COVID-19康复者恢复期血浆及COVID-19静注人免疫球蛋白的IgG亚类检测分析

目的:探讨COVID-19康复者恢复期血浆及COVID-19静注人免疫球蛋白(human intravenous immunoglobulin，IVIG)(COVID-19-IVIG)IgG及亚类的水平。方法:选择2020年2月至3月国药集团武汉血液制品有限公司采集的COVID-19康复者恢复期血浆及制备的COVID-...

Analysis of IgG subclasses in convalescent plasma and COVID-19 human intravenous immunoglobulin

Objective  To investigate the levels of IgG and its subclasse in convalescent plasma of COVID-19 and COVID-19 human intravenous immunoglobumin (IVIG) (COVID-19-IVIG). Methods  The convalescent plasma collected and COVID-19-IVIG made by Sinopharm Wuhan Plasma-derived Biotherapies Co., Ltd. from February to March 2020 were selected as study group, and healthy human plasma and IVIG were selected as control group. Immunonephelometry was used to detect and compare IgG, IgA, IgM levels and the IgG subclass level of the samples. The correlations of IgG subclasses and other proteins in COVID-19-IVIG were analyzed. Results  The levels of IgG3 and IgG4 in healthy human plasma were significantly higher than those in convalescent plasma (P<0.05), but there was no significant difference in IgG1 and IgG2 levels (P>0.05). In convalescent plasma, the level of IgM was positively correlated with blood type[correlation coefficient(r)=0.649] and antibody titer （r=0.696）(P<0.05), while IgG1(r=0.745) and IgG2(r=0.952) levels were positively correlated with IgG (P<0.05). COVID-19-IVIG IgG1 / was significantly higher than the convalescent plasma (t=3.633, P<0.05), while IgG4 / was lower (t=-4.899, P<0.05), and there was no significant difference in IgG2 / (t=-0.974) and IgG3/(t=-0.280) (P>0.05). There was no significant difference in the distribution of IgG subclasses between COVID-19-IVIG and IVIG (P>0.05). In COVID-19-IVIG, only IgG2 was negatively correlated with α2-macroglobulin (P<0.05). Conclusion  The convalescent plasma and healthy human plasma has similar distribution of IgG subclasses. During the preparation of COVID-19-IVIG, there is a change in the distribution level of IgG subclasses. The IgG subclasses were complete, and their levels are similar to IVIG.