The difference of immunologic parameters between SARS patients of mild type and severe type

The aim of this study is to study the difference of immunologic parameters between severe acute respiratory syndrome (SARS) patients of mild type and severe type. Data including white blood cell (WBC) count, lymphocyte count, CD3, CD4 and CD8 T lymphocyte count, levels of C3, C4, ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein) from 1291 patients with SARS in each week from onset of illness were recorded. The clinical progress of each sign was analysed and the difference between mild type and severe type was compared. Lymphocyte count, CD8 T lymphocyte count declined in the first two weeks and recovered from the third week, while CRP and C4 levels rose in the first week and then recovered gradually. Lymphocyte count and CD8 T lymphocyte count of severe cases were much lower than that of mild type (P0.01), while CRP and C4 levels in severe type were much higher than that of mild type (P0.01). Lymphocyte count, CD8 T lymphocyte count, CRP and C4 levels are useful signs for the diagnosis of SARS of severe type and are valuable for the evaluation of its severity.