Female gender

Advanced age

Pre-transplant UTI

Higher grade of immunosuppression

Acute rejection episodes

Impaired graft function

Postoperative bladder catheterization

Problems in ureteral anastomosis or presence of ureteral stents

Surgical manipulation of the graft

 Diabetes mellitus

Pregnancy

History of vesicoureteral reflux

History of polycystic kidney disease

Cadaveric donor

Cytomegalovirus disease

Repeated episodes of asymptomatic bacteriuria as a risk factor for pyelonephritis

Schistosomiasis