OBJECTIVE

To study abnormal changes of T lymphocyte and its activated subsets in severe acute respiratory syndrome (SARS) patients.

METHODS

Flow cytometer with multi-color flouroscence and hematology analyzer were used to detect the expression of T lymphocyte and its activated a subsets in 240 SARS patients including 50 cases of critical type and 190 cases of common type.

RESULTS

Statistical analysis by means of SAS software showed that there was significant decrease in absolute counts (AC) of T lymphocyte and its subsets in SARS patients when compared with normal people, while percentages (PC) of CD3+CD25+ and CD3+ HLA-DR+ subsets were increased markedly. Compared with common type, there was significant decrease in absolute counts of critical type of T lymphocyte, CD4+, CD25+CD3+, CD28+CD4+, and CD95+CD4+subsets. The ACs of T lymphocytes including CD4 and CD8 subsets in different phases were as below: III > II > I. The ACs of subsets involved in activation such as CD3+ HLA-DR+/lym, CD3+CD25+/lym, CD28+CD4+/CD4, CD28+CD8+/CD8, and CD38+CD4+/CD4 all were highest in group III. In addition, the AC and PC of CD95+CD4+/CD4 and CD95+CD8/CD8 subset in group III were highest while group I was lowest.

CONCLUSIONS

With depressing cellular immunity, the activation of T lymphocytes were suppressed obviously in SARS patients, especially for critical patients.