Inadequate (Ax) Transbronchial Lung Transplant Biopsies-Scope and the Potential Contributing Factors.

BACKGROUND: Transbronchial biopsy is the cornerstone for the evaluation of graft function after lung transplant and a standard of care to diagnose acute cellular rejection. However, the yield from these biopsies is variable, with about 15% to 50% of samples being judged as nondiagnostic, leading to additional procedures. The factors contributing to the nondiagnostic sampling have not been delineated, and the discordance in sample assessment between the bronchoscopist and pathologist has not been quantified. METHODS: A retrospective cohort of patients who had bronchoscopies with biopsies for surveillance and graft assessment at a large-volume transplant center was studied. The occurrence of nondiagnostic alveolar sampling was assessed, and the patient demographics and procedural characteristics were compared with the diagnostic group. RESULTS: We included 128 patients in our study and found the inadequacy rate for alveolar tissue sampling to be 15.5%. The median number of passes made by the bronchoscopist was 9, and the number of samples assessed by the bronchoscopist was 8, with a median of 6 adequate samples identified by the pathologist. The frequency of previous biopsies, history of prior inadequate samples, need for a higher number of pass attempts, presence of airway abnormalities, and the use of general anesthesia increased the odds of inadequate sampling. CONCLUSIONS: Patients with the identified factors may be at risk of inadequate sampling on transbronchial biopsies. The bronchoscopist could consider getting additional samples to avoid a nondiagnostic alveolar sample. Further multicenter studies would help to elucidate other contributing factors.

Cytomegalovirus prevention in thoracic organ transplantation: A single-center evaluation of letermovir prophylaxis.

BACKGROUND: Cytomegalovirus (CMV) infection is common following thoracic organ transplantation and causes substantial morbidity and mortality. Letermovir is a novel antiviral agent used off-label in this population for CMV prevention. Our goal was to understand patterns of letermovir use and effectiveness when applied for CMV prophylaxis after thoracic transplantation. METHODS: We retrospectively evaluated letermovir use among thoracic transplant recipients at an academic transplant center who initiated letermovir from January 2018 to October2019 for CMV prophylaxis. We analyzed indication, timing, and duration of prophylaxis; tolerability; and occurrence of breakthrough CMV DNAemia and disease. RESULTS: Forty-two episodes of letermovir prophylaxis occurred in 41 patients, including 37 lung and 4 heart transplant recipients. Primary prophylaxis (26/42, 61.9%) was utilized mainly due to myelosuppression (25/26, 96.2%) and was initiated a median of 315 days post-transplant (interquartile range [IQR] 125-1139 days). Sixteen episodes of secondary prophylaxis (16/42, 38.1%) were initiated a median of 695 days post-transplant (IQR 537-1156 days) due to myelosuppression (10/16, 62.5%) or prior CMV resistance (6/16, 37.5%). Median duration of letermovir prophylaxis was 282 days (IQR 131-433 days). Adverse effects required letermovir cessation in 5/42 (11.9%) episodes. Only one episode (2.4%) was complicated by clinically significant breakthrough CMV infection. Transient low-level CMV DNAemia (<450 IU/ml) occurred in 15 episodes (35.7%) but did not require letermovir cessation. CONCLUSIONS: Letermovir was well tolerated and effective during extended prophylactic courses with only one case of breakthrough CMV infection in this cohort of thoracic transplant recipients. Further prospective trials of letermovir prophylaxis in this population are warranted.