[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.


CONCLUSIONS
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.
He
Li
L
Department of Pathology, First Military Medical University, Guangzhou 510515, China. HELY@fimmu.com
Ding
Yan-qing
YQ
Wang
Wei
W
Zhang
Qing-ling
QL
Zhang
Jin-hua
JH
Geng
Jian
J
Cai
Jun-jie
JJ
D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D017493:Leukocyte Common Antigens; D008168:Lung / Q000276:immunology; D008198:Lymph Nodes / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D045169:Severe Acute Respiratory Syndrome / Q000276:immunology* / Q000473:pathology; D013154:Spleen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology
D019394:Ki-67 Antigen; D017493:Leukocyte Common Antigens