[Successful Treatment of Seasonal Influenza A (H3N2) infection-related Hemophagocytic Lymphocytosis in an Elderly Man].

ABSTRACT

A 79-year-old man experienced severe chronic obstructive pulmonary disease (COPD) and was receiving treatment for ischemic heart disease. Starting from dizziness and chilliness, he lost consciousness after few days. He was taken to our emergency department. On initial evaluation, he complained of dyspnea and was afebrile with a pulse rate, blood pressure, and respiratory rate of 105 beats/min, 112/98mmHg, and 28 breath/min, respectively. His respiratory sounds were clear and chest radiography did not show any abnormal shadows, but his arterial blood gas examination showed type II respiratory failure. Because the nasopharyngeal seasonal influenza A virus (IAV) test was positive, the patient was admitted with the diagnosis of acute exacerbation of COPD due to IAV. We administered peramivir, a specific anti-influenza drug, and started mechanical ventilation. Over time, he started to show signs of disseminated intravascular coagulation, such as multiple organ failure and thrombocytopenia. Subsequently, blood tests showed elevation of ferritin and soluble interleukin 2 receptor (sIL2R); microscopic examination of the peripheral blood revealed hemophagocytosis. Secondary hemophagocytic lymphohistiocytosis (HLH) due to IAV was diagnosed and together with corticosteroid therapy, intravenous gamma globulin was administered from the 3rd clinical day. The patint was saved with our early diagnosis and treatment of HLH and was discharged on the 92nd clinical day. Viral-induced HLH, formerly known as virus-associated hemophagocytic syndrome (VAHS), leads to multiple organ failure due to a cytokine storm scattered by viral-infected pathogenic inflammatory cells. It is well known that pandemic swine flu causes secondary HLH leading to poor outcomes. Currently, not much is known about HLH due to seasonal flu; particularly, IAV (H3N2)-related HLH cases are rare and reported cases showed poor outcomes as well. With an early diagnosis and minimum immunotherapy, we report herein on a case of IAV (H3N2)-related HLH which was treated successfully.