Abstract：
Patients with haematological malignancies might develop life-threatening toxoplasmosis, especially after allogeneic haematopoietic stem-cell transplantation (HSCT). Reactivation of latent cysts is the primary mechanism of toxoplasmosis following HSCT; hence, patients at high risk are those who were seropositive before transplantation. The lack of trimethoprim-sulfamethoxazole prophylaxis and various immune status parameters of the patient are other associated risk factors. The mortality of toxoplasma disease-eg, with organ involvement-can be particularly high in this setting. We have developed guidelines for managing toxoplasmosis in haematology patients, through a literature review and consultation with experts. In allogeneic HSCT recipients seropositive for Toxoplasma gondii before transplant, because T gondii infection mostly precedes toxoplasma disease, we propose weekly blood screening by use of quantitative PCR (qPCR) to identify infection early as a pre-emptive strategy. As trimethoprim-sulfamethoxazole prophylaxis might fail, prophylaxis and qPCR screening should be combined. However, PCR in blood can be negative even in toxoplasma disease. The duration of prophylaxis should be a least 6 months and extended during treatment-induced immunosuppression or severe CD4 lymphopenia. If a positive qPCR test occurs, treatment with trimethoprim-sulfamethoxazole, pyrimethamine-sulfadiazine, or pyrimethamine-clindamycin should be started, and a new sample taken. If the second qPCR test is negative, clinical judgement is recommended to either continue or stop therapy and restart prophylaxis. Therapy must be continued until a minimum of two negative PCRs for infection, or for at least 6 weeks for disease. The pre-emptive approach is not indicated in seronegative HSCT recipients, after autologous transplantation, or in non-transplant haematology patients, but PCR should be performed with a high level of clinical suspicion.
摘要：
血液恶性肿瘤患者可能会发展危及生命的弓形虫病，特别是在异基因造血干细胞移植（HSCT）后。潜伏囊肿的再激活是HSCT后弓形虫病的主要机制；因此，高危患者是移植前血清反应阳性的患者.缺乏甲氧苄啶-磺胺甲恶唑的预防和患者的各种免疫状态参数是其他相关的危险因素。弓形虫疾病的死亡率-例如，器官受累-在这种情况下可能特别高。我们已经制定了血液病患者弓形虫病管理指南，通过文献综述和专家咨询。在移植前弓形虫血清阳性的同种异体HSCT受体中，因为弓形虫感染大多先于弓形虫病，我们建议通过使用定量PCR(qPCR)每周进行血液筛查,以早期识别感染,作为一种先发制人的策略.由于甲氧苄啶-磺胺甲恶唑的预防可能会失败，应将预防和qPCR筛查相结合。然而,即使在弓形虫疾病中，血液中的PCR也可能是阴性的。预防的持续时间应至少为6个月，并在治疗诱导的免疫抑制或严重的CD4淋巴细胞减少期间延长。如果qPCR检测阳性，甲氧苄啶-磺胺甲恶唑治疗，乙胺嘧啶磺胺嘧啶,或乙胺嘧啶-克林霉素应该开始，和一个新的样本。如果第二次qPCR检测是阴性的，临床判断建议继续或停止治疗并重新开始预防.必须继续治疗，直到至少有两个感染的PCR阴性，或至少6周的疾病。血清阴性的HSCT接受者没有采用先发制人的方法，自体移植后，或非移植血液病患者，但PCR应在高度临床怀疑的情况下进行.
