[Dynamics of peripheral blood B lymphocytes and natural killer cells in patients with severe acute respiratory syndrome].

Objective: To study the dynamics of peripheral blood B lymphocytes and natural killer (NK) cells in patients with severe acute respiratory syndrome (SARS).

Methods: The absolute numbers of peripheral blood B lymphocytes and NK cells in 602 serial samples from 240 patients with SARS were counted, using flow cytometry, and compared with that of normal population.

Results: The absolute numbers of peripheral blood B lymphocytes and NK cells in SARS patients were significantly lower than that of the normal population (P < 0.001) and were much lower in SARS patients with severe or extremely severe types, as compared with that of moderate or mild type cases (P < 0.001). The amount of B lymphocytes in recovery SARS patients increased at the 2nd week after onset, and gradually becoming normal at the 5th week of the disease onset. The number of NK cells was in the low level at onset, and keep decreasing at the 2nd week. However, it was increasing with the recovery of the disease, but did not reach to normal level at the 5th week after onset.

Conclusion: The absolute numbers of peripheral blood B lymphocytes and NK cells were associated with the severity of the disease, and detection of these two kinds of cells was useful for predicting the prognosis of SARS.