Furukawa Kazuna, Mizuno Katsumi, Azuma Minami, Yoshida Yurika, Den Hiroki, Iyoda Masayuki, Nagao Saeko, Tsujimori Yuta
Department of Pediatrics, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan.
Department of Hygiene, Public Health, and Preventative Medicine, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan.
J Hum Lact. 2022 May;38(2):262-269. doi: 10.1177/08903344221075050. Epub 2022 Feb 10.
Developing a simple quantitative tool for mastitis diagnosis is essential. The Ion-Selective Electrode for sodium has been reported to reliably measure sodium concentrations in human milk.
To determine whether an Ion-Selective Electrode measurement of sodium:potassium ratios could serve as a diagnostic tool for mastitis and, if so, to determine the diagnostic cut-off value.
A total of 107 milk samples, including 55 from milk bank donors and 52 from participants with mastitis, were studied. The sodium:potassium ratios were determined in 33 samples (without mastitis = 15; with mastitis = 18) by the Ion-Selective Electrode and ion chromatography. The remaining 74 samples (donor milk = 40; participants with mastitis = 34) were analyzed by Ion-Selective Electrode only. Values were averaged over three measurements for each method.
The median postpartum months of donors and participants with mastitis were 2 and 3 months, respectively. The mean () sodium:potassium ratios without and with mastitis were 0.5 (0.1) and 1.7 (1.2), respectively. A positive correlation existed between sodium:potassium ratios obtained from the two methods ( = 0.98). Area under the curve values were 0.951 (95% CI [0.904, 0.986]) for the Ion-Selective Electrode ( = 107) and 0.978 (95% CI [0.926, 1.000]) for the ion chromatography ( = 33) methods. The optimal cut-off value for the Ion-Selective Electrode method was 0.60, with 86.5% sensitivity and 92.7% specificity.
The Ion-Selective Electrode was sufficiently accurate for the diagnosis of mastitis. Cohort studies are needed to explore the relationship between sodium:potassium ratios and clinical outcomes.
开发一种简单的乳腺炎诊断定量工具至关重要。据报道，钠离子选择性电极可可靠地测量人乳中的钠浓度。
确定通过离子选择性电极测量钠钾比是否可作为乳腺炎的诊断工具，若可以，则确定诊断临界值。
共研究了107份乳汁样本，其中55份来自母乳库捐赠者，52份来自乳腺炎患者。通过离子选择性电极和离子色谱法测定了33份样本（无乳腺炎=15份；有乳腺炎=18份）的钠钾比。其余74份样本（捐赠者乳汁=40份；乳腺炎患者=34份）仅通过离子选择性电极进行分析。每种方法的测量值取三次测量的平均值。
捐赠者和乳腺炎患者的产后中位月数分别为2个月和3个月。无乳腺炎和有乳腺炎时的平均（）钠钾比分别为0.5（0.1）和1.7（1.2）。两种方法测得的钠钾比之间存在正相关（=0.98）。离子选择性电极法（=107）的曲线下面积值为0.951（95%CI[0.904,0.986]），离子色谱法（=33）的曲线下面积值为0.978（95%CI[0.926,1.000]）。离子选择性电极法的最佳临界值为0.60，灵敏度为86.5%，特异性为92.7%。
离子选择性电极对乳腺炎的诊断足够准确。需要进行队列研究以探索钠钾比与临床结局之间的关系。
