CD4 and hemorrhagic fever with renal syndrome: To better assess the effect of viral control through HTNV-Gn/Gc-specific CD4+T cells in HFRS patients, we carefully examined the kinetics of the frequency of IFN-γ-secreting CD4+T cells, the plasma HTNV RNA load, and the serum creatinine levels during the course of HFRS in patients with different disease severities.