Abstract Introduction/Rationale The pathogenesis of ILD has been associated with shortening of telomeres which recent evidence suggests may be associated with active Epstein Barr Virus (EBV) infection. One of the most direct methods of determining EBV activity is through shedding in saliva. Epstein Barr Virus (EBV) shedding in saliva is commonly seen in Multiple Sclerosis (MS) and in some connective tissue diseases. However, the degree of EBV saliva shedding in individuals with interstitial lung disease (ILD) remains unclear, despite a substantial proportion of these patients experiencing acute respiratory infections. The aim of this study was to determine whether patients with ILD have increased prevalence of EBV shedding when compared with control groups. Method Weekly saliva samples, using salivettes, were collected over a 12-week period from people with fibrotic idiopathic ILD and controls without lung disease. Participants collected additional daily saliva samples during periods of acute respiratory worsening (ARW). A symptom diary was recorded during the study period. Real-time quantitative PCR (qPCR) measuring EBV DNA levels was conducted for saliva samples. Significant EBV shedding was defined as EBV 5.8copies/uL. Results 471 weekly saliva samples were collected from 29 patients with fibrotic idiopathic ILD (387 samples) and seven age and gender matched controls (84 samples). Mean age was 71.4years and 27% were female. 13.8% had a history of infectious mononucleosis. Of the ILD patients, 8 (28%) experienced ARW during the study period, and an additional 44 samples were collected during these ARW. Median EBV load in saliva was 42.70 copies/uL with a large variation (range 0-7813.29), with no difference between ILD patients and controls. All participants had high prevalence of any EBV detected (EBV0 copies/uL) throughout the 12-week period of testing: ILD patients, 276/343=80.5%; controls, 71/84=84.5% (p = 0.393). Those with ILD were more likely to have significant EBV shedding (EBV5.8 copies/uL, 130/343=37.9%) compared to controls (22/84=26.2%), p = 0.045. EBV shedding during acute respiratory worsening was present in 12/44, 27% of samples, with wide variation, with some experiencing a spike in shedding during the symptomatic period, some experiencing spikes before symptom onset, and some with no spike in EBV load. Conclusions ILD patients are more likely to have significant EBV saliva shedding compared to controls. EBV shedding in ILD patients is higher than in reported levels in MS patients. These results support further investigation into the pathogenic role of EBV and potential use of antiviral treatment for ILD patients. (393/400 words) This abstract is funded by: n/a
Tsai et al. (Fri,) studied this question.