Central nervous system (CNS) complications can occur in 9%–15% of patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The clinical manifestations of the CNS complications are non-specific, with most of them being disturbances of consciousness, convulsions, headaches, fever, and epilepsy, making it difficult to infer the cause of the complications based on clinical manifestations. We retrospectively analyzed the sensitivity and feasibility of metagenomic next generation sequencing (mNGS) in the diagnosis of CNS infections after allo-HSCT. Lumbar punctures were performed on 20 patients with CNS symptoms after receiving alternative donor HSCT(AD-HSCT) at the Affiliated Cancer Hospital of Zhengzhou University from February 2019 to December 2020, and their cerebrospinal fluid (CSF) was collected. The mNGS technique was used to detect pathogens in the CSF. Routine CSF testing, biochemical analyses, G experiments, GM experiments, ink staining, acid-fast staining, and bacterial cultures were carried out, and quantitative PCR (qPCR) tests were used to detect cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK polyomavirus (BKPyV), and human alphaherpesvirus (HHV). A total of 29 tests were performed with 21 of them being positive. Of the five negative patients, three were diagnosed with a posterior reversible encephalopathy syndrome, one as having transplantation-associated thrombotic microangiopathy, and one with transient seizure caused by hypertension. Fifteen patients tested positive, of which four had single infections and eleven had mixed infections. Five cases of fungal infections, six cases of bacterial infections, and 13 cases of viral infections were detected. Among the 13 cases of viral infections, ten cases were CMV(HHV-5); three were BKPyV; two were Torque teno virus (TTV); Two were HHV-1,two were EBV(HHV4), and one each of HpyV5 and HHV-6B. Thirteen patients tested positive for virus while the qPCR detection method of 6 identical specimens were below the minimum detection limit(<1×10³ U/ml). The mNGS technique is highly sensitive, and it can be used to diagnose CNS infections after allo-HSCT.

9%–15% 的异基因造血干细胞移植 (allo-HSCT) 患者可能会出现中枢神经系统 (CNS) 并发症。中枢神经系统并发症的临床表现无特异性，多为意识障碍、抽搐、头痛、发热、癫痫等，难以根据临床表现推断并发症的原因。我们回顾性分析了宏基因组二代测序（mNGS）在allo-HSCT后CNS感染诊断中的敏感性和可行性。于2019年2月至2020年12月在郑州大学附属肿瘤医院接受替代供体造血干细胞移植（AD-HSCT）后出现中枢神经系统症状的20例患者进行腰椎穿刺，采集脑脊液（CSF）。mNGS 技术用于检测脑脊液中的病原体。常规进行脑脊液检测、生化分析、G实验、GM实验、墨染、抗酸染色、细菌培养，并采用定量PCR（qPCR）检测巨细胞病毒（CMV）、EB病毒（EBV） )、BK 多瘤病毒 (BKPyV) 和人类甲型疱疹病毒 (HHV)。共进行了 29 项测试，其中 21 项呈阳性。在 5 名阴性患者中，3 名被诊断为后部可逆性脑病综合征，1 名患有移植相关血栓性微血管病，1 名患有高血压引起的短暂性癫痫发作。15 名患者检测呈阳性，其中 4 人为单一感染，11 人为混合感染。真菌感染5例，细菌感染6例，发现病毒感染13例。13例病毒感染中，CMV(HHV-5)10例；三个是 BKPyV；两个是Torque Teno病毒（TTV）；两个是HHV-1，两个是EBV(HHV4)，以及HpyV5和HHV-6B各一个。13名患者病毒检测呈阳性，6份相同样本的qPCR检测方法低于最低检测限（<1×10^{3 单位}/毫升）。mNGS技术灵敏度高，可用于allo-HSCT后CNS感染的诊断。