Asymptomatic Bacteriuria & Risk of Urinary Tract Infection in Renal Transplants (ASB)

• Prevalence of Asymptomatic Bacteriuria and Risk of Developing Symptomatic Urinary Tract Infections or Renal Allograft Injury in Renal Transplant Patients [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  Determine the prevalence and natural history of asymptomatic bacteriuria (ASB) and the host factors associated with the development of symptomatic UTI in renal allograft recipients. We will enroll renal transplant recipients, perform urine cultures and follow all patients with ASB to determine the prevalence of ASB and the host characteristics associated with ASB and the development of symptomatic UTI.
  
  

• Host Characteristics of Renal Transplant Patients with Asymptomatic Bacteriuria at Risk to Develop Symptomatic Urinary Tract Infection [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  We will measure blood and urine immunoglobulin and cytokine levels in patients with ASB and symptomatic UTI to determine if these host's immune parameters predict the outcome of ASB, including the development of symptomatic UTI.
  
  
• Determine the characteristics of uropathogenic bacteria that cause acute allograft injury in renal transplant patients. [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  We will determine the expression of key uropathogenic virulence factors, including P fimbriae, Dr adhesins, and mono-mannose-binding type 1 fimbriae, on E. coli isolated from RTPs with ASB to determine if strains that express such virulence factors are more likely to cause symptomatic UTI and AAI, compared to E. coli that do not express these virulence factors.
  
  

Blood samples and urine cultures will be obtained from asymptomatic renal transplant clinic patients. If the urine culture is positive (> or = 105 cfu/ml), we will determine the host and bacterial virulence factors associated with asymptomatic bacteriuria (ASB) and compare these results to transplant patients that develop a symptomatic UTI. The patient's clinical information, laboratory data and the bacterial isolate responsible for the UTI will be collected at the time of their clinic visit and subsequently analyzed.

After the first visit (Day 0 after signing consent) blood and urine will be collected, subjects will be put into either ASB Positive or ASB Negative groups based upon the results of their urine culture. From that point, those who test into the ASB Negative group will have an additional urine culture, either by returning to the clinic or by sending a urine culture mailer kit, and if cultures remain negative, they will be discharged from the study after reviewing medications, adverse events and completing a urinary tract infection risk questionnaire.

For those who test into the ASB Positive group, those subjects will be monitored by the subject returning to the clinic on Day 10-14, at 1 month, 2 month, 3 month and 6 months for blood and urine collection, review of medications and adverse events, and completing a urinary tract infection risk questionnaire. Should the subject have symptoms of a UTI, the subject will be treated with the appropriate antibiotic for which the bacterial isolated from their urine culture is sensitive. Patients will return to the clinic 10-14 days later for a repeat urine culture, complete a urinary tract infection risk questionnaire, and have a repeat urine culture to confirm they are urinary tract infection free. At this point, the subject will be discharged from the study after reviewing medications and adverse events.

It is predicted that 75% of patients will test into the ASB Negative Group and do not require antibiotic therapy. We predict that 25% of patients will test into the ASB Positive Group, but that less than 5% of these patients will ultimately develop a symptomatic UTI and require antibiotic treatment.