Mughrabi, Abdallah

ABSTRACT Introduction Cytomegalovirus (CMV) causes substantial morbidity after solid organ transplantation. Valganciclovir (VGCV) remains a first‐line prophylactic agent, but it has significant myelosuppressive effect. Letermovir is approved for CMV prophylaxis in high‐risk kidney transplant recipients, but data on its use outside of that population are limited. We describe characteristics and outcomes of letermovir prophylaxis in non‐kidney transplant recipients. Methods We performed a retrospective, multi‐center study of all adult non‐kidney solid organ transplant recipients (SOTr) who received letermovir (March 2018–June 2024) for CMV prophylaxis. Outcomes included breakthrough and post‐prophylaxis delayed‐onset CMV infections, adverse events, and survival. Results A total of 64 patients were included in the final analysis. Of those, letermovir was used for primary prophylaxis in 56.2% of patients, while the remainder received it for secondary prophylaxis. The main rationale behind selecting letermovir was myelosuppression related to VGCV. During the median follow‐up of 361 days (IQR, 190–536), 40.6% remained on letermovir (median, 387 days); 25.0% completed prophylaxis (median, 116 days); and 34.3% discontinued prematurely (median, 49 days), mainly for cost barriers or adverse effects. Breakthrough infections occurred in 9 patients (14.1%), but only three (4.7%) were clinically significant. After stopping letermovir, 39.5% (15/38 among those who discontinued letermovir) developed post‐prophylaxis delayed‐onset CMV infection. Overall survival was 81.2%; there was one death attributed to CMV. Conclusion In this cohort of non‐kidney solid organ recipients, letermovir was well tolerated with low rates of clinically significant breakthrough infections. Early discontinuation was commonly cost‐driven. Post‐prophylaxis delayed‐onset CMV infections remain common. Large‐scale registry studies are needed to provide evidence for use of letermovir in non‐kidney transplant recipients.

Abstract Background Adenovirus is a ubiquitous dsDNA virus with potential for end-organ disease. End-organ or disseminated adenoviral disease (EOD) occurs more frequently in hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) recipients. We aim to characterize the clinical manifestations and outcome of adenovirus viremia in adults, including HSCT and SOT recipients. We describe severity of illness, organ-involvement, and graft and patient survival. Methods This retrospective, multi-site, study enrolled adults patients with positive adenovirus PCR in blood and other clinical specimens from January, 2010 through April, 2025. We excluded patients with insufficient medical records, follow up less than 30 days, and isolated conjunctivitis without viremia. EOD was defined by the presence of clinical signs or symptoms consistent with organ involvement, confirmed by a positive adenovirus PCR or by histopathology. Descriptive and comparative statistics were performed using R. Results Fifty patients with adenovirus viremia were included in this study. The most common immunocompromising conditions were corticosteroid use (84%, n = 42), HSCT (40%, n = 20) and SOT (34%, n = 17) (Table 1). Only 3 patients (6%) had no known immunocompromising condition. 20 patients (40%) had EOD while 30 patients (60%) had isolated viremia. Lungs were the most affected organ, followed by the gastrointestinal tract and liver (Figure 1). EOD was more prevalent in older patients (60 vs. 41 years, p =0.03) and in those with higher initial plasma viral load (673364 vs. 6593, p=0.005). The most common treatment was reduction in immunosuppression (Table 2). Cidofovir was more often used in patients with EOD. Adenovirus-related outcomes were worse in patients with EOD [higher rates of mortality (45% vs. 13.3%) and ICU admission (60% vs. 20%)] vs. without EOD (Table 3). Conclusion Adenovirus viremia is associated with high mortality in a cohort of mostly immunocompromised adults, particularly those with EOD. Older age and a higher initial plasma viral load are associated with EOD. Patients with EOD had worse clinical outcomes such as ICU admission and adenovirus-related mortality. Disclosures All Authors: No reported disclosures