Galla Luisa, Cosma Chiara, Bertan Michela, Altinier Sara, Zaninotto Martina, Basso Daniela, Burlina Alberto, Padoan Andrea, Plebani Mario
Laboratory Medicine Unit, University-Hospital of Padova, Padova, Italy.
QI.Lab.Med, Spinoff of University of Padova, Padova, Italy.
Clin Chem Lab Med. 2022 Oct 26;61(2):311-315. doi: 10.1515/cclm-2022-0948. Print 2023 Jan 27.
Serosurveys can be used to monitor COVID-19 seroprevalence and conduct surveillance. Dried blood spot (DBS), used increasingly as a valuable sample to assay severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies (Ab), has several advantages, particularly in infants, due to the limited amount of blood required and its utility in testing a large number of samples in a limited time-frame. We evaluated SARS-CoV-2 IgG Ab prevalence in newborn DBS in the Trentino region of Italy, during the time period January 2020 - December 2021.
Anti-SARS-CoV-2 IgG levels were determined in DBS by means of Anti-SARS-CoV-2 QuantiVac IgG ELISA assay (Euroimmun, Lubeck, Germany).
Analyses included 2,400 DBS from newborns (54% M, 46% F), samples being collected 2-3 days after birth. The first DBS that tested positive for anti-SARS-CoV-2 IgG antibodies was found in March 2020 and, up to May 2020, only 4 positive results were detected overall. Starting from June 2020, the positivity thresholds increased according to the epidemiological waves of the COVID-19 pandemic in Italy, with a robust increment in the winters of 2020 and 2021. The percentage of positive DBS rose from 0 to 6% to 10-47%, in 2020 and 2021, respectively.
This study demonstrates DBS is a suitable tool for both epidemiological purposes and surveillance in the SARS-CoV-2 pandemic, particularly in newborns and pregnant women, saving blood waste and sparing patients any discomfort.
血清学调查可用于监测新冠病毒病（COVID-19）的血清流行率并开展监测。干血斑（DBS）作为一种用于检测严重急性呼吸综合征冠状病毒2（SARS-CoV-2）抗体（Ab）的宝贵样本，因其所需血量有限且能在有限时间内检测大量样本，具有诸多优势，在婴儿中尤为如此。我们评估了2020年1月至2021年12月期间意大利特伦蒂诺地区新生儿干血斑中SARS-CoV-2 IgG抗体的流行率。
采用抗SARS-CoV-2定量Vac IgG酶联免疫吸附测定法（Euroimmun，德国吕贝克）测定干血斑中的抗SARS-CoV-2 IgG水平。
分析纳入了2400份新生儿干血斑样本（男性占54%，女性占46%），样本于出生后2至3天采集。2020年3月发现首例抗SARS-CoV-2 IgG抗体检测呈阳性的干血斑，截至2020年5月，总体仅检测到4例阳性结果。从2020年6月起，阳性阈值随意大利COVID-19疫情的流行波而升高，在2020年和2021年冬季显著增加。2020年和2021年，干血斑阳性率分别从0%升至6%，再升至10%至47%。
本研究表明，干血斑是SARS-CoV-2大流行期间开展流行病学研究和监测的合适工具，尤其适用于新生儿和孕妇，可避免血液浪费，减少患者不适。
