Late recurrent urinary tract infections may produce renal allograft scarring even in the absence of symptoms or vesicoureteric reflux.
BACKGROUND
The significance of late urinary tract infections (UTIs) after renal transplantation and their association with scarring and graft dysfunction remains controversial. We sought to define the prevalence of renal scarring in allograft recipients with a history of late recurrent UTIs, to determine whether the presence of vesicoureteric reflux (VUR) confers an increased risk of scarring and to establish whether scarring correlates with graft dysfunction.


METHODS
Among 307 renal allograft recipients, we identified 56 (18%) with late recurrent UTIs (> or =3/year). A total of 32 patients had undergone further investigation by both 2,3 dimercapto-succinic acid single-photon emission computed tomography (99mTc-DMSA SPECT) scan and micturating cystourethrogram (MCUG).


RESULTS
Of the 32 patients, 24 (75%) had scars on 99mTc-DMSA SPECT and 15 (47%) had reflux on MCUG. Thirteen of these 15 patients with reflux (87%) had scars, although there was no significant correlation between number of scars and degree of reflux. Eleven of 17 patients (65%) with UTIs but without VUR had scars, as did 12 of 14 (86%) with previous graft pyelonephritis. The pattern of scarring (typically multiple focal cortical defects) suggested infection as the cause. This pattern was not seen in a contemporary cohort with vascular occlusions and was rarely seen in patients with chronic allograft nephropathy. Scarring was not associated with inferior graft survival (median follow-up, 15 years).


CONCLUSIONS
In patients with late UTIs, renal scarring is a frequent finding. Scarring may occur even in asymptomatic patients without VUR. The lack of an effect on graft survival may reflect successful intervention with prophylactic antibiotics and surveillance urine cultures. Late recurrent UTIs may be damaging to renal allografts, even in the absence of reflux.
Dupont
Peter J
PJ
Department of Nephrology and Transplantation, Royal Free Hospital, London, United Kingdom.
Psimenou
Erasmia
E
Lord
Rozanne
R
Buscombe
John R
JR
Hilson
Andrew J
AJ
Sweny
Paul
P
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002921:Cicatrix / Q000209:etiology* / Q000473:pathology; D005260:Female; D006085:Graft Survival / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000382:microbiology / Q000473:pathology / Q000503:physiopathology; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000473:pathology / Q000502:physiology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055502:Secondary Prevention; D014552:Urinary Tract Infections / Q000150:complications* / Q000209:etiology / Q000473:pathology; D014718:Vesico-Ureteral Reflux / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology
D000900:Anti-Bacterial Agents