C60-08 The Role of Serial Flexible Bronchoscopy and Bronchoalveolar Lavage in Adenovirus Infection in a Pediatric Solid Organ Transplant Recipient

Abstract Introduction Adenovirus infection is associated with significant morbidity and mortality in immunocompromised hosts, with higher viral loads associated with worse outcomes. These patients are also high risk for life-threatening adenovirus infection and quantitative monitoring of viral load is critical for assessing response to therapy while also maintaining awareness of the possibility for discordant levels of adenovirus in the plasma and bronchoalveolar lavage (BAL). We present a case of an infant with persistent adenoviral load in BAL samples despite negative plasma levels. Case Description An 11-month-old male underwent orthotopic liver transplant for biliary atresia with an immediate post-operative course complicated by adenovirus pneumonia and viremia, resulting in acute hypoxemic and hypercarbic respiratory failure and acute respiratory distress syndrome necessitating veno-venous extracorporeal membrane oxygenation. The patient was treated with reduced immunosuppression, multiple treatments with weekly cidofovir, and compassionate/investigational use of adoptive viral-specific T-cell (VST) therapy as a single infusion. Serial flexible bronchoscopies with BAL were performed for both airway clearance and quantitative adenovirus load, which indicated a downtrending BAL adenovirus levels that peaked at 2.2 x 109. Plasma became undetectable approximately 4 weeks after initial infection and treatment, at which point BAL levels were 1.5 × 107. Discussion The quantitative adenovirus levels in the BAL provided data useful for assessing response to adenovirus therapy and informing clinical decisions. Just days after VST, we noticed greater decreases in adenovirus levels in the BAL and undetectable levels in the plasma, which led the infectious disease team to determine that one VST infusion was sufficient as long as levels continued to downtrend. Although plasma levels became negative, the plan was to continue treatment with cidofovir until the adenovirus was undetectable in BAL samples. Reliance on plasma adenovirus levels alone in viremia can lead to underestimation of the burden of disease in the lungs and premature discontinuation of therapy. Further research is needed to define optimal timing and frequency of surveillance with plasma and BAL adenovirus levels to improve outcomes in pediatric transplant recipients. As greater interest in VST emerges and becomes more widely implemented, pediatric pulmonologists should have a greater awareness of the important role of serial BAL sampling in the management of life threatening adenovirus infection. Serial BAL sampling is critical when there is evidence of pulmonary involvement, even when plasma is negative or becomes negative in viremia. This abstract is funded by: None