Over the last few years there has been a lot of "good starts" when it comes to novel treatments of allergies and asthma. From a vaccine for cat allergies to bronchial thermoplasty for asthmatics, there have been a myriad of treatments, in varying stages of testing, that offer hope for the millions who suffer from environmental and food allergies as well as asthma. As the latest in this line, the FDA recently "fast tracked" a novel approach to desensitizing those with peanut allergies.
This new therapy is Viaskin® Peanut. From their website,
"Epicutaneous immunotherapy (EPIT®) consists in repeated application of antigen with Viaskin® on intact skin. EPIT induces a decrease of allergen specific responses (i.e. decrease of allergen-specific IgE, decrease of TH2 cytokine production, and decrease of local and systemic response after exposure to allergen) and increase of regulatory responses (i.e. increase of allergen-specific IgG2a or IgG4, increase of regulatory T cells (Tregs)."
In plain English, this is a patch that allows small but steady amounts of the peanut allergen (antigen) to be absorbed by the skin. This patch has a small air pocket built into it where it moisture condenses. This allows the antigen to combine with the moisture and be more readily absorbed by the skin. Langerhans cells, specialized immune system cells, capture the allergen in this outermost layer of the skin and migrate it to the lymph nodes. Here is where the modification (desensitization) takes places. As this process repeats it essentially trains the immune system to down-regulate and promote a long term tolerance of the allergen.
Upon reviewing the performance of the patch in earlier rounds of clinical trials, the Food and Drug Administration granted the patch a breakthrough therapy designation. This allows for faster development and review of the treatment. This the first drug designed for food allergies, that has received this designation. So why do certain treatments get this "fast track"? It all comes down to results. From adults to children as young as 12, test results show year long treatments with the patch resulted in patients demonstrating the ability to be exposed to at least ten times the amount of the allergen previously needed to elicit a response.
With this type of treatment, there are no painful shots or needles, or weekly appointments for sublingual drops. This patch bypasses traditional sublingual and desensitization treatments. There's also less risk to the patient actually having an allergic reaction since the allergen never reaches the bloodstream to trigger a full-fledged allergic response.
An easy way to visualize this is to think of a brownie. Before the treatment a patient may have an allergic reaction after eating a brownie that had a single, small piece of peanut in it. After the treatment, the patient could eat a handful of peanuts with no reaction. For those with food allergies, this kind of cushion can represent the difference between a trip to the emergency room after snack time and being just fine.
Now, with the FDA designation, there's a very real chance that this treatment could be available within in the next five years.
For more information on the clinical trials.
For more information on Viaskin and DBV Technologies.
Author: K. Gilmore
The team introduced Viaskin® Peanut, an epicutaneous immunotherapy (EPIT/ allergy patch), to encourage peanut tolerance via patches containing micro doses of peanut proteins. The epidermis is potentially ideal for allergen administration, as it is a safer route of allergen absorption in lieu of direct exposure to the vascularized circulatory system. Another factor that makes it prime location are the presence of Langerhans cells that specialize in antigen presentation. These act as "mediators of tolerance" for the immune system in the skin, and can be used in the favor of building peanut protein tolerances.
The year long therapy trial consisted of 221 peanut-allergic individuals who were treated with patches consisting of a various doses of peanut protein. All patients were tested at the beginning of the study to measure their initial peanut protein tolerance. After administering doses of the protein, ranging from 50 micrograms to 250 micrograms, their baseline test results were then compared to their tolerance levels at the end of the study.
Results showed that greater than 95% of the patients complied to the study (1% dropping out due to adverse affects) , and children treated with 250 microgram patches experienced a 19-fold increase in tolerance to peanut allergies! This means that at the end of the study they were able to tolerate 1 gram of peanut protein, the equivalent of 4 peanuts.
Viaskin® Peanut is the first of it's kind for combating food allergies, but initial results hint that it could be the first food allergy patch for other food allergies as well (seafood, tree nuts, soy, etc.). Beyond the patch itself, this study can also help us better understand how the body builds a defense for allergens. Understanding the mechanism is critical, particularly since food allergies are complex and usually require food avoidance, low dose immunotherapy or special diets. They cannot treated like environmental allergies such as pet dander allergies or pollen allergies, which can be treated with allergy shots, pills or sublingual immunotherapy (SLIT).
This EPIT therapy is promising for parents, patients, and practitioners. Food allergies are particularly challenging for parents who must constantly watch their younger children's diets, which can be strained in social or school related situations. Food allergies also affect nutrient intake, which can lead to potential growth hindrance and nutrient deficiency, as reported by the Journal of Academy of Nutrition and Dietetics. Practitioners may soon be able to give more options to patients, providing relief in fighting potentially lethal peanut allergies. We hope to see more advancement in this study, and see it become an accessible form of immunotherapy on the pharmacy shelves.
Author: R. Power
Researchers started by examining the role gut bacteria play in food sensitivities and food allergies in two groups of mice. Playing on the "hygiene hypothesis" researchers put together one group of mice that were raised in a sterile environment. In the other group, the mice were given a large dose of antibiotics at just two weeks of age. After being given peanut extract, both groups were observed, and from here researchers began introduction specific groups of bacteria to see if they had any effect on the allergic response. Specifically, Bacteroides and Clostridia bacteria groups were the focus, two types that are commonly found in wild mice.
The results were very interesting. First, mice that were given antibiotics showed a high sensitivity to the peanut extract. Antibiotics given early in life have recently been shown to be linked to a myriad of problems later on, including things like the development of allergies and asthma. Of the second group, the reaction to the peanut allergen was even more severe with some showing signs of anaphylaxis. While the introducing Bacteroides into the gut of mice had little effect, Clostridia was another story.
In both groups of mice, the introduction of Clostridia bacteria into the mice resulted in reduced allergic responses to the peanut allergen. This is extremely important for two reasons. First, it shows a link between specific gut bacteria and the development of allergies, again highlighting the link between the microbiome and the health of the animal. Second, these results point toward the potential of treating food allergies with the use of probiotics.
This study also refines the "hygiene theory" somewhat. While traditionally, it was suggested that a lack of exposure to germs and microbes early on could lead to the immune system overreacting to innocuous substances like dust mites, peanuts, or pollen, these results would suggest that a more sterile environment or perhaps even an overuse of antibiotics could lead to less diverse and less numerous gut bacteria, which would in turn be setting the stage for allergen sensitivity.
While the notion of treating allergies or food sensitivities with probiotics are still many years away, this latest research solidifies the link between gut bacteria and allergies. More importantly, it opens the door for potentially novel, new treatments of allergies, asthma and possibly other allergic diseases.
To read the abstract of this study.
Allergy-free peanuts? While it may seem a bit farfetched, this is just what they are working on. Started with a cashew extract (oil), researchers are treating the proteins found in the oil with heat and sodium sulfite. You may recognize sodium sulfite, as it's a preservative commonly found in a variety of foods. What this process does is change the molecular look of reaction-causing protein in the cashew, making it more difficult for immunoglobin (IgE - the antibody that kicks off your body's response, aka, allergic reaction) to recognize and bind with the protein.
Test results showed that when mixing unmodified and modified cashew proteins with the IgE of a nut allergic person, 50% fewer of the IgE molecules bonded with the altered proteins. This is important for a few reasons. Even though this isn't the first experiment to attempt this, it is the first that uses a compound generally regarded as safe (GRAS) to disrupt the protein structure of the allergen. It is also important because unlike other treatments, it is aimed at treating the food, not the person. Lastly, its success shows the potential for reducing or possibly even eliminating the binding of IgE to food allergens, the root of the allergic response.
For now results show a allergy-reduced nut, which isn't as helpful a non-allergenic one. However, these results at least point towards the possibility of this as a solution. What's up next for researchers? Modifying whole cashews then ensuring the cashews still taste they way they should! Until then, avoidance remains the best option for most dealing with severe food allergies.
To read the full abstract of the research.
For more information on food allergies.
Author: K. Gilmore
Similar to the mechanism used with successful cancer vaccines, the new dust mite vaccine uses an adjuvant (an agent that enhances the body's immune response) in addition to the antigen (the substance that actually induces the immune system to produce antibodies). The way this works is a package (of the adjuvant and antigen) is introduced to a patient. The adjuvant essentially raises the alarm, calling the immune system forward to what it perceives as an "all hands on deck" situation. The immune system absorbs and disposes of the package, but the tangible result of this is speeding up the adsorption process and increasing the rate of absorption of the vaccine.
In this instance, the adjuvant (CpG) was packaged with the vaccine and given to mice. Not only was the package absorbed 90% of the time but subsequent daily exposure to the dust mite allergen showed higher production of antibodies and lower rates of lung inflammation. While more research is needed, this outcome is one of the very best that researchers could have hoped for.
With nearly 10% of the population allergic to dust mites, they are easily among the most common allergens on the planet. Often found in mattresses, carpet, upholstered furniture and bedding, dust mites are microscopic pests that feed on dead skin cells. They are one reason why your mattress can double in weight after ten years of use. Millions of these tiny creatures call your mattress home, and it is their tiny decomposing body parts and feces that cause the sneezing, wheezing, congestion, and coughing that are commonly associated with dust mite allergies.
The most common methods of coping with dust mite allergies often include a mix of several things, including allergen avoidance (the use of quality allergy bedding covers or a HEPA air purifier, more frequent cleaning and removal of carpet from the home), medication to the treat the symptoms (most commonly antihistamines), and allergy shots (to increase the tolerance of the allergen). Each of these tackle different aspects of the allergy, and even with promising research such as this, a vaccine or simpler longterm solution is still likely several years away.
For more information, see the official University of Iowa press release.
Author: K. Gilmore
P.S. Just in case you were wondering what CpG stands for... the "C" is for cytosine triphospate deoxynucleotide. The "G" is for guanine triphosphate deoxynucleotide, and the "p" is for the phosphodiester that links the two nucleotides. You may recognize cytosine and guanine. They are two of the four bases of DNA (along with adenine and thymine), and that concludes today's biology lesson!
Immunotherapy has been a successful form of allergy relief for wasp-sting allergies and grass pollen. At its core, immunotherapy is a long, slow process of reintroducing tiny amounts of a particular allergen to patients. Over time, the amounts of the substance patients ingest or are exposed to increases with that hope of leading to a higher, long term tolerance of the allergen. With regard to peanut allergies, this has been the most successful study so far, and gives hope to parents who are constantly on the lookout for even trace amounts of peanuts that can send the severely allergic into anaphylactic shock. In the future this type of treatment could relieve much of the worry associated with trace amounts of allergens causing severe reactions and help lift many of the precautionary diet restrictions those with food allergies often have to impose.
While we wait for more research, long term test results, and potential FDA approval for this treatment, avoidance remains one of the best options for those dealing with food allergies. Though peanut butter might not be one the menu just yet, here are some Peanut/ nut substitute suggestions without the risk of allergic reactions.
- Sunflower seed butter
- Soy nut butter
Author: R. Power
Like traditional allergy shots, the idea behind the treatment is to desensitize people who are allergic to cats. The big difference between this and traditional shots is two-fold. First, the shots are not subcutaneous, meaning they are more shallow and do not go beneath the skin. Second, the length of the proposed treatment would be significantly shorter, four to eight months as opposed to the more traditional three to five years worth of shots. This can not only make the process more convenient but hopefully less costly and invasive.
The current trial is accepting people who have had cat allergies for at least two years, have a cat living at home with them, and are between the ages of 12 and 65. As the largest clinical study of this treatment to date, the CATALYST (Cat Allergy Study) is accepting over 1100 volunteers from seven countries.
For people coping with cat allergies, this could be a dramatic step forward in treatment. Often times allergists recommend removing your cat from the household, and as one of the most common household pets, those with cat allergies often have allergic reactions outside of their own homes. Cat dander is one of the smallest of common household allergens, and to make matters worse, it's "sticky". This means that in places where cats have been, it's often extremely difficult to remove cat dander since it adheres to walls, furnishings, and flooring, nearly everything in a room. Nearly one in three households have cats. In addition to allergies, there is also a link to asthma reactions and cats, with one study showing over a quarter of asthma attacks being triggered by cat allergen. So, the potential that a shorter, less invasive and successful treatment holds a great deal of hope for the millions with allergies or asthma.
The basis of the treatment is the proprietary ToleroMune technology. Molecules called SPIRES (Synthetic Peptide Immuno-Regulatory Epitopes) generate regulatory T cells. These T cells control the allergic response and stimulate tolerance of specific allergens.
Circassia is also working on a similar treatment for dust mite allergies, and back in September of 2013 they announced results of their phase-two trials. In this study, patients who had received four doses of the treatment over 12 weeks showed significant improvement one year after the start of the trial. This smaller phase-two study will likely in the steps of the cat allergy trials. With success, they will move on to larger, clinical, phase-three trials. In addition dust mites, Circassia has also finished phase-two trials of the same treatment for ragweed and grass allergies.
While we continue to patiently wait and hope, avoidance and more traditional measures, like the use of a high quality HEPA air purifier or antihistamines remain some of the best way to reduce allergic reactions to cat.
For more information on these phase-three clinical trials, contact your local certified allergist or visit the clinicaltrials.gov website
Author: K. Gilmore
Over the last year or two, researchers have paid closer attention to the microbes living on and in us, and how these things can dramatically affect our lives, particularly when it comes to immune responses. Published this week in the Proceedings of the National Academy of Sciences, new research suggests an interesting link between exposure to dog-associated house dust and the subsequent development of allergic diseases like asthma and allergies, and interestingly enough, at the middle of this research is a very specific type of gut bacteria, Lactobacillus johnsonii.
During the our first few years of life, we begin to develop a very diverse microbiome of bacteria (think of a microbiome as a community of bacteria living inside your gastrointestinal system), and from immune responses to metabolism, these tiny inhabitants are proving to be critical in the development of allergic disease. In this instance, researchers tested dog-associated dust exposure as well as simple supplementation of Lactobacillus johnsonii into the gut.
When exposed to the "dog dust", the pre-adult mice showed less response to an airway allergen challenge, fewer activated T cells and reduced Th2 cytokine expression, all key indicators of allergic response. For another set of mice who weren't exposed to the dust, but instead had the numbers of Lactobacillus johnsonii in their gastrointestinal system supplemented orally (think - they gave the mice a Lactobacillus johnsonii probiotic), similar but not as strong results appeared. This second set of mice showed that while increased number of the Lactobacillus johnsonii bacteria in the gut did correlate with fewer allergic reactions and less allergic response, this correlation was much stronger in the mice who were exposed to dog-associated house dust. This seems to show that while that specific microorganism is helpful, a greater diversity in the microbiome also plays a role in immune system development and protection against allergic disease.
The results are just another step in process of unraveling allergic disease, but is a truly critical one for two reasons. First, researchers were able to identify a very specific microorganism that shows a strong link to preventing the development of allergic disease. Secondly, the "dog dust" shows that not only did it lead to increased level of this beneficial microorganism but also helped promote a more diverse array of microbes living in the intestinal system, and that as other research has suggested, this variety is also import in preventing the development of allergic disease.
Undoubtedly, more attention and research will continue, and maybe soon, the link between allergic disease and the tiny microbes around us can become clear enough to begin devising ways to actually reduce the chances of children developing asthma and allergies in the first place! Wouldn't that be something?br>
To read the full PDF of the research or for more condensed abstract.
On a side note, I discovered, Nestle (the food company, which consequently has a research facility in Switzerland) is responsible for the genetic sequencing of this bacterium, Lactobacillus johnsonii and uses it in some of its probiotic products.
Author: K. Gilmore
Vacuum cleaners can release large concentrations of particles, both in their exhaust air and from resuspension of settled dust (Duchaine et al. 2013). The aim of this study was to evaluate particles emitted into the air from various vacuum cleaners. Tests and measurements were made based on dust inside dust bags or dust bins (some were bagless) and from air emitted from the machine while in use. Duchaine and her team quantified how much bacteria and mold could be found within these tests with a particular focus on Clostridium botulinum, Salmonella spp and Penicillium/Aspergillus. While Salmonella is fairly commonly known, the other two are related to botulism and mold, respectively. For infants/toddlers and those with allergies or compromised immunity, this study can be somewhat worrisome.
There have been previous studies on vacuum cleaners that have established that dust bags can be a reservoir for certain types of microbes, and in one particular instance during the 1950's vacuums have gotten attention for this, as a dust bag was the sole source of a Salmonella outbreak amongst infants in a hospital ward.
Before, you toss your vacuum, consider some of the findings on this study. No appreciable levels of the microorganisms, with the exception of mold spores (which varied more widely in terms of measurable amounts), was found in the emissions. While there were some present, the concentration was extremely low. In the dust bag though, the story was a bit different. Concentrations of the different microbes found were fairly consistent, regardless of brand (of vacuum), and this leads researchers to believe that "vacuum emissions could potentially lead to short and more intense bioaerosol exposures than those due to resuspension of settled dust" given the emission rate of most vacuums.
At this point, it is likely worth noting a couple things. First, brands of the vacuum cleaners used were not disclosed. The near two dozen units were collected from the homes of staff and students at the university. The age of the vacuums tested ranged 6 months to 22 years and the prices from $75 to $800 (AUD - Australian), and each vacuum was tested as it arrived. Additionally, samples could not be obtained from all the units involved. A little over half of the models tested produced measurable results, in terms of emissions and dust bag content. The next thing to keep in mind is this. For test purposes, researchers used HEPA filter air through the vacuums, to ensure uniformity but also to introduce as pure of a medium as possible.
This was an interesting research topic, since dust is often overlooked as a conglomerate of debris with no life or benefit. But here we have live microorganisms amongst nonliving material. This could also shed some light onto what kind of vacuum do you want to purchase. If this blog has got you thinking about switching your vacuum to something a little more vacuum sealed, here are few things to consider.
Filtration matters - The fact that researchers used HEPA filtered air in their tests is telling, particularly when you compare it to the size of some of the microbes examined. Mold spores typically range in size from 3 to 40 microns while Clostridium botulinum, a rod-shaped microbe, can be .5-2 microns wide by 1.6 to 22 microns long. Certified HEPA filters capture 99.97% of particles 0.3 microns and larger.
Vacuums With a Bag Should Be Better - The entire point of the research piece was to focus on bioaerosols that vacuums can create and emit throughout the home. What is the point of trapping microbes only to expose yourself to them when you empty the dust bin?
Particularly Sensitive Groups, Pay Heed to What You Clean With - You often get what you pay for, and not all vacuums marketed as "HEPA" are equal. Some have been independently tested and certified (like Miele or Dyson), and other haven't. Even if you decide to pay for a vacuum with high end filtration, you are likely selling yourself short if you then use cheaper, aftermarket replacement dust bags or filters.
Lastly, On the Microscopic Level, Seals Matter - Vacuums that features seals to prevent air leakage and those that have dust bags that seal when you go to remove them are going to be advantageous.
Although this research does shed some light on potential bacterial exposure, don't fret because these types of infections are very rare. Overall, this statement from the study says a lot, "The vacuum characteristics here are likely to be the main predictor of emission, rather than dust content." However, if you're in a position where you have to crash on the floor at a friends or grandmas... you may want to consider a blowup mattress!
To read the full research article.
Author: R. Power
Polyunsaturated fatty acids is a broad category that includes many compounds, including the most commonly known Omega 3 (n-3) as well as the lesser known Omega 6 (n-6) and Omega 9 (n-9) fatty acids. The role these acids play in the human diet is complex and still continues to evolve, though Omega 3 and others are most commonly associated with anti-inflammatory properties.
Studies over the last few decades have shown a general lack of these compounds in the western diet and associated it with an increase in inflammatory diseases such as heart disease, Type 2 diabetes, COPD and even asthma. Omega 3 fatty acids are most commonly found in fish oils as well as some plant oils, and as a more recent trend, have been appearing in increasing amounts on store shelves, as dietary supplements. More recent research blurs the lines a bit by suggesting that things like Omega 3 may not be the miracle cure all the hype would lead you to believe, yet most concede that while the positives may not be as grand as originally billed, there are few drawbacks.
This latest piece of research builds upon a piece originally published in 2008 that produced similar results but on a smaller scale. In this Swedish study published in PLOS One, roughly 800 children were chosen from a population based group of 1228 born in the same year. From this group, samples of the umbilical cord serum were taken then analyzed and compared with standardized allergy test results taken over the course of the next 13 years.
The results showed that in children at age 13 demonstrated higher rates of respiratory allergies than those whose mothers had lower levels of PUFAs at birth. Not only did children with respiratory allergies exhibit this link but so did children who suffered from chronic skin rashes. Those who exhibited higher rates of allergies also had lower levels of mono-unsaturated fats found in the cord blood sample. So to simplify this - Higher levels of Omega 3 and Omega 6 fatty acids found in the cord blood correlated with higher rates of respiratory allergies and chronic skin rashes (think eczema), and it did not matter if the mother had a history of allergies or not. The correlation rates were still higher regardless of maternal allergy history.
So what does all this mean? For now, not much. This research piece is just another step along the way of understanding the origins of allergic disease. Though researchers demonstrated this correlation, what they could not determine was the mechanism behind this. The working theory is that the PUFAs dampen inflammation and the immune activation process, the same process that is thought to "train" an infants immune system to determine is harmful and what is not. This seems to fit since much of allergic disease is the immune system's overreaction to harmless "allergens." Further research is still needed to discover what the exact mechanism behind this is as well how to approach the consumption of PUFAs during pregnancy.
To read the full research article.
Author: Kevin Gilmore