To further explore the value of application of SARS‐CoV‐2 IgM and IgG antibodies in the diagnosis and predication for course and prognosis of COVID‐19, we conducted a retrospective study that the level of SARS‐CoV‐2 IgM and IgG antibodies were tested in serial blood samples collected from 105 confirmed COVID‐19 patients and 197 non‐COVID‐19 patients using the MCLIA. Here, CD40LG is linked to COVID-19.