Can we predict fall asthma exacerbations? Validation of the seasonal asthma exacerbation index

Asthma affects about 1 in 11 American children, making it one of the most common diseases of childhood.  It carries a huge burden on families, especially during exacerbations when disease activity suddenly flares, leading to breathlessness and even death.  In this month’s issue of JACI, Hoch and colleagues discuss their research in validating the Seasonal Asthma Exacerbation Predictive Index, the saEPI (J Allergy Clin Immunol 2017; 140(4): 1130-1137).  The saEPI is a score ranging from 0 to 16 that can help predict how likely a child is to have an asthma flare.  Using data from the Preventative Omalizumab or Step-Up Therapy for Fall Exacerbations (PROSE) study, they looked at 348 children randomized to two groups: one with omalizumab, and another with guideline-based therapy alone.  They then calculated and validated the saEPI, moreover the authors looked at other factors that were associated with exacerbations.  In short, they found that children who required more aggressive treatment (high doses of inhaled corticosteroids), had higher blood eosinophils, and were younger were more likely to have a flare.  The saEPI, on the other hand, was better at determining which children were unlikely to have an asthma exacerbation.  The authors encourage providers to use data such as this to personalize their care of children at risk for asthma exacerbations. Because the children that were part of the PROSE study were largely from inner-city and minority populations and the study inclusion criteria limited some children from particpating, a similar analysis should also be performed in a more general population of children, as well as adults.  Regardless, the researchers conclude by noting the importance of such an index in managing children with asthma until even better methods are identified to classify children with asthma at risk for an asthma exacerbation.

Role of viral infections in the development and exacerbation of asthma in children

Wheezing is a common complaint among parents of infants.  About 1 in 5 children have acute wheezing illnesses in their first two years of life.  This is important because an overwhelming majority of these wheezing illnesses are related to viruses, and are linked to asthma development.  In this month’s issue of JACI, Jartti and Gern review the role of viral infections in the development of asthma in children (J Allergy Clin Immunol 2017; 140(4): 895-906). 

They survey the viruses -rhinoviruses, respiratory syncytial viruses, and others – and how they impact the developing set of lungs.  Genetic variation and low interferon responses are two factors that increase the risk of these types of infections.  In addition, increased eosinophil counts in blood and nasal mucus and atopic eczema all increase the risk of later asthma. 

Additionally, viral infections can lead to exacerbations in children who already have asthma.  This may explain why the rates of asthma exacerbations are higher during the fall and winter, and why omalizumab, a potent medication for asthma control, may help to prevent exacerbations due to viruses like rhinovirus.  The authors conclude that these insights may allow for new strategies to help prevent and manage viral wheezing illnesses so that they don’t lead to and worsen later asthma.

Promising approaches for the treatment and prevention of viral respiratory illnesses

There are hundreds of viruses that cause respiratory tract infections.  While most of us think about them as nuisances causing cough and wheezing, they bear a huge toll on health, especially in people who have lung diseases like asthma and COPD, as well as an economic toll in lost workdays and inappropriate use of medical resources.  In this month’s issue of JACI, Papadopoulos and colleagues look at the treatment and prevention of these diseases (J Allergy Clin Immunol 2017; 140(4): 921-932). 

They look at new medications that target the specific viruses in their reproductive phases.  In addition, they review how natural products like echinacea can prevent recurrent respiratory tract infections.  On the other side, there are promising insights about the use of immunostimulators in order to boost the body’s own responses to these viruses.  Vitamin D, probiotic supplements, exercise and meditation are all helpful in resolving these infections. But perhaps the most promising strategies are in prevention, where vaccines are being developed to prime the immune system to fight against viruses.  Currently, vaccines are available only against influenza virus.  There are other developments on the horizon and may have a tremendous effect on addressing these diseases. The authors conclude that multiple strategies are necessary and that there may be tremendous benefits in such research, especially when it comes to dealing with more severe diseases that can cause epidemics and pandemics.