In a patient with HELLP syndrome, which parameter in the Tennessee classification system distinguishes complete from partial (class 2) HELLP syndrome?
- A Platelet count 50,000–100,000/μL with LDH >600 IU/L
- B Platelet count 100,000–150,000/μL with AST ≥70 IU/L and LDH ≥600 IU/L ✓
- C Platelet count <50,000/μL with ALT >2× upper limit of normal
- D AST ≥70 IU/L alone with normal platelet count
Correct answer: B. Platelet count 100,000–150,000/μL with AST ≥70 IU/L and LDH ≥600 IU/L
Explanation
The Tennessee (Sibai) classification of HELLP distinguishes Class 1 (complete: platelets <50,000/μL), Class 2 (platelets 50,000–100,000/μL), and Class 3 (partial or atypical HELLP: platelets 100,000–150,000/μL with AST ≥40 IU/L and LDH ≥600 IU/L). Option B correctly describes Class 3 (partial), which is often referred to as 'atypical HELLP.' In partial HELLP, not all three criteria of the classic triad are fully met or thresholds are borderline, distinguishing it from complete HELLP. The Mississippi triple-class system also uses platelet nadir but differs in cutoffs.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.