肺泡灌洗液宏基因组检测辅助诊断肝移植术后肺弓形虫感染1例

韩冰, 王健, 蔡浩, 张亦弛, 赵帅, 丁瀚, 顾劲扬

PDF(994 KB)

文章检索
精准医学杂志 ›› 2023, Vol. 38 ›› Issue (5) : 469-470. DOI: 10.13362/j.jpmed.202305022
病例报告

肺泡灌洗液宏基因组检测辅助诊断肝移植术后肺弓形虫感染1例

作者信息 +
History +

摘要

关键词

肝移植; 弓形虫病; 支气管肺泡灌洗; 宏基因组; 序列分析,DNA

本文编辑

耿波, 厉建强

引用本文

导出引用
韩冰 , 王健 , 蔡浩 , 张亦弛 , 赵帅 , 丁瀚 , 顾劲扬. 肺泡灌洗液宏基因组检测辅助诊断肝移植术后肺弓形虫感染1例. 精准医学杂志. 2023, 38(5): 469-470 https://doi.org/10.13362/j.jpmed.202305022
患者,男,58岁,因“肝炎后肝硬化失代偿”于2021年12月28日在我院行心脏死亡供体原位肝脏移植术,术前于普通病房住院进行治疗,患者Child评分10分C级,MELD评分12分。供体为女性,55岁,死因为颅内出血,有颅内手术史,病程15 d,有肺部感染,宏基因组痰液检测示肺炎克雷伯杆菌感染,血培养及宏基因组检测均为阴性。受者手术顺利,术后进行常规抗感染、免疫抑制等治疗,早期恢复良好。
2022年1月14日胸部CT平扫提示患者右肺散在炎性病变(图1A),无发热,少许咳嗽,咳痰少,痰培养阴性,以头孢曲松他唑巴坦抗感染进行治疗。2022年1月25日患者出现低热,体温37.8 ℃,复查胸部CT显示右肺下叶炎性病灶较前范围增大(图1B),痰培养仍阴性,抗生素升级为美罗培南。此后患者间歇性体温升高,最高达到38.8 ℃,2022年1月30日患者心率显著增高,呼吸急促,血气分析结果提示呼吸性碱中毒合并代偿性代谢性酸中毒,予以面罩吸氧,次日患者血氧饱和度降低,血常规检查结果显示白细胞急剧升高,达到32.9×109/L,中性粒细胞96%,胸部CT检查提示右下肺实变(图1C)。
图1 患者不同时间点的胸部CT平扫结果

A:2022年1月14日胸部CT平扫示双肺散在炎性病变;B:2022年1月25日胸部CT平扫示右下肺炎症进展;C:2022年1月31日胸部CT平扫示双肺炎症进展,右下肺实变

Full size|PPT slide

患者因低氧血症转入ICU治疗,予替加环素+美罗培南+利霉素钠+卡泊芬净+磺胺甲 唑加强抗感染并停用免疫抑制药物,同日行气管插管及纤支镜检查见气管插管远端气管黏膜肥厚,黏膜表面黄色痰液附着,无法吸出,气管壁及部分支气管开口内见黄色黏稠分泌物附着,以5 mL生理盐水灌洗后回收3 mL送痰培养及宏基因组学检测,后者检测结果显示,刚地弓形虫序列数58 450,相对丰度99.8%,近平滑念珠菌序列数177,相对丰度93.6%,见图2A。同期血液样本送宏基因组学检测结果显示,刚地弓形虫序列数2 103,相对丰度99.7%,见图2B,继续给予上述抗感染的治疗方案,但效果不佳,患者发生了多器官功能障碍综合征,并于2022年2月3日主动要求出院。
图2 患者肺泡灌洗液及血液样本宏基因组测序结果

A:肺泡灌洗液样本;B:血液样本

Full size|PPT slide

讨论 弓形虫是一种猫科动物和其他温血动物的细胞内原生动物寄生虫,大多数宿主(80%)是无症状的,但是免疫抑制状态的实体器官移植(SOT)患者,具有较高的弓形虫感染的风险而且死亡率比较高[1]
在心脏移植中,当供体为弓形虫IgG阳性而受者为血清阴性(Donor+/Recipient-)时,受者弓形虫病发病率最高[2],在非心脏移植受者中发病率不足1%,但病死率却高达43%。国内SOT患者术后弓形虫感染的报道并不多,孙雁等[3]和冀晓东等[4]分别报道了1例肝移植术后弓形虫脑炎患者,均最终死亡。
临床表现方面,移植患者的弓形虫病最常见症状为发热,根据累及部位不同,有肺炎、心肌炎、脑脓肿等临床表现。大多数的病例(82%)在移植后的前6个月发病,通常是肺部或播散性感染[2]。本病例患者早期少许咳嗽,痰少,后经纤支镜检查发现痰液极黏稠,后逐渐出现发热及呼吸困难。
弓形虫病诊断多依赖实验室检查。最直接的证据当然是通过显微镜技术在体液或组织中查到速殖体,但相对耗时且需要相当高技能才能获得可靠的检测结果[5]。目前常用的是弓形虫抗体IgM和IgG的血清学检验,但具有免疫功能缺陷的移植患者不能仅凭血清学检查结果准确诊断。PCR对弓形虫急性感染的检测更敏感,特别是对于已知供受体弓形虫IgG状态不一致者,以及因无法耐受磺胺甲 唑的预防致弓形虫感染风险增加者帮助较大。此外,连续定量PCR检测能够检测出弓形虫载量的升降,有助于记录对治疗的反应。对于SOT受者急性弓形虫病的诊断,美国移植学会(AST)指南建议对血液和体液进行PCR检测,并对受累组织进行活检以鉴定速殖子(强推荐、低级别)[2]
宏基因组测序可检测样本中的所有目标DNA,并提供快速准确的病原信息,是一种革命性DNA检测方法。器官移植后受者处于免疫抑制状态,罕见病原体感染风险增高,临床中多采用宏基因组测序的方法进行检测。我中心曾应用宏基因组二代测序成功检测出1例肝移植术后中枢神经系统曲霉菌感染[6]。RANI等[7]通过宏基因组二代测序法对比分析了肾移植受者和健康对照者尿液样本中抗生素耐药基因,用以指导抗生素的使用。综上,宏基因组测序在器官移植术后抗感染精准诊断和治疗中的应用范围越来越广,价值也越来越大。
该类病人治疗方面,AST指南推荐用乙胺嘧啶、磺胺嘧啶和亚叶酸钙诱导治疗至少6周(强推荐、低级别),并建议在诱导后终生抑制治疗(弱推荐、低级别)[2]。有队列研究显示早期诊断及针对性治疗能够将弓形虫感染患者的生存率从65%提高到77%[8]。此外,为预防移植后弓形虫病的发生,AST指南还推荐筛查所有IgG阳性的供受者,高危受者(Donor+/Recipient-)可采用磺胺甲 唑预防弓形虫病[2]
本例患者通过宏基因组二代测序辅助诊断,明确为肝移植术后弓形虫病,并采用磺胺甲 唑积极治疗,但并未能逆转病情挽救患者生命。鉴于器官移植术后弓形虫感染发病率低,特别是我国报道的更少,结合文献和本病例分析,对于器官移植患者有肺部感染征象,但培养无细菌真菌感染依据,特别是常规经验性抗感染效果不佳的患者,可通过纤支镜检查获取肺泡灌洗液行宏基因组二代测序辅助诊断,以明确是否存在肺部弓形虫感染,尽量做到早诊早治,以提高移植后弓形虫感染的治愈率,改善患者预后。
作者声明:韩冰、王健、蔡浩、张亦弛、顾劲扬参与了研究设计;韩冰、赵帅、丁瀚参与了论文的写作和修改。所有作者均阅读并同意发表该论文,且均声明不存在利益冲突。

参考文献

[1]
LAHOZ R M, MORRIS M I, INFECTIOUS DISEASES COMMUNITY OF PRACTICE OF THE AMERICAN SOCIETY OF TRANSPLANTATION. Tissue and blood protozoa including toxoplasmosis, Chagas disease, leishmaniasis, Babesia, Acanthamoeba, Balamuthia, and Naegleria in solid organ transplant recipients-Guidelines from the American society of transplantation infectious diseases community of practice[J]. Clin Transplant, 2019, 33(9):e13546.
[2]
DARD C, MARTY P, BRENIER-PINCHART M P, et al. Management of toxoplasmosis in transplant recipients: An update[J]. Expert Rev Anti Infect Ther, 2018, 16(6):447-460.
Toxoplasmosis is a life-threatening parasitic disease for hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) recipients. The risk of toxoplasmosis in transplant patients mainly depends on the degree of immunosuppression, the tropism of Toxoplasma gondii for the grafted tissue, and the seroprevalence in the general population. Although transplant recipients with toxoplasmosis have a high mortality rate, there are neither well-defined recommendations nor a consensus for the management of this disease in these patients. Areas covered. This review focuses on the management of toxoplasmosis in transplant recipients and discusses the various strategies for diagnosis, prevention, treatment, and follow-up in clinical practice. The literature search was conducted on publications in English and French using the search terms 'Toxoplasma gondii,' 'organ transplant,' and 'transplant recipients.' Expert commentary. The diagnosis of toxoplasmosis has greatly improved over the last two decades, but it is still a fatal illness. Non-specificity of the symptoms, resulting in a delay before diagnosis, and therapeutic failure are the main causes of death. The development of active treatments against cysts is one of the current challenges that will considerably improve the management of toxoplasmosis in transplant recipients by clearing chronic infection to avoid T. gondii reactivation.
[3]
孙雁, 于立新. 原位肝移植术后弓形虫脑炎一例[J]. 中华器官移植杂志, 2018, 39(8):499-501.
[4]
冀晓东, 赵晨希, 夏爽, 等. 肝移植后中枢神经系统弓形虫感染1例[J]. 实用器官移植电子杂志, 2020, 8(5):390-392.
[5]
LIU Q, WANG Z D, HUANG S Y, et al. Diagnosis of toxoplasmosis and typing of toxoplasma gondii[J]. Parasit Vectors, 2015, 8:292.
Toxoplasmosis, caused by the obligate intracellular protozoan Toxoplasma gondii, is an important zoonosis with medical and veterinary importance worldwide. The disease is mainly contracted by ingesting undercooked or raw meat containing viable tissue cysts, or by ingesting food or water contaminated with oocysts. The diagnosis and genetic characterization of T. gondii infection is crucial for the surveillance, prevention and control of toxoplasmosis. Traditional approaches for the diagnosis of toxoplasmosis include etiological, immunological and imaging techniques. Diagnosis of toxoplasmosis has been improved by the emergence of molecular technologies to amplify parasite nucleic acids. Among these, polymerase chain reaction (PCR)-based molecular techniques have been useful for the genetic characterization of T. gondii. Serotyping methods based on polymorphic polypeptides have the potential to become the choice for typing T. gondii in humans and animals. In this review, we summarize conventional non-DNA-based diagnostic methods, and the DNA-based molecular techniques for the diagnosis and genetic characterization of T. gondii. These techniques have provided foundations for further development of more effective and accurate detection of T. gondii infection. These advances will contribute to an improved understanding of the epidemiology, prevention and control of toxoplasmosis.
[6]
韩冰, 王健, 赵帅, 等. 肝移植术后中枢神经系统曲霉感染一例[J]. 中华移植杂志(电子版), 2021, 15(1):49-51.
[7]
RANI A, RANJAN R, METWALLY A A, et al. Abundance of multidrug resistance efflux pumps in the urinary metagenome of kidney transplant patients[J]. Biomed Res Int, 2020, 2020:5421269.
[8]
CAMPBELL A L, GOLDBERG C L, MAGID M S, et al. First case of toxoplasmosis following small bowel transplantation and systematic review of tissue-invasive toxoplasmosis following noncardiac solid organ transplantation[J]. Transplantation, 2006, 81(3):408-417.
Toxoplasmosis prophylaxis is standard following heart and heart lung transplantation, when an increased risk of allograft transmitted Toxoplasma is well-recognized. In contrast, prophylaxis and routine serologic evaluation of donors and recipients for Toxoplasma in noncardiac solid organ transplantation (SOT) is not recommended. We report the first case of disseminated toxoplasmosis following small bowel transplantation, presumably transmitted via the transplanted intestine and systematically review reported cases of toxoplasmosis in noncardiac SOT recipients to determine if current guidelines should be reconsidered.Systematic MEDLINE review was performed for tissue invasive toxoplasmosis in noncardiac SOT recipients and analysis of clinical features, serologic status, and treatment regimens with respect to mortality.Fifty-two cases of toxoplasmosis in noncardiac SOT recipients were identified. Eighty-six percent developed disease within 90 days of transplantation. Presentation was nonspecific and consisted of fever (77%), respiratory distress (29%), neurologic manifestations (29%), and bone marrow suppression (26%). Multivariate analyses demonstrated that localized disease (odds ratio [OR]=37.36, 95% CI 1.85-754.85), treatment received (OR=1.814, 95% CI 1.193-3.480) and donor and recipient serostatus (OR=1.39, 95% CI 1.068-1.815) were predictors of survival. High-risk recipients (donor seropositive/recipient seronegative) developed disease earlier (16 days vs. 31 days P=0.002) and were less likely to survive (OR=0.14, 95% CI 0.03-0.69) than standard-risk recipients.Toxoplasmosis is recognized following noncardiac SOT. Reduction of morbidity and mortality necessitates knowledge of donor and recipient Toxoplasma serostatus, prophylaxis, early diagnosis, and treatment. The findings support a reconsideration of pretransplantation evaluation and prophylaxis strategies in SOT recipients.

基金

促进市级医院临床技能与临床创新能力三年行动计划重大临床研究项目(SHDC2020CR3005A)
上海市教委高峰高原人才计划(20191910)
上海市科委“科技创新行动计划”国内科技合作项目(21015801600)
PDF(994 KB)

470

Accesses

0

Citation

Detail

段落导航
相关文章

/