CHALLENGES IN DIAGNOSING FAMILIAL HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS: THE ROLE OF T-CELL BIOMARKERS IN THE EARLY DIAGNOSIS OF HEREDITARY HLH

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a rare and potentially life-threatening syndrome. In this article, we describe a case of hereditary HLH in an infant, highlighting the challenges in diagnosis and the significance of the biomarker CD38high/HLA-DR+ cells among CD8+ T cells for the early diagnosis of HLH. Case Presentation: A 1.5-month-old male infant presented with persistent fever and hepatosplenomegaly. Initial laboratory tests revealed pancytopenia, hyperferritinemia. Despite the similarity in clinical manifestations between HLH and sepsis, distinguishing the two is crucial due to their differing treatment approaches. Discussion: The infant's condition was complicated by acute T-cell activation, a finding characteristic of HLH but absent in sepsis. Specifically, CD38high/HLA-DR+ effector cells were identified with prominent CD8+ T-cell activation. These findings underscore the importance of specific biomarkers in the early diagnosis of HLH. Conclusion: The identification of CD38high/HLA-DR+ T cells may serve as a valuable diagnostic tool for clinicians in recognizing HLH early, ultimately guiding appropriate treatment.