Molecular detection of human herpesviruses in pleural effusions after lung transplantion

Background Lymphocytic pleural effusions of unclear etiology are frequent after lung transplantation and are associated with adverse outcomes. Reactivation of human herpesviruses, in particular Epstein-Barr Virus (EBV), has been demonstrated to account for a share of unclear pleural effusions in immunocompetent and -compromised patients. Here, we assessed the detection of human herpesviruses in a large lung transplant pleural effusion cohort. Methods A prospectively sampled cohort of 99 pleural effusions of 67 lung transplant recipients was analyzed for HSV-1, HSV-2, EBV, CMV, HHV-6 and HHV-7 by qPCR. Clinical characteristics were compared between virus-positive versus negative pleural effusions. RESULTS EBV could be detected in 35 %, HHV-6 in 19 %, CMV in 4 % and HHV-7 in 1 % of assessed pleural effusion samples, whereas HSV-1 and HSV-2 could not be detected. Median viral load for EBV was 1500 copies/ml, for HHV-6 1300 copies/ml and for CMV 163 copies/ml. Overall, no relevant differences were found comparing the characteristics of EBV-, HHV6- and CMV-positive versus negative pleural effusions. Conclusions Herpesviruses can be detected in low copy numbers in a share of lung transplant pleural effusions. However, they do not seem to account for the high rate of unclear lymphocytic effusions after lung transplantation.