Sikhosana Mpho L, Welch Richard, Musekiwa Alfred, Makatini Zinhle, Ebonwu Joy, Blumberg Lucille, Jassat Waasila
Department of Virology, National Health Laboratory Service, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa.
Department of Virology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Front Epidemiol. 2024 Apr 26;4:1375975. doi: 10.3389/fepid.2024.1375975. eCollection 2024.
Since there are currently no specific SARS-CoV-2 prognostic viral biomarkers for predicting disease severity, there has been interest in using SARS-CoV-2 polymerase chain reaction (PCR) cycle-threshold (Ct) values to predict disease progression.
This study assessed the association between in-hospital mortality of hospitalized COVID-19 cases and Ct-values of gene targets specific to SARS-CoV-2.
Clinical data of hospitalized COVID-19 cases from Gauteng Province from April 2020-July 2022 were obtained from a national surveillance system and linked to laboratory data. The study period was divided into pandemic waves: Asp614Gly/wave1 (7 June-22 Aug 2020); beta/wave2 (15 Nov 2020-6 Feb 2021); delta/wave3 (9 May-18 Sept 2021) and omicron/wave4 (21 Nov 2021-22 Jan 2022). Ct-value data of genes specific to SARS-CoV-2 according to testing platforms (Roche-ORF gene; GeneXpert-N2 gene; Abbott-RdRp gene) were categorized as low (Ct < 20), mid (Ct20-30) or high (Ct > 30).
There were 1205 recorded cases: 836(69.4%; wave1), 122(10.1%;wave2) 21(1.7%; wave3) and 11(0.9%;in wave4). The cases' mean age(±SD) was 49 years(±18), and 662(54.9%) were female. There were 296(24.6%) deaths recorded: 241(81.4%;wave1), 27 (9.1%;wave2), 6 (2%;wave3), and 2 (0.7%;wave4) ( < 0.001). Sample distribution by testing platforms was: Roche 1,033 (85.7%), GeneXpert 169 (14%) and Abbott 3 (0.3%). The median (IQR) Ct-values according to testing platform were: Roche 26 (22-30), GeneXpert 38 (36-40) and Abbott 21 (16-24). After adjusting for sex, age and presence of a comorbidity, the odds of COVID-19 associated death were high amongst patients with Ct values 20-30[adjusted Odds Ratio (aOR) 2.25; 95% CI: 1.60-3.18] and highest amongst cases with Ct-values <20 (aOR 3.18; 95% CI: 1.92-5.27), compared to cases with Ct-values >30.
Although odds of COVID19-related death were high amongst cases with Ct-values <30, Ct values were not comparable across different testing platforms, thus precluding the comparison of SARS-CoV-2 Ct-value results.
由于目前尚无用于预测疾病严重程度的特定新冠病毒预后病毒生物标志物，人们对利用新冠病毒聚合酶链反应（PCR）循环阈值（Ct）值来预测疾病进展产生了兴趣。
本研究评估了住院新冠病毒疾病（COVID-19）病例的院内死亡率与新冠病毒特异性基因靶点的Ct值之间的关联。
从国家监测系统获取2020年4月至2022年7月来自豪登省的住院COVID-19病例的临床数据，并与实验室数据相关联。研究期间分为疫情波次：D614G/第一波（2020年6月7日至8月22日）；β/第二波（2020年11月15日至2021年2月6日）；δ/第三波（2021年5月9日至9月18日）和奥密克戎/第四波（2021年11月21日至2022年1月22日）。根据检测平台（罗氏-开放阅读框基因；GeneXpert-N2基因；雅培-RdRp基因）对新冠病毒特异性基因的Ct值数据进行分类，分为低（Ct＜20）、中（Ct 20-30）或高（Ct＞30）。
共记录1205例病例：836例（69.4%；第一波），122例（10.1%；第二波），21例（1.7%；第三波）和11例（0.9%；第四波）。病例的平均年龄（±标准差）为49岁（±18），662例（54.9%）为女性。共记录296例（24.6%）死亡：241例（81.4%；第一波），27例（9.1%；第二波），6例（2%；第三波）和2例（0.7%；第四波）（P＜0.001）。检测平台的样本分布为：罗氏1033例（85.7%），GeneXpert 169例（14%），雅培3例（0.3%）。根据检测平台，Ct值的中位数（四分位间距）为：罗氏26（22-30），GeneXpert 38（36-40），雅培21（16-24）。在对性别、年龄和合并症的存在进行校正后，与Ct值＞30的病例相比，Ct值在20-30之间的患者中，COVID-19相关死亡的几率较高[校正优势比（aOR）2.25；95%置信区间：1.60-3.18]，而Ct值＜20的病例中最高（aOR 3.18；95%置信区间：1.92-5.27）。
尽管Ct值＜30的病例中COVID-19相关死亡的几率较高，但不同检测平台的Ct值不可比，因此无法比较新冠病毒Ct值结果。
