National Center for Global Health and Medicine - Research Institute, Kumamoto University - Department of Clinical Sciences, National Center for Global Health and Medicine - Biostatistics Section, National Center for Global Health and Medicine - AIDS Clinical Center, Sysmex Corporation, Sysmex Corporation, National Center for Global Health and Medicine - Department of Clinical Research, National Center for Global Health and Medicine - Department of Refractory Viral Infections, National Center for Global Health and Medicine - Department of Refractory Viral Infections, JCHO Kumamoto General Hospital, JCHO Kumamoto General Hospital, JCHO Kumamoto General Hospital, JCHO Kumamoto General Hospital, National Center for Global Health and Medicine - AIDS Clinical Center, Kumamoto University - Joint Research Center for Human Retrovirus Infection, National Center for Global Health and Medicine - AIDS Clinical Center, National Center for Global Health and Medicine - Department of Clinical Research, National Center for Global Health and Medicine - Department of Clinical Research, Sysmex Corporation, Sysmex Corporation, affiliation not provided to SSRN and National Center for Global Health and Medicine - Research Institute