947. Nocardiosis in Renal Transplant Recipients Linked to Decreased Utilization of Trimethoprim/Sulfamethoxazole During COVID-19

Background The renal transplant population is at increased risk of Nocardiosis due to impaired T-cell mediated immunity with immunosuppression. Pneumocystis jirovecii (PJP) prophylaxis with trimethoprim/sulfamethoxazole (TMP/SMX) provides coverage against Nocardia spp. unlike alternative agents such as atovaquone (ATQ), aerosolized pentamidine (AP), and dapsone. During the COVID-19 pandemic, patients receiving AP were transitioned to ATQ to avoid the use of nebulized medication. This, in turn, led to decreased use of TMP/SMX as patients on oral ATQ were not reassessed for the use of TMP/SMX as would have occurred while on AP. Additionally, an increased incidence of Nocardia infections was observed during this time. The objective of this study was to determine the association between the incidence of Nocardia infections and number of TMP/SMX prophylaxis-days in pre- versus COVID-19 cohorts. Methods This was a single center retrospective chart review of all renal transplant recipients between September 2018 – August 2019 (pre-COVID-19 cohort) and April 2020 – March 2021 (COVID-19 cohort). Patients were included if they were at least 18 years of age and a recipient of a cadaveric or living donor kidney transplant. Exclusion criteria included multi-organ transplant, pediatric patients, and repeat transplants. The primary outcome was incidence of Nocardiosis within the first 6 months post-transplant in the pre- and COVID-19 cohorts. Results A total of 218 patients were included (Table 1). Induction therapy and initial immunosuppression did not differ significantly between groups, nor did rates of rejection within 180 days of transplant (Table 2). Although the pre-COVID-19 cohort had a higher rate of neutropenia, there was no difference in median absolute lymphocyte count between the two groups. The COVID-19 cohort had a decreased percentage of TMP/SMX prophylaxis-days (59.2% vs. 72.5%, p < 0.0001) and an increased incidence of Nocardia infections in the first 6 months post-transplant (4% vs. 0%, p=0.0292). All 4 cases of Nocardia infections occurred in patients receiving ATQ. Conclusion The increased incidence of Nocardiosis was associated with a decreased use of TMP/SMX for PJP prophylaxis which may have been an unintended consequence of increased use of ATQ in lieu of AP during COVID-19. Disclosures All Authors: No reported disclosures

Tolerability of Aerosolized Versus Intravenous Pentamidine for Pneumocystis jirovecii Pneumonia Prophylaxis in Immunosuppressed Pediatric, Adolescent, and Young Adult Patients

OBJECTIVES Pentamidine is an antifungal that is used alternatively to sulfamethoxazole-trimethoprim for the prophylaxis and treatment of Pneumocystis jirovecii pneumonia (PJP). The primary objective of this study was to assess the tolerability of aerosolized versus intravenous pentamidine for PJP prophylaxis in pediatric, adolescent, and young adult immunosuppressed patients. Secondary objectives included comparing pentamidine formulation reaction to dosing frequency and diagnosis. METHODS This retrospective chart review used electronic medical record (EMR) data from patients at a tertiary care pediatric teaching institution from January 1, 2014, to January 1, 2017. Information used from the EMR included pentamidine dosing, ordering, and laboratory values. Inclusion criteria consisted of patients with a cancer diagnosis, hematopoietic stem cell transplant (HSCT) recipients, and renal transplant recipients who received pentamidine for PJP prophylaxis. RESULTS Ninety-six patients met inclusion criteria, of which 31 received aerosolized pentamidine. Ten of the 96 patients experienced a drug-related reaction to either aerosolized or intravenous pentamidine (p = 0.134). Nine of 10 patients who experienced a reaction received intravenous pentamidine versus 1 patient who received aerosolized pentamidine (p = 0.132). In those patients who reacted to pentamidine there was a higher incidence of reactions after subsequent administration (p = 0.039) and in patients with a blood cancer diagnosis (p = 0.042). CONCLUSIONS Data suggest that patients who receive aerosolized pentamidine may tolerate therapy better compared to intravenous administration. Additional studies involving larger numbers of pediatric, adolescent, and young adult patients are needed for stronger statistically significant clinical differences in tolerability of aerosolized versus intravenous pentamidine.

Is Aerosolized Pentamidine for Pneumocystis Pneumonia Prophylaxis in Renal Transplant Recipients Not as Safe as We Might Think?

ABSTRACTOutbreaks ofPneumocystispneumonia have been described in renal transplant recipients. Aerosolized pentamidine is frequently used for prophylaxis in this setting. We report our experience with aerosolized pentamidine use in 56 renal transplant recipients. We found high rates of adverse reactions in patients with chronic respiratory disease.