Register for Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially life-threatening disorder of the immune system characterized by excessive, uncontrolled activation of immune cells (B lymphocytes and macrophages). The massive release of pro-inflammatory signaling molecules (cytokines) can cause damage to various organs. The clinical presentation of the disease is highly variable; symptoms may include fever, an enlarged spleen and liver, and a reduced blood cell count, which can result in a wide range of symptoms. Various genetic defects can predispose individuals to the onset of the disease. In this case, the condition is referred to as primary HLH. Causes of secondary or acquired HLH may include infections (e.g., with the Epstein-Barr virus, EBV), autoimmune diseases, or cancers. Treatment of secondary HLH depends on the underlying cause. In primary HLH, donor stem cell transplantation is often the only therapy aimed at a cure. Despite available treatment options, patients may die from the consequences of HLH.

The goal of this registry study is to create an international, structured collection of HLH case data, which will serve as the foundation for future interventional studies. As part of the HLH registry, patients’ current treatments are recorded in detail. In addition, demographic data (e.g., age and sex), the presence of various diagnostic criteria, and the underlying genetic defects, among other factors, are recorded. Since HLH is a severe disease, therapeutic studies are urgently needed—a challenge compounded by the rarity and highly variable clinical presentation of this condition. The HLH Registry is intended to assess the feasibility of future studies, and the study design for intervention trials will be developed based on this data collection.

Furthermore, this initiative aims to expand the network of HLH centers and improve the infrastructure for treating this rare disease. Participation in this registry study does not involve the investigation of any new form of therapy. No end date for the study has been set at this time.

Women, men, as well as children and adolescents with primary HLH can participate in this registry study.