Macrophage Activation Syndrome: A Report of Two Cases and a Literature Review

Table 3

Diagnostic criteria for macrophage activation syndrome: the HScore.

The diagnosis of MAS requires calculating the HScore
(1) Known underlying immunosuppression: 0 (no) or 18 (yes)
(2) Temperature (°C): 0 (<38.4), 33 (38.4–39.4), or 49 (>39.4)
(3) Organomegaly: 0 (no), 23 (hepatomegaly or splenomegaly), or 38 (hepatomegaly and splenomegaly)
(4) No. of cytopenias^†: 0 (1 lineage), 24 (2 lineages), or 34 (3 lineages)
(5) Ferritin (ng/ml): 0 (<2000), 35 (2000–6000), or 50 (>6000)
(6) Triglyceride (mmoles/L): 0 (<1.5), 44 (1.5–4), or 64 (>4)
(7) Fibrinogen (g/L): 0 (>2.5) or 30 (≤2.5)
(8) Serum glutamic oxaloacetic transaminase (IU/L): 0 (<30) or 19 (≥30)
(9) Hemophagocytosis features on bone marrow aspirate: 0 (no) or 35 (yes)
Then, measure the assigned probability^‡
HScore	Probability of hemophagocytic syndrome, %
90	<1
100	1
110	3
120	5
130	9
140	16
150	25
160	40
170	54
180	70
190	80
200	88
210	93
220	96
230	98
240	99
250	>99

Human immunodeficiency virus positive or receiving long-term immunosuppressive therapy (i.e., glucocorticoids, cyclosporine, and azathioprine). ^†Defined as a hemoglobin level of ≤9.2 g/dl and/or a leukocyte count of ≤5000 cells/µL and/or a platelet count of ≤110,000 cells/µL. ^‡The best cutoff value for HScore was 169, corresponding to a sensitivity of 93%, a specificity of 86%, and accurate classification of 90% of the patients. Table 3 is copied from Fardet et al. [19].