A Case of COVID-19 Vasculitis Complicated by Hemophagocytic Lymphohistiocytosis

Abstract

Abstract Title: A Case of COVID-19 Vasculitis Complicated by Hemophagocytic Lymphohistiocytosis Background Hemophagocytic lymphohistiocytosis (HLH) is an acute and rapidly progressive systemic inflammatory disorder characterized by cytopenia, excessive cytokine production, and hyperferritinemia resulting in multi-organ failure. Primary HLH is mainly due to genetic inheritance whereas secondary HLH is due to malignancy, infection, or autoimmune stimulus. COVID-19 can involve all organ systems, including the circulatory system, causing thrombosis and vascular dysfunction leading to cutaneous vasculitis. Severe COVID-19 infection causes cytokine hyperinflammation, triggering an intense immune response that may be the mechanism of HLH development. We chose this case to review the clinical picture of HLH development in a patient with a history of COVID-19 vasculitis and its severe outcomes. Case Presentation A 67-year-old male presented with bilateral lower extremity ulcerated lesions. Patient had COVID-19 infection seven months prior and was treated with steroids, antibiotics, and oxygen support without complication. However, one month later he developed bilateral lower extremity vasculitis. Antibody panel was inconclusive and skin biopsy of the lesions showed medium and small vessel vasculitis secondary to COVID-19 thrombotic vasculopathy. Subsequently oral steroid therapy, rituximab and IVIG infusion were given. However, the lesions progressively worsened and the patient went into septic shock requiring vasopressors and stress dose of corticosteroids. He developed pancytopenia with ANC nadir of 900, thrombocytopenia (PLT: 29k), LDH of 1300 U/L, ferritin 20,000 ng/nL. Bone marrow aspirate revealed mostly non-viable cells, scattered megakaryocytes, and scattered macrophages with hemophagocytosis. Based on the clinical history and morphological findings, hemophagocytic lymphohistiocytosis was diagnosed. The patient received filgrastim and dexamethasone, however, he clinically deteriorated and passed within four days of diagnosis. Discussion COVID-19 induces a wide range of clinical symptoms, including vasculitis. Hemophagocytic lymphohistiocytosis is a very rare condition with high mortality and should be considered in the differential diagnosis of patients with prolonged non-resolving fever and multisystem involvement. Due to its rarity and variable presentation, a high degree of clinical suspicion is warranted to diagnose HLH in the setting of COVID-19 vasculitis. We hope that presenting this case will result in earlier diagnosis and intervention to prevent long-term morbidity and mortality as seen in our case.