Deciphering the clinical profile and diagnostic framework of hemophagocytic lymphohistiocytosis in a tertiary care setting

Abstract Background: Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory disorder marked by intense yet ineffective immune activation, resulting in hemophagocytosis, systemic inflammation, and multi-organ dysfunction. The diagnosis has traditionally depended on the 2004 HLH criteria, while the HScore, introduced in 2014, presents an alternative diagnostic approach. Materials and Methods: A 2-year study was conducted on patients referred to the hematology division for bone marrow evaluation. Patients with fever, cytopenia, and organomegaly underwent comprehensive biochemical and hematological assessments, including bone marrow aspiration. HLH diagnosis was established using both the HScore and the 2004 HLH criteria. Results: Among 48 patients with fever, organomegaly, and cytopenia, 16 (33%) met the HLH diagnostic threshold with an HScore above 169, and 12 cases (75%) showed evidence of hemophagocytosis in the bone marrow. Based on the 2004 HLH criteria, 11 cases (29%) met the diagnostic requirements, achieving scores above five out of eight parameters. Conclusion: A timely and accurate diagnosis of HLH is crucial, as delays can lead to worse outcomes. Employing the 2004 criteria and the HScore is an effective diagnostic strategy, with the HScore showing higher accuracy.