🧬 HScore (Hemophagocytic Syndrome/HLH Probability)
The HScore estimates the probability of secondary (reactive) hemophagocytic lymphohistiocytosis (HLH) from nine weighted clinical, laboratory, and cytological items.
A cutoff around 169 gives roughly 82% sensitivity and 88% specificity for reactive HLH, while a score above 250 corresponds to >99% probability and below 90 to low probability (original synthesis · not guideline verbatim).
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When to use
Enter temperature, ferritin, triglycerides, fibrinogen and AST, and select immunosuppression status, organomegaly, number of cytopenic lineages, and marrow hemophagocytosis; the tool returns a 0–337 score and probability band.
How it works
Weighted sum of nine items (immunosuppression 18; temperature ≤38.4 = 0 / 38.4–39.4 = 33 / >39.4 = 49; organomegaly 0/23/38; cytopenias 0/24/34; ferritin <2000 = 0 / 2000–6000 = 35 / >6000 = 50; triglycerides <1.5 = 0 / 1.5–4 = 44 / >4 = 64; fibrinogen ≤2.5 g/L = 30; AST ≥30 = 19; marrow hemophagocytosis 35). A cutoff ≈169 maximizes accuracy.
Key points
- A cutoff around 169 gives roughly 82% sensitivity and 88% specificity for reactive HLH, while a score above 250 corresponds to >99% probability and below 90 to low probability (original synthesis · not guideline verbatim).
- Sepsis, severe infection, and other hyperinflammatory states overlap with HLH, so the score complements rather than replaces sIL-2R, NK-cell activity, marrow review, and identification of the trigger.
- Ferritin and triglycerides carry the most weight, so trending these values can support an evolving diagnosis when the initial score is intermediate.
References
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Known immunosuppression (HIV/long-term immunosuppressants) | Yes |
|---|---|
| Temperature | 39 °C |
| Organomegaly | None (0) |
| Cytopenic lineages (Hb≤9.2/WBC≤5000/PLT≤110k) | 1 lineage (0) |
| Ferritin | 3000 ng/mL |
| Triglycerides | 3.0 mmol/L |
| Fibrinogen | 2.0 g/L |
| AST | 60 U/L |
| Hemophagocytosis on bone marrow | Yes |
→HScore214/337
- Interpretation：Suggests HLH (≥169)
- Common cutoff：≥169
| Known immunosuppression (HIV/long-term immunosuppressants) | No |
|---|---|
| Temperature | 39 °C |
| Organomegaly | Both hepato- and splenomegaly (38) |
| Cytopenic lineages (Hb≤9.2/WBC≤5000/PLT≤110k) | 3 lineages (34) |
| Ferritin | 3000 ng/mL |
| Triglycerides | 3.0 mmol/L |
| Fibrinogen | 2.0 g/L |
| AST | 60 U/L |
| Hemophagocytosis on bone marrow | No |
→HScore233/337
- Interpretation：Suggests HLH (≥169)
- Common cutoff：≥169
Frequently asked questions
- What is HScore (Hemophagocytic Syndrome/HLH Probability)?
- The HScore estimates the probability of secondary (reactive) hemophagocytic lymphohistiocytosis (HLH) from nine weighted clinical, laboratory, and cytological items.
- How is HScore (Hemophagocytic Syndrome/HLH Probability) calculated? What is the core formula?
- Weighted sum of nine items (immunosuppression 18; temperature ≤38.4 = 0 / 38.4–39.4 = 33 / >39.4 = 49; organomegaly 0/23/38; cytopenias 0/24/34; ferritin <2000 = 0 / 2000–6000 = 35 / >6000 = 50; triglycerides <1.5 = 0 / 1.5–4 = 44 / >4 = 64; fibrinogen ≤2.5 g/L = 30; AST ≥30 = 19; marrow hemophagocytosis 35). A cutoff ≈169 maximizes accuracy.
- When is HScore (Hemophagocytic Syndrome/HLH Probability) used?
- Enter temperature, ferritin, triglycerides, fibrinogen and AST, and select immunosuppression status, organomegaly, number of cytopenic lineages, and marrow hemophagocytosis; the tool returns a 0–337 score and probability band.
- What are the key clinical points for HScore (Hemophagocytic Syndrome/HLH Probability)?
- A cutoff around 169 gives roughly 82% sensitivity and 88% specificity for reactive HLH, while a score above 250 corresponds to >99% probability and below 90 to low probability (original synthesis · not guideline verbatim). Sepsis, severe infection, and other hyperinflammatory states overlap with HLH, so the score complements rather than replaces sIL-2R, NK-cell activity, marrow review, and identification of the trigger. Ferritin and triglycerides carry the most weight, so trending these values can support an evolving diagnosis when the initial score is intermediate.
- What are the limits and cautions when using HScore (Hemophagocytic Syndrome/HLH Probability)?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is HScore (Hemophagocytic Syndrome/HLH Probability) calculated in practice? Can you show a worked example?
- Inputs: Known immunosuppression (HIV/long-term immunosuppressants) Yes, Temperature 39 °C, Organomegaly None (0), Cytopenic lineages (Hb≤9.2/WBC≤5000/PLT≤110k) 1 lineage (0), Ferritin 3000 ng/mL, Triglycerides 3.0 mmol/L, Fibrinogen 2.0 g/L, AST 60 U/L… → Result: HScore 214 /337（Interpretation: Suggests HLH (≥169), Common cutoff: ≥169） Inputs: Known immunosuppression (HIV/long-term immunosuppressants) No, Temperature 39 °C, Organomegaly Both hepato- and splenomegaly (38), Cytopenic lineages (Hb≤9.2/WBC≤5000/PLT≤110k) 3 lineages (34), Ferritin 3000 ng/mL, Triglycerides 3.0 mmol/L, Fibrinogen 2.0 g/L, AST 60 U/L… → Result: HScore 233 /337（Interpretation: Suggests HLH (≥169), Common cutoff: ≥169）