Babikir IH, et al. - The plasma and urine levels of human LL-37 in patients with urinary tract infection (UTI) were investigated in this study. Among these patients, LL-37 was notably increased compared with normal control subjects. The levels of LL-37 increased in association with severity of UTI. In the patient’s urine as well as in the patient’s plasma, the increased level was evident. Subjects with suspected UTI could be identified with detection of increased levels of LL-37. Thereby suggesting the utility of LL-37 as a good marker for diagnosing UTIs.