PB0593 - The final diagnosis of macrophage activation syndrome and immunodeficiency disease in a case presenting with multiple thrombosis

Background: Deep vein thrombosis in childhood is not always caused by another underlying disease. In this case, a diagnosis of other concomitant disease than expected was made.

Aims: It may be necessary to investigate concomitant diseases in thrombosis in children, which is less common than in adults.

Methods: A 15-year-old girl with no known disease presented with swelling and pain in the left knee and thigh area and underwent radiological imaging, which revealed thrombus in the left iliac, common femoral, superficial femoral and deep femoral, popliteal and crural veins. She underwent thromboembolectomy twice by interventional radiology and then an inferior vena cava thrombus filter was urgently placed. She was hospitalized and started on enoxaparin. In her clinical follow-up, she had a persistent febrile course, and was diagnosed with macrophage activation syndrome due to pancytopenia, elevated CRP, low sedimentation, maculopapular rash all over the body, splenomegaly and hemophagocytosis in the bone marrow aspiration. She was started on HLH chemotherapy protocol. Plasma apheresis and immunoglobulin infusion were performed and the patient went into remission. Thrombophilia gene mutation analysis revealed FV Leiden G1691A and MTHFR C677T heterozygous, other mutations were negative. Protein C, S and ATIII levels were normal. There was no consanguinity between the parents.

Results: As a result of genetic research performed due to recurrent infection and low immunoglobulin, he was diagnosed with immunodeficiency 36 with lymphoproliferation (MIM: 616005). The patient is still receiving anticoagulation with warfarin and Ig replacement therapy every 3 weeks.

Conclusion(s): The development of immune deficiency and macrophage activation syndrome as the final diagnosis during follow-up in a patient presenting with multiple deep venous thrombosis is a rare clinical presentation. We believe that it is important to investigate other underlying diseases in multiple thrombosis.