Extracellular DNA (ecDNA) is a promising candidate marker for the early diagnosis and monitoring of urinary tract infections (UTIs). The aim of our study is to describe the dynamics of ecDNA in the plasma and urine of patients with urosepsis as well as in a mouse model of UTI. Samples of blood and urine were collected from adult patients with UTIs and obstructive uropathy (n = 36) during the first 3 days at the hospital and during a follow-up. Bacterial burden and urinary ecDNA were evaluated in a mouse UTI model (n = 26) at baseline; 24, 48, and 72 h after UTI induction; and 7 days after UTI induction. The plasma ecDNA did not change during urosepsis, but the plasma DNase activity increased significantly at the follow-up. The urinary ecDNA decreased significantly during hospitalization and remained low until the follow-up (90% lower vs. admission). No change was seen in the urinary DNase activity. C-reactive protein (CRP) and procalcitonin are positively correlated with plasma and urinary ecDNA. A UTI caused sepsis in 23% of mice. The urinary ecDNA decreased by three-fold and remained low until day 7 post-infection. Urinary bacterial burden is correlated with urinary ecDNA. Urinary ecDNA is a potential non-invasive marker for monitoring the effects of treatment during urosepsis and is related to UTI progression in the experimental animal model.

The result of a kidney transplantation may be affected by certain congenital or acquired urological diseases that need to be addressed before, during or after the kidney transplant. Complications accompanying kidney transplantation are not fundamentally different from the events that accompany other diffi cult surgical procedures. However, their course is usually modifi ed by adverse circumstances in the recipient -uremia, dialysis treatment, immunosuppression. The incidence of urological complications is reported in the range of 1 to 30 % of the transplants, and they represent up to one half of all surgical complications. They can cause a signifi cant morbidity and mortality and can lead to a delayed onset of the function and even to a loss of the transplanted kidney. Urological complications that need to be addressed before kidney transplantation include anomalies or pathological changes in the lower urinary tract, pelvic involvement in atherosclerosis or previous kidney transplants, infectious foci in lithiasis or pyonephrosis, large polycystic kidneys and malignancies. During the kidney transplantation itself, vascular complications, and complications connected with the reconstruction of the lower urinary tract can occur. Other complications are bacterial and viral infections and malignancies. All these complications require a rapid and accurate diagnosis and subsequent targeted treatment with intention to maintain a functional kidney transplant (Fig. 11, Ref. 36).