SARS患者红细胞天然免疫黏附功能变化的探讨

The changes of erythrocyte innate-immune-adhesion function in SARS

目的 研究SARS患者红细胞天然免疫黏附功能 (erythrocyteinnateimmuneadhesionfunction ,EIIAF)的变化及与红细胞CR1数量、循环补体C3、C4及免疫复合物含量等变化之间的关系 ,探讨引起EIIAF变化的可能原因。方法 EIIAF检测 :将 10 0 μl枸橼酸钠抗凝的待测病人血浆和 1μl离心沉淀红细胞 ,直接加到 15 0 μl定量分装的靶细胞管中 ,充分混匀 ,37℃水浴 30min ,结合 5个或以上红细胞的靶细胞为 1个黏附单位 ,计算黏附率。正常人血浆和红细胞与病人红细胞和血浆互换试验 :洗涤病人红细胞 ,与正常人血浆进行EIIAF检测 ,同时将正常人红细胞与病人血浆进行EIIAF检测作为对照。红细胞补体Ⅰ型受体 (CR1)定量测定 :采用细胞酶免法。补体C3、C4含量 ,采用免疫比浊法测定。循环免疫复合物采用凝集法。结果 6 5例SARS患者在出现发热等临床症状 1～ 3d内EIIAF即不同程度地下降 ,EIIAF的下降程度与患者发热、全身中毒症状及肺部炎症渗出的程度密切相关。重症SARS和因呼吸窘迫综合症死亡的患者其EIIAF接近完全消失 ;肺部阴影全部吸收时EIIAF回升到正常水平 ,并一过性地高于自身正常水平 ,然后再有不同程度的下降。正常人红细胞在SARS病人血浆中的EIIAF明显受到抑制 ,病人红细胞在正常人血浆中的EIIAF无明显回升。?

Objective To study the changes of erythrocyte innate immune adhesion function (EIIAF), the quantitative expression of complement receptor 1 on erythrocyte, genomic density of ECR1, the contents of C3, C4 in blood circulation and complement immune complex in patients with SARS were examined. Methods Fast assay of erythrocyte innate immune adhesion function (EIIAF) has been used as follows: One μl of red blood cell and 100μl plasma of patient is mixed with 150μl of quantitative target antigen cells at 37℃ for 30 min. One tumor cell attached by 5 erythrocytes or more was counted as one rosette. The ratio of rosettes was calculated. The EIIAF of control red cells, and SARS red cells were washed three times with 0.15mol/L salt in healthy plasma assay and compared with same type blood cell and plasma. Complement immune complex and C3, C4 in circulation were detected by ELISA. Results The ability of EIIAF in 65 cases with SARS with fever for three days was significantly lower than that of healthy individuals ( P <0.01) or before SARS. There is a good relationship between the changes of EIIAF and clinic symptom especially in those with severe fever or with severe inflammation in pneumonia. The EIIAF is nearly disappeared in severe SARS the patients died of ARDS. EIIAF will be returned to near the normal level when the patients get better, and recovered. The EIIAF of normal red cells incubated with SARS patients′ plasma is decreased. The quantitative expression of complement receptor 1 on erythrocyte was all decreased in the severe SARS cases, and showed a parallel change with EIIAF. There is a lower EIIAF but high number of CR1 in three cases of sub clinical SARS. C3 and C4 decreased inconspicuously in early phase of diseases, but decreased gradually while the status getting well. CIC is significantly increased in acute phase and decreased when EIIAF is raised to normal level. Conclusion Decreased EIIAF may be the result of losing CR1 on erythrocytes because of immune clearance by complement activation. There may be some substance suppressing the activity of EIIAF in plasma. The dynamic balance of immune damage and immune clearance may be the important factores of pathogenesis of SARS.