Urinary biomarkers at hospital admission and community-acquired acute kidney injury: A prospective cohort.

BACKGROUND

We aimed to determine the sensitivity and specificity of a 13-urinary biomarker (uBM) panel for identifying community-acquired acute kidney injury (CA-AKI) and to assess whether these biomarkers were independently associated with CA-AKI.

METHODS

This prospective observational study was conducted at a tertiary care hospital. Adults admitted through the emergency department were included. CA-AKI was defined as a ≥0.3 mg/dl decrease in serum creatinine (SCr) within 48 hours or a ≥50% decrease within 7 days. Blood samples were collected daily for SCr measurement, and urine samples were obtained at admission for uBM assessment. All the uBM were classified as abnormal when they exceeded the 75th percentile of the distribution.

RESULTS

731 patients were included (55% male, median age of 61 years; 48% had hypertension, 28% had diabetes mellitus, and 23% had heart failure). The main reasons for hospitalization were respiratory (32%), genitourinary (15%), and cardiovascular (11%) diseases. CA-AKI was diagnosed in 26% of the patients. Compared with patients without CA-AKI, those with CA-AKI showed higher rates of elevation in four uBM: KIM-1 (31% vs. 23%; p=0.032), TIMP-2*IGFBP-7 (30% vs. 23%; p=0.045), clusterin (32% vs. 22%; p=0.011), and MCP-1 (33% vs. 22%; p=0.003). The sensitivity and specificity of uBM for detecting CA-AKI ranged from 23% to 33% and from 74% to 78%, respectively, and the area under the receiver operating characteristic curve (AUC) ranged from 0.485 to 0.554. Logistic regression analyses identified conditions independently associated with CA-AKI, including: hypotension [OR (95% CI): 2.07 (1.33-3.23); p=0.001], dehydration [OR (95% CI): 2.01 (1.40-2.91); p<0.001], chronic kidney disease [OR (95% CI): 2.00 (1.19-3.35); p=0.009], genitourinary tract disease [OR (95% CI): 2.00 (1.26-3.10); p=0.003], chronic liver disease [OR (95% CI): 1.69 (1.09-2.61); p=0.018], and elevation of one or more of the following uBM: KIM-1, TIMP-2*IGFBP-7, clusterin, and MCP-1 [OR (95% CI): 1.51 (1.06-2.14); p=0.022].

CONCLUSION

The expression of one or more of four uBM at emergency department admission (KIM-1, TIMP-2*IGFBP-7, clusterin, and MCP-1) may help identify patients with a higher probability of having CA-AKI, even with modest AUC results.