No association between Human herpes virus, Herpes virus Saimiri and idiopathic pulmonary fibrosis

Herpes viruses have been thought to play a pathogenic role in the pathophysiology of idiopathic pulmonary fibrosis (IPF). We aimed to assess the presence of Human herpes viruses and of the simian herpes virus Saimiri in lung samples to evaluate their potential role in IPF. Methods: We performed real-time PCR assays to determine the presence of Human α-herpes viruses (HSV-1, HSV-2, VZV), β-herpes viruses (hCMV, HHV-6, HHV-7), γ-herpes viruses (EBV, HHV-8), and of herpes virus Saimiri DNA on IPF explants (n=18) or IPF lung biopsy (n=1). Emphysematous lung samples obtained after transplantation (n=2) or samples distant from lung cancer surgery (n=7) or pneumothorax surgery (n=1) were used as controls. Results: At least one herpes virus DNA was detected in 27/29 (93%) of lung samples, with no difference between IPF (n=18/19) and controls (n=9/10, p=1.00). The mean number of herpes virus DNA detected was 1.52 in IPF patients and 1.10 in controls (p=0.10). The rate of co-infections did not significantly differ between IPF (n=9/19) and control patients (n=2/10, p=0.23). All samples were negative for Human α-herpes viruses. Human CMV DNA was detected in 2/19 (10.5%) IPF samples and in 1/10 (10.0%) controls. EBV was detected in 12/19 (68%) IPF and in 5/10 (50%) control samples (p=0.69). Regarding herpes virus Saimiri, no viral DNA was detected in lung samples, neither from IPF nor control groups, whereas it was detected in control cell lines. Conclusion: We found no difference for the prevalence of Human herpes viruses between IPF and control lung samples. Herpes virus Saimiri DNA was not detected in any of the lung biopsies. These data do not support a role for herpes virus infection in IPF.