Objective: To analyze the antibody levels and dynamic changes in patients infected with 2019-novel coronavirus(2019-nCoV). Methods: The average age of 72 corona virus disease 2019 (COVID-19) patients was (45.53±16.74)years(median age:47 year), including (44.88±17.09) years(median age:46 year) for 38 males and (46.32±16.52)years (median age:46 year) for 34 females in Loudi City, Hunan Province. There is no significant difference in genders between the severe and mild groups (χ²=0.916, P>0.05). There is a significant difference in the age between the severe and mild groups (F=3.315, P<0.05). The blood samples of 72 discharged patients were collected and the consistence of IgM and IgG antibodies were detected by chemiluminescence method. SPSS25.0 was used for gender, age, case type and antibody analysis of variance, χ2 test and other analysis. Results: The average time of the serum samples collection of 72 patients was (34.89±9.02)days (median time: 34 days) from onset of COVID-19, and (14.53±8.35) days (median time: 14 days) from discharge. The positive rate of IgM or IgG was 97.22% (70/72), and the positive rate of IgM and IgG was 48.61% (35/72) and 97.22% (70/72) respectively. Serum COVID-19 antibodies were detected in 72 patients from 1st to 40th days after discharge. The average concentration of IgM in 1-7 days, 8-14 days, 15-21 days, 22-28 days, above 29 days were 21.91(7.07-52.84)AU/ml, 14.16(6.19-32.88)AU/ml, 11.36(6.65-42.15)AU/ml, 8.15(3.66-30.12)AU/ml, 2.98(0.46-6.37)AU/ml. There was no significant difference in the time of IgM antibody concentration (H= 8.439, P>0.05). The average concentrations of IgG in 1-7 days, 8-14 days, 15-21 days, 22-28 days, 29 days and above were 169.90 (92.06-190.91) AU/ml, 163.89 (91.19-208.02) AU/ml, 173.31 (95.06-191.28) AU/ml, 122.84 (103.19-188.34) AU/ml, 101.98 (43.75-175.30) AU/ml, respectively, (H=2.232, P>0.05). The IgM becomes negative after the 3rd week of discharge and decreases rapidly with time. The IgG concentration higher than IgM during the same period, and keep at high level without any change, and decrease in the fourth week. Among them, 5 cases developed "re-infection" within 1-3 weeks after discharge, and the rate of "re-infection" was 6.94% (5/72 cases). Conclusions: After the COVID-19 patients are discharged from the hospital, the level of antibodies produced varies greatly among individuals, but the overall changes in antibodies have a certain pattern. It is recommended to strengthen the antibody monitoring during hospitalization and after discharge from the hospital to reduce the "re-infection" rate and potential risk of infection.
目的： 分析新型冠状病毒确诊病例出院后患者抗体水平，探讨新型冠状病毒感染者抗体的产生及动态变化规律。 方法： 2020年1~3月份湖南省娄底市72例新型冠状病毒肺炎确诊病例年龄范围（45.53±16.74）岁，中位数年龄47岁［其中男性38例，年龄（44.88±17.09）岁，中位数年龄46岁；女性34例，年龄（46.32±16.52）岁，中位数年龄47岁］，其病情严重程度在性别上差异无统计学意义（χ²＝0.916，P>0.05），在年龄分布上病情严重程度总体差异有统计学意义（F=3.315，P<0.05）。通过血清抗体浓度监测反映病例出院后抗体水平，收集以上72例患者出院后的血液标本，采用化学发光法检测血清中的IgM和IgG抗体浓度，并应用SPSS25.0进行性别、年龄、病例分型及抗体之间的方差分析、χ²检验等分析。 结果： 72例新型冠状病毒肺炎患者血清标本采集时间距发病时间为（34.89±9.02）天、中位数34天，距出院时间为（14.53±8.35）天、中位数14天，抗体检测结果显示IgM和IgG总抗体阳性率97.22%（70/72），其中IgM阳性率48.61%（35/72），IgG阳性率97.22%（70/72）。出院后1~40天内，72例患者血清新型冠状病毒肺炎抗体， IgM在1-7天、8-14天、15-21天、22-28天、29天及以上的浓度分别为21.91（7.07~52.84）AU/ml、14.16（6.19~32.88）AU/ml、11.36（6.65~42.15）AU/ml、8.15（3.66~30.12）AU/ml、2.98（0.46~6.37）AU/ml，整体上IgM抗体浓度在时间上差异无统计学意义（H=8.439， P>0.05）。IgG在1-7天、8-14天、15-21天、22-28天、29天及以上的浓度分别为169.90（92.06~190.91）AU/ml、163.89（91.19~208.02）AU/ml、173.31（95.06~191.28）AU/ml、122.84（103.19~188.34）AU/ml、101.98（43.75~175.30）AU/ml，整体上IgG抗体浓度在时间上差异无统计学意义（H=2.232， P>0.05），但有一定的变化趋势。IgM浓度较低，随时间增长而下降较快，并于出院第3周后转阴；同期IgG浓度较高，出院3周内保持较高水平且基本无变化，出院第4周开始下降。其中5例在出院后1~3周内出现“复阳”，“复阳”率为6.94%（5/72例）。 结论： 新型冠状病毒患者出院后，个体间产生抗体水平差异较大，但抗体变化整体具有一定的规律。.
Keywords: 2019-novel coronavirus; IgG antibody; IgM antibody.