Biomarker-based Assessment of Urinary Tract Infection in Persons with Spinal Cord Injury

Abstract

BackgroundUrinary tract infection (UTI) is the most common infection and the second leading cause of death in spinal cord injury (SCI) patients. However, there is currently no consensus about the clinical criteria for UTI in SCI patients and the lack of a universal definition of asymptomatic bacteriuria (ABU) make the diagnosis even more complex and the treatment recommendations problematic. Prompt diagnosis and timely treatment of UTI are important to prevent possible progression to sepsis. Elevated concentrations of some biomarkers may be correlated with infection and their serial measurements may be helpful to assess the effectiveness of antibiotic therapy.MethodsFifteen SCI participants were enrolled for either lower UTI, upper UTI (pyelonephritis), ABU, or control. Patients suspected of having any inflammation or infection other than UTI were excluded. Participants were monitored for their serum procalcitonin (PCT) and c-reactive protein (CRP) levels initially and every 3 days once the UTI was confirmed and antibiotics prescribed. In addition, the urine was cultured initially and every three days in patients with UTI for correlation with biomarkers. UTI/ABU was assessed by patient’s physician.ResultsBoth mean initial PCT and CRP were significantly higher in patients with lower UTI (P = 0.027 and P = 0.001, respectively) and those with upper UTI (P = 0.044 and P < 0.0001, respectively) compared with control and ABU participants. PCT and CRP were generally reduced to the normal levels gradually during the course of antibiotic therapy for those patients with UTI that were placed on antibiotic therapy. Mean bacterial colonies grown from initial urine cultures in patients with upper or lower UTI were >100,000 CFU/mL. Control participants had urine cultures of ≤1,000 CFU/mL). Generally, cultures from UTI patients placed on antibiotics were negative for the organism(s) treated for during or after the completion of antibiotic therapy.ConclusionSerum concentrations of CRP and PCT may be used to aid in the early assessment of UTI in SCI patients in the absence of other sources of inflammation and/or infection. In general, CRP measurements are more pronounced than PCT measurements in patients with ABU or lower UTI. However, PCT levels elevate conspicuously in patient with pyelonephritis.Disclosures All authors: No reported disclosures.