Haematology Oncology Critical Care

HScore for Reactive Haemophagocytic Syndrome (HLH)

Estimates the probability of reactive haemophagocytic syndrome (rHPS / HLH) using 9 clinical and laboratory parameters.

Used in: Anaemia

Score interpretation

HLH Very Unlikely (< 1%) 0–89

HScore < 90: < 1% probability of reactive HLH.

→ HLH unlikely. Consider alternative diagnoses.

HLH Unlikely (~3%) 90–129

HScore 90–129: ~1–3% probability of HLH.

→ Low probability. Monitor. Repeat ferritin. Consider bone marrow biopsy if clinical suspicion persists.

Intermediate Probability (~8%) 130–149

HScore 130–149: ~8% probability of reactive HLH.

→ Intermediate probability. Bone marrow biopsy recommended. NK cell activity, sCD25. Urgent haematology review.

High Probability (~15–22%) 150–168

HScore 150–168: ~15–22% probability of reactive HLH.

→ High clinical suspicion. Treat presumptively if clinical scenario fits. HLH-2004 or DEP protocol.

HLH Very Likely (> 60–93%) 169–400

HScore ≥ 169: > 60–93% probability of reactive HLH. Sensitivity 93%, specificity 86% at this threshold.

→ Initiate HLH treatment immediately (dexamethasone ± etoposide ± ciclosporin). Treat underlying trigger. ICU-level care.

Interpretation bands for the HScore. Apply clinical judgement and local guidance.

Fardet L et al. Development and Validation of the HScore, a Score for the Diagnosis of Reactive Hemophagocytic Syndrome. Arthritis Rheumatol. 2014;66(9):2613-2620.

Curated clinical cross-links plus same-class fallbacks.

Drugs

Pathways

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.