Abstract：
No effective treatments can ameliorate symptoms of long COVID patients. Our study assessed the safety and efficacy of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) in the treatment of long COVID patients. Ten long COVID patients were enrolled and received intravenous infusions of UC-MSCs on Days 0, 7, and 14. Adverse events and clinical symptoms were recorded, and chest-high-resolution CT (HRCT) images and laboratory parameters were analyzed. During UC-MSCs treatment and follow-up, we did not observe serious adverse events, the symptoms of long COVID patients were significantly relieved in a short time, especially sleep difficulty, depression or anxiety, memory issues, and so forth, and the lung lesions were also repaired. The routine laboratory parameters did not exhibit any significant abnormalities following UC-MSCs transplantation (UMSCT). The proportion of regulatory T cells gradually increased, but it was not statistically significant until 12 months. The proportion of naive B cells was elevated, while memory B cells, class-switched B-cells, and nonswitched B-cells decreased at 1 month after infusion. Additionally, we observed a transient elevation in circulating interleukin (IL)-6 after UMSCT, while tumor necrosis factor (TNF)-α, IL-17A, and IL-10 showed no significant changes. The levels of circulating immunoglobulin (Ig) M increased significantly at month 2, while IgA increased significantly at month 6. Furthermore, the SARS-CoV-2 IgG levels remained consistently high in all patients at Month 6, and there was no significant decrease during the subsequent 12-month follow-up. UMSCT was safe and tolerable in long COVID patients. It showed potential in alleviating long COVID symptoms and improving interstitial lung lesions.
摘要：
没有有效的治疗方法可以改善长期COVID患者的症状。我们的研究评估了人脐带间充质干细胞（UC-MSCs）治疗长型COVID患者的安全性和有效性。招募了10名长型COVID患者，并在第0、7和14天接受了UC-MSCs的静脉输注。记录不良事件和临床症状,和胸部高分辨率CT（HRCT）图像和实验室参数进行分析。在UC-MSCs治疗和随访期间，我们没有观察到严重的不良事件，长期COVID患者的症状在短时间内明显缓解，尤其是睡眠困难，抑郁或焦虑,内存问题,等等，肺部病变也得到了修复。UC-MSCs移植（UMSCT）后，常规实验室参数未显示任何明显异常。调节性T细胞的比例逐渐增加，但直到12个月才有统计学意义。幼稚B细胞比例升高,而记忆B细胞，类交换B细胞，输注后1个月，未转换的B细胞减少。此外,我们观察到UMSCT后循环白细胞介素（IL）-6的短暂升高，而肿瘤坏死因子(TNF)-α,IL-17A,IL-10无明显变化。循环免疫球蛋白（Ig）M水平在第2个月显着增加，而IgA在第6个月显着增加。此外，所有患者的SARS-CoV-2IgG水平在第6个月时始终保持较高水平,在随后的12个月随访中没有显著下降.UMSCT在长期COVID患者中是安全和耐受的。它显示出缓解长期COVID症状和改善间质性肺损伤的潜力。
