HEMOLYTIC UREMIC and NEPHRITIC/NEPHROTIC SYNDROMES

HEMOLYTIC UREMIC SYNDROME   acquired renal insufficiency triad: nephropathy, thrombocytopenia, microangiopathic hemolytic anemi...

HEMOLYTIC UREMIC SYNDROME

 

1. acquired renal insufficiency
2. triad: nephropathy, thrombocytopenia, microangiopathic hemolytic anemia
3. more common from 6 months to 4 years old
4. etiology: E. coli toxin O157:H7 verotoxin or Shigella toxin (“hamburger disease”) causes endothelial damage
5. prodrome of bloody diarrhea 5-7 days before onset of renal insufficiency
6. history – weakness, lethary, oliguria
7. physical exam – pallor, jaundice (hemolysis), edema, petechiae, hepatosplenomegaly, hypertension
8. investigations – CBC, platelets, reticulocytes, blood smear, Coombs, urinalysis, renal function
9. prognosis: 5-10% mortality, 10-30% kidney damage
10. supportive treatment, dialysis if severe; steroids not helpful

 

NEPHRITIC SYNDROME

Acute, subacute or chronic

• hematuria with RBC casts, proteinuria (< 50 mg/kg/day, not nephrotic-range), hypertension,
• renal failure (oliguria)

post-streptococcal glomerulonephritis

• most common in children, especially in 4-8 year olds, M > F
• occurs 1-3 weeks following Group A hemolytic Strep infection (throat/impetigo)
• diffuse, proliferative glomerulonephritis
• diagnosed by elevated serum antibody titres against Strep antigens
• 95% of children recover completely within 1-2 weeks
• 5-10% have persistent hematuria

Major Causes of Acute Glomerulonephritis

 

NEPHROTIC SYNDROME

 

1. severe proteinuria (> 50 mg/kg/day, or > 40 mg/m2/hr) hypoalbuminemia (< 25 g/L), edema, hyperlipidemia
2. histopathology
   • minimal change disease (76%)
   • focal segmental glomerular sclerosis (7%)
   • membranous glomerulonephritis (8%)
   • membranoproliferative glomerulonephritis (5%)
3. minimal change disease
   • peak occurrence between 2-6 years old
   • 90% are steroid-responsive

 

Treatment

 

1. salt and water restriction
2. diuretics may be required
3. prednisone for 8 weeks; if no response, renal biopsy may be required
4. frequent relapses or steroid resistance may require immunosuppressant cytotoxic agents

Children with nephrotic syndrome are at risk of

 

1. infections (peritonitis, cellulitis)
2. hypercoagulability (PE, renal vein thrombosis)
3. side effects of drugs (diuretics, steroids, immunosuppressants)
4. hypotension, shock, renal failure