Clinical case of hemophagocytic lymphohistiocytosis: rare or undiagnosed syndrome?

Hemophagocytic lymphohistiocytosis (hemophagocytic syndrome, HLH) is a life-threatening hyperinflammatory condition associated with a high mortality rate; it is characterized by hyperstimulation of histiocytes and cytotoxic T-cells, which leads to cytokine storm and multisystemic injury. Aim. To present our own clinical case of the HLH development at the key aspects of pathogenic mechanisms, differential diagnosis, and therapeutic management of this syndrome. Materials and methods. This article provides information on the HLH development in a 69-year-old man with the onset of this syndrome prior to a diagnosis of the underlying disease - splenic marginal zone lymphoma. The article summarizes the current literature data on clinical manifestations, diagnosis, and treatment of HLH. Results. This article describes a case of secondary HLH from our clinical practice. The most common causes of HLH are malignant neoplasm, infectious factors and rheumatic diseases (when associated with the latest, HLH is called "macrophage activation syndrome"). The main clinical symptoms are prolonged high fever and hepatosplenomegaly, typical laboratory changes such as cytopenia, hyperferritinemia, hypertriglyceridemia, elevated liver enzymes and low fibrinogen levels. Conclusions. Despite typical clinical features, HLH is a condition that often remains unrecognized and it is characterized by a poor prognosis. Prompt prescription of adequate treatment can improve patients' prognoses and increase the survival rate.