Reply to swine flu and hemophagocytic syndrome

Abstract

To the Editor Dr. Viroj indicated that other infection could not be ruled out in our case [1]. While the patient received erythromycin 1,000 mg/day IV for 5 days, no bacterial pathogens were detected in sputum cultures by bronchoalveolar lavage fluid (BALF). All viral antibody tests such as for parainfluenza, coxsackie, rhinovirus, and RS virus were negative; only that for flu A was positive. We believe that influenza virus (H1N1) pneumonia should be diagnosed with radiologic findings. Dr. Viroj suggested that there is no proof that virusassociated hemophagocytic syndrome (VAHS) in the cases reported by Beutel [2] is totally caused by swine flu virus induction. Unfortunately, we could not confirm that Beutel et al. ruled out other causes of hemophagocytic syndrome (HPS) in the report. However, we guess that occurrence of HPS triggers a similar cytokine storm similarly in those patients, resulting in severe inflammation such as acute respiratory distress syndrome (ARDS) or systemic inflammatory response syndrome (SIRS) [3]. Thus, bicytopenia or pancytopenia should be monitored. Although previous reports have not demonstrated that influenza virus is a common pathogen causing HPS [4], we think that HPS could possibly occur in patients with influenza virus (H1N1).