Effects of reported beta-lactam allergies on pneumonia outcomes in lung transplant recipients.

BACKGROUND: The effects of reported beta-lactam allergies on clinical outcomes have been understudied in lung transplant recipients. We evaluated reported beta-lactam allergies on clinical outcomes in this population. METHODS: A single-center retrospective cohort analysis was performed. One hundred and nine lung transplant recipients were identified and screened for a diagnosis of pneumonia. This cohort was divided into those with a reported beta-lactam allergy and those without a beta-lactam allergy. Antibiotic use was compared between groups. We also compared several clinical metrics, including rates of readmission, mortality, Clostridium difficile infection (CDI), allograft dysfunction, and isolation of carbapenem or fluoroquinolone non-susceptible organisms after treatment. RESULTS: Of the 109 lung transplant recipients, 18 (16.5%) were identified as having a reported beta-lactam allergy. Patients with a beta-lactam allergy label (BLAL) were found to have decreased utilization of beta-lactams (p < .001) and a trend toward increased use of carbapenems (p = .062) and aztreonam (p = .080). BLAL patients were found to have higher rates of CDI (p = .049) but were not found to have increased readmissions, mortality, allograft dysfunction, or isolation of carbapenem or fluoroquinolone non-susceptible organisms. Patients without a BLAL were found to have higher rates of acute kidney injury (AKI) (p = .035). CONCLUSIONS: Lung transplant recipients with BLAL are more likely to develop CDI, possibly due to increased use of carbapenems. We also found that patients without beta-lactam allergy were more likely to develop AKI. A multicenter study with a larger sample size might clarify the individual contributions of mutually confounding clinical parameters.

Daptomycin-Resistant Enterococcus Bacteremia Is Associated With Prior Daptomycin Use and Increased Mortality After Liver Transplantation.

BACKGROUND: Risk factors for acquisition of vancomycin-resistant Enterococcus (VRE) include immunosuppression, antibiotic exposure, indwelling catheters, and manipulation of the gastrointestinal tract, all of which occur in liver transplant recipients. VRE infections are documented in liver transplantation (LT); however, only one single center study has assessed the impact of daptomycin-resistant Enterococcus (DRE) in this patient population. METHODS: We conducted a retrospective multicenter cohort study comparing liver transplant recipients with either VRE or DRE bacteremia. The primary outcome was death within 1 year of transplantation. Multivariable logistic regression analyses were performed to calculate adjusted odds ratios for outcomes of interest. RESULTS: We identified 139 cases of Enterococcus bacteremia following LT, of which 78% were VRE and 22% were DRE. When adjusted for total intensive care unit days in the first transplant year, liver-kidney transplantation, and calcineurin inhibitor use, patients with DRE bacteremia were 2.65 times more likely to die within 1 year of transplantation (adjusted odds ratio [aOR], 2.648; 95% CI, 1.025-6.840; P = .044). Prior daptomycin exposure was found to be an independent predictor of DRE bacteremia (aOR, 30.62; 95% CI, 10.087-92.955; P < .001). CONCLUSIONS: In this multicenter study of LT recipients with Enterococcus bacteremia, DRE bacteremia was associated with higher 1-year mortality rates when compared with VRE bacteremia. Our data provide strong support for dedicated infection prevention and antimicrobial stewardship efforts for transplant patients. Further research is needed to support the development of better antibiotics for DRE and practical guidance focusing on identification and prevention of colonization and subsequent infection in liver transplant recipients at high risk for DRE bacteremia.