Occupation increases risk of severe exacerbation in workers with asthma

Much research has been published on the association of new-onset asthma diagnosis and occupation. Not surprisingly, the association is significant and has implicated both sensitizing and non-sensitizing agents.

Recently, Henneberger et al. (Eur Respir J 2010, 36:743-750) asked another related question: Is severe asthma exacerbation in current asthma patients associated with occupation? Using the European Community Respiratory Health Survey results, they compiled a cohort of workers with current asthma that reported severe exacerbation in a 12 month period. The authors focused on asthma worsening as related to jobs with high risk of exposure to irritants. They found that the relative risk was significant for occupations with high exposure to dust, gas, and fumes and used that to calculate the population-attributable risk percentage. Approximately 15% of severe asthma exacerbations were associated with occupation. Further, the authors found that both sensitizing and non-sensitizing occupational exposures were implicated, which, they pointed out, was consistent with published reports for occupational, new-onset asthma.

Wrapping up, the authors commented that the size of their cohort provided more robust statistical indices and their focus on current asthma exacerbation delineated more clearly the distinction between occupational asthma and work-exacerbated asthma.

Tell us what you think. Please feel free to post your own comments and/or predictions below. Topics and articles that you think would be of interest in our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.

Smoking ban in Scotland has greater impact than expected

In a recent issue of the New England Journal of Medicine, Mackay et al. (N Engl J Med 2010, 363:1139-1145) follow up on the outcome of a 2006 smoking ban in enclosed public places in Scotland. The law was enacted to protect workers exposed to occupational smoke, such as bar workers. To examine evidence for a wider impact, data from the Scottish Morbidity Record (SMR) was pulled for asthma-attributed hospital admissions for infants and children up to 14 years.

Banning smoking in public places has been shown to reduce acute myocardial infarction deaths and hospitalizations as well as decrease hospital admissions because of respiratory conditions, but there have been no studies on how the bans affect asthma in children.

In Scotland, prior to the 2006 ban, there was an increasing trend in admissions for childhood asthma symptoms. After the ban, Mackay et al. report a significant reduction in asthma-related admissions by 13%. They discuss previous studies that have reported significant reduction in respiratory symptoms of workers exposed to occupational smoke as well – even if they are smokers.

Of particular interest, Mackay et al. discuss concerns among Scottish public health officials that the ban would cause increased smoking in the home. In fact, studies had found that voluntary smoking bans in the home increased after the legislation based on objective findings of salivary cotinine in children from those homes.

Tell us what you think. Please feel free to post your own comments and/or predictions below. Topics and articles that you think would be of interest in our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.

The Lancet focuses on asthma

To coincide with the European Respiratory Society meeting in Barcelona, which starts on September 18th, The Lancet's September 4 issue highlights asthma in four review articles. The articles cover areas of asthma care in vulnerable populations, areas that are in desperate need of attention as the incidence rises and patients with asthma are living longer.

Gibson et al. (Lancet 2010, Vol 376:803-813) discuss the complexity and lack of research on management of elderly patients with asthma, noting that their age and comorbidities exclude them from most clinical trials. Bush and Saglani (Lancet 2010, Vol. 376:814-825) hit the other age-related knowledge gap; that is, pediatric asthma patients, especially those with severe, refractory asthma. They comment that this population faces the same obstacles to clinical research that elderly patients with asthma have. Moreover, clinical trials in this age group are needed to understand medical needs in young children.

Busse et al. (Lancet 2010, Vol 376:826-834) discuss the need for better understanding of the mechanisms by which respiratory viruses increase risk of asthma as well as increase susceptibility asthma exacerbation in order to more effectively manage and prevent asthma. Finally, Lambrecht and Hammad (Lancet 2010, Vol. 376:835-843) review the state of knowledge about dendritic cells and their collusion with airway epithelium that results in allergic sensitization and asthma.

Tell us what you think. Please feel free to post your own comments and/or predictions below. Topics and articles that you think would be of interest in our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.

NIH Director responds to stem cell research injunction

Francis S. Collins, M.D., Ph.D., Director, National Institutes of Health, released a statement two days after a controversial injunction on stem cell research was issued by the US District Court of the District of Columbia. Dr. Collins stated that “(t)he recent court ruling that halted the federal funding of human embryonic stem cell research could cause irreparable damage and delay potential breakthroughs to improve care for people living with serious diseases and conditions such as spinal cord injury, diabetes, or Parkinson’s disease. The injunction threatens to stop progress in one of the most encouraging areas of biomedical research, just as scientists are gaining momentum—and squander the investment we have already made.” (For the complete statement go to: http://www.nih.gov/about/director/08262010statement_stemcellinjunction.htm.)

The preliminary injunction ordering the temporary halt of all government funding of stem cell research is based on the case Sherley vs. Sebelius. The suit is brought by Christian groups to challenge President Obama’s reversal of the Bush administration’s increased restrictions on NIH funding of stem cell research under the Dickey-Wicker Amendment

The Dickey-Wicker Amendment prohibits federal funding for “(1) the creation of a human embryo or embryos for research purposes; or (2) research in which a human embryo or embryos are destroyed, discarded, or knowingly subjected to risk of injury or death greater than that allowed for research on fetuses in utero under” applicable federal regulations.

President Bush’s executive order in 2001 permitted funding induced pluripotential stem cell (iPSC) research, but prohibited federal funding for research on embryonic stem cells (ESCs) that were created after the date of the policy statement. Interestingly, federal funding remained available for research on ESCs that were created by private researchers prior to his policy statement.

Two physicians, Drs. James Sherley, of the Boston Biomedical Research Institute, and Theresa Deisher, of Ave Maria Biotechnology Company, are co-plaintiffs with Nightlight Christian Adoptions and the Christian Medical Association. Ave Maria Biomedical Research Institute is a Seattle-based firm co-founded by Dr. Deisher to establish ethical alternatives to embryonic stem cell research.

Tell us what you think. Please feel free to post your comments below. Topics and articles that you think would be of interest in our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.

Vitamin D deficiency implicated in bronchopulmonary allergic aspergillosis

Will a simple, daily dose of sunshine correct the majority of our immune problems? Vitamin D deficiency has been associated with asthma, IgE levels, atopy, and obesity. Now new research has associated vitamin D deficiency with allergic bronchopulmonary aspergillosis (ABPA), which is, in turn, associated with Aspergillus fumigatus colonization in cystic fibrosis (CF) patients; however, only a small percentage of affected CF patients develop ABPA.

Kreindler et al. (J Clin Invest 2010, doi:10.1172/JCI42388) investigated this observation by comparing the Th2 profiles of ABPA CF patients and colonized, non-ABPA CF patients. They found that ABPA CF patients were characterized by a TSLP- & OX40L-driven Th2 environment. In contrast, non-ABPA CF patients did not have an excessive Th2 response and had high levels of TGF-β producing Tregs. Since vitamin D has been associated with Treg development, the authors assessed vitamin D levels in both groups; they found that ABPA patients were significantly deficient relative to the non-ABPA group. They went on to demonstrate that vitamin D deficiency lowered Tgfb mRNA and raised OX40L levels in mice. Treatment with vitamin D reversed these conditions.

Kreindler and coauthors suggested that their data demonstrated that vitamin D increases the proportion of TGF-β to OX40L favoring the induction of Tregs rather than Th2 cells.

Tell us what you think. Please feel free to post your comments below. Topics and articles that you think would be of interest in our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.

Immunotherapy in asthma: a recent Cochrane review says “YES, but”

Specific immunotherapy is widely accepted in allergic rhinitis but it has long been a controversial treatment for asthma. Dr. Michael J. Abramson started the first Cochrane Collaboration review on the subject in the mid 1990s and two updates have since been published. The most recent one was published in the Cochrane Database of Systematic Reviews 2010 Issue 8 (Abramson MJ, Puy RM, Weiner JM, Injection allergen immunotherapy for asthma). The authors searched the Cochrane Airways Group Trials Register up to 2005, Dissertation Abstracts and Current Contents. Their selection criteria focused on “randomized controlled trials using various forms of allergen specific immunotherapy to treat asthma and reporting at least one clinical outcome.”
In all, 88 trials were included, of which 13 were new trials. These trials included 42 that looked at immunotherapy for house mite allergy and six that looked at multiple allergens. Their results were as follows:

Concealment of allocation was assessed as clearly adequate in only 16 of these trials. Significant heterogeneity was present in a number of comparisons. Overall, there was a significant reduction in asthma symptoms and medication, and improvement in bronchial hyper-reactivity following immunotherapy. There was a significant improvement in asthma symptom scores (standardized mean difference -0.59, 95% confidence interval -0.83 to -0.35) and it would have been necessary to treat three patients (95% CI 3 to 5) with immunotherapy to avoid one deterioration in asthma symptoms. Overall it would have been necessary to treat four patients (95% CI 3 to 6) with immunotherapy to avoid one requiring increased medication. There was no consistent effect on lung function. If 16 patients were treated with immunotherapy, one would be expected to develop a local adverse reaction. If nine patients were treated with immunotherapy, one would be expected to develop a systemic reaction (of any severity).

The authors conclude that immunotherapy is effective in asthma albeit there is a risk for local or systemic adverse effects (such as anaphylaxis). This indicates that immunotherapy in asthma should be prescribed by specialists and administered with care, in particular in patients with asthma.

Dust from desert storms: Another aggravation for asthma patients

Pollution, ozone, pollen, airborne animal dander, smoke, and now globally distributed mineral dust. These are just a sample of things that are demonstrated to increase the discomfort of asthma sufferers. Dust problems are not just local issues; Saharan dust is distributed across the equatorial zone all the way to Central America as well as southern North American and northern South America. Now there is evidence of significant association between global distribution of dust from these storms and asthma hospitalizations.

This interesting result comes from a study by Kanatani et al. (AJRCCM 2010, doi:10.1164/rccm.201002-0296OC) in which they use optical data from tropospheric monitoring stations in Japan from 2005 to 2009 and compare “heavy dust events,” originating in the Chinese and Mongolian deserts, with asthma hospitalizations in 8 hospitals in Toyama.

They find a significant association between heavy dust events and hospitalizations for asthma exacerbation. This is notable for the higher percentage of boys affected than girls, though the study population had fewer boys than girls. The authors also found that the effect of the dust event persisted up to 6 days after exposure.