Hosseini MohammadBagher, Esmaili Heydar Ali, Abdoli Oskouei Shahram, Gojazadeh Morteza, MokariYamchi Ziba, Layegh Vahideh, Emami Leyla, MokariYamchi Amin
1 Pediatric Health Research Center, Tabriz University of Medical Sciences , Tabriz, Iran .
2 Department of Clinical Pathology, Faculty of Medicine, Tabriz University of Medical Sciences , Tabriz, Iran .
Breastfeed Med. 2016 Dec;11:557-560. doi: 10.1089/bfm.2016.0107. Epub 2016 Oct 18.
The aim of this study was to evaluate the freeze-thawing method in reducing viral load of cytomegalovirus (CMV) in breast milk of mothers of preterm infants.
In this study, 169 nursing mothers of preterm infants were evaluated serologically for CMV infection. We found 29 (17.15%) nursing mothers who had serologic evidence of CMV infections consistent with recent infection (N = 2, IgG + IgM +) or prior infection (N = 27 IgG + IgM-). Two to 6 weeks after delivery, breast milk of seropositive mothers (N = 29) was evaluated for CMV load by real-time polymerase chain reaction (PCR) before and after freezing at -20°C for 72 hours. All preterm infants with milk results positive for DNA particles of CMV (N = 25) were followed up for signs and symptoms of CMV infection until 3 months of age, together with urine testing for CMV by real-time PCR.
Examination of breast milk by real-time PCR of the seropositive mothers showed 25 of them with CMV DNA particles in their breast milk. After freezing and thawing, we found virus DNA in 4 of 25 (16%) of the breast milk samples and there was no CMV DNA particles in 21 (84%) of them. In these samples, mean viral load before freezing was 76.04 ± 34.08 copies/μL (20-135.00 copies/μL) and after freezing it was 6.75 ± 4.34 copies/μL (0.00-13.00 copies/μL). Freezing showed a significant decrease in viral load of the samples (p = 0.001).
The study showed that the freeze-thawing method is an effective method in reducing the CMV load in breast milk samples.
本研究的目的是评估冻融法对降低早产儿母亲母乳中巨细胞病毒（CMV）病毒载量的效果。
本研究对169名早产儿的哺乳母亲进行了CMV感染的血清学评估。我们发现29名（17.15%）哺乳母亲有CMV感染的血清学证据，其中2名符合近期感染（IgG + IgM +），27名符合既往感染（IgG + IgM -）。分娩后2至6周，对血清学阳性母亲（n = 29）的母乳在-20°C冷冻72小时前后，通过实时聚合酶链反应（PCR）评估CMV载量。对所有母乳CMV DNA颗粒检测结果为阳性的早产儿（n = 25）进行随访，观察其CMV感染的体征和症状直至3月龄，并同时通过实时PCR对尿液进行CMV检测。
对血清学阳性母亲的母乳进行实时PCR检测显示，其中25名母亲的母乳中有CMV DNA颗粒。冻融后，25份母乳样本中有4份（16%）检测到病毒DNA，21份（84%）未检测到CMV DNA颗粒。在这些样本中，冷冻前平均病毒载量为76.04 ± 34.08拷贝/μL（20 - 135.00拷贝/μL），冷冻后为6.75 ± 4.34拷贝/μL（0.00 - 13.00拷贝/μL）。冷冻使样本的病毒载量显著降低（p = 0.001）。
该研究表明，冻融法是降低母乳样本中CMV载量的有效方法。
