DETECTION OF ADENOVIRUS E1A DNA IN PULMONARY FIBROSIS USING NESTED POLYMERASE CHAIN-REACTION

The history of patients with idiopathic pulmonary fibrosis (IPF) shows that the disease may be preceded by a viral-like illness. Although vi ruses have not been demonstrated, it is possible that viruses were not detected in culture because they do not replicate during latency. We investigated the presence of adenovirus in IPF and interstitial pneumo nia associated with collagen vascular disease (CVD-IP), using the nest ed polymerase chain reaction (PCR) and in situ hybridization (ISH) for the E1A region of the adenovirus genome. Studies were performed on lu ng tissues obtained by transbronchial lung biopsy from 19 patients wit h IPF, 10 patients with CVD-IP and, for comparison, from 20 patients w ith sarcoidosis. The E1A DNA was present in 3 out of 19 (16%) cases of IPF, in 5 of 10 (50%) cases of CVD-IP, and in 2 of 20 (10%) cases of sarcoidosis, The incidence of E1A DNA in CVD-IP was significantly high er than that in sarcoidosis (p<0.05), In patients with IPF and CVD-IP, E1A DNA was more prevalent in patients treated with corticosteroids ( 6 out of 9 cases; 67%) than in those without it (2 out of 20 cases; 10 %) (p<0.01), ISH studies showed that 1 out of 8 cases of IPF and CVD-I P, in which E1A DNA was detected by PCR, was positive for E1A DNA. We conclude that adenovirus E1A is unlikely to be aetiologically involved in the pathogenesis of idiopathic pulmonary fibrosis or interstitial pneumonia associated with collagen vascular disease, However, a latent adenovirus infection may be reactivated or may newly infect the host following corticosteroid administration.