Nephrotic Syndrome Flashcards
is characterised by
It is characterised by Heavy proteinuria (>3.5 g/24 hr in adults or >40 mg/m2/hr in children), Hypoalbuminemia (<2.5 g/dL), Edema Hyperlipidemia.
Etiology
(90%) of nephrotic syndrome in children is a form of the
idiopathic nephrotic syndrome (INS)
while (10%) is secondary .
Idiopathic nephrotic syndrome
3 types
Minimal change disease (85%) Mesangial proliferation (5%), Focal segmental glomerulosclerosis (10%).
The secondary cases are related to other GN
Membranoproliferative GN (MPGN)
- Membranous nephropathy
- other systemic diseases
- drugs
- infections
Causes of Proteinuria
TRANSIENT PROTEINURIA
ORTHOSTATIC (POSTURAL) PROTEINURIA
TUBULAR DISEASES
GLOMERULAR DISEASES
TRANSIENT PROTEINURIA causes
FeverExerciseDehydrationCold exposureCongestive heart failureSeizureStress
False-positive proteinuria
may be seen in patients with gross hematuria,
contamination with antiseptic agents (chlorhexidine and benzalkonium chloride),
urinary pH greater than 7.0
UTI
False-negative proteinuria
occur with dilute urine or when the predominant urinary protein is not albumin
a Upr/Ucr ratio normal and abnormal value
Normal < 20mg/mmol
Nephrotic range > 200mg/mmol
Pathophysiology of edema
An increase in permeability of the glomerular capillary wall, which leads to massive proteinuria and hypoalbuminemia
Hypoalbuminemia causes a decrease in the plasma oncotic pressure ,and fluid transudation from the intravascular compartment to the interstitial space…leads to edema
Pathophysiology of elevated lipid levels
Hypoalbuminemia stimulates generalized hepatic protein synthesis, including synthesis of lipoproteins.
Lipid catabolism is diminished
pathophysiology of proteinuria
injury to the podocytes
as with Various forms of INS associated with mutations in podocyte genes, with the slit-diaphragm and podocyte cytoskeleton proetiens (nephrin and podocin
MCD clinical picture
100% nephrotic
10-20% hematuria
10% hypertension
Doesn’t progress to end stage renal failure
90% response to steroids
It is more common in males than in females (2:1)
Frequency 75% in children, 15% in adults
appears between the ages of 2 - 6 yr
Present with edema, which is initially noted around the eyes and in the lower extremities
edema may become generalized, with the development of ascites, pleural effusions, and genital edema .
hypertension and gross hematuria are uncommon
Differential diagnosis:
for MCD
protein-losing enteropathy,
hepatic failure,
congestive heart failure,
Other chronic glomerulonephritis, and protein malnutrition
investigation for MCD
- Urine R&M .. For protein and RBC
- 24h urine collection or Upr/ucr ratio
- Urine culture
- Serum albumin
- KFT
- CBC
- C3 and C4 level
- HBV and HCV serology
- ANA , DS-DNA and AsO titre if needed
when renal biopsy is needed in MCD
Atypical presentation:
hematuria ( gross )
hypertension,
renal insufficiency, hypocomplementemia
age < 1yr or > 12yr
Response to steroid ttt (SDNS, SRNS, FRNS )
Diagnosis MCD
Urinary protein excretion in the nephrotic range (exceeds 40 mg/m2/hr) in children
microscopic hematuria may be present in 20% of children
serum albumin is < 2.5 g/dL,
Serum creatinine value is usually normal
increased serum cholesterol and triglyceride
C3 and C4 levels are normal.
Renal biopsy is not required for diagnosis in most children with Idiopathic nephrotic syndrome ..(MCD)
Minimal change disease (85%):
light microscopy glomeruli appear normal or show a minimal increase in mesangial cells and matrix.
Immunofluorescence : are negative,
Electron microscopy simply reveals effacement of the epithelial cell foot processes.
Focal segmental glomerulosclerosis in pathology lab
glomeruli show mesangial proliferation and segmental scarring on light microscopy .
immunofluorescence microscopy shows IgM and C3 staining.
Electron microscopy shows segmental scarring of the glomerular tuft with obliteration of the glomerular capillary lumen
Mesangial proliferation
in pathology lab
diffuse increase in mesangial cells and matrix on light microscopy.
Immunofluorescence microscopy shows mesangial IgM and/or IgA staining.
Electron microscopy reveals increased numbers of mesangial cells and matrix as well as effacement of the epithelial cell foot processes.
Treatment of MCD
Intravenous administration of 25% Albumin
- Steroids
- other medications eg(cyclophosphamide, cyclosporin
Complications
Drug Side Effects:
Steroids : (cushingoid appearance, hypertension, cataracts, and/or growth failure)
Cyclophosphamide (neutropenia, disseminated varicella, hemorrhagic cystitis, alopecia, sterility
Ciclosporin ( hypertension, nephrotoxicity, hirsutism, and gingival hyperplasia, neutropenia
Infections
Spontaneous bacterial peritonitis is the most frequent type of infection
Thrombosis
why Infection is the major complication of nephrotic syndrome
Increased susceptibility to bacterial infections owing to urinary losses of immunoglobulins and properdin factor B, defective T cell-mediated immunity, immunosuppressive therapy, malnutrition, edema……
most common organism causing peritonitis
Streptococcus pneumoniae is the most common organism causing peritonitis, gram-negative bacteria such as Escherichia coli may also cause it
