Department of Midwifery, University of West Attica, Athens, Greece.
Department of Obstetrics and Gynecology, Skåne University Hospital, Malmö-Lund, Sweden.
J Obstet Gynaecol. 2020 May;40(4):461-467. doi: 10.1080/01443615.2019.1628191. Epub 2019 Jul 29.
Neutrophil gelatinase-associated lipocalin (NGAL) and its complex with matrix metalloproteinase-9 (MMP-9) are present in a variety of human tissues and extracellular fluids. The aim of this pilot prospective case-control study was to detect NGAL and MMP-9/NGAL complex in human breast milk postpartum in women with normal and pregnancies that developed insulin-depended gestational diabetes mellitus (iGDM). We detected both biomarkers in human breast milk and concentrations were determined at the first day of colostrum secretion and two days after, in 22 normal pregnancies and 13 pregnancies with iGDM. Mean NGAL concentration decreased significantly from the first to the second sample, in both groups. Mean MMP-9/NGAL complex concentration decreased also significantly from the first to the second sample in normal pregnancies. Mean complex concentration was significantly higher in diabetic pregnancies compared to normal ones in the second sample.IMPACT STATEMENT There is limited information on the presence of Neutrophil gelatinase-associated lipocalin (NGAL) in human milk and its physiological role. It is the first time that MMP-9/NGAL complex is detected in human milk in both normal and pregnancies complicated with insulin-depended gestational diabetes mellitus (iGDM). We confirm the presence of NGAL in colostrum of normal pregnancies and for the first time we detected NGAL in milk of pregnancies with iGDM. Concentrations of NGAL and MMP-9/NGAL complex tend to lessen postpartum in both groups. Pregnancies with iGDM compared to normal ones showed significantly higher concentration of MMP-9/NGAL complex two days after the beginning of lactation. Further studies are necessary to determine the levels of NGAL and MMP-9/NGAL complex in human milk postpartum in normal and pathological pregnancies. Taking into consideration the well-established NGAL's ability to act as a bacteriostatic agent and its mucosal healing activity in gastrointestinal track, early breastfeeding of neonates is a logical recommendation. Finally, new studies on the actual physiological role of milk NGAL in neonates are necessary.
中性粒细胞明胶酶相关脂质运载蛋白 (NGAL) 及其与基质金属蛋白酶-9 (MMP-9) 的复合物存在于多种人体组织和细胞外液中。本研究旨在检测正常产妇和患有胰岛素依赖型妊娠期糖尿病（iGDM）产妇产后人乳中的 NGAL 和 MMP-9/NGAL 复合物。我们检测了 22 例正常妊娠和 13 例 iGDM 产妇产后第 1 天和第 2 天初乳分泌时人乳中的这两种生物标志物，并确定了它们的浓度。两组中，NGAL 浓度均从第 1 次样本到第 2 次样本明显下降。在正常妊娠组中，MMP-9/NGAL 复合物浓度也从第 1 次样本到第 2 次样本明显下降。与正常妊娠组相比，糖尿病妊娠组第 2 次样本中的复合浓度显著升高。
目前关于 NGAL 在人乳中的存在及其生理作用的信息有限。这是首次在正常妊娠和胰岛素依赖型妊娠期糖尿病（iGDM）孕妇的人乳中检测到 MMP-9/NGAL 复合物。我们证实了 NGAL 在正常妊娠初乳中的存在，并且首次在 iGDM 妊娠妇女的乳汁中检测到了 NGAL。在两组中，产后 NGAL 和 MMP-9/NGAL 复合物的浓度都有降低的趋势。与正常妊娠组相比，iGDM 妊娠组在开始哺乳后第 2 天的 MMP-9/NGAL 复合物浓度明显升高。进一步的研究有必要确定正常和病理妊娠产后人乳中 NGAL 和 MMP-9/NGAL 复合物的水平。考虑到 NGAL 作为抑菌剂的良好作用及其在胃肠道中的黏膜愈合活性，早期对新生儿进行母乳喂养是合理的建议。最后，有必要对初乳 NGAL 在新生儿中的实际生理作用进行新的研究。
