ToolsCalculators
HScore for Reactive Hemophagocytic Syndrome
Estimates the probability of reactive (secondary) hemophagocytic lymphohistiocytosis in adults.
HScore for Reactive Hemophagocytic Syndrome
Known underlying immunosuppression (HIV positive, or long-term immunosuppressive therapy)
Maximum temperature
Organomegaly
Number of cytopenias (Hb <=9.2 g/dL and/or WBC <=5,000/mm^3 and/or platelets <=110,000/mm^3)
Serum ferritin
ng/mL
Fasting triglycerides
Fibrinogen
g/L
AST (SGOT)
U/L
Hemophagocytosis features on bone marrow aspirate
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When to use
- Adults with unexplained fever, cytopenias, hepatosplenomegaly, and/or markedly elevated ferritin, to estimate the probability of reactive HLH before pursuing bone marrow biopsy or genetic testing.
Formula
Sum of 9 weighted variables: immunosuppression (0/18), max temperature (0/33/49), organomegaly (0/23/38), number of cytopenias (0/24/34), ferritin (0/35/50), triglycerides (0/44/64), fibrinogen (0/30), AST (0/19), and bone-marrow hemophagocytosis (0/35). Range 0-337; higher scores indicate a higher probability of HLH.
Pearls and pitfalls
- Developed and validated in a multicentre cohort of 312 adults with an expert-adjudicated diagnosis of reactive HLH versus not.
- The original publication provides a continuous score-to-probability curve; 169 points is only the single empirically optimal binary cut-off (best sensitivity/specificity trade-off), not a fixed 'probability tier' boundary.
- Not designed for or validated in the primary (genetic) HLH of infancy, where the HLH-2004 criteria are preferred.