Supplementary Material for: A cohort study of the long-term influences of SARS-CoV-2 on kidney allograft outcomes in Chinese recipients: 1-year follow-up experience

Introduction: To investigate the long-term effects of the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection and novel coronavirus disease (COVID-19) on prognosis of kidney transplant recipients. Methods: A 1-year retrospective study was carried out among 362 domestic kidney transplant recipients who were divided into observational (COVID-19) and control groups. Stratification analysis was then carried out to investigate whether repeated infections and infection severity could influence graft prognosis. Kaplan-Meier curves assessed 1-year graft survival, while one-way analysis of variance (ANOVA) compared graft function and laboratory parameters. Generalized estimating equations and repeated measures ANOVA confirmed the magnitude of the impact of COVID-19 on kidney grafts. Generalized logistic regression and Cox regression established a model for analyzing COVID-19 risk factors. Meta-analysis and subgroup analysis were performed for validation. Results: Exposure of COVID-19 had a significant effect on graft function within 1 year (P<0.001), and this kind of effect was mostly brought by severer infections in the stratification analysis regarding graft survival rate (P<0.001), estimated glomerular filtration rate (eGFR) level (P<0.001), and 1-year eGFR slope (P=0.014). Diagnostic model showed tacrolimus patients less likely to get severe COVID-19 than cyclosporine (P=0.004). Hyperglycemia (P=0.004) and low hemoglobin (P=0.023) adverse for severe pneumonia. Hemoptysis, hypo lymphopenia, high procalcitonin, and ferritin linked to poor allograft outcomes with SARS-CoV-2 infection. Conclusions: COVID-19 severity linked to poor kidney allograft prognosis. Hyperglycemia, low hemoglobin, and drug protocols including cyclosporine rather than tacrolimus correlated with COVID-19 pneumonia. Hemoptysis, low lymphocytes, high procalcitonin or ferritin were concerned with kidney allograft prognosis post-COVID-19.

研究背景：本研究旨在探讨新型严重急性呼吸综合征冠状病毒（SARS-CoV-2）感染及新型冠状病毒肺炎（COVID-19）对肾移植受者预后的长期影响。研究方法：本研究纳入362名国内肾移植受者，开展为期1年的回顾性研究，将受试者分为COVID-19感染观察组与对照组。随后通过分层分析探讨重复感染及感染严重程度是否会对移植物预后产生影响。采用Kaplan-Meier曲线（Kaplan-Meier curves）评估1年移植物存活率，通过单因素方差分析（one-way analysis of variance, ANOVA）比较移植物功能与实验室指标；采用广义估计方程（Generalized estimating equations）与重复测量方差分析（repeated measures ANOVA）明确COVID-19对肾移植物的影响程度；采用广义Logistic回归（Generalized logistic regression）与Cox回归（Cox regression）构建COVID-19危险因素分析模型，并通过Meta分析（Meta-analysis）与亚组分析（subgroup analysis）进行验证。研究结果：COVID-19暴露史对肾移植受者1年内的移植物功能具有显著影响（P<0.001），分层分析显示该影响主要由重症感染所致，在移植物存活率（P<0.001）、估算肾小球滤过率（estimated glomerular filtration rate, eGFR）水平（P<0.001）及1年eGFR斜率（P=0.014）的分析中均得到验证。危险因素诊断模型结果显示，相较于环孢素治疗患者，他克莫司治疗患者发生重症COVID-19的风险更低（P=0.004）。高血糖（P=0.004）与低血红蛋白血症（P=0.023）为重症肺炎的危险因素。咯血、淋巴细胞减少、降钙素原及铁蛋白水平升高与SARS-CoV-2感染后移植物不良预后相关。研究结论：COVID-19感染严重程度与肾移植物不良预后密切相关。高血糖、低血红蛋白血症以及采用环孢素而非他克莫司的免疫抑制方案与COVID-19肺炎的发生相关。咯血、淋巴细胞减少、降钙素原及铁蛋白水平升高与COVID-19感染后肾移植物预后不良相关。