HScore for reactive hemophagocytic syndrome (Fardet 2014)

The HScore estimates how likely reactive hemophagocytic syndrome is, from nine features: known immunosuppression, temperature, enlarged liver or spleen, the number of blood cell lines that are low, ferritin, triglycerides, fibrinogen, SGOT (AST) and hemophagocytosis on a bone marrow aspirate. Each feature adds a set number of points, and the total runs from 0 to 337. Magent's HScore calculator adds the points for the bands you choose and reports whether the total reaches 169, the cut-off from the original paper.

Not a medical device. Not a diagnosis or dosing recommendation.

Use this calculator via API

Hematology calculators
Fardet L et al. · 2014
The HScore table
Worked examples
Frequently asked questions

What is the HScore?

Reactive hemophagocytic syndrome, also called secondary HLH, is a severe state of immune overactivation set off by another illness. It can be hard to recognise because its features overlap with sepsis and other conditions.

Fardet and colleagues built the HScore from patients assessed for reactive hemophagocytic syndrome. They weighted each feature by how strongly it pointed towards the syndrome, so some items, such as very high triglycerides, carry many more points than others.

The calculator adds the points. It doesn't turn the total into a probability.

The HScore table

Item                                   Band                         Points
Known underlying immunosuppression     no / yes                     0 / 18
Temperature (°C)                       <38.4 / 38.4-39.4 / >39.4     0 / 33 / 49
Organomegaly                           none / liver or spleen /
                                       liver and spleen              0 / 23 / 38
Cytopenia lineages                     1 / 2 / 3                     0 / 24 / 34
Ferritin (ng/ml)                       <2000 / 2000-6000 / >6000     0 / 35 / 50
Triglycerides (mmol/L)                 <1.5 / 1.5-4.0 / >4.0         0 / 44 / 64
Fibrinogen (g/L)                       >2.5 / 2.5 or less            0 / 30
SGOT / AST (IU/L)                      <30 / 30 or more              0 / 19
Hemophagocytosis on marrow aspirate    no / yes                     0 / 35

HScore 0 to 337;  score_ge_169 = true when the total is 169 or more

Exact expression the calculator uses:

HScore = immunosuppression (true 18) + temperature_band (lt_38_4 0, 38_4_to_39_4 33, gt_39_4 49) + organomegaly (none 0, hepato_or_spleno 23, hepato_and_spleno 38) + cytopenia_lineages (1 → 0, 2 → 24, 3 → 34) + ferritin_band (lt_2000 0, 2000_to_6000 35, gt_6000 50) + triglyceride_band (lt_1_5 0, 1_5_to_4 44, gt_4 64) + fibrinogen_band (gt_2_5 0, le_2_5 30) + sgot_band (lt_30 0, ge_30 19) + marrow_hemophagocytosis (true 35); Fardet 2014 Table 4; max 337; score_ge_169 iff total >= 169 (Table 5 best cutoff)

Inputs

Input	Values
`immunosuppression`	true or false (for example HIV, or long-term glucocorticoids, cyclosporine or azathioprine)
`temperature_band`	`lt_38_4`, `38_4_to_39_4`, `gt_39_4`
`organomegaly`	`none`, `hepato_or_spleno`, `hepato_and_spleno`
`cytopenia_lineages`	1, 2 or 3
`ferritin_band`	`lt_2000`, `2000_to_6000`, `gt_6000`
`triglyceride_band`	`lt_1_5`, `1_5_to_4`, `gt_4`
`fibrinogen_band`	`gt_2_5`, `le_2_5`
`sgot_band`	`lt_30`, `ge_30`
`marrow_hemophagocytosis`	true or false

All nine are required, and you choose the band from the patient's results. The calculator doesn't take raw lab values. In the paper, a lineage counts as low with hemoglobin 9.2 g/dL or less, white cells 5000/mm³ or less, or platelets 110000/mm³ or less.

How the calculation works

Choose bands. For each item, pick the band that matches the result.
Look up points. Each band has a fixed number of points.
Add. The total runs from 0 to 337.
Compare. score_ge_169 is true when the total is 169 or more.

A positive marrow aspirate is one item among nine. It adds 35 points, and the score can reach 169 without it.

Worked examples

These use Magent's own expected values for the calculator.

Example 1: every item at its lowest

No immunosuppression, temperature below 38.4 °C, no organomegaly, one low lineage, ferritin below 2000, triglycerides below 1.5, fibrinogen above 2.5, SGOT below 30, no marrow finding.
HScore 0; score_ge_169 false.

Example 2: one item, temperature above 39.4 °C

Temperature band gt_39_4, the rest at their lowest.
HScore 49.

Example 3: one item, triglycerides above 4 mmol/L

Triglyceride band gt_4, the rest at their lowest.
HScore 64, the largest single item.

Example 4: four items adding to 168

Triglycerides above 4 (64), ferritin above 6000 (50), marrow hemophagocytosis (35) and SGOT 30 or more (19).
HScore 168; score_ge_169 false, one point short.

Example 5: four items adding to 169

Triglycerides above 4 (64), temperature above 39.4 °C (49), enlarged liver and spleen (38) and immunosuppression (18).
HScore 169; score_ge_169 true.

History of the HScore

Fardet L, Galicier L, Lambotte O, Marzac C, Aumont C, Chahwan D, Coppo P and Hejblum G published the score in Arthritis and Rheumatology in 2014, in "Development and validation of the HScore, a score for the diagnosis of reactive hemophagocytic syndrome". In their data, a cut-off of 169 had a sensitivity of 93% and a specificity of 86%, and classified 90% of patients correctly.

When it's used

The HScore is worked out when a patient has features that raise the question of reactive hemophagocytic syndrome, such as persistent fever, low blood counts and a very high ferritin.

Where it's used

Hospital wards, intensive care units, haematology and rheumatology services.

Who uses it

Haematologists, rheumatologists, intensivists and internists. The calculator adds the points and checks the cut-off.

Limits of the calculation

It was built for the reactive form of the syndrome.
Results near 169 sit close to the line, and the score can change as results come in.
It isn't the HLH-2004 criteria set, which uses different items.
The calculator gives a total and a yes/no for 169. It doesn't give a probability.
This page doesn't say what a result means for a particular person.

Clinical decisions belong to a qualified clinician who knows the patient.

4Ts scores the likelihood of heparin-induced thrombocytopenia.
SIC scores sepsis-induced coagulopathy.
SIRS counts signs of a systemic inflammatory response, which can overlap with the HScore's features.

Glossary

Hemophagocytosis: immune cells engulfing blood cells, seen on a marrow aspirate.
Organomegaly: enlarged liver (hepatomegaly) or spleen (splenomegaly).
Cytopenia lineage: a blood cell line (red cells, white cells or platelets) that is low.
SGOT: an older name for AST, a liver enzyme.

Common mistakes

Entering raw lab values. The calculator takes bands, not numbers.
Using the wrong triglyceride unit. The bands are in mmol/L.
Treating the marrow finding as required. It's one of nine items, and the score can reach 169 without it.
Treating 169 as certain. It's a cut-off with known false positives and false negatives.

Source

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. DOI: 10.1002/art.38690. PMID: 24782338

Frequently asked questions

What is the HScore cut-off?

In the original paper it had a sensitivity of 93% and a specificity of 86%.

What is the maximum HScore?

337.

Is the HScore the same as the HLH-2004 criteria?

No. HLH-2004 is a separate criteria set with different items. The HScore is a weighted points score.

Does the score need a bone marrow result?

The marrow item is one of nine and adds 35 points if present. The calculator requires all nine inputs.

Does the calculator give a probability?

No. It returns the total and whether it reaches 169.