[Secondary hemophagocytic syndromes]

Area of Science:

• Immunology
• Pathophysiology
• Critical Care Medicine

Context:

• Hemophagocytic lymphohistiocytosis (HLH) represents a life-threatening systemic inflammatory syndrome.
• It stems from immune system dysregulation, involving T cells and NK cells, leading to hypercytokinemia and organ damage.
• Secondary HLH is associated with infections, autoimmune diseases, and malignancies, complicating diagnosis and management.

Purpose:

• To review the clinical presentation, diagnostic challenges, and treatment strategies for secondary HLH.
• To highlight the difficulties in diagnosing and managing secondary HLH due to nonspecific symptoms and overlapping conditions.
• To provide insights based on literature review and clinical observations.

Summary:

• Secondary HLH is characterized by unremitting fever, hepatosplenomegaly, and laboratory abnormalities like cytopenias and hyperferritinemia.
• Diagnosis is challenging due to nonspecific clinical features, mimicking sepsis or systemic inflammatory response syndrome.
• Current diagnostic criteria and therapeutic protocols primarily address genetic HLH, leaving secondary forms with limited specific guidelines.

Impact:

• Improved understanding of secondary HLH diagnostic pitfalls and clinical manifestations.
• Potential to guide the development of specific diagnostic and therapeutic guidelines for secondary HLH.
• Enhanced clinical recognition and management of this critical condition, potentially improving patient outcomes.