严重急性呼吸综合征患者外周血B细胞亚群及CD40表达变化的意义

目的　探讨严重急性呼吸综合征 (SARS)患者外周血B1细胞、B细胞数量及CD4 0 表达在病程中的变化规律及其与疾病严重程度的关系。方法　用三色流式细胞技术对 162例SARS临床诊断病例外周血B1细胞 (CD+ 19CD+ 5 )数、B细胞 (CD+ 19)数及B细胞CD40 的平均荧光强度 (CD4 0 MF)进行检测并与 3 0例肺炎支原体感染组患者及 3 0名健康对照者外周血B1细胞数、B细胞数及CD40 MF作比较。结果　SARS临床诊断病例B细胞总数为 ( 2 92± 181)× 10 6 /L ,显著高于健康对照组的 ( 2 0 0± 65)× 10 6/L(F =6 17,P <0 0 5) ,但显著低于肺炎支原体感染患者的 ( 3 59± 168)× 10 6 /L(F =6 2 8,P <0 0 5) ;在病程的 11～ 2 0天B1细胞数为 ( 2 4± 14 )× 10 6 /L ,显著低于健康对照组的 ( 3 9± 2 0 )× 10 6 /L(F =4 2 3 ,P <0 0 5) ;病程的前 10天CD4 0 MF为 ( 9 8± 1 6) ,显著低于健康对照组的 ( 12 6± 4 4) (F =5 13 ,P <0 0 5)。SARS重症组与轻症组B细胞数分别为 ( 3 4 7± 156)× 10 6/L及 ( 2 68± 2 11)× 10 6/L ,两者比较差异具有非常显著性 (F =7 11,P <0 0 1)。结论　 ( 1)SARS患者外周血B细胞、B1细胞的数量及CD40 MF的表达均受到不同程度影响 ,其中B细胞数量与SARS病情严重程度相关。 ( 2 )B细胞、B

B cell subsets and the expression of CD40 in peripheral blood of patients with severe acute respiratory syndrome

OBJECTIVE: To explore the changing patterns of B cell subsets and the expression of CD40 on B cells in the course of severe acute respiratory syndrome (SARS) and their relationship to the severity of the disease. METHODS: Peripheral blood from 162 cases of SARS, 30 cases of mycoplasma pneumonia and 30 healthy adult volunteers were measured for the number of total B cells (CD19+ B cell), CD5 positive B cells (B1 cell) and mean fluorescent intensity of CD40 on B cell (CD40MF) using tri-color flow cytometry to analyze the distribution of the above parameters in SARS, mycoplasma pneumonia and healthy adult volunteers and their relation to the severity of SARS. RESULTS: The number of total B cells of clinically diagnosed SARS was (292 +/- 181) x 10(6)/L, significantly greater than that of healthy adults which was (200 +/- 65) x 10(6)/L (F = 6.17, P < 0.05) but smaller than that of patients infected with mycoplasma pneumonia which was (359 +/- 168) x 10(6)/L (F = 6.28, P < 0.05). During day 11 - 20 of the disease, the number of B1 cells of SARS patients was (24 +/- 14) x 10(6)/L smaller than that of healthy adults which was (39 +/- 20) x 10(6)/L (F = 4.23, P < 0.05). In the early stage of SARS (within 10 days), the expression of CD40 decreased significantly as compared with healthy adults (F = 5.13, P < 0.05). The number of B cells in severe SARS and mild cases were (347 +/- 156) x 10(6)/L and (268 +/- 211) x 10(6)/L respectively. The difference was statistically significant (F = 7.11, P < 0.01). CONCLUSIONS: B cells, B1 cells and the expression of CD40 on B cells were involved in the pathogenesis of SARS. The B cell count correlated with the severity of SARS. The monitoring of B cells, B1 cells and the expression of CD40 on B cells is useful in the differential diagnosis of SARS.