[Study of laboratory characteristic of 4 patients with sporadic severe acute respiratory syndrome in 2004].

Objective: To analyze the laboratory characteristics of patients with sporadic severe acute respiratory syndrome (SARS) in China.

Methods: The laboratory findings of the 4 cases with SARS occurring in Guangzhou, People's Republic of China, in 2004 were analyzed and compared with that during epidemic.

Results: Leukopenia and lymphocytopenia were seen in all the patients. Two patients had slightly decreased peripheral blood T lymphocyte count. Alanine aminotransferase (ALT) and aspartate transaminase (AST) levels increased slightly in 3 patients. No hypoxemia was seen in all the patients. Both SARS-IgM and IgG sero-conversion occurred earlier in all the patients with the titer increased more than 4-fold shortly. Neutralization test was positive in all the patients. SARS coronary virus (SARS-CoV) RNA was detected by polymerase chain reaction (PCR) in pharyngeal swabs only in 1 patient.

Conclusion: The 4 sporadic SARS patients in 2004 have milder manifestations, shorter course of disease with no complications during an epidemic, compared with patients seen previously. The change in laboratory findings is less than that, which might be attributable to milder virulence of the SARS-CoV. The antibody appears earlier in these patients. The SARS-CoV is eliminated rapidly.