AN ANALYSIS OF LYMPHOCYTE SUBGROUPS IN THE LUNG AND IMMUNE ORGANS IN AN AUTOPSY CASE OF SEVERE ACUTE RESPIRATORY SYNDROME / 解放军医学杂志

ABSTRACT

Objective To explore the status of immune responses in the lungs and the changes in lymphocyte subgroups in the immune organs in a patient having been suffered from severe acute respiratory syndrome (SARS). Methods The distribution and number of lymphocyte subgroups in the lungs and immune organs from an autopsy case of SARS were analyzed by using immunochemical staining with an array of monoclonal antibodies including CD3, CD4, CD8, CD20, CD57, CD68, S-100 and HLA-DR. Healthy spleen and lymph nodes were used as normal controls. Results CD8 + T lymphocytes constituted the major component of infiltration of inflammatory cells in the pulmonary interstitium. A semi-quantitative analysis of lymphocyte subgroups revealed that the percentage of CD3 +, CD4 +, CD8 + or CD20 + lymphocyte in a total of 31 thoracic lymph nodes of the SARS case were decreased by 74.2%, 67.7%, 74.2%, and 83.9%, respectively, compared with healthy controls. However, the percentages of lymphocyte subgroups in the celiac lymph nodes were less decreased than those in thoracic lymph nodes. The numbers of CD20 + , CD3 +, CD4 + and CD8 + lymphocytes were also decreased. CD20 + lymphocyte were notably decreased in the spleen, while CD57 +, CD68 +, S-100 + and HLA-DR + cells were increased relatively in the lymph nodes and spleen. Conclusions The results suggested that cellular immune responses were predominant in the lung of SARS patient, and it might play an important role in getting rid of coronaviruses in the infected cells and inducing immune mediated injuries to the lungs. There might be a decrease in number and imbalance in various degrees in the proportion of lymphocyte subgroups in the immune organs of the patients with severe SARS, and these changes might have a tendency to be more remarkable in lymphatic tissue situated closer to the lungs.