Herpesviruses Detection by Quantitative Real-Time Polymerase Chain Reaction in Bronchoalveolar Lavage and Transbronchial Biopsy in Lung Transplant: Viral Infections and Histopathological Correlation

The monitoring of herpesvirus infection plays a central role in lung transplantation (LT). Herein we evaluated the prevalence of human cytomegalovirus (HCMV), human herpesvirus-6 (HHV-6), human herpesvirus-7 (HHV-7), and Epstein-Barr Virus (EBV) DNA in bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) specimens from LT patients. We associated the findings with the occurrence of interstitial pneumonia, acute rejection, or organizing pneumonia. Viral DNA was detected using real-time polymerase chain reaction (PCR) on 76 paired samples (BAL and TBB) from 27 patients who were receiving a universal combined prophylaxis (cytomegalovirus [CMV] immunoglobulin [Ig] + gancyclovir or valgancyclovir). Histopathological analysis was performed in accordance with the International Society for Heart and Lung Transplantation (ISHLT) criteria. Overall, HCMV results were positive in 25/76 (32.9%) specimens (BAL and/or TBB); HHV-6 in 16 (21.1%); HHV-7 in 40 (52.6%); and EBV in 13 (17.1%). Interstitial pneumonia was diagnosed in 6/76 (7.9%) cases: 5 (83.3%) were positive to HCMV (combined specimens; P < .0001); 5 (83.3%) to HHV-7; and 2 (33.3%) to EBV. An acute rejection episode was diagnosed in 19/76 (25%) cases: 7 (36.8%) were positive to HCMV; 5 (26.3%) to HHV-6; 10 (52.6%) to HHV-7, and 3 (15.8%) to EBV. No significant association was observed between virus detection or load and acute rejection. Organizing pneumonia was diagnosed in 4/76 (5.3%) cases: 1 (25%) positive to HCMV; 4 (100%) to HHV-6 (P < .05); 2 (50%) to HHV-7; and none to EBV. In conclusion, the prevalence of HCMV tended to be lower than that reported in the literature, confirming the importance of universal combined prophylaxis. HCMV was a relevant agent for interstitial pneumonia; although the small numbers limit the statistical analysis, our data did not support an association between herpesviruses and acute rejection episodes, whereas the role of HHV-6 in the pathogenesis of organizing pneumonia deserves further study. Viral detection on TBB could represent an adjunctive tool to complement that on BAL.