肾移植术后微小病毒B19V感染与相关贫血的临床特点分析

目的探讨肾移植术后受者人微小病毒B19(human parvovirus B19,B19V)感染所致贫血的临床特点及其治疗方案。方法以在中国人民解放军联勤保障部队第九二四医院器官移植中心接受同种异体肾移植手术的5例受者术后出现顽固性贫血为观察对象,实验室检查均为小细胞低色素性贫血,在排除常见贫血原因后,血液宏基因二代测序(metagenomic next-generation sequencing,mNGS)检测人微小病毒B19V阳性,给予患者促红素、口服铁剂、静脉注射人免疫球蛋白(400 mg/kg,第1~5天)、调整免疫抑制方案(他克莫司部分减量,部分调整他克莫司为环孢素)等综合治疗。结果在5例患者中,经综合治疗后,4例(80%)患者病情得到明显缓解,1例出现复发,经再次静脉注射人免疫球蛋白后好转,治疗期间1例合并急性排斥反应。结论肾移植术后对于出现不明原因贫血且进行性加重的患者,应警惕人微小病毒B19V感染的可能。规范疗程静脉注射人免疫球蛋白是肾移植术后人微小病毒B19V感染导致纯红细胞再生障碍性贫血的首选治疗方法,对于复发患者,再次应用仍然有效。联合调整免疫抑制剂方案等综合治疗,可获得理想疗效。同时在治疗期间还需密切监测移植肾功能状态,防止出现移植肾排斥反应。

妊娠妇女人细小病毒B19感染状况分析

目的分析我院就医孕前及怀孕妇女的细小病毒B19的感染情况,为妇幼保健提供数据。方法采用酶联免疫方法检测孕前及孕期妇女血清中特异性IgM抗体按照不同条件进行分组及数据分析。结果细小病毒B19特异性IgM抗体阳性率6.72%,近两年无明显差别,不同季节具有显著性差别。结论在孕前及孕期妇女存在一定的细小病毒B19感染,应广泛开展检查,提高人口出生素质。

Molecular phenotypes of human parvovirus B19 in patients with myocarditis

AIM:To investigate molecular phenotypes of myocardial B19V-infection to determine the role of B19V in myocarditis and dilated cardiomyopathy(DCM).METHODS:Endomyocardial biopsies(EMBs) from 498 B19V-positive patients with myocarditis and DCMwere analyzed using molecular methods and functional experiments.EMBs were obtained from the University Hospitals of Greifswald and Tuebingen and additionally from 36 German cardiology centers.Control tissues were obtained at autopsy from 34 victims of accidents,crime or suicide.Identification of mononuclear cell infiltrates in EMBs was performed using immunohistological staining.Anti-B19V-IgM and anti-B19V-IgG were analyzed by enzyme-linked immunosorbent assay(ELISA).B19V viral loads were determined using in-house quantitative real-time polymerase chain reaction(PCR).For B19V-genotyping a new B19V-genotype-specific restriction fragment length polymorphism(RFLP)-PCR was established.B19V-genotyping was verified by direct DNAsequencing and sequences were aligned using BLAST and BioEdit software.B19V P6-promoter and HHV6-U94-transactivator constructs were generated for cell culture experiments.Transfection experiments were conducted using human endothelial cells 1.Luciferase reporter assays were performed to determine B19Vreplication activity.Statistical analysis and graphical representation were calculated using SPSS and Prism5 software.RESULTS:The prevalence of B19V was significantly more likely to be associated with inflammatory cardiomyopathy(iCMP) compared to uninflamed DCM(59.6% vs 35.3%)(P < 0.0001).The detection of B19V-mRNA replication intermediates proved that replication of B19V was present.RFLP-PCR assays showed that B19V-genotype 1(57.4%) and B19V-genotype 2(36.7%) were the most prevalent viral genotypes.B19V-genotype 2 was observed more frequently in EMBs with iCMP(65.0%) compared to DCM(35%)(P = 0.049).Although there was no significant difference in gender-specific B19V-loads,women were more frequently infected with B19V-genotype 2(44.6%) than men(36.0%)(P = 0.0448).Coinfection with B19V and other cardiotropic viruses was found in 19.2% of tissuesamples and was associated with higher B19V viral load compared to B19V-monoinfected tissue(P = 0.0012).The most frequent coinfecting virus was human herpes virus 6(HHV6,16.5%).B19V-coinfection with HHV6 showed higher B19V-loads compared to B19V-monoinfected EMBs(P = 0.0033),suggesting that HHV6 had transactivated B19V.In vitro experiments confirmed a 2.4-fold increased B19V P6-promoter activity by the HHV6 U94-transactivator.CONCLUSION:The finding of significantly increased B19V loads in patients with histologically proven cardiac inflammation suggests a crucial role of B19V-genotypes and reactivation of B19V-infection by HHV6-coinfection in B19V-associated iCMP.Our findings suggest that B19V-infection of the human heart can be a causative event for the development of an endothelial cell-mediated inflammatory disease and that this is related to both viral load and genotype.

自然流产与感染人类微小病毒B19的相关性分析

目的：通过分析人类微小病毒B19(B19V)在自然流产组和正常分娩组的分布情况，探讨B19V感染与人类自然流产之间的关系。方法：自然流产组92人，采集血液及流产组织为检测标本；正常分娩组42人，采集产妇血液及新生儿脐带血为检测标本。用聚合酶链反应(PCR)方法检测B19V。结果：自然流产病人血液中B19V的检出率为20．6％(19／92)，其流产组织中B19V的检出率为27．2％(25／92)。正常产妇血液及其新生儿脐血B19V的检出率均为4．8％(2／42)。经卡方检验，B19V在流产组和对照组的分布情况的差别有显著性(P<0．05，P<0．01)。结论：B19V在流产组的分布情况显著高于对照组，提示B19V感染可能是导致孕妇流产的较重要的因素之一，在临床实践中应引起注意。

新型细小病毒PARV4的特性及其与人细小病毒B19的关系

新型细小病毒PARV4(Parvovirus 4,PARV4)为细小病毒家族中的单链线状DNA病毒。PARV4能在血液、肝、骨髓以及淋巴组织中检测到,而此病毒是否会致病至今尚未明确。PARV4与人细小病毒B19的生物学特性及理化特性十分类似。鉴于B19V对于血液/血液制品安全性的重要性已经或正在引起人们的广泛重视并实施控制,PARV4也逐渐受到关注。本文在概述人细小病毒的基础上,对PARV4的理化学与生物学特性、PARV4的流行病学特性与致病性、PARV4与B19V及其他细小病毒的异同,以及PARV4在原料血浆中的污染状况等进行综述。

Seroprevalence of acute human parvovirus B19 viraemia among anaemic children in ibadan city, Nigeria

Objective: To determine the seroprevalence of B19V IgM as a measure of acute infection and associated risk factors among < 5 years children at Oyo state, Nigeria. Methods: One hundred and sixteen (116) and thirty eight (38) blood samples were individually collected from severe anaemia and age-matched non-anaemic children between 1-60 months old at Oyo state, Nigeria. EDTA anticoagulated blood was tested for their packed cell volume, while sera were tested for human parvovirus IgM antibodies using microhaematocrit centrifuge and Enzyme Linked Immunosorbent Assay, respectively. Interviewer-based questionnaires were used to collect participants' sociodemographic variables. Results: Anti-B19V IgM was detected in 17 (14.7%) severe anaemia subjects, whereas, only 2 (5.3%) non-anaemia subjects had B19V IgM. The prevalence of parvovirus B19 IgM antibodywas higher in anaemic subjects than non-anaemic control group. There is significant association between the seroprevalence of anti-B19V IgM and family size (P=0.001), number of siblings (P=0.032) and education status (P=0.01) of anaemic children but seroprevalence of anti-B19V IgM is not significantly associated with gender, family type and age (P>0.05). Conclusions: The seroprevalence of 14.7% among anaemic children confirm that these infections are endemic in Nigeria. This level of infectivity suggests that there is a high risk of transmission to healthy children as well as children with underlying haemolytic or acquired anaemia in Nigeria.

瑶族无偿献血者人细小病毒B19感染研究

目的了解广东瑶族无偿献血者人细小病毒B19感染现状。方法采用ELISA法检测血液中抗-HPV B19 IgG,并用PCR法对部分血样进行HPV B19 DNA检测。结果 376名瑶族无偿献血者检出HPV B19 IgG阳性110例,阳性率29.26%,男、女阳性率分别为28.87%和29.67%。147例标本检出HPV B19 DNA 10例,阳性率6.80%,男、女HPV B19 DNA阳性率分别为6.58%和7.04%。42例HPV B19 IgG阳性血液中HPV B19 DNA阳性率9.52%,105例HPV B19 IgG阴性血液中HPV B19 DNA阳性率5.71%,HPV B19 IgG阳性标本与阴性标本中HPV B19 DNA阳性率差异无统计学意义(P>0.05)。结论瑶族无偿献血者存在较高HPV B19既往感染。

重组人细小病毒B19 VP2病毒样颗粒的制备及免疫原性初步研究

目的利用汉逊酵母系统重组表达人细小病毒B19(human parvovirus B19,B19V)主要衣壳蛋白VP2,并对VP2病毒样颗粒(virus-like particles,VLP)进行理化性质研究及免疫效果评价。方法重组表达B19V VP2蛋白,并使其自组装成VLP;通过高密度发酵和系列层析纯化步骤获得VP2-VLP;SDS-PAGE和凝胶过滤高效液相色谱检测蛋白质纯度,动态光散射和透射电镜观察颗粒形态,并检测VP2-VLP磷脂酶活性。采用ELISA和红细胞凝集抑制试验检测小鼠体内VP2-VLP特异性IgG抗体和中和抗体水平。结果本研究制备的重组VP2-VLP纯度大于95%,颗粒均一且形态良好,大小近似天然病毒颗粒;VLP可与特异性单克隆抗体结合,磷脂酶A2活性为阴性;吸附佐剂后的VP2-VLP能够诱导小鼠产生高滴度的特异性IgG抗体和中和抗体。结论汉逊酵母表达系统制备的B19V VP2-VLP可作为候选靶抗原用于B19V预防性疫苗的开发。