Measurement of subgroups of peripheral blood T lymphocytes in patients with severe acute respiratory syndrome and its clinical significance.

Tang, Xiaoping; Yin, Chibiao; Zhang, Fuchun; Fu, Yonggui; Chen, Weilie; Chen, Yanqing; Wang, Jian; Jia, Weidong; Xu, Anlong

OBJECTIVE To investigate the changes of subgroups of peripheral blood T lymphocytes in patients with severe acute respiratory syndrome (SARS) and its clinical significance. METHODS Subgroups of blood T lymphocytes in 93 patients with SARS were detected by flow cytometer. The results detected in 64 normal subjects and 50 patients with AIDS served as controls. RESULTS The numbers of CD(3)(+), CD(4)(+), and CD(8)(+) lymphocytes all significantly decreased in acute phase of patients with SARS [(722 +/- 533)/microliter, (438 +/- 353)/microliter, (307 +/- 217)/microliter] compared with those in normal controls [(1527 +/- 470)/microliter, (787 +/- 257)/microliter, (633 +/- 280)/microliter, all P <0.01], which was different from what we observed in patients with AIDS who had decreased CD(4)(+) [(296 +/- 298)/microliter] but increased CD(8)(+) [(818 +/- 566)/microliter] counts. The counts of CD(3)(+), CD(4)(+), and CD(8)(+) lymphocytes decreased more apparently in patients with severe SARS. All the five patients who died had CD(4)(+) counts less than 200/microliter. As the patients' condition improved, CD(3)(+), CD(4)(+), and CD(8)(+) counts gradually returned to normal ranges. CONCLUSION The damage of cellular immunity is probably an important mechanism of pathogenesis of SARS.