BERKELEY, CA (UroToday Inc.) - Urinary tract infection (UTI) in children is a common health problem, with a cumulative incidence of 2 8% by 10 yr of age. Vesicoureteral Reflux (VUR) occurs in approximately 30% of children who have at least one urinary tract infection. Human and animal data demonstrate that urinary tract infection in the presence of VUR may cause acute pyelonephritis and renal scarring. The outcome measures in clinical studies of VUR are recurrent UTI and renal scarring. Published guidelines advocate active treatment of VUR in childhood with the intention of preventing renal scarring. UTI in renal transplant patients pose major health concerns with clinical signs and symptoms ranging from asymptomatic bacteriuria to graft abscess or urosepsis.

Transplant patients from the Children's Hospital and Regional Medical Center in Seattle, Washington with a pre-transplant diagnosis of reflux nephropathy were assessed regarding the association of persistent native refluxing systems and voiding dysfunction (VD) with post-transplant UTI. They reviewed 11 patients between the age of 8 and 19 yr who underwent renal transplantation from 1992 to 2003 for renal failure caused by reflux nephropathy. The group consisted of five boys and six girls. Culture documented, symptomatic UTI were investigated. The symptoms included any combination of the following: fever, flank/abdominal pain, dysuria, urinary frequency/urgency/incontinence, malodorous urine, or malaise. These UTI were correlated with pre- and post-transplant UTI rates, VD, grade of VUR (IRS Grading System), concomitant nephrectomy, or nephroureterectomy with refluxing remnants, and pretransplant cross trigonal ureteral reimplantation.

Follow up ranged from 9 months to 13 yr (median 42 months). Pretransplant cystograms revealed international grade 4 or 5 VUR in 10 patients and grade III VUR in one patient. Post-transplant VUR into the native system was noted on the following patients: (i) Those who underwent nephrectomy with partial ureterectomy above the level of the pelvic brim. These patients had VUR into ureteral remnants. (ii) Two of the three patients who underwent pretransplant reimplantations to correct VUR prior to ESRD had persistent VUR. Three patients with VD were treated with timed voiding, biofeedback, and anticholinergic therapy with improvement of the VD. Improvement of VD parameters was documented by lower voiding pressure and bladder emptying on video urodynamic studies carried out for a pretransplant urologic evaluation. Once VD was managed, only the children with persistent native refluxing systems had significantly increased numbers of bladder infections.

The group concludes that a refluxing native system especially in the clinical setting of VD is correlated with a high rate of recurrent urinary tract infections post transplant. Although their patient population is only 11 patients, renal transplantation for ESRD as a result of reflux nephropathy is a rare occurrence, which must be taken into consideration.

The 63% (seven of 11) incidence of UTI in this specific renal transplant population is consistent with previously published occurrence rates; however, the observation that most of the infections occurred in patients with persistent refluxing systems has never been previously documented. Further investigations involving a larger cohort or a multicenter analysis may reveal a more statistically significant correlation between refluxing systems and UTI in renal transplant patients.

They summarize that their study suggests that a cause of UTI in renal transplant patients with ESRD because of reflux nephropathy may be due to a persistent refluxing native system. VD may potentially exacerbate the reflux and infection rate and recommend ureteral resection of the native system ureter at time of nephrectomy with consideration of native distal ureterectomy, when present, if infections persist.

Pediatric Transplantation 0 (0), -. doi: 10.1111/j.1399-3046.2005.00316.x