目的：探讨既往新型冠状病毒（新冠）感染对多发性骨髓瘤（multiple myeloma ，MM）患者接受自体造血干细胞移植（autologous hematopoietic stem cell transplantation， auto-HSCT）后造血功能和免疫功能重建，以及移植相关并发症的影响。方法：回顾性分析2022年7月1日至2023年7月31日在上海交通大学医学院附属瑞金医院血液科接受auto-HSCT的 MM患者临床资料，根据移植前新冠感染史将患者分为感染组和非感染组，比较2组患者在造血细胞植入时间、移植相关感染、植入综合征、免疫球蛋白恢复、淋巴细胞亚群以及移植后疗效评估等方面的差异。结果：共纳入63例患者，感染组32例，非感染组31例。2组患者移植后粒系和巨核系植入时间、移植相关感染及植入综合征发生率均无统计学差异。感染组移植前外周血CD3⁺T、CD3⁺CD8⁺T和CD19⁺B淋巴细胞计数均高于非感染组（P<0.05），但移植后上述淋巴细胞亚群计数2组间无统计学差异。移植后第8天感染组干扰素（interferon，IFN）-γ较非感染组显著升高（P=0.011）。移植后3个月感染组患者多克隆免疫球蛋白恢复比例较非感染组低（P=0.026），但2组患者疗效评估差异无显著性。结论：MM患者感染新冠痊愈后接受auto-HSCT是安全可靠的，植入时间未见延长，移植相关并发症未见增加，但既往新冠感染者存在免疫功能异常，尤其是移植后多克隆免疫球蛋白重建滞后，建议及时补充人免疫球蛋白，预防感染等并发症。

Objective To assess the impact of prior COVID-19 infection on clinical outcomes in terms of engraftment, treatment emergent complications, and immune reconstitution in multiple myeloma (MM) patients after autologous hematopoietic stem cell transplantation (auto-HSCT). Methods Data of MM patients who underwent auto-HSCT from July 1, 2022, to July 31, 2023, in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine were retrospectively analyzed. The clinical indices including engraftment time, transplant-related infection, engraftment syndrome, immunoglobulin reconstitution, circulating lymphocytes composition, and short-term efficacy were compared in the two cohorts who had or had not been infected by COVID-19 prior to auto-HSCT. Results Sixty-three patients were included. Thirty-two recovered from COVID-19 before auto-HSCT and the remaining 31 did not show evidence of COVID-19 infection. No differences were observed across the two groups in the rates of infections, neutrophil engraftment, platelet engraftment, as well as the incidence of engraftment syndrome. Preceding auto-HSCT, the numbers of CD3⁺T, CD3⁺CD8⁺T and CD19⁺B lymphocytes in patients recovered from COVID-19 were significantly higher than those in COVID-19-free group (P<0.05); however, such a disparity was not present after auto-HSCT. At day 8 post-infusion, interferon(IFN)-γ level of COVID-19 group was higher as compared with that of non-infected group (P=0.011).The rate of polyclonal immunoglobulins recovery in COVID-19-affected cohort was 3.1%, which was lower than that in non-infected patients three months post auto-HSCT (P=0.026), while there was no difference in depth of therapeutic response between the two groups. Conclusions The data indicates that auto-HSCT can be safely administered in MM patients who completely recovered from COVID-19, but their immunoglobulins reconstitution was relatively delayed upon adoptive transfer. Timely and routine intravenous immunoglobin supplements are recommended for minimizing the risk of infection.