Serum Level Detection of SARS Coronavirus Antibodies IgM and IgG in Patients with Atypical Pneumonias and its Clinical Significance

To explore the clinical significance in serum level detection of antibodies IgM and IgG against coronavirus of severe acute respiratory syndrome (SARS) in patients with atypical pneumonia.By enzyme linked immunosorbent assay(ELISA), serum levels of antibodies IgM and IgG against SARS were detected in 16 SARS patients, 147 isolated patients with fever and 23 healthy subjects. Positive SARS antibody IgM was detected in 8 out of 12 hospitalized SARS patients, while positive SARS antibody IgG was detected in 9 out of 12 patients during discharge from the hospital. After leaving hospital for 6 months, high titers of SARS antibody IgG still could be detected in 7 recovered patients ; at the same time, SARS antibody IgM was detectable in 2 patients. Serum dynamic observation on 2 serious SARS patient indicated that high titers of SARS IgM and IgG were persistently found from admission till discharge . Weakly positive SARS antibody IgM was detected once in 2 mild SARS patients ; SARS antibody IgG was demonstrated in 6 patients of isolated fever ward from admission till discharge, two among them showed higher titers. Positive SARS antibody was absent in all healthy subjects.[Conclusion]Detection of antibodies IgM and IgG against coronavirus of SARS by ELISA can be used as one auxiliary measure for clinical examination and diagnosis of SARS patients.