Secondary hemophagocytic lymphohistiocytosis in Turkish children

Area of Science:

• Pediatrics
• Infectious Diseases
• Hematology

Background:

• Secondary hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome.
• It often occurs in conjunction with infections, malignancies, or autoimmune diseases.
• Understanding the epidemiology and triggers of secondary HLH in children is crucial for timely diagnosis and management.

Purpose of the Study:

• To determine the frequency of secondary HLH in hospitalized children.
• To identify the common underlying causes and infectious triggers of secondary HLH.
• To report the treatment outcomes and survival rates in this pediatric population.

Main Methods:

• Retrospective analysis of pediatric patients diagnosed with secondary HLH between January 1998 and January 2005.
• Data collection included patient demographics, underlying conditions, infectious agents, treatment, and outcomes.
• Frequency calculated as a percentage of total hospitalized patients.

Main Results:

• Eighteen children (2 weeks-72 months) were diagnosed with secondary HLH, representing 0.05% of total hospitalizations.
• Bacterial infections were the most frequent trigger (44.5%), followed by cytomegalovirus (28%) and Epstein-Barr virus (5.5%).
• Leishmaniasis and herpes simplex virus were each diagnosed in 11% of patients. The overall survival rate was 61%.

Conclusions:

• Secondary HLH in children is a rare but serious condition with significant mortality.
• Infections, particularly bacterial and viral, are primary drivers of secondary HLH in pediatric patients.
• Improved diagnostic strategies and targeted treatments are needed to enhance survival rates for secondary HLH.