In a patient presenting with fever, petechiae, and microangiopathic haemolytic anaemia, the pentad of TTP includes all of the following EXCEPT:
- A Thrombocytopenia
- B Renal failure (creatinine >200 µmol/L) ✓
- C Neurological manifestations
- D Fever
Explanation
The classic pentad of TTP (Thrombotic Thrombocytopenic Purpura) consists of: (1) microangiopathic haemolytic anaemia, (2) thrombocytopenia, (3) neurological symptoms (confusion, focal deficits), (4) fever, and (5) renal dysfunction — but importantly, in TTP the renal failure is MILD (creatinine typically <180 µmol/L). Severe renal failure (creatinine >200 µmol/L) is the hallmark of HUS (Haemolytic Uraemic Syndrome), not TTP. The deficiency of ADAMTS-13 (<10% activity) with ultra-large vWF multimers causing microvascular platelet thrombi preferentially affects the brain in TTP, sparing kidneys relative to HUS.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.