Hunold Katherine M, Schwaderer Andrew, Stephens Julie A, Wexler Randell, Camargo Carlos A, Suer Ozan Y, Wei Lai, Hains David, Southerland Lauren T, Bischof Jason J, Caterino Jeffrey M
Department of Emergency Medicine, The Ohio State University College of Medicine, Columbus, Ohio, USA.
Division of Nephrology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
J Am Geriatr Soc. 2025 Mar 10. doi: 10.1111/jgs.19431.
BACKGROUND/OBJECTIVE: Antimicrobial peptides have demonstrated promise as biomarkers for urinary tract infection (UTI) in older adults (age ≥ 65 years). However, it is unknown if urinary AMP levels also increase in asymptomatic bacteriuria. Our objective was to determine if AMP levels vary between older adult patients with and without asymptomatic bacteriuria.
This was a preplanned secondary analysis of older adults enrolled in a cross-sectional study of patients presenting to a family medicine clinic for a non-acute visit and without urinary symptoms. Asymptomatic bacteriuria was considered present if a patient had a positive culture defined as (> 10,000) colony-forming units (CFUs) of a single organism. All other culture results were considered negative. Urinalysis results are presented based on the presence/absence of asymptomatic bacteriuria. Urinary levels of 4 AMPs (human neutrophil peptides 1-3 (HNP 1-3), human alpha-defensin-5 (HD-5), human beta-defensin-2 (hBD-2), and cathelicidin (LL-37)) are reported as median and interquartile range. The Wilcoxon Rank Sum test was used to compare the log-transformed AMP values between the groups.
The analytic cohort included 162 older adult patients; 18 (11%) had asymptomatic bacteriuria. Urinalysis results varied between asymptomatic older adult patients with positive asymptomatic bacteriuria and negative cultures, but AMP values did not differ (p > 0.2 for all four AMPs).
AMPs did not differ between asymptomatic older adult patients with positive and negative cultures in this secondary analysis. AMPs should be further studied as if they increase in older adults with symptomatic UTI, they may then be able to distinguish negative culture/asymptomatic bacteriuria from true infection where urinalysis cannot.
背景/目的：抗菌肽已被证明有望作为老年人（年龄≥65岁）尿路感染（UTI）的生物标志物。然而，尚不清楚无症状菌尿症患者的尿液抗菌肽水平是否也会升高。我们的目的是确定有和没有无症状菌尿症的老年患者之间抗菌肽水平是否存在差异。
这是一项对参与横断面研究的老年人进行的预先计划的二次分析，该横断面研究的对象是到家庭医学诊所进行非急性就诊且无泌尿系统症状的患者。如果患者的单一微生物培养结果为阳性（定义为>10,000个）菌落形成单位（CFU），则认为存在无症状菌尿症。所有其他培养结果均视为阴性。根据有无无症状菌尿症呈现尿液分析结果。报告了4种抗菌肽（人中性粒细胞肽1 - 3（HNP 1 - 3）、人α - 防御素 - 5（HD - 5）、人β - 防御素 - 2（hBD - 2）和杀菌肽（LL - 37））的尿液水平，以中位数和四分位数间距表示。采用Wilcoxon秩和检验比较两组之间经对数转换的抗菌肽值。
分析队列包括162名老年患者；18名（11%）有无症状菌尿症。无症状菌尿症阳性且培养阴性的老年患者与培养阴性的老年患者之间尿液分析结果有所不同，但抗菌肽值无差异（所有四种抗菌肽的p值均>0.2）。
在这项二次分析中，无症状菌尿症培养阳性和阴性的老年患者之间抗菌肽无差异。如果抗菌肽在有症状的UTI老年患者中升高，那么它们可能能够区分阴性培养/无症状菌尿症与尿液分析无法区分的真正感染，因此应对抗菌肽进行进一步研究。
