Post-Tx Infection Risks Identified
Hospitalization more likely in pediatric patients.
Younger age, female gender, and antibody induction are among the risk factors for infection-related hospitalizations following renal transplantation, according to two studies.
In one study, investigators who examined U.S. Renal Data System (USRDS) data from 28,924 primary renal transplant recipients concluded that hospitalization for a viral infection (HVI) is more likely to occur among pediatric patients compared with those older than 50 years.
Other risk factors for HVI include receiving an organ from a donor infected with cytomegalovirus (CMV), end-stage renal disease (ESRD) due to systemic lupus erythematosus (SLE), and mycophenolate mofetil use at initial post-transplant discharge. That report also demonstrates that the risk of hospitalization for bacterial infections (HBI) is increased by delayed graft function, pre-transplant diabetes, and female gender.
The other study, which analyzed data from the North American Pediatric Renal Transplant Cooperative Study for the same issues, showed that younger age and antibody induction in children are associated with increased rates of hospitalization for infection (HI), HVI, and HBI.
Both studies were led by Vikas R. Dharnidharka, MD, of the University of Florida in Gainesville, and published consecutively in the same issue of the American Journal of Transplantation (2007;7:653-661;662-666).
In the USRDS study, Dr. Dharnidharka's group found that renal transplant recipients younger than 18 are at 2.4 times higher risk of hospitalization for viral infection compared with recipients older than 50, after adjusting for potential confounders. Recipients who had a CMV-positive donor were at 48% increased risk compared with recipients of an organ from a CMV-negative donor. ESRD due to SLE increased the risk by 33% compared with other diagnoses, and MMF use at discharge increased the risk by 24%.
With respect to HBI, delayed graft function and pre-transplant diabetes increased the risk by 37% and 66%, respectively. Female gender was associated with a 21% increased risk compared with males. "The increased risk for females for bacterial infection may reflect their greatly increased risk of UTI, especially late after transplant," the authors wrote.
They noted that their findings demonstrate the contrasting risk factors for hospitalization associated with bacterial and viral pathogens. "Tailoring immunosuppression or targeted monitoring for infections in high-risk groups may enable a reduction in serious infection incidence and may improve graft and patient survival," they concluded.
The pediatric study included 3,106 pediatric transplant recipients, of whom 23.4% and 23.9% experienced HBI and HVI, respectively, and 8.9% were hospitalized for both. In the two years following transplantation, the HI rate was 64.2% for children up to one year of age compared with 31% for patients older than 12.
Patients up to one year old at transplant had HBI and HVI rates of 40.3% and 43.3%, respectively, compared with 17.5% and 18.9% for children older than 12 years. Patients receiving monoclonal or polyclonal antibody had a 24% rate of HBI and 29% rate of HVI compared with 21% and 21%, respectively, for children receiving no induction. The two groups had equivalent graft survival. Thus, antibody induction may not offer the same advantages as previously seen and may worsen the risk for infections.
"Being cognizant of these factors while determining the need for and length of anti-infective prophylaxis in pediatric patients receiving renal transplantation could continue the improvements made in graft and patient survival with the use of newer [immunosuppressive] agents," the authors said.