Rapid loss of both CD4^+ and CD8^+ T lymphocyte subsets during the acute phase of severe acute respiratory syndrome

Objective To study the alteration of peripheral lymphocyte subsets in severe acute respiratory syndrome (SARS) patients and to help improve the early diagnosis of the disease Methods Anti coagulating blood samples from 98 SARS patients in the acute phase, 56 normal healthy blood donors, and from patients infected by HIV, CMV and EBV were collected The T lymphocyte subsets were counted by flow cytometry using fluorescence labeled specific monoclonal antibodies Results A significant decrease was observed in all SARS patients in their peripheral CD4 + and CD8 + T lymphocyte absolute counts [256(104)×10 6/L and 256 (117)×10 6/L, respectively], which were also lower than those of the patients infected with HIV, CMV and EBV All patients infected with HIV, CMV and EBV had significantly higher CD8 + T lymphocyte counts in comparison with normal controls Conclusions Decrease of both CD4 + and CD8 + T lymphocytes of patients is related to onset of SARS T lymphocyte subset analysis would help improve the early diagnosis of the disease