Investigation of the diagnostic value of alpha defensin-5 and cathepsin-S levels in the diagnosis of urinary tract infection in children with neurogenic bladder undergoing clean intermittent catheterization

Neurogenic bladder(NB) occurs as a result of damage to the afferent and efferent fibres controlling bladder and sphincter functions, fibres of motor and sensory pathways and medulla spinalis centres. Recurrent urinary tract infection (UTI) and chronic kidney disease (CKD) are the most important causes of mortality and morbidity in children with NB. Residual urine accumulation, which is a common consequence of bladder dysfunction, increases the risk of UTI by creating a favourable environment for bacterial growth. The aim of our study was to evaluate the levels of alpha defensin-5, cathepsin-S and neutrophil gelatinase-associated lipocalin (NGAL), which are new biomarkers in the diagnosis of UTI in patients with NB who were undergoing active clean intermittent catheterisation (CIC). Fifty patients with NB who underwent active TAC in the Department of Paediatric Nephrology, Eskisehir Osmangazi University Faculty of Medicine, and 30 children were included as control group. Patients were divided into three groups as UTI, asymptomatic bacteriuria and sterile pyuria group. Urine samples obtained from the patients were analysed for alpha defensin-5, cathepsin-S and NGAL by ELISA. Forty-two per cent (n=21) of the children with NM were girls and 70 per cent (n=21) of the control group were girls. When patients with NB were compared with the control group, alpha defensin-5/creatinine, cathepsin-S/creatinine, NGAL/creatinine values were higher in patients with neurogenic bladder compared with the control group (p=0.000, p=0.001, p=0.01, respectively). When urinary alpha defensin-5/creatinine, cathepsin-S/creatinine and NGAL/creatinine values of UTI, asymptomatic bacteriuria, sterile pyuria and healthy control group were compared, a significant increase was observed in patients with UTI (p<0.005, p<0.005, p<0.005, p<0.005, respectively). Our study supports that urinary alpha defensin-5, urinary cathepsin-S and urinary NGAL levels can be used in the diagnosis of UTI in patients with NM.