Ravelli et al came up with a different set of criteria for patients with MAS based on data of patients reported in literature10. A comparison of the 2 criteria in a retrospective longitudinal study11 (albeit with a very small sample size) showed that the Ravelli et al criteria to be much more sensitive and enabled patients to be diagnosed much earlier than when the HLH-2004 criteria was used. In both SoJIA and uncontrolled rheumatic disease the patient is liable to have high WBC counts and high platelet counts. Bone marrow suppression which is one of the pathognomic features of MAS would be picked up very late if absolute cut off values were utilized. Kelly et al used the same arguments in their review to suggest that in MAS/ReHLH, the trend of change in laboratory parameters would be more useful than absolute cut offs.