ABSTRACT
Objective:To investigate the development of specific IgM and IgG antibody against the novel coronavirus in patients with SARS (severe acute respiratory syndrome).Methods:IgM and IgG antibodies against the SARS virus in the sera of the first week, second week, third week, fourth week, eighth week, twelfth week after onset of the illness in the 20 patients with SARS were detected by the indirect enzyme linked immunosorbent assay.Results:IgM and IgG were found negative in the first week after onset of clinical symptoms in all 20 patients with serial sera. Of these 20 patients, 16 were IgM positive and 17 IgG positive in week 2. All 20 patients were IgG positive since the third week and maintained a high level up to 3 months. However, patients with IgM positive was gradually decreasing from week 3 and none of 20 patients was IgM positive in week 12.Conclusion:Specific IgM antibody were found in most patients with SARS during the acute or early convalescent phase and disappeared by the twelfth week after onset of illness. Positive IgM reflected the recent infection of SARS virus. Serum IgG antibodies persisted for a longer period after infection and might be protective and provide immunity from recurrence of symptomatic disease.