Malhotra Indu, Mungai Peter, Muchiri Eric, Kwiek Jesse J, Meshnick Steven R, King Christopher L
Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH 44106-7286, USA.
J Infect Dis. 2006 Jul 15;194(2):176-83. doi: 10.1086/505150. Epub 2006 Jun 12.
It is unknown whether the presence of Plasmodium falciparum malaria parasites in umbilical cord blood denotes infection acquired antenatally or contamination with infected maternal blood at delivery.
Parasites were quantified by real-time quantitative polymerase chain reaction (RTQ-PCR) and were genotyped in paired maternal- and cord-blood samples obtained from 632 pregnant Kenyan women and their newborns. Placental alkaline phosphatase (PLAP) and polyclonal immunoglobulin E levels were also quantified in paired maternal- and cord-blood samples, as markers of admixture of maternal blood with cord blood.
Sixty-six cord-blood samples (10.4%) contained falciparum malaria, as detected by RTQ-PCR. For 25 of the infected cord-blood samples, either absence of infection was noted in paired maternal-blood samples at delivery (n=16) or amplicon levels in cord-blood samples were 10-fold higher than those in maternal-blood samples (n=9). Of the paired maternal- and cord-blood samples that were both infected, 57% showed discordant malaria parasite strains. There was no correlation between maternal parasitemia and levels of PLAP and immunoglobulin E in cord blood. PLAP levels, however, were significantly higher in cord-blood samples obtained from newborns of primigravid or secundigravid women with placental malaria, compared with cord-blood samples obtained from newborns of women without placental malaria or multigravid women. These findings indicate that parity and placental malaria are risk factors for maternofetal transfusion.
Malaria parasites identified in cord blood are acquired antenatally by transplacental transmission of infected erythrocytes. Primigravid and secundigravid women with placental malaria are at increased risk for congenital infection.
脐血中出现恶性疟原虫疟疾寄生虫是表示产前获得感染还是分娩时受感染的母体血液污染尚不清楚。
通过实时定量聚合酶链反应（RTQ-PCR）对寄生虫进行定量，并对从632名肯尼亚孕妇及其新生儿获得的配对母体和脐血样本进行基因分型。还对配对的母体和脐血样本中的胎盘碱性磷酸酶（PLAP）和多克隆免疫球蛋白E水平进行了定量，作为母体血液与脐血混合的标志物。
通过RTQ-PCR检测，66份脐血样本（10.4%）含有恶性疟原虫。在25份受感染的脐血样本中，要么在分娩时配对的母体血液样本中未发现感染（n = 16），要么脐血样本中的扩增子水平比母体血液样本中的高10倍（n = 9）。在配对的母体和脐血样本均受感染的情况下，57%显示疟原虫菌株不一致。母体寄生虫血症与脐血中PLAP和免疫球蛋白E水平之间无相关性。然而，与无胎盘疟疾妇女或多胎妊娠妇女的新生儿的脐血样本相比，患有胎盘疟疾的初产妇或经产妇的新生儿的脐血样本中PLAP水平显著更高。这些发现表明，产次和胎盘疟疾是母胎输血的危险因素。
脐血中鉴定出的疟原虫是通过感染红细胞的胎盘传播在产前获得的。患有胎盘疟疾的初产妇和经产妇发生先天性感染的风险增加。
