News Beyond Our Pages
Authors: Marc E. Rothenberg, Jean Bousquet
Journal: Journal of Allergy and Clinical Immunology (2017)

Chronic obstructive lung diseases, including chronic obstructive pulmonary disease (COPD), asthma, and the emerging disorder of asthma-COPD overlap syndrome (ACOS), are major global health burdens. Previous longitudinal studies have demonstrated that diminished lung function in early adulthood increases the risk for later development of COPD. In this study Bui et al (Am J Respir Crit Care Med 2017; https://doi.org/10.1164/rccm.201606-1272OC) examined whether lung function during childhood similarly affects the risk for chronic obstructive lung disease later in life using a cohort of more than 8000 children from Tasmania. Spirometric measurements were obtained when subjects were aged 7 years and then repeated at age 52 years. The authors found associations between decreased lung function at age 7 years and increased risk for COPD and ACOS, but not asthma. Furthermore, children in the bottom 25% of lung function were at increased risk for ACOS in adulthood. This study brings new insights into the origin of COPD and ACOS. The authors conclude that diminished lung function in childhood increases risk for COPD and ACOS later in life and suggest screening of lung function in children to help prevent COPD and ACOS. Figure attribution to user James Heilman, MD (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0), via Wikimedia Commons.Diminished lung function in childhood increases risk for COPD and ACOS later in life Diminished lung function in childhood increases risk for COPD and ACOS later in life A large amount of the health care costs of asthma are driven by episodic exacerbations. A proposed way to decrease the rate of exacerbations is by reducing allergen exposure. However, studies performed in the general population could not find a beneficial effect. Murray et al (Am J Respir Crit Care Med 2017; https://doi.org/10.1164/rccm.201609-1966OC) performed a randomized, double-blind intervention study to determine the effect of the use of mite-impermeable bedcovers on asthma exacerbations in children who had presented to the hospital with an asthma exacerbation. Two hundred eighty-four children with both asthma and sensitization to house dust mite used either mite-impermeable or placebo (permeable) bed encasings. After 12 months of use, the percentage of subjects with at least 1 exacerbation requiring a hospital visit was lower among the group using mite-impermeable covers compared with the placebo group (29.3% vs 41.5%, P = .047). Additionally, the risk for hospital admission was 45% lower compared with the placebo group (P = .006). Overall, the authors found that mite-impermeable bed covers decrease asthma exacerbation frequency and suggest their use for highly selected asthmatic children. This study provides strong evidence to support the utility of bed casings in asthmatic children. Figure attribution by user, Hangsna (own work) [CC0], via Wikimedia Commons, Creative Commons license.Mite-impermeable bed covers decrease asthma exacerbation frequency Mite-impermeable bed covers decrease asthma exacerbation frequency IL-31 has been implicated in causing the itching symptoms that occur with atopic dermatitis. Nemolizumab, an inhibitory humanized mAb directed against IL-31 receptor A, showed benefit in ameliorating itching in a previous phase 1 study. Ruzicka et al (N Engl J Med 2017;376:826-35; https://doi.org/10.1056/NEJMoa1606490) performed a randomized phase 2 clinical trial with 264 patients with atopic dermatitis to determine the effectiveness of monthly doses of nemolizumab in patients with decreasing pruritus. After 12 weeks, the severity of itching symptoms, as defined by the pruritus visual analog scale, had decreased by 44%, 60%, and 63% with nemolizumab treatment of 0.1, 0.5, or 2.0 mg/kg body weight, respectively. Treatment with all 3 doses showed statistically significant improvement (P < .01) compared with placebo (−20.9%). Skin signs of eczema improved as well. This study reveals that monthly nemolizumab treatment decreases itching symptoms and skin condition in patients with atopic dermatitis.Monthly nemolizumab treatment decreases itching symptoms and skin condition in patients with atopic dermatitis Monthly nemolizumab treatment decreases itching symptoms and skin condition in patients with atopic dermatitis We asked author Timothy Ruzicka, MD, of Städtische Klinikum München (Munich, Germany) to comment on this study. He writes, “So far, no effective treatment exists for pruritus in atopic eczema, with antihistamines showing questionable efficacy at best. Nemolizumab is the first targeted treatment for pruritus directed at Interleukin-31 receptor A. Not only pruritus, but also the severity of atopic eczema was improved by monthly subcutaneous injections.” Type 2 innate lymphoid cells (ILC2s) are thought to promote allergy through robust cytokine production. However, the kinetics of their responses after allergen challenge and their exact roles in allergic airway disease have remained unclear because airway biopsy specimens are limited and cannot be serially collected over time. To alleviate this issue, Dhariwal et al (Am J Respir Crit Care Med 2017; https://doi.org/10.1164/rccm.201609-1846OC) used a novel and noninvasive protocol to perform serial collections of nasal tissue. In this study nasal lining fluids and curettage samples were collected from asthmatic patients with multimorbid allergic rhinitis or healthy control subjects before and after a single exposure to allergen through a nasal spray. Immune cell and soluble mediator compositions of these specimens were then determined. Before allergen exposure, atopic patients had increased levels of eosinophils and ILC2s compared with control subjects. After allergen exposure, atopic patients had increased levels of immune cells, including ILC2s, eosinophils, and neutrophils, as well as proallergic cytokines and lipid mediators. Finally, the highest levels of ILC2s were found in atopic patients with the most severe allergic disease. These findings demonstrate that ILC2s are important in early responses to aeroallergens. Furthermore, this new methodology might allow for better understanding of the functions of other rare immune cell populations in allergic patients.ILC2s are important in early responses to aeroallergensNews items were written by medical writer Jared Travers.Find more News Beyond Our Pages online at www.jaci-nbop.blogspot.com. ILC2s are important in early responses to aeroallergens News items were written by medical writer Jared Travers. Find more News Beyond Our Pages online at www.jaci-nbop.blogspot.com.