Table 1.

Data collection of variables for HLH-2004 criteria and HScore

Variables	Time range with regard to maximum ferritin (when not assessed at day of ferritin maximum)
Hemoglobin, platelets, white blood cell count [min]	± 3 days
Fibrinogen [min]	± 3 days
Triglycerides [max]	± 5 days
Body temperature [max]	± 5 days
AST [max]	± 3 days
NK cell activity, CD107a [max]	± 10 days
sIL-2R	Study period
Hepatomegaly, splenomegaly	Study period
Hemophagocytosis	Study period
Preexisting immunosuppression	Obtained from medical records before study period

AST aspartate aminotransferase, Max maximum, Min minimum, NK natural killer cell, sIL-2R soluble interleukin-2 receptor