Acute Allograft Pyelonephritis Following Renal Transplantation

Park, Joo Hyun; Bok, Hyun Jung; Park, Jung Hee; Yang, Chul Woo; Kim, Yong Soo; Kim, Suk Young; Bang, Byung Kee

Abstract

OBJECTIVE
Urinary tract infections are mostly benign, but allograft pyelonephritis may induce renal dysfunction or acute rejection. The purpose of this study was to evaluate the frequency of acute allograft pyelonephritis and its influence on graft function and induction of allograft rejection.
METHODS
We reviewed the medical records of 1167 renal transplant recipients retrospectively. The allograft pyelonephritis was defined as pyuria with overt clinical manifestations such as fever and graft tenderness. In cases of poor response to antibiotics, abdominal CT and/or graft biopsy were done.
RESULTS
During mean follow-up period of 60.9+/-46.8 months, there were 100 episodes of acute allograft pyelonephritis in 65 patients(5.6%). Seventeen patients (26.2%) had recurrent pyelonephritis. Primary renal disease and recipient sex were important predisposing factors for acute allograft pyelonephritis. In patients whose primary renal disease was chronic pyelonephritis or polycystic kidney disease, the prevalance was 30.8% and 18.2% respectively, while in patients with other primary diseases the prevalance ranged from 3.8% to 5.7% (p<0.05). In female patients, the prevalance of pyelonephritis was 14%, which was much higher than that in male patients(2%) (p<0.01). Thirty one out of 100 cases showed deterioration of renal function defined as an increase in serum creatinine by more than 50% of baseline. In twenty five out of 31 cases, grafted kidney biopsy was performed. In 9 cases(36%), the biopsy showed acute rejection together with pyelonephritis, which was mainly manifested by tubulitis. Renal dysfunction occurred mostly in patients who had septicemia or whose previous serum creatinine was higher than 1.2 mg/dl. Renal CT, which was performed in 34 cases, showed findings consistent with acute focal bacterial nephritis (AFBN) in 13 cases (38.2%). Voiding cystourethrogram was performed in 11 patients and six patients (54.5%) were found to have vesicoureteral reflux. E.Coli was the most frequent causative organism (63.6%).
CONCLUSION
Acute allograft pyelonephritis was frequently associated with acute focal bacterial nephritis and graft rejection. Imaging study and graft biopsy were helpful for accurate diagnosis and proper management of acute allograft pyelonephritis in cases of renal dysfunction. In patients who have acute rejection together with pyelonephritis, rejection therapy including methylprednisolone pulses in addition to antibiotic therapy for pyelonephritis is recommended.