Evaluation of IFNγ and Inflammatory Mediators in Patients With Hemophagocytic Lymphohistiocytosis

This is a observational study designed to determine the levels of pro-inflammatory markers in adult patients diagnosed with HLH and to assess the relationship between the biomarkers and disease activity in these patients during the HLH course. Inflammatory markers include IFNγ and IFNγ-induced chemokines C-X-C chemokine ligand 9 and C-X-C chemokine ligand 10. In addition to the blood samples for the biomarker analysis, relevant information gathered by the treating physician will be collected in a data collection form. Whenever possible, collection of serum samples for biomarker analysis and relevant information should occur at HLH diagnosis, at regular time intervals during the treatment course (not more than once a week) up to resolution of HLH. Blood samples will also be sent to the study sponsor (NovImmune S.A.) for cytokine testing. Before patient's samples are sent to the sponsor for testing, patient's name and any personal identifying information will be coded to protect participant's privacy.