Institute of Veterinary Clinical Science, School of Veterinary Medicine, College of Bio-Resources and Agriculture, National Taiwan University, No. 153, Sec. 3, Keelung Rd, Taipei, 106, Taiwan.
Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung-Hsing University, 145 Xingda Rd., Taichung, 40227, Taiwan.
BMC Vet Res. 2019 Aug 27;15(1):306. doi: 10.1186/s12917-019-2048-9.
Neutrophil gelatinase-associated lipocalin (NGAL), a promising renal biomarker, can exists as a monomer, a dimer and/or in a NGAL/matrix metalloproteinase-9 (MMP-9) complex form when associated with different urinary diseases in humans and dogs. In this study, the presence of the various different molecular forms of NGAL in cat urine (uNGAL) was examined and whether these forms are correlated with different urinary diseases was explored.
One hundred and fifty-nine urine samples from cats with various different diseases, including acute kidney injury (AKI, 22 cats), chronic kidney disease (CKD, 55 cats), pyuria (44 cats) and other non-renal and non-pyuria diseases (non-RP, 26 cats), as well as healthy animals (12 cats), were collected. The molecular forms of and concentrations of urinary NGAL in these cats were analyzed, and their uNGAL-to-creatinine ratio (UNCR) were determined. The cats with AKI had the highest UNCR (median: 2.92 × 10), which was followed by pyuria (median: 1.43 × 10) and CKD (median: 0.56 × 10); all of the above were significantly higher than the healthy controls (median: 0.17 × 10) (p < 0.05). Three different NGAL molecular forms as well as the MMP-9 monomer were able to be detected in the cat urine samples. Moreover, the cases where urine NGAL monomer were present also had significantly higher levels of BUN (median: 18.9 vs 9.6 mmol/L) and creatinine (327.1 vs 168 umol/L). The presence of dimeric NGAL was found to be associated with urinary tract infections. Most cats in the present study (126/159, 79.2%) and more than half of healthy cats (7/12, 58.3%) had detectable NGAL/MMP-9 complex present in their urine.
The monomeric and dimeric molecular forms of uNGAL suggest upper and lower urinary tract origins of disease, respectively, whereas the presence of the uNGAL/MMP-9 complex is able to be detected in most cats, including seemingly healthy ones.
中性粒细胞明胶酶相关脂质运载蛋白（NGAL）是一种很有前途的肾生物标志物，当与人和犬的不同尿路疾病相关时，它可以以单体、二聚体和/或 NGAL/基质金属蛋白酶-9（MMP-9）复合物的形式存在。在这项研究中，检测了猫尿中各种不同分子形式的 NGAL（uNGAL）的存在情况，并探讨了这些形式是否与不同的尿路疾病相关。
收集了 159 份来自患有各种不同疾病的猫的尿液样本，包括急性肾损伤（AKI，22 只猫）、慢性肾病（CKD，55 只猫）、脓尿（44 只猫）和其他非肾性和非脓尿性疾病（非 RP，26 只猫）以及健康动物（12 只猫）。分析了这些猫的尿 NGAL 的分子形式和浓度，并测定了它们的尿 NGAL 与肌酐比值（UNCR）。AKI 猫的 UNCR 最高（中位数：2.92×10），其次是脓尿（中位数：1.43×10）和 CKD（中位数：0.56×10）；所有这些均明显高于健康对照组（中位数：0.17×10）（p<0.05）。在猫尿样本中能够检测到三种不同的 NGAL 分子形式和 MMP-9 单体。此外，尿液 NGAL 单体存在的病例的 BUN（中位数：18.9 对 9.6mmol/L）和肌酐（327.1 对 168μmol/L）水平也明显更高。发现二聚体 NGAL 的存在与尿路感染有关。本研究中的大多数猫（159 只中的 126 只，79.2%）和超过一半的健康猫（12 只中的 7 只，58.3%）的尿液中都可检测到 NGAL/MMP-9 复合物。
uNGAL 的单体和二聚体分子形式分别提示疾病的上尿路和下尿路起源，而 uNGAL/MMP-9 复合物的存在能够在大多数猫，包括看似健康的猫中检测到。
