免疫细胞在SARS病变组织中的表达及其作用

目的观察并探讨免疫细胞标志物及其活化抗原在严重急性呼吸综合征(severe acute respiratory syndrome,SARS)病变组织中的表达及其在SARS发病中的作用。方法采用14种免疫细胞标志物及其活化抗原,用免疫组化DAB及碱性磷酸酶(AP)双重染色法检测3例SARS尸检病变肺、脾、淋巴结免疫细胞及其活性表达情况。结果(1)病变肺、脾、淋巴结内均可见大量增生的单核巨噬细胞,部分经CD25标记显示阳性(活化单核巨噬细胞)。(2)肺组织炎症灶内可见散在的CD45RO阳性T淋巴细胞,而KI67阳性的T淋巴细胞(活化T淋巴细胞)则很少表达。(3)淋巴结内经KI67及CD45RO双染标记的T淋巴细胞(活化的T淋巴细胞)呈散在阳性;T淋巴细胞亚群数量均明显减少,CD4 、CD8 T淋巴细胞及NK细胞减少则更为严重。结论单核巨噬细胞在SARS发病过程中活性显著增加,为主要反应细胞,而T淋巴细胞亚群则显著减少。单核细胞及T淋巴细胞可能在SARS发病机制中起着重要作用。

Expression of immune cells and their roles in the involved tissues of SARS patients

Objective To study the expression of the immune cell markers and their active antigens in the involved tissues of patients with severe acute respiratory syndrome (SARS). Methods Specimens of the lungs, spleens and lymph nodes were obtained from autopsy of 3 SARS cases to investigate the expression of the immune cells and their activities with double immunohistochemical staining (DAB and AP) by using 14 immune cell markers and their active antigens. Results A large quantity of proliferated macrophages could be observed in the lungs, spleens and lymph nodes of the SARS patients, some of which were positive for CD25 marker (active macrophages). In the lungs of the 3 patients, localized necrosis occurred where infiltration of CD45RO ( ) T lymphocytes was observed, with only scarce Ki67 ( ) T lymphocytes (active T lymphocytes) and B lymphocytes. In the lymph nodes, scattered T lymphocytes positive for Ki67 and CD45RO markers (active T lymphocytes) were seen, but the T lymphocytes subpopulations were obviously decreased, which was especially so with CD4 and CD8 T lymphocytes and NK cells. Conclusion Significantly enhanced activity of the macrophages occurs in SARS as the major reactive cells, but T lymphocyte subsets are obviously decreased, indicating the important roles of the macrophages and T lymphocytes in the pathogenesis of SARS.