Graft Loss and CLAD-Onset Is Hastened by Viral Pneumonia After Lung Transplantation

BACKGROUNDCommunity-acquired respiratory virus (CARV) infections occur frequently after lung transplantation and may adversely impact outcomes. We hypothesized that while asymptomatic carriage would not increase the risk of chronic lung allograft dysfunction (CLAD) and graft loss, severe infection would. METHODSAll lung transplant cases between January 2000 and July 2013 performed at our center were reviewed for respiratory viral samples. Each isolation of virus was classified according to clinical level of severityasymptomatic, symptomatic without pneumonia, and viral pneumonia. Multivariate Cox modeling was used to assess the impact of CARV isolation on progression to CLAD and graft loss. RESULTSFour thousand four hundred eight specimens were collected from 563 total patients, with 139 patients producing 324 virus-positive specimens in 245 episodes of CARV infection. Overall, the risk of CLAD was elevated by viral infection (hazard ratio [HR], 1.64; P < 0.01). This risk, however, was due to viral pneumonia alone (HR, 3.94; P < 0.01), without significant impact from symptomatic viral infection (HR, 0.97; P = 0.94) nor from asymptomatic viral infection (HR, 0.99; P = 0.98). The risk of graft loss was not increased by asymptomatic CARV infection (HR, 0.74; P = 0.37) nor symptomatic CARV infection (HR, 1.39; P = 0.41). Viral pneumonia did, however, significantly increase the risk of graft loss (HR, 2.78; P < 0.01). CONCLUSIONSWith respect to CARV, only viral pneumonia increased the risk of both CLAD and graft loss after lung transplantation. In the absence of pneumonia, respiratory viruses had no impact on measured outcomes.