泌尿道感染是否會影響全自動尿液生化分析儀UC-3500檢測蛋白尿的能力？

周奕儒¹、張尚仁¹、楊緒棣¹、楊淳淳²

¹台北慈濟醫院 泌尿科，²檢驗科

Does urinary tract infection impact the performance of Fully Automated Urine Chemistry Analyzer UC-3500 in detecting albuminuria?

Yi-Ju Chou¹、Shang-Jen Chang¹、Stephen Shei-Dei Yang¹ and Chun-Chun Yang²

Division of Urology¹ and General Laboratory², Taipei Tzu Chi Hospital, New Taipei City, Taiwan

Purpose:

Albuminuria is a vital component for defining chronic kidney disease. Recent studies have shown promising results in detecting albuminuria via reagent test strips that are interpreted with an automatic analyzer. The aim of this study was to assess the performance of an automatic analyzer in detecting albuminuria and to evaluate the impacts of urinary tract infection on albuminuria.

Materials and Methods: 

From January 2016 to June 2019, we prospectively enrolled female patients with uncomplicated urinary tract infection in our study. Midstream urine from each patient before and after one week of cephalexin treatment was collected for urinalysis using the Fully Automated Urine Chemistry Analyzer UC-3500 (Sysmex, Kobe, Japan), urine culture, and quantitative measurement of the albumin/creatine ratio. The results of positive albuminuria (albumin to creatinine ratio > 30 mg/g) were compared with UC-3500. Changes in the urine albumin to creatinine ratio and severity of albuminuria after antibiotic treatment were also evaluated.

Results:

Fifty-four female patients (age: 50.52 ± 16.20 years) were included in our study. During the first visit, 35 patients (64.81%) were assessed as having albuminuria based on a urine albumin to creatinine ratio = greater than 30 mg/g. After one week of oral antibiotic treatment, only 12 patients (22.22%) had persistent albuminuria. UC-3500 demonstrated a sensitivity of 91.49% and specificity of 73.77% for predicting albuminuria. The agreement between UC-3500 and the reference method showed good agreement (kappa: 0.63, 95% confidence interval: 0.49–0.78). However, during the acute phase of urinary tract infection, the agreement decreased to 0.49 (95% confidence interval: 0.24–0.73). The urine albumin to creatinine ratio significantly decreased after antibiotic treatment (Hodges–Lehman median difference: −0.54, p < 0.0001).

Conclusion:

Due to its good sensitivity and specificity, UC-3500 is an effective screening tool for albuminuria. However, albuminuria could be present if the patient has a urinary tract infection. Prior to screening for albuminuria, it is important to rule out the effects of urinary tract infection.