Introduction: Macrophage activation syndrome (MAS) is a hyperinflammatory condition, potentially fatal, that can be triggered by various autoinflammatory diseases, infections and malignancies.

Report: A 13-year old boy presented with a 4-days history of fever and myalgia. Exams showed anemia, thrombocytopenia, leukopenia and raised CRP. Blood smear was consistent with microcytic anemia. On admission he underwent IVIG infusion and ceftriaxone. His clinical conditions deteriorated with unremitting fever, dyspnoea, hypotension and hepatosplenomegaly. Trilineage cytopenia, high ferritin, increased CRP, decreased ESR, hypofibrinogemia, hypertrigliceridemia and hypoalbuminemia were consistent with the diagnosis of Hemophagocytic Lympho-Histiocitosis (HLH). Myeloaspirate showed excessive macrophage activity with hemophagocytosis and no blasts. Hemocultures, and PCR for bacteria and viruses on blood resulted negative. Genetic risk factors for MAS/fHLH were negative. He was started on high-dose corticosteroids and on etoposide and cyclosporine shortly after, due to poor response. Two doses of anakinra were also given for persisting fever. Due to the scarce improvement, other possible infectious MAS triggers were reconsidered: PCR for malaria resulted positive and his peripheral blood smears confirmed forms P. falciparum (parasite index 1%). He was started on iv artesunato and quinine chlorydrate with subsequent clinical improvement. Oral steroids and cyclosporine were gradually tapered in 30 days. He did not have history of recent travels out of Italy.

Conclusion: The association between MAS and malaria has been occasionally described. In our patient, malaria was diagnosed only after the failure of specific treatment for MAS. As many features of malaria and MAS can overlap, clinicians should be alert to investigate both conditions in cases with unremitting fever and pancytopenia.

0860 - MACROPHAGE ACTIVATION SYNDROME IN A PATIENT LATELY DIAGNOSED WITH MALARIA