A69-33 Resistant CMV Infection Leading to Organizing Pneumonia

Abstract Introduction CMV infection can affect patients with solid-organ transplants, especially in a donor-positive/recipient-negative(D+/R-) transplant. This population has the highest risk of resistant CMV due to prolonged prophylaxis.1 Organizing pneumonia can occur due to alveolar injury and can have a similar radiologic presentation to CMV pneumonitis.2 There are case reports of developing organizing pneumonia after CMV infection, but none with CMV resistance. Case Presentation A 66-year-old man with deceased donor kidney transplant 6 months prior and CMV mismatch (on valganciclovir) presented with 3 weeks of diarrhea. Vitals and physical exam showed no abnormalities. Labs revealed leukopenia and negative blood, respiratory and GI cultures. CMV viral load was 90,313 IU/mL. Chest x-ray showed no abnormalities. Ganciclovir was started for CMV infection, and immunosuppression was reduced. On day 3, he became febrile and required oxygen. CT chest showed diffuse alveolar airspace disease, so a bronchoscopy was performed. Bronchoalveolar lavage was positive for CMV 5,900,000 IU/mL and immunohistochemistry CMV stains were positive and revealed intracytoplasmic viral inclusions. Repeat CMV viral load was 1,143,034 IU/mL, raising suspicion for CMV resistance. Testing was sent for UL97 and UL54 mutation. UL97 mutation was positive, indicating resistance, so treatment was switched to Foscarnet. He had reduction in CMV viral load from 6.06 to 2.4 log10 copies. However, respiratory status continued to decline. CT chest showed worsening consolidations concerning for organizing pneumonia. Repeat bronchoscopy confirmed organizing pneumonia with no evidence of ongoing CMV. Steroids were initiated for treatment of organizing pneumonia with continuation of anti-CMV therapy and weekly monitoring of CMV viral load. The patient significantly improved and was discharged home without any supplemental oxygen. Discussion 90% of cases of ganciclovir resistance occur in D+/R- solid organ transplant.1 Foscarnet and cidofovir are active against mutation in UL97 kinase, which phosphorylates ganciclovir activating its antiviral activity. Mutations in UL54 DNA polymerase genes cause resistance against all available drugs.1 In CMV pneumonitis, consideration of resistance is important. There are case reports of CMV pneumonitis causing organizing pneumonia, but no rates available given its rarity. In our case, steroids were safely given for organizing pneumonia with continuation of anti-CMV treatment and close monitoring. References: 1.Hakki, M., 2025 Jan-. This abstract is funded by: None