The Number of Natural Killer Cells and Their Membrane Immunoglobulin - Like Receptor Decreased in the Peripheral Blood in Patients with Severe Acute Respiratory Syndrome

摘要

Objective To investigate the number of the natural killer cells (NK cell) and the expression of their immunoglobulin - like receptor CD158b in the peripheral blood of severe acute respiratory syndrome (SARS) patients as well as their relationship to the severity of the disease. Methods Peripheral blood from 221 cases of SARS, 34 cases of myoplasma pneumonia and 44 health adults were measured for the number of total NK cells (TNK) ,CD158b positive NK ceUs(CD158b~+ NK) and CD158b positive rate of NK cells (NKCD158b~+ %) using tri - color flow cytometry to analyze the distribution of the above parameters in SARS, myoplasma pneumonia and health adults and the relation of them to the severity of SARS. Results TNK,CD158b~+ NK and NKCD158b~+ % of SARS were significantly lower than those of myoplasma pneumonia (P<0.05,P<0.05,P<0.05)and health control respectively( P < 0.01, P < 0.01, P < 0.05) . TNK, CD158b~+ NK and NKCD158b~+ % in 72 cases of severe SARS were significantly lower than those of 149 light ones( P < 0.05, P < 0.05, P < 0.05). No significant differences were found between light group of SARS and myoplasma pneumonia in TNK, CD158b~+ NK and NKCD158b~+ % . Except CD158b~+ NK in light SARS patients was fewer than that of health control, there is no significant difference between them in TNK and NKCD158b~+ % .TNK, CD158b~+ NK and NKCD158b~+ % of 174 cases of SARS with anti - SARS specific antibodies IgG and/or IgM positive were significantly lower than those without anti - SARS antibody in serum (48 cases) (P<0.05,P<0.01,P<0.01). There were no significant differences among SARS without anti -SARS antibody,myoplasma pneumonia and health control in TNK, CD158b~+ NK and NKCD158b~+ % . Conclusion The number of NK cells and the expression CD158b on the surface of NK cells decreased in SARS and were related to the severity of the disease and the presence of serum anti - SARS specific antibodies or not; No decrease were observed on the number of NK cells and the expression of immunoglubin - like receptor CD158b in myoplasma pneumonia. The monitory of TNK,CD158b~+ NK and NKCD158b~+ % is useful in the differentiate diagnosis of SARS and pneumonia.