LAUSR

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Adenovirus pneumonia is mainly reported in children or in military recruits living in close quarters prior to vaccine implementation. Case reports in adults are traditionally described in severely immunocompromised individuals after organ transplant or in Acquired Immunodeficiency Syndrome. In this case we describe severe adenovirus pneumonia in a patient treated with monthly rituximab. CASE PRESENTATION: A 50 year-old male with multiple sclerosis (MS) treated with monthly rituximab, presents with 8 days of worsening dyspnea. He endorsed mild cough and abdominal discomfort. Two days prior, his dyspnea became severe. He and his wife, who works at a daycare center, tested negative in an outpatient center for COVID19 virus. He denied changes in taste, smell, chest pain or any known COVID19 contacts. Initial chest X-ray revealed multifocal opacities suggestive of bronchopneumonia. He was started on empiric cefepime and azithromycin. Inflammatory markers ferritin, D-dimer, CRP and ESR were elevated at 1257, 869, 184 and 63 respectively. His initial swab for COVID19 virus was negative. On admission, he required supplemental oxygen at 15L via non-rebreather mask to maintain oxygen saturation of 92-96%. Throughout his course, he was tested 6 times for COVID19 all of which resulted as negative. A respiratory viral panel sent on admission detected adenovirus. He was started on a treatment course of cidofovir with probenecid. Treatment initiation was delayed due to lag time of 9 days from the viral panel sent to the results becoming available. Unfortunately, after a prolonged hospital stay, he developed respiratory failure but elected to not be intubated. He became dependent on non-invasive ventilatory support and passed away on day 26 of admission. DISCUSSION: Rituximab is an off label therapy for MS. It acts as a chimeric monoclonal Bcell antiCD20 antibody, halting Bcell production, and reducing Tcell activation and antigen presentation 2. Patients taking rituximab are considered immunosuppressed and are at higher risk for infection;however, per our literature review, there have been no reported cases of adenovirus bronchopneumonia deaths associated with rituximab. Adenovirus is associated with classic "flu like" syndrome in children. In adults the virus is usually benign, presenting with mild gastrointestinal and less commonly mild upper respiratory symptoms 1. Patients undergoing rituximab treatment are at an increased risk of infection with hepatitis B, PML and PJP pneumonia 3,4. CONCLUSIONS: Treatment for severe adenovirus pneumonia is cidofovir and probenecid. Small studies have shown it to be efficacious in pediatric populations 5,6. Due to the high prevalence of COVID19, availability bias remained high and the negative predictive value of PCR tests were low 7. Despite negative PCR tests, the presence of adenovirus was thought of as a red herring leading to a 9 day delay in treatment. REFERENCE #1: M;, Lynch JP;Fishbein M;Echavarria. "Adenovirus." Seminars in Respiratory and Critical Care Medicine, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/21858752/. Chisari, Clara Grazia, et al. "Rituximab for the Treatment of Multiple Sclerosis: a Review." Journal of Neurology, Springer Berlin Heidelberg, 8 Jan. 2021, www.ncbi.nlm.nih.gov/pmc/articles/PMC7790722/. REFERENCE #2: Randall, Katrina L. "Rituximab in Autoimmune Diseases." Australian Prescriber, NLM-Export, Aug. 2016, www.ncbi.nlm.nih.gov/pmc/articles/PMC4993704/. Doan ML, Mallory GB, Kaplan SL, Dishop MK, Schecter MG, McKenzie ED, Heinle JS, Elidemir O. Treatment of adenovirus pneumonia with cidofovir in pediatric lung transplant recipients. J Heart Lung Transplant. 2007 Sep;26(9):883-9. doi: 10.1016/j.healun.2007.06.009. PMID: 17845926. REFERENCE #3: Ganapathi, Lakshmi, et al. "Use of Cidofovir in Pediatric Patients with Adenovirus Infection." F1000Research, U.S. National Library of Medicine, www.ncbi.nlm.nih.gov/pmc/articles/PMC4863673/. Coleman, Jamie J, et al. "COVID-19 to Be or Not to Be;That Is the Diagnostic Question." Postgraduate Medical Journal, U.S. National Library of Medicine, www.ncbi.nlm.nih.gov/pmc/articles/PMC7306267/. DISCLOSURES: No relevant relationships by Sarah Bjork, source=Web Response No relevant relationships by Eitan Fleischman, source=Web Response No relevant relationships by Ruth Minkin, source=Web Response