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Oct 27, 2026, 16:13

Lesley Van Wyk: DIC vs TTP vs HUS – The Key Diagnostic Clues

Lesley Van Wyk, Laboratory Manager at National Health Laboratory Service, shared a post on LinkedIn:

“DIC vs TTP vs HUS

Three important causes of microangiopathic haemolytic anaemia (MAHA) with thrombocytopenia — but how do you distinguish them?

1.DIC — Disseminated Intravascular Coagulation

Widespread coagulation activation – microthrombi and consumption of platelets and clotting factors.
Triggers: Sepsis, trauma, malignancy and obstetric complications.
Labs: lower Platelets, higher PT/aPTT, lower fibrinogen and higher D-dimer (typical pattern). Pearl: Think DIC in a critically ill patient with abnormal coagulation tests.

2.TTP — Thrombotic Thrombocytopenic Purpura

Severe ADAMTS13 deficiency – accumulation of large von Willebrand factor multimers and platelet-rich microthrombi.

Features: Thrombocytopenia, MAHA and potentially severe neurological or cardiac involvement.
Labs: lower Platelets, schistocytes, usually normal PT/aPTT; ADAMTS13 activity typically less than 10%.
Pearl: Suspected TTP is a haematological emergency. Start urgent specialist-directed treatment without waiting for ADAMTS13 results when clinical suspicion is high.

3.HUS — Haemolytic Uraemic Syndrome

Microvascular injury predominantly affecting the kidneys.

Typical HUS: Often follows Shiga toxin-producing E. coli infection, sometimes with bloody diarrhoea.

Atypical HUS: Usually complement-mediated; can occur at any age.
Labs: MAHA, thrombocytopenia and prominent acute kidney injury; PT/aPTT are usually normal.

4.Diagnostic Approach

Confirm MAHA: blood film, LDH, indirect bilirubin, haptoglobin and reticulocytes.
Check coagulation: prolonged PT/aPTT and falling fibrinogen support DIC.
Suspect TTP: send ADAMTS13 activity urgently and involve haematology immediately.
Suspect HUS: assess renal function and arrange stool Shiga toxin testing when indicated.

Red flag: MAHA with thrombocytopenia can be life-threatening. Urgent assessment is essential.

High-Yield Takeaway: