Risk Factors Associated to Mortality In Pediatric Patients with Hemophagocytic Lymphohistiocytosis

Background: Objective: Identify risk factors associated to mortality in pediatric patients with hemophagocytic lymphohistiocytosis.

Methods: retrospective cross-sectional study of medical records with discharge diagnosis of Hemophagocytic syndrome/Hemophagocytic lymphohistiocytosis (ICD-10;D76.1/D76.2) from Jan2004-May2011 in a pediatric-tertiary-care-center. Descriptive and risk analysis were made on SPSS Statistics V17.0.

Results: Thirty medical records were analyzed. Median-for-age: 2 years 8 months, (range:2months-to-15years). Sex distribution: 14 girls(47%), 16 boys(53%). Median of symptoms duration: 1 month (range:3days-to-7years). Reported symptoms and physical signs at hospital admission: fever n=28(93%), asthenia/adynamia n=11(37%), skin findings n=10(33%), epistaxis n=5(17%), gastrointestinal bleeding n=4(13%), hepatomegaly n=27(90%), splenomegaly n=21(70%), lymphadenopathies n=14(47%), paleness n=14(47%), purpura n=5(17%). Laboratory findings: anemia n=29(97%), LDH elevation n=28(93%), hypoalbuminemia n=27(90%), thrombocytopenia n=26(87%), hypertransaminasemia n=25(83%), haemophagocytosis n=22(73%), hypertrigliceridemia n=21(70%), hypofibrinogenemia n=20(67%), leucopenia n=19(63%), hyperferritinemia n=15(50%). In 18 patients(60%) active infection was evident at hospital admission: pneumonia n=9(50%), gastroenteritis n=2(11%), meningitis n=1(5%), others n=6(33%). Epstein-Barr virus infection was diagnosed in 7 patients(23%).

All patients were treated according to HLH-2004 guidelines. Overall mortality 63%(n=19), 9(47%) died from septic-shock, 7(36%) haemorraghic-shock, and 1(5%) with acute liver failure. Differences between non-survivours and survivours by (x²): hypofibrinogenemia (53%vs.13%;p=0.039), epistaxis (17%vs.0%;p=0.023), evident clinical infection (47%vs.13%;p=0.044), elevated LDH levels (63%vs.30%;p=0.039), hemophagocytosis (57%vs.17%;p=0.024). Risk factors associated to mortality: history of epistaxis (OR=1.78,CI95%1.26-2.52;p=0.023), evident clinical infection at hospital admission (OR=2.41,CI95%1.08-5.8;p=0.044). Normal levels of LDH showed diminished mortality risk (OR=0.32,CI95%0.18-0.55;p=0.039).

Conclusions: the present study describes the most common clinical, physical and laboratory findings in patients with haemophagocytic lymphohistiocytosis attended in our hospital. We were able to identify risk factors associated to mortality, and 1 protective factor.