Hemolytic uremic syndrome

Hemolytic uremic syndrome

Types:-
1. Typical HUS:- caused by shiga-like toxin producing enterohemorrhagic E.coli (0157:H7), shiga toxin of Shigella; typically manifests with bloody diarrhea after ingestion of undercooked beef.
2. Atypical HUS:- occurs due to hereditary or acquired complement dysregulation; the most
common defect present in atypical HUS is factor H deficiency; associated with low C3 levels
and normal C4 levels.

Clinical Features:-
@HUS
H – Hemolysis (i.e. Microangiopathic Hemolytic Anemia / MAHA)
U – Uremia (i.e. Acute Renal Failure)
S – Scarce Platelets (i.e. Thrombocytopenia)
1. Microangiopathic hemolytic anemia
2. Acute renal failure
3. Thrombocytopenia

Diagnosis:-
1. CBC shows anemia (i.e. low hemoglogin) and low platelets (i.e. bleeding time is elevated).
2. PBS shows Schistocytes (>2-3/hpf).
3. Coombs' test is Negative.
4. PT, aPTT and fibrinogen are Normal
5. Deranged RFT (i.e. elevated Serum creatinine and/or BUN).
6. Indirect bilirubin is elevated and LDH is elevated.
7. Serum haptoglobin is low.

8. Serology of EHEC E.coli (O157:H7) suggests typical HUS.

Management:-
1. Supportive measures include intravenous fluids, blood transfusions (if Hb <7gm/dL), dialysis (if acute renal failure).
2. Avoid antibiotics (antibiotics trigger the release of toxins and worsens the condition).

3. Platelet transfusion is contraindicated.
4. Eculizumab is given for atypical HUS.