1001. Feasibility and Outcomes of a Pre-Transplant Antibiotic Allergy Evaluation Program for Allogeneic Hematopoietic Cell Transplant (HCT) Candidates

BACKGROUND: Antibiotic allergies impact the management of hematopoietic cell transplant (HCT) patients who are often prescribed antibiotics for infection prophylaxis and treatment. We evaluated the feasibility and outcomes of an antibiotic allergy evaluation program prior to allogeneic HCT. METHODS: In August 2017, we implemented a program to expedite allergy clinic referrals for adult allogeneic HCT candidates who reported an antibiotic allergy at their initial pre-transplant evaluation visit (PTEV). Allergy labels and clinical data including outcomes of allergy evaluation were prospectively collected for patients with PTEVs between 8/10/17 and November 15/18. The use of selected antibiotics was collected in the 100 days following HCT among patients with a reported β-lactam allergy (BLA). Choice of prophylactic agent for Pneumocystis jiroveci among patients with reported sulfa allergies was assessed among HCT recipients after engraftment. RESULTS: Of 276 allogeneic HCT candidates, 109 (39.5%) reported >= 1 antibiotic allergy (Table 1). Of the 109, 69 (63%) were referred for allergy evaluation; 83% (57/69) of those referred were evaluated at a median of 14 days after PTEV, and a median of 18 days before transplant. Among evaluated patients, 45 (79%) had >= 1 antibiotic allergy de-labeled including 74% (28/38) of those with BLA (Figure 1). Of the 10 patients whose BLAs could not be delabeled, 1 had a possible immediate IgE-mediated reaction, 5 had a delayed type IV hypersensitivity, and 4 had other reactions or required additional testing. Post-transplant antibiotic use among evaluated vs. nonevaluated patients reporting BLA is shown in Figure 2. Among 31 patients with reported sulfa allergies who underwent HCT, those who were evaluated received TMP-SMX rather than alternative prophylaxis more often (48%; 11/23) than those who were not evaluated (25%; 2/8). 10 (43%) of 23 evaluated patients were delabeled; 7 of 10 delabeled patients received TMP-SMX. CONCLUSION: Antibiotic allergies are frequently reported among HCT candidates. Pre-transplant antibiotic allergy evaluation was feasible, led to de-labeling of the majority of reported allergies, and may alter antibiotic prescribing and increase the use of preferred agents following transplant. [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.