髓源性抑制细胞在慢性乙型肝炎患者外周血中的表达及作用

Expression and the role of myeloid-derived suppressor cells in the peripheral blood in patients with chronichepatitis B

目的探讨CHB患者外周血髓源性抑制细胞（MDSC）的频率与调节性T淋巴细胞（Treg）频率变化的相关性及临床意义。方法CHB患者45例，其中轻、中度23例，重度22例；健康对照者15例。流式细胞仪检测PBMC中MDSC、Treg频率，采用Spearman相关分析MDSC频率与临床指标、MDSC频率与Treg频率问的相关性。结果CHB患者外周血MDSC中位频率为0．414％，明显高于健康对照组的0．226％，差异有统计学意义（z=-2．356，P0．0189）；且CHB患者MDSC频率与ALT和AST水平呈负相关（r值分别为-0．480和-0．478，均P％0．01），而与HBVDNA水平无相关（r=-0．049，P=0．75）；ALT≤5×正常值上限（ULN）和AST≤3×ULN的CHB患者MDSC升高显著；CHB患者外周血中MDSC频率与Treg频率的变化呈正相关（r=0．345，P=0．02）。结论MDSC的增殖和活化可能是抑制HBV清除的机制之一；MDSC与Treg细胞频率的变化存在相关性，MDSC在CHB中发挥的免疫抑制作用可能与Treg增殖有关。

Objective To investigate the correlation between the frequency of myeloid-derived suppressor cells （MDSC） and the frequency of regulatory T cells （Treg） in the peripheral blood in patients with chronic hepatitis B （CHB） and its clinical significance. Methods A total of 45 CHB patients including 23 mild to-moderate CHB patients, 22 severe CHB patients, and 15 healthy controls were enrolled. The frequencies of MDSC and Treg in the peripheral blood were studied using flow cytometry and its correlation with clinical data was analyzed by Sepearman correlation analysis. Results The median frequency of MDSC in CHB patients was 0. 414~, which was significantly higher than that in healthy controls 0. 226% （Z=-2. 356, P=0. 018 9）. The frequency of MDSC in CHB patients was negatively correlated with the level of alanine transaminase （ALT） and aspartate transaminase （AST） （r=- 0. 480, -0. 478; both P〈0.01）, but had no relations with hepatitis B virus （HBV） viral load （r=-0. 049, P= 0.75）. An increase frequency of MDSC was observed in CHB patients with an ALT of 5 ）〈 upper limits of normal （ULN） or less or AST of 3 × ULN or less. The frequency of MDSC in CHB patients was positively correlated with that of Treg （r= 0. 345, P = 0. 02）. Conclusions The activation and proliferation of MDSC may facilitate and maintain HBV persistent infection. The change of the frequency of MDSC is in line with that of Treg, indicating that immunosuppressive functions of MDSC may be related with the development of Treg in CHB.