The association between serum 25-hydroxy vitamin d level and urine cathelicidin in children with a urinary tract infection

Objective: cathelicidin is an important antimicrobial peptide in the urinary tract. cathelicidin expression is strongly stimulated by 1,25-dihydroxy vitamin d in epithelial cells,macrophages/monocytes,and neutrophils. vitamin d and cathelicidin status in children with urinary tract infection (uti) caused by escherichia coli is unknown. to establish the relationship between serum vitamin d and urine cathelicidin levels in children with a uti caused by escherichia coli. methods: serum 25-hydroxy vitamin d and urine cathelicidin levels were measured in 36 patients with uti (mean age 6.8±3.6 years,range: 0.25-12.6 years) and 38 controls (mean age 6.3±2.8 years,range: 0.42-13 years). results: there were no significant differences in urine cathelicidin levels between the study and control groups (p>0.05). eight (22.2%) patients in the study group and 21 (58.3%) children in the control group were found to have sufficient vitamin d (≥20 ng/ml). patients with sufficient vitamin d had higher urine cathelicidin levels than the controls with sufficient vitamin d (respectively 262.5±41.1 vs. 168±31.6 ng/ml,p=0.001). there were no significant differences between the patients and controls with insufficient vitamin d (p>0.05). conclusion: the children with vitamin d insufficiency may not be able to increase their urine cathelicidin level during uti caused by escherichia coli. there is a need of prospective studies in order to prove a beneficial effect of vitamin d supplementation for the restoration of cathelicidin stimulation and consequently for prevention of uti recurrence. © journal of clinical research in pediatric endocrinology.