Background
Enterovirus 71 (EV71) infection can lead to a rapidly progressing, life-threatening, and severe neurological disease in young children, including the development of human hand, foot, and mouth disease (HFMD). This study aims to further characterize the specific immunological features in EV71-mediated HFMD patients presenting with differing degrees of disease severity. Methodology: Comprehensive cytokine and chemokine expression were broadly evaluated by cytokine antibody array in EV71-infected patients hospitalized for HFMD compared to Coxsackievirus A16-infected patients and age-matched healthy controls. More detailed analysis using Luminex-based cytokine bead array was performed in EV71-infected patients stratified into diverse clinic outcomes. Additionally, immune cell frequencies in peripheral blood and EV71-specific antibodies in plasma were also examined. Principal findings: Expression of several cytokines and chemokines were significantly increased in plasma from EV71-infected patients compared to healthy controls, which further indicated that: (1) GM-CSF, MIP-1β, IL-2, IL-33, and IL-23 secretion was elevated in patients who rapidly developed disease and presented with uncomplicated neurological damage; (2) G-CSF and MCP-1 were distinguishably secreted in EV71 infected very severe patients presenting with acute respiratory failure; (3) IP-10, MCP-1, IL-6, IL-8, and G-CSF levels were much higher in cerebrospinal fluid than in plasma from patients with neurological damage; (4) FACS analysis revealed that the frequency of CD19(+)HLADR(+) mature B cells dynamically changed over time during the course of hospitalization and was accompanied by dramatically increased EV71-specific antibodies. Our data provide a panoramic view of specific immune mediator and cellular immune responses of HFMD and may provide useful immunological profiles for monitoring the progress of EV71-induced fatal neurological symptoms with acute respiratory failure.