially hyperglycemia leads to hyperfiltration (increased GFR) and increased glomerular hydrostatic pressure
7-13 years of disease: microalbuminuria (30-300mg/24hr) appears – incipient nephropathy
10-20 years of disease: macroalbuminuria (>300mg/24hr)
After: persistent & progressive proteinuria, HTN, higly variable decline in GFR (1-24ml/min/year)
Diabetic Nephropathy (Pathology)
Earliest lesions: expansion of mesangial matrix & thickening of GBM
Later lesions: diffuse global glomerulosclerosis with:
- Diffuse increase in mesangial matrix and diffuse thickenin gof GBM
- Kimmelstiel-Wilson nodules (nodular glomerulosclerosis); nodules ocntain lipids and fibrin
- Fibrin cap an capsular drop (plasma proteins)
- Ischemia: causes tubular atrophy, interstitial fibrosis
- Hyaline arteriosclerosis
Diabetic Nephropathy (Pathogenesis)
