Role of genetic susceptibility to latent adenoviral infection and decreased lung function

Which is a real valuable screening tool for lung cancer and measure thoracic diseases, chest radiography or low-dose computed tomography?: A review on the current status of Japan and other countries

Chest radiography (CR) has been used as a screening tool for lung cancer and the use of low-dose computed tomography (LDCT) is not recommended in Japan. We need to reconsider whether CR really contributes to the early detection of lung cancer. In addition, we have not well discussed about other major thoracic disease detection by CR and LDCT compared with lung cancer despite of its high frequency. We review the usefulness of CR and LDCT as veridical screening tools for lung cancer and other thoracic diseases. In the case of lung cancer, many studies showed that LDCT has capability of early detection and improving outcomes compared with CR. Recent large randomized trial also supports former results. In the case of chronic obstructive pulmonary disease (COPD), LDCT contributes to early detection and leads to the implementation of smoking cessation treatments. In the case of pulmonary infections, LDCT can reveal tiny inflammatory changes that are not observed on CR, though many of these cases improve spontaneously. Therefore, LDCT screening for pulmonary infections may be less useful. CR screening is more suitable for the detection of pulmonary infections. In the case of cardiovascular disease (CVD), CR may be a better screening tool for detecting cardiomegaly, whereas LDCT may be a more useful tool for detecting vascular changes. Therefore, the current status of thoracic disease screening is that LDCT may be a better screening tool for detecting lung cancer, COPD, and vascular changes. CR may be a suitable screening tool for pulmonary infections and cardiomegaly.

Valaciclovir for Epstein-Barr Virus Suppression in Moderate-to-Severe COPD: A Randomized Double-Blind Placebo-Controlled Trial

BACKGROUND

Epstein-Barr virus (EBV) frequently is measured at high levels in COPD using sputum quantitative polymerase chain reaction, whereas airway immunohistochemistry analysis has shown EBV detection to be common in severe disease.

RESEARCH QUESTION

Is valaciclovir safe and effective for EBV suppression in COPD?

STUDY DESIGN AND METHODS

The Epstein-Barr Virus Suppression in COPD (EViSCO) trial was a randomized double-blind placebo-controlled trial conducted at the Mater Hospital Belfast, Northern Ireland. Eligible patients had stable moderate-to-severe COPD and sputum EBV (measured using quantitative polymerase chain reaction) and were assigned randomly (1:1) to valaciclovir (1 g tid) or matching placebo for 8 weeks. The primary efficacy outcome was sputum EBV suppression (defined as ≥ 90% sputum viral load reduction) at week 8. The primary safety outcome was the incidence of serious adverse reactions. Secondary outcome measures were FEV1 and drug tolerability. Exploratory outcomes included changes in quality of life, sputum cell counts, and cytokines.

RESULTS

From November 2, 2018, through March 12, 2020, 84 patients were assigned randomly (n = 43 to valaciclovir). Eighty-one patients completed trial follow-up and were included in the intention-to-treat analysis of the primary outcome. A greater number of participants in the valaciclovir group achieved EBV suppression (n = 36 [87.8%] vs n = 17 [42.5%]; P < .001). Valaciclovir was associated with a significant reduction in sputum EBV titer compared with placebo (-90,404 copies/mL [interquartile range, -298,000 to -15,200 copies/mL] vs -3,940 copies/mL [interquartile range, -114,400 to 50,150 copies/mL]; P = .002). A statistically nonsignificant 24-mL numerical FEV1 increase was shown in the valaciclovir group (difference, -44 mL [95% CI, -150 to 62 mL]; P = .41). However, a reduction in sputum white cell count was noted in the valaciclovir group compared with the placebo group (difference, 2.89 [95% CI, 1.5 × 106-7.4 × 106]; P = .003).

INTERPRETATION

Valaciclovir is safe and effective for EBV suppression in COPD and may attenuate the sputum inflammatory cell infiltrate. The findings from the current study provide support for a larger trial to evaluate long-term clinical outcomes.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT03699904; URL: www.

CLINICALTRIALS

gov.

Evaluation of chest radiography and low-dose computed tomography as valuable screening tools for thoracic diseases

BACKGROUND

Recent studies have shown that low-dose computed tomography (LDCT) is effective for the early detection of lung cancer. However, the utility of chest radiography (CR) and LDCT for other thoracic diseases has not been as well investigated as it has been for lung cancer. This study aimed to clarify the usefulness of the veridical method in the screening of various thoracic diseases.

METHODS

Among individuals who had received general health checkups over a 10-year period, those who had undergone both CR and LDCT were selected for analysis. The present study included 4317 individuals (3146 men and 1171 women). We investigated cases in which abnormal opacity was detected on CR and/or LDCT.

RESULTS

A total of 47 and 124 cases had abnormal opacity on CR and LDCT, respectively. Among these, 41 cases in which the abnormal opacity was identified by both methods contained 20 treated cases. Six cases had abnormalities only on CR, and none of the cases required further treatment. Eighty-three cases were identified using LDCT alone. Of these, many cases, especially those over the age of 50 years, were diagnosed with thoracic tumors and chronic obstructive pulmonary disease, which required early treatment. In contrast, many cases of pulmonary infections have improved spontaneously, without any treatment.

CONCLUSION

These results revealed that LDCT allowed early detection of thoracic tumors and chronic obstructive pulmonary disease, especially in individuals over the age of 50 years. CR is still a useful imaging modality for other thoracic diseases, especially in individuals under the age of 49 years.

Proposing a Neurotropic Etiology for Acute Posterior Multifocal Placoid Pigment Epitheliopathy and Relentless Placoid Chorioretinitis

Purpose

To reassess the underlying pathophysiology of acute posterior multifocal placoid pigment epitheliopathy (APMPPE) and relentless placoid chorioretinitis (RPC) through comparison with the non-inoculated eye of the von Szily animal model of neurotropic viral retinal infection.

Methods

Narrative review.

Results

Literature reports of isolated neurotropic viral entities and rising serological viral titers in APMPPE after presentation support a potential direct infective etiology. In general, viral transport along axons results in mitochondrial stasis and disruption of axoplasmic flow. Clinical manifestations of axoplasmic flow disruption in APMPPE/RPC may signify the passage of virus along the neuronal pathway. From a case series of 11 patients, we demonstrate a timely, spatial, and proportional association of optic disc swelling with APMPPE lesion occurrence. Signs within the inner retina appear to precede outer retinal lesions; and acute areas of outer nuclear layer (ONL) hyperreflectivity appear to be the result of coalescence of multiple hyperreflective foci resembling axonal spheroids (which occur as a consequence of axoplasmic disruption) and follow the Henle fiber layer neurons. Underlying areas of retinal pigment epithelium (RPE) hyper-autofluorescence follow ONL hyperreflectivity and may signify localized infection. Areas of apparent choriocapillaris hypoperfusion mirror areas of RPE/Bruch's membrane separation and appear secondary to tractional forces above. Increases in choroidal thickness with lesion occurrence and focal areas of choriocapillaris hypoperfusion are observed in both APMPPE/RPC and the von Szily model.

Conclusions

The neurotrophic infection model provides significant advantages over the existing primary choriocapillaris ischemia hypothesis to account for the range of imaging signs observed in APMPPE and RPC.

T cell responses in respiratory viral infections and chronic obstructive pulmonary disease

ABSTRACT

Respiratory viruses are major human pathogens that cause approximately 200 million pneumonia cases annually and induce various comorbidities with chronic obstructive pulmonary disease (COPD), resulting in significant health concerns and economic burdens. Clinical manifestations in respiratory viral infections and inflammations vary from asymptomatic, mild, to severe, depending on host immune cell responses to pathogens and interactions with airway epithelia. We critically review the activation, effector, and regulation of T cells in respiratory virus infections and chronic inflammations associated with COPD. Crosstalk among T cells, innate immune cells, and airway epithelial cells is discussed as essential parts of pathogenesis and protection in viral infections and COPD. We emphasize the specificity of peptide antigens and the functional heterogeneity of conventional CD4+ and CD8+ T cells to shed some light on potential cellular and molecular candidates for the future development of therapeutics and intervention against respiratory viral infections and inflammations.

Naturally occurring variants in the transmembrane and cytoplasmic domains of the human Coxsackie- and adenovirus receptor have no impact on virus internalisation

The Coxsackie- and adenovirus receptor (CAR) mediates homophilic cell-cell contacts and susceptibility to both human pathogenic viruses through its membrane-distal immunoglobulin domain. In the present study, we screened five missense variants of the human CAR gene for their influence on adenovector or Coxsackievirus entry into Chinese hamster ovary cells. The CAR variants facilitated virus internalisation to a similar extent as wild type CAR. This underlines CAR's presumed invariance and essential physiological role in embryogenesis.

Respiratory viral infection: a potential "missing link" in the pathogenesis of COPD

Chronic obstructive pulmonary disease (COPD) is currently the third most common cause of global mortality. Acute exacerbations of COPD frequently necessitate hospital admission to enable more intensive therapy, incurring significant healthcare costs. COPD exacerbations are also associated with accelerated lung function decline and increased risk of mortality. Until recently, bacterial pathogens were believed to be responsible for the majority of disease exacerbations. However, with the advent of culture-independent molecular diagnostic techniques it is now estimated that viruses are detected during half of all COPD exacerbations and are associated with poorer clinical outcomes. Human rhinovirus, respiratory syncytial virus and influenza are the most commonly detected viruses during exacerbation. The role of persistent viral infection (adenovirus) has also been postulated as a potential pathogenic mechanism in COPD. Viral pathogens may play an important role in driving COPD progression by acting as triggers for exacerbation and subsequent lung function decline whilst the role of chronic viral infection remains a plausible hypothesis that requires further evaluation. There are currently no effective antiviral strategies for patients with COPD. Herein, we focus on the current understanding of the cellular and molecular mechanisms of respiratory viral infection in COPD.

HLA distribution in COPD patients

BACKGROUND

Auto-immunity may contribute to the pathogenesis of chronic obstructive pulmonary disease (COPD), particularly to the presence of emphysema. Auto-immune diseases are characterized by an abnormal distribution of HLA class II alleles (DR and DQ). The distribution of DRB1 and DQB1 alleles has not been investigated in COPD.

METHODS

To this end, HLA medium-low resolution typing was performed following standardized protocols in 320 clinically stable COPD patients included in the PAC-COPD study. Results were compared with controls of the same geographical and ethnic origin, and potential relationships with the severity of airflow limitation and lung diffusing capacity impairment were explored in patients with COPD.

RESULTS

The distribution of DRB1 and DQB1 alleles in COPD was similar to that of controls except for a significantly higher prevalence of DRB1*14 in patients with severe airflow limitation and low diffusing capacity.

CONCLUSIONS

By and large, HLA distribution was similar in COPD patients and controls, but the HLA class II allele DRB1*14 may contribute to the pathogenesis of severe COPD with emphysema.

Updates on the COPD gene list

A genetic contribution to develop chronic obstructive pulmonary disease (COPD) is well established. However, the specific genes responsible for enhanced risk or host differences in susceptibility to smoke exposure remain poorly understood. The goal of this review is to provide a comprehensive literature overview on the genetics of COPD, highlight the most promising findings during the last few years, and ultimately provide an updated COPD gene list. Candidate gene studies on COPD and related phenotypes indexed in PubMed before January 5, 2012 are tabulated. An exhaustive list of publications for any given gene was looked for. This well-documented COPD candidate-gene list is expected to serve many purposes for future replication studies and meta-analyses as well as for reanalyzing collected genomic data in the field. In addition, this review summarizes recent genetic loci identified by genome-wide association studies on COPD, lung function, and related complications. Assembling resources, integrative genomic approaches, and large sample sizes of well-phenotyped subjects is part of the path forward to elucidate the genetic basis of this debilitating disease.

A genome-wide association study identifies two novel promising candidate genes affecting Escherichia coli F4ab/F4ac susceptibility in swine

Enterotoxigenic Escherichia coli (ETEC) expressing F4 fimbria is the major pathogenic bacteria causing diarrhoea in neonatal and post-weaning piglets. Previous studies have revealed that the susceptibility to ETEC F4ab/F4ac is an autosomal Mendelian dominant trait and the loci controlling the F4ab/F4ac receptor are located on SSC13q41, between markers SW207 and S0283. To pinpoint these loci and further validate previous findings, we performed a genome-wide association study (GWAS) using a two generation family-based population, consisting of 301 piglets with phenotypes of susceptibility to ETEC F4ab/F4ac by the vitro adhesion test. The DNA of all piglets and their parents was genotyped using the Illumina PorcineSNP60 BeadChip, and 50,972 and 50,483 SNPs were available for F4ab and F4ac susceptibility, respectively, in the association analysis after quality control. In summary, 28 and 18 significant SNPs (p<0.05) were detected associated with F4ab and F4ac susceptibility respectively at genome-wide significance level. From these significant findings, two novel candidate genes, HEG1 and ITGB5, were firstly identified as the most promising genes underlying F4ab/F4ac susceptibility in swine according to their functions and positions. Our findings herein provide a novel evidence for unravelling genetic mechanism of diarrhoea risk in piglets.