Laboratory of Virology, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém, Pará, Brazil.
Amaral Costa Diagnostic Medicine, Belém, Pará, Brazil.
BMC Infect Dis. 2021 May 15;21(1):443. doi: 10.1186/s12879-021-06156-x.
In this study, the prevalence and persistence of anti-SARS-CoV-2 (severe acute respiratory syndrome-coronavirus) IgG was evaluated in volunteers 90 days after COVID-19 (coronavirus disease 2019) diagnosis by correlating response dynamics with clinical conditions, epidemiological characteristics, and disease severity.
The study recruited 200 volunteers aged 18 years or older of both sexes diagnosed with COVID-19. Of the 200 volunteers initially selected, the 135 individuals who underwent serological testing for anti-SARS-CoV-2 antibodies on the first visit to the laboratory, were invited to return, after 90 days, and provide a new blood sample for a second assessment of the presence of anti-SARS-CoV-2 IgG antibody. Disease severity and longevity of symptoms were evaluated for each individual and associated with the serological profile.
Among the 135 individuals who underwent a previous serological test for anti-SARS-CoV-2 antibody, 125 showed reactivity to IgG (92.6%). Of the 125 individuals with detectable IgG in the first test, 87 (69.6%) showed persistence of this antibody after 90 days and 38 (30.4%) lost IgG reactivity in the second evaluation. The frequency of all reported symptoms was higher in individuals who maintained IgG persistence after 90 days of symptoms. Symptom manifestations lasted ≥21 days in the group with a persistent IgG response (39.6%) and ≤ 7 days in the group with a nonpersistent IgG response (50.0%). The length of hospital stay and supplemental oxygen use were higher in individuals with a persistent IgG response.
The results of the present study show a high frequency of loss of anti-SARS-CoV-2 IgG antibodies within 3 months after COVID-19 diagnosis in the Brazilian Amazon.
本研究通过将反应动力学与临床状况、流行病学特征和疾病严重程度相关联，评估了志愿者在 COVID-19（2019 年冠状病毒病）诊断后 90 天内抗 SARS-CoV-2（严重急性呼吸综合征冠状病毒）IgG 的流行率和持续性。
该研究招募了 200 名年龄在 18 岁及以上的男女志愿者，这些志愿者均被诊断患有 COVID-19。在最初选择的 200 名志愿者中，有 135 名在首次就诊实验室时接受了 SARS-CoV-2 抗体血清学检测的志愿者被邀请返回，90 天后提供新的血液样本，以第二次评估抗 SARS-CoV-2 IgG 抗体的存在情况。对每个个体的疾病严重程度和症状持续时间进行了评估，并与血清学特征相关联。
在之前接受过 SARS-CoV-2 抗体血清学检测的 135 名个体中，有 125 名显示出对 IgG 的反应性（92.6%）。在第一次检测中 IgG 可检测到的 125 名个体中，有 87 名（69.6%）在 90 天后 IgG 抗体仍存在持续性，而有 38 名（30.4%）在第二次评估中失去了 IgG 反应性。在症状持续 90 天后 IgG 持续性的个体中，所有报告症状的频率更高。在 IgG 持续反应组（39.6%）中，症状持续时间≥21 天，而在 IgG 非持续反应组（50.0%）中症状持续时间≤7 天。在 IgG 持续反应个体中，住院时间和补充氧气使用时间更长。
本研究结果表明，在巴西亚马逊地区，COVID-19 诊断后 3 个月内，抗 SARS-CoV-2 IgG 抗体的丢失频率较高。
