Department of Renal Medicine, Salford Royal NHS Foundation Trust, Salford, M6 8HD, UK.
Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
BMC Nephrol. 2021 Apr 27;22(1):154. doi: 10.1186/s12882-021-02366-2.
End-stage renal disease (ESRD) patients receiving haemodialysis (HD) are a vulnerable group of patients with increased mortality from COVID-19. Despite improved understanding, the duration of host immunity following COVID-19 infection and role of serological testing alone or in addition to real-time reverse transcription polymerase chain reaction (rRT-PCR) testing in the HD population is not fully understood, which this study aimed to investigate.
There were two parts to this study. Between 15th March 2020 to 15th July 2020, patients receiving HD who tested positive on rRT-PCR for SARS-CoV-2 were recruited into the COVID-19 arm, whilst asymptomatic patients without a previous diagnosis of COVID-19 were recruited to the epidemiological arm of the Salford Kidney Study (SKS). All patients underwent monthly testing for anti-SARS-CoV-2 antibodies as per routine clinical practice since August 2020. The aims were twofold: firstly, to determine seroprevalence and COVID-19 exposure in the epidemiological arm; secondly, to assess duration of the antibody response in the COVID-19 arm. Baseline characteristics were reviewed between groups. Statistical analysis was performed using SPSS. Mann-Whitney U and Chi-squared tests were used for testing significance of difference between groups.
In our total HD population of 411 patients, 32 were PCR-positive for COVID-19. Of the remaining patients, 237 were recruited into the SKS study, of whom 12 (5.1%) had detectable anti-SARS-CoV-2 antibodies. Of the 32 PCR-positive patients, 27 (84.4%) were symptomatic and 25 patients admitted to hospital due to their symptoms. Of the 22 patients in COVID-19 arm that underwent testing for anti-SARS-CoV-2 IgG antibodies beyond 7 months, all had detectable antibodies. A higher proportion of the patients with COVID-19 were frail compared to patients without a diagnosis of COVID-19 (64.3% vs 34.1%, p = 0.003). Other characteristics were similar between the groups. Over a median follow up of 7 months, a higher number of deaths were recorded in patients with a diagnosis of COVID-19 compared to those without (18.7% vs 5.9%, p = 0.003).
Serological testing in the HD population is a valuable tool to determine seroprevalence, monitor exposure, and guide improvements for infection prevention and control (IPC) measures to help prevent local outbreaks. This study revealed HD patients mount a humoral response detectable until at least 7 months after COVID-19 infection and provides hope of similar protection with the vaccines recently approved.
接受血液透析 (HD) 的终末期肾病 (ESRD) 患者是 COVID-19 死亡率增加的脆弱群体。尽管有了更好的认识，但 COVID-19 感染后宿主免疫的持续时间以及血清学检测单独或与实时逆转录聚合酶链反应 (rRT-PCR) 检测联合应用在 HD 人群中的作用仍未完全了解，本研究旨在对此进行调查。
本研究分为两部分。2020 年 3 月 15 日至 2020 年 7 月 15 日，接受 rRT-PCR 检测 SARS-CoV-2 呈阳性的 HD 患者被纳入 COVID-19 组，而无症状且无 COVID-19 既往诊断的患者被纳入索尔福德肾脏病研究 (SKS) 的流行病学组。自 2020 年 8 月以来，所有患者每月根据常规临床实践进行抗 SARS-CoV-2 抗体检测。目的有两个：首先，确定流行病学组的血清流行率和 COVID-19 暴露情况；其次，评估 COVID-19 组的抗体反应持续时间。对两组间的基线特征进行了回顾性分析。使用 SPSS 进行统计分析。使用 Mann-Whitney U 和卡方检验来检验组间差异的显著性。
在我们的 411 名 HD 患者总人群中，有 32 名 PCR 检测 COVID-19 呈阳性。在其余患者中，有 237 名患者被纳入 SKS 研究，其中 12 名（5.1%）检测到抗 SARS-CoV-2 抗体。在 32 名 PCR 阳性患者中，有 27 名（84.4%）有症状，有 25 名因症状住院。在 COVID-19 组中，有 22 名患者接受了超过 7 个月的抗 SARS-CoV-2 IgG 抗体检测，所有患者均检测到抗体。与无 COVID-19 诊断的患者相比，COVID-19 患者中有更高比例的体弱患者（64.3%比 34.1%，p=0.003）。两组其他特征相似。中位随访 7 个月期间，COVID-19 诊断患者的死亡人数高于无 COVID-19 诊断患者（18.7%比 5.9%，p=0.003）。
在 HD 人群中进行血清学检测是一种有价值的工具，可用于确定血清流行率、监测暴露情况，并指导感染预防和控制 (IPC) 措施的改进，以帮助预防局部暴发。本研究表明，HD 患者可产生至少在 COVID-19 感染后 7 个月仍可检测到的体液免疫反应，并为最近批准的疫苗提供了类似的保护希望。
