Purpose
Community acquired respiratory virus (CARV) infections occur frequently after lung transplantation. We hypothesized that severe infection would increase the risk of chronic allograft dysfunction and graft death, while asymptomatic carriage would not.
Methods
We retrospectively reviewed all lung transplant recipients between January 2000 and July 2013 at the University of California, Los Angeles. Bronchoscopy was performed according to a surveillance protocol at 1 day, 1 week, 1, 3, 6, and 12 months post-transplant. Additional samples were sent from bronchoscopy, sputum, and nasopharyngeal washes when clinically indicated. CARV pneumonia was defined as a positive viral test with symptoms and a consistent radiographic infiltrate. Graft death was defined as patient death or re-transplant. BOS was defined according to International Society for Heart and Lung Transplantation (ISHLT) guidelines. We used multivariate Cox modeling to assess the relationship between CARV infection and outcomes.
Results
Of 563 total patients, 139 produced 324 positive specimens in 245 episodes of viral infection (repeat samples within 30 days were excluded). The most frequently isolated viruses were coxsackie/echovirus (20.4%), rhinovirus/enterovirus (19.2%), parainfluenza (18.4%), coronavirus (14.3%), and human metapneumovirus (8.2%). The overall risk of CLAD was elevated with any CARV infection (HR 1.79, p <0.01), though when analyzed as parallel predictors in subgroup analysis, only clinical pneumonia remained statistically significant (HR 1.64, p = 0.03). Asymptomatic viral infection (HR 1.50, p = 0.08) and symptomatic viral infection (HR 1.03, p = 0.91) did not meet statistical significance. Viral pneumonia significantly increased the risk of graft death (HR 2.58, p <0.01). However, overall CARV infection (HR 0.92, p = 0.60), asymptomatic CARV infection (HR 0.76, p = 0.24), and symptomatic CARV infection (HR 0.78, p = 0.42) did not.
Conclusion
Viral pneumonia increases the risk of graft death and CLAD after lung transplantation. Overall CARV infections also appear to increase the risk of CLAD, although in our cohort this risk was primarily driven by those with viral pneumonia. Asymptomatic viral carriage and symptomatic CARV infection without pneumonia did not appear to impact graft survival.