What's in a name? HLH/hyperinflammatory syndromes

In this issue of Blood, Rocco et al 1 report insights into the role of interferon gamma (IFN-) in mortality associated with adult hemophagocytic lymphohistiocytosis (HLH).In a retrospective study of 171 clinically annotated patients older than 15 years with hyperinflammatory syndromes, 126 patients met the criteria for HLH (based on 4/8 HLH-2004 criteria or an HScore 169).In addition to the standard laboratory parameters, the authors added measurement of C-X-C-motif ligand-9 (CXCL9), an accepted surrogate marker of IFN--driven inflammation and an established mediator of the hyperinflammation associated with primary HLH in associated animal models.The authors reported that a CXCL9 level 16 100 pg/mL is uniquely associated with 90-day mortality in adult patients with HLH, both for malignancy-associated HLH and non-malignancy-associated HLH.Furthermore, higher CXCL9 levels portend worse prognoses.There was no association between CXCL9 and acute mortality in the HLH-negative cohort.