High cytomegalovirus serology and subsequent COPD-related mortality: a longitudinal study

Circulating CC16, immune response to Mycoplasma pneumoniae and lung function: a population-based, multi-cohort study

BACKGROUND

Sufficient levels of club cell secretory protein (CC16) are essential to protect against lung function impairments. Experimental studies have demonstrated that CC16 modulates inflammatory responses and protects against airway hyperresponsiveness following Mycoplasma pneumoniae (Mp) infection. Individuals with asthma have low CC16 levels and increased susceptibility to Mp infection. Here we determine whether low CC16 and Mp seropositivity have combined effects on lung function deficits predisposing to airflow limitation, particularly in asthma.

METHODS

Serum levels of CC16 and IgG antibodies against Mp (MpIgG) were measured in adult participants from cohorts BAMSE, MAAS, LSC, and TESAOD. Participants were then stratified into four groups: normal CC16/MpIgG-, normal CC16/MpIgG+, low CC16/MpIgG-, low CC16/MpIgG+. Associations between these groups and lung function (FEV1 and FEV1/FVC) were assessed by linear regression, adjusting for covariates. Meta-analyzed estimates were calculated.

RESULTS

Low CC16 was associated with decreased lung function in the total population, but no combined effects of CC16 and MpIgG were observed. Among asthmatic participants, the low CC16/MpIgG + group had remarkably lower FEV1/FVC z-scores (-0.84, CI: 1.29, -0.38) compared to the reference group, and Mp seropositivity was associated with significant deficits in FEV1/FVC z-scores among those with low CC16 (-0.60, CI: 1.08, -0.12), but not among those with normal CC16 (-0.10, CI: 0.56, 0.36).

CONCLUSION

This suggests that individuals with asthma with low levels of CC16 combined with a history of Mp infection may be more susceptible to deficits in FEV1/FVC, the hallmark of airflow limitation, emphasizing the need for prospective studies designed to test this hypothesis.

Pulmonary Immunocompromise in Human Immunodeficiency Virus Disease

The spectrum of pulmonary disease in people with human immunodeficiency virus (PWH) across the lifespan has shifted from acute, infectious, and acquired immunodeficiency syndrome (AIDS)-defining illnesses to a greater burden of chronic, non-communicable processes. Here, the authors review the epidemiology and risk factors of pulmonary disease in PWH across the lifespan during the contemporary antiretroviral therapy era. The authors focus on recommendations for clinical care of pulmonary disease relevant to PWH, including emerging data from recent and ongoing clinical trials.

COPD in People with HIV: Epidemiology, Pathogenesis, Management, and Prevention Strategies

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disorder characterized by airflow limitation and persistent respiratory symptoms. People with HIV (PWH) are particularly vulnerable to COPD development; PWH have demonstrated both higher rates of COPD and an earlier and more rapid decline in lung function than their seronegative counterparts, even after accounting for differences in cigarette smoking. Factors contributing to this HIV-associated difference include chronic immune activation and inflammation, accelerated aging, a predilection for pulmonary infections, alterations in the lung microbiome, and the interplay between HIV and inhalational toxins. In this review, we discuss what is known about the epidemiology and pathobiology of COPD among PWH and outline screening, diagnostic, prevention, and treatment strategies.

HIV-associated lung disease

Lung disease encompasses acute, infectious processes and chronic, non-infectious processes such as chronic obstructive pulmonary disease, asthma and lung cancer. People living with HIV are at increased risk of both acute and chronic lung diseases. Although the use of effective antiretroviral therapy has diminished the burden of infectious lung disease, people living with HIV experience growing morbidity and mortality from chronic lung diseases. A key risk factor for HIV-associated lung disease is cigarette smoking, which is more prevalent in people living with HIV than in uninfected people. Other risk factors include older age, history of bacterial pneumonia, Pneumocystis pneumonia, pulmonary tuberculosis and immunosuppression. Mechanistic investigations support roles for aberrant innate and adaptive immunity, local and systemic inflammation, oxidative stress, altered lung and gut microbiota, and environmental exposures such as biomass fuel burning in the development of HIV-associated lung disease. Assessment, prevention and treatment strategies are largely extrapolated from data from HIV-uninfected people. Smoking cessation is essential. Data on the long-term consequences of HIV-associated lung disease are limited. Efforts to continue quantifying the effects of HIV infection on the lung, especially in low-income and middle-income countries, are essential to advance our knowledge and optimize respiratory care in people living with HIV.

Associations of Smoking, Cytomegalovirus Serostatus, and Natural Killer Cell Phenotypes in Smokers With and At Risk for COPD

Introduction

Chronic obstructive disease (COPD) risk factors, smoking, and chronic infection (cytomegalovirus [CMV]) may mold natural killer (NK) cell populations. What is not known is the magnitude of the effect CMV seropositivity imparts on populations of smokers with and at risk for COPD. We investigate the independent influence of CMV seropositivity on NK cell populations and differential effects when stratifying by COPD and degree of smoking history.

Methods

Descriptive statistics determine the relationship between cytotoxic NK cell populations and demographic and clinical variables. Multivariable linear regression and predictive modeling were performed to determine associations between positive CMV serology and proportions of CD57+ and natural killer group 2C (NKG2C)+ NK cells. We dichotomized our analysis by those with a heavy smoking history and COPD and described the effect size of CMV seropositivity on NK cell populations.

Results

When controlled for age, race, sex, pack-years smoked, body mass index, and lung function, CMV+ serostatus was independently associated with a higher proportion of CD57+, NKG2C+, and NKG2C+CD57+ NK cells. CMV+ serostatus was the sole predictor of larger NKG2C+ and CD57+NKG2C+ populations. Associations are more pronounced in those with COPD and heavy smokers.

Conclusions

Among Veterans who are current and former smokers, CMV+ serostatus was independently associated with larger CD57+ and NKG2C+ populations, with a larger effect in heavy smokers and those with COPD, and was the sole predictor for increased expression of NKG2C+ and CD57+NKG2C+ populations. These findings may be broadened to include the assessment of longitudinal NK cell population change, accrued inflammatory potential, and further identification of pro-inflammatory NK cell population clusters.

Human Cytomegalovirus Infection and Cardiovascular Disease: Current Perspectives

Infections with human cytomegalovirus (HCMV) are often asymptomatic in healthy adults but can be severe in people with a compromised immune system. While several studies have demonstrated associations between cardiovascular disease in older adults and HCMV seropositivity, the underlying mechanisms are unclear. We review evidence published within the last 5 years establishing how HCMV can contribute directly and indirectly to the development and progression of atherosclerotic plaques. We also discuss associations between HCMV infection and cardiovascular outcomes in populations with a high or very high burden of HCMV, including patients with renal or autoimmune disease, transplant recipients, and people living with HIV.

A high CMV-specific T cell response associates with SARS-CoV-2-specific IL-17 T cell production

Human cytomegalovirus (CMV) is a widespread persistent herpes virus requiring lifelong immune surveillance to maintain latency. Such long-term interactions with the immune system may be associated with deleterious effects including immune exhaustion and senescence. Regarding the COVID-19 pandemic, we asked whether CMV-specific cellular and humoral activity could influence immune responses toward SARS-CoV-2 and/or disease severity. All adults with mild (n = 15) and severe (n = 14) COVID-19 were seropositive for anti-CMV IgG, but negative for IgM antibodies. Antibody titers did not correlate with COVID-19 severity. Six patients presented elevated frequencies of CMV-specific CD4 + and CD8 + T cells producing IFNγ, IL-17, and TNFα, designated as CMV high responders (hiT CMV). In comparison to low CMV responders, hiT CMV individuals exhibited higher frequencies of SARS-CoV-2-specific CD4 + IL-17 + and CD8 + IFNγ + , IL-17 + or TNFα + T cells. These results indicate that high frequencies of CMV-specific T cells may be associated with a SARS-CoV-2-reactive profile skewed toward Th17-dominated immunity.

Acute and Chronic Changes in Gene Expression After CMV DNAemia in Kidney Transplant Recipients

Cytomegalovirus (CMV) viremia continues to cause significant morbidity and mortality in kidney transplant patients with clinical complications including organ rejection and death. Whole blood gene expression dynamics in CMV viremic patients from onset of DNAemia through convalescence has not been well studied to date in humans. To evaluate how CMV infection impacts whole blood leukocyte gene expression over time, we evaluated a matched cohort of 62 kidney transplant recipients with and without CMV DNAemia using blood samples collected at multiple time points during the 12-month period after transplant. While transcriptomic differences were minimal at baseline between DNAemic and non-DNAemic patients, hundreds of genes were differentially expressed at the long-term timepoint, including genes enriching for pathways important for macrophages, interferon, and IL-8 signaling. Amongst patients with CMV DNAemia, the greatest amount of transcriptomic change occurred between baseline and 1-week post-DNAemia, with increase in pathways for interferon signaling and cytotoxic T cell function. Time-course gene set analysis of these differentially expressed genes revealed that most of the enriched pathways had a significant time-trend. While many pathways that were significantly down- or upregulated at 1 week returned to baseline-like levels, we noted that several pathways important in adaptive and innate cell function remained upregulated at the long-term timepoint after resolution of CMV DNAemia. Differential expression analysis and time-course gene set analysis revealed the dynamics of genes and pathways involved in the immune response to CMV DNAemia in kidney transplant patients. Understanding transcriptional changes caused by CMV DNAemia may identify the mechanism behind patient vulnerability to CMV reactivation and increased risk of rejection in transplant recipients and suggest protective strategies to counter the negative immunologic impact of CMV. These findings provide a framework to identify immune correlates for risk assessment and guiding need for extending antiviral prophylaxis.

Accelerated immunosenescence, oxidation and inflammation lead to a higher biological age in COPD patients

Chronic obstructive pulmonary disease (COPD) is characterised by inflammatory and oxidative alterations in the lung and extrapulmonary compartments, through involvement of the immune system. Several leukocyte functions are health markers and good predictors of longevity, and high pro-inflammatory and oxidative states are related to more aged profiles. Here, we aimed to investigate the aging rate in terms of immunosenescence in COPD men with respect to healthy age-matched controls. Several neutrophil (adherence, chemotaxis, phagocytosis, superoxide anion stimulated production) and lymphocyte (adherence, chemotaxis, lymphoproliferation, natural killer activity) functions, cytokine concentrations released in response to lipopolysaccharide (tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, IL-10) and redox parameters (intracellular glutathione content, basal superoxide anion level) were assessed in circulating leukocytes of men with moderate and severe stages of COPD, and compared to healthy age-matched volunteers. The biological age or aging rate in each participant was determined using the values of leukocyte functions. The results indicated impairment of immune functions in COPD patients, both in innate and adaptive immunity, and higher pro-inflammatory and oxidative states in peripheral leukocytes than controls. In general, these changes were more remarkable at the severe stage of airway obstruction. Importantly, COPD patients were found to be aging at a faster rate than age-matched healthy counterparts.

Lung virome: New potential biomarkers for asthma severity and exacerbation

BACKGROUND

Although some respiratory virus infections are known to contribute to the development and exacerbation of asthma, commensal viromes in airway have not been extensively studied due to technical challenges.

OBJECTIVES

This study investigated the characteristics of the virome in asthmatic airways.

METHODS

Both the bacteriome and virome profiles in sputum from 12 healthy individuals, 15 patients with nonsevere asthma, and 15 patients with severe asthma were analyzed and assessed for the association with clinical characteristics such as severity, exacerbation, Asthma Control Test (ACT), and lung function.

RESULTS

While analysis of the 16S ribosomal RNA bacteriome in the airway showed no differences, clear contrasts in the diversity and composition of airway viromes were observed between healthy controls and patients with asthma. Herpesviruses were the most abundant type of virus in the asthma group (44.6 ± 4.6%), mainly with cytomegalovirus (CMV) and EBV accounting for 24.5 ± 3.3% and 16.9 ± 3.5%, respectively, in contrast to those in the healthy controls (5.4 ± 2.5% and 7.1 ± 3.0%, respectively). CMV and EBV were more abundant in patients with asthma who experienced exacerbation, and their abundance showed correlation with more severe asthma, lower ACT score, and lower lung function. On the contrary, bacteriophage that is abundant in healthy controls was severely reduced in patients with asthma in the order of nonsevere and severe asthma and presented significant positive correlation with ACT and FEV₁/forced vital capacity.

CONCLUSIONS

Lung viromes, especially, CMV, EBV, and bacteriophage may be potential biomarkers of asthma severity and exacerbation.