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Detection of adenovirus E1A DNA in pulmonary fibrosis using nested polymerase chain reaction
K Kuwano1, Y Nomoto, R Kunitake
1Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University, Higashiku, Fukuoka, Japan.
Abstract:
The history of patients with idiopathic pulmonary fibrosis (IPF) shows that the disease may be preceded by a viral-like illness. Although viruses 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 pneumonia associated with collagen vascular disease (CVD-IP), using the nested polymerase chain reaction (PCR) and in situ hybridization (ISH) for the E1A region of the adenovirus genome. Studies were performed on lung tissues obtained by transbronchial lung biopsy from 19 patients with IPF, 10 patients with CVD-IP and, for comparison, from 20 patients with 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 higher 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-IP, 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.
Insights
Adenovirus E1A DNA was detected in some idiopathic pulmonary fibrosis (IPF) and collagen vascular disease-interstitial pneumonia (CVD-IP) patients. Corticosteroid treatment was linked to higher adenovirus detection rates in these lung diseases.
Area of Science:
- Pulmonology
- Virology
- Pathogenesis
Background:
- Idiopathic pulmonary fibrosis (IPF) may follow viral-like illnesses, but direct viral evidence is lacking.
- Latency may prevent virus detection via traditional culture methods.
- Adenovirus is a potential candidate pathogen in interstitial lung diseases.
Purpose of the Study:
- To investigate the presence of adenovirus E1A DNA in lung tissues of patients with IPF and collagen vascular disease-interstitial pneumonia (CVD-IP).
- To compare adenovirus detection rates between IPF, CVD-IP, and sarcoidosis patient groups.
- To explore the association between adenovirus detection and corticosteroid treatment.
Main Methods:
- Nested polymerase chain reaction (PCR) and in situ hybridization (ISH) were used to detect adenovirus E1A DNA.
- Lung tissue samples were obtained from 19 IPF, 10 CVD-IP, and 20 sarcoidosis patients.
- Statistical analysis was performed to compare detection rates.
Main Results:
- Adenovirus E1A DNA was detected in 16% of IPF, 50% of CVD-IP, and 10% of sarcoidosis cases.
- Detection rates were significantly higher in CVD-IP compared to sarcoidosis (p<0.05).
- E1A DNA was more prevalent in IPF and CVD-IP patients treated with corticosteroids (67%) versus those not treated (10%) (p<0.01).
Conclusions:
- Adenovirus E1A is unlikely to be directly causative in IPF or CVD-IP pathogenesis.
- Corticosteroid administration may be associated with adenovirus reactivation or new infection in these conditions.
- Further research is needed to elucidate the role of latent adenovirus infections in interstitial lung diseases.