Viral Respiratory Tract Infection During the First Postoperative Year Is a Risk Factor for Chronic Rejection After Lung Transplantation

Magnusson, Jesper; Westin, Johan; Andersson, Lars-Magnus; Lindh, Magnus; Brittain-Long, Robin; Nordén, Rickard; Riise, Gerdt C.

Upper or lower VRTI was defined as detection of a viral pathogen by real-time PCR in either an NPH or BAL fluid sample. Subjects who had a positive PCR test for at least 1 viral pathogen in either BAL or NPH samples during the first year were considered "VRTI positive." A bacterial respiratory tract infection was defined as a positive culture for bacteria in BAL or sputum and symptoms consistent with respiratory tract infection, as evaluated by an experienced transplant pulmonologist. A fungal infection was defined as significant presence of aspergillus or candida in BAL and/or sputum culture and symptoms and/or bronchoscopic findings consistent with fungal infection. Significant CMV viremia was defined as increasing levels of CMV-DNA in the blood. For seronegative transplant recipients, when CMV-DNA was detected for the first time, for CMV-seropositive recipients when levels increased above 3.0 log 10 copies/mL. Repeated elevated Epstein-Barr virus (EBV)-DNA (REED) was defined as 2 separate EBV-DNA measurements above 3.1 log 10 copies/mL at least 1 month apart. Acute rejection was defined as either a lung biopsy showing rejection of the International Society for Heart and Lung Transplantation grade A1 or higher, 15 or, in the absence of a biopsy (n = 3), typical physical and radiological findings followed by a prompt response to high-dose corticosteroid therapy.