Peanut Oral Immunotherapy (OIT)

Tailong Xu

Food allergies have been on the rise for decades, and are still growing among people today. Today, researchers estimate a whopping 15 million Americans with food allergies, with a vast majority being children. The prevalence rate of food allergies in children has just about doubled from 1997 to 2002 (Hofmann). Currently, the only source of alleviation for the adverse reactions of peanut anaphylaxis is strict abstinence from the source. However, there have been recent breakthroughs in a new type of revolutionary treatment dubbed Oral Immunotherapy Treatment (OIT). The new treatment consists of applying staggered doses of serum or food derivatives to increase tolerance through desensitization with epinephrine to combat the reactions toward the specific allergen. This new therapy can be seen all over current news and articles on the intranet for the purpose of treating peanut allergies. Currently, there exists a wide spectrum of opinions regarding oral immunotherapy as a treatment for allergy to peanuts. Boasting impressive success rates, oral immunotherapy may be able to aid us in the fight, not only against peanut allergies, but against many other food allergies as well.

The procedure for oral immunotherapy seems to be rather similar to desensitization to any other irritant. Children in age from three to fourteen years of age were treated in a study conducted by Blumchen et al. In a short term rushed procedure, increasing doses of crushed roasted peanuts were given to patients 2 to 4 times a day for seven days. Depending on how tolerant the patients already were to peanut, the dosage increase increments ranged from 20% to up to being doubled in each dose (Blumchen). In a long-term buildup procedure, dosage was increased every 2 to 4 weeks. If any side effects occurred, the dose would be decreased. The results of the study showed that while the rushed protocol was shown to be effective in increases tolerance to other allergens, it is not seen to be effective in children with peanut allergies. The long-term procedure allowed more than half of the patients to reach the target tolerance level (500mg), which would be an ample amount to protect against children accidentally coming into contact with peanut products.

OIT is seen to be relatively effective in increasing the peanut tolerance in children to a median of 1g from an average 0.19g. Additionally, the study from Blumchen et al. shows that only 2.6% of the applied doses showed any sign of negative response. All people who demonstrated a serious adverse response had some form of asthma prior to the study. Currently, OIT seems to be a very promising and fruitful procedure in the works. Rather than completely eradicate any anaphylactic shock or allergic response, OIT allows patients to be able to tolerate greater levels of food-specific allergen.

Current popular and professional opinion of OIT as a potential treatment for allergy to peanuts, or otherwise has shown to be fragmented in regards to OIT’s recent emergence as a potential viable treatment. Thyagarajan et al. expresses strong belief that peanut OIT is not yet ready for clinical use. Similar to current public uproar against genetically modified foods, many believe that there is not yet enough known about OIT for it to be used on patients with severe peanut anaphylaxis, especially children. Even many doctors are hesitant to apply OIT to patients in case of violating the Hippocratic Oath, a sacred oath taken by all doctors to never intentionally cause harm to patients.

A study done by Hofmann et al. looks to find the most potential sources of complication in the oral immunotherapy treatment process. Of course, the most obvious risk to patients with peanut allergy is making them eat peanuts and peanut derivatives, which definitely can aggravate their symptoms. The demanding regimen may prove to be rather taxing on the patients’ bodies and affect the function of other mechanisms. Patients seem to express the most severe symptoms during the initial “escalation phase” of treatment when the dosage of peanut serum is first increased. Additionally, since OIT dosage must be applied daily, home dosage is necessary. Home treatment has its potential dangers beyond the watchful eye of the doctor or healthcare provider, but so far has not been shown to be hazardous to the patient. Some patients report mild symptoms such as upper respiratory symptoms and skin inflammation during exercise after dosing or dosing without having a meal (Varshney). Common side effects include vomiting, abdominal pain, and worsening of preexisting asthma (Hofmann).

Contrastingly, many people feel that OIT is ready to be implemented in the clinical environment. As of today, there have been no fatal cases of response to the treatment, and there haven’t been any reported instances of unexpected behaviour or reaction. Additionally, survey results report that a vast majority of patients who have undergone the controversial treatment report an increase in quality of life. The target peanut tolerance level for OIT is more than enough to account for any accidental exposure to peanuts or peanut derivatives. Patients are able to live with greater freedom in choices without fear of serious adverse allergic reaction. The first randomized controlled double blind study conducted by Varshney et al. highlights the effect of peanut oral immunotherapy compared to a placebo control. Peanut specific antibody IgE were seen to decrease significantly in patients undergone therapy treatment, and IgG4 antibody count and average T cell count was shown to have increased compared to the control group. These results suggest that oral immunotherapy somehow desensitizes the immune system to the peanut specific allergens as a mode of alleviation. Thus, OIT treatment has the potential to boost the tolerance to peanut derivatives of afflicted patients to a level by which anaphylaxis no longer has an impact on daily life.

We know now that peanut oral immunotherapy is effective to a certain degree, but the mechanism by which treatment happens is unclear. The most common theory is that inducing allergic response in minute doses builds up IgG4 markers over time so that the patient’s immune system becomes desensitized over time to tolerate greater doses of allergen. There is a significant decrease in IgE (immunoglobulin E) specific to peanuts, which has receptors that recognize the allergen for peanuts and causes the inflammatory and humoral immune response we know as anaphylaxis. IgG4 is generally used as an indicator or greater tolerance because it shows that T cells are producing more IgG4 instead of IgE antibodies. Jones et al. tested the theory of desensitization in an immune regulation study. Results showed decrease in serum factors as well as decline in basophil activation. These changes in the humoral response support the theory of immune system desensitization linked with a weaker response to irritant allergens.

By analyzing the spectrum of perspectives on the issue of OIT treatment, we are able to have a greater understanding of the controversy surrounding peanut oral immunotherapy as an ethical treatment to be implemented in our current healthcare. The development of allergy treatment is still a relatively young discipline. It’s too soon to determine if oral immunotherapy is merely a novelty approach on an age-old affliction, but it is my belief that development of OIT treatment is integral in setting off the spark of human ingenuity towards the direction of allergy treatment and a brighter future for all.

Works Cited

Blumchen, K. et al. (2010). Oral peanut immunotherapy in children with peanut anaphylaxis. J ALLERGY CLIN IMMUNOL , 126 (1), 83-91.

Hofmann, A. M. et al. (2009). Safety of a peanut oral immunotherapy protocol in children with peanut allergy. J ALLERGY CLIN IMMUNOL , 124 (2).

Mansfield, L. (2013). Oral immunotherapy for peanut allergy in clinical practice is ready . Allergy and Asthma Proceedings , 34 (3), 205-209.

Thyagarajan, A. et al. (2010, July). Peanut Oral Immunotherapy (OIT) is Not Ready for Clinical Use. J ALLERGY CLIN IMMUNOL , 31-32.

Varshney, P. et al. (2011). A randomized controlled study of peanut oral immunotherapy: Clinical desensitization and modulation of the allergic response. J ALLERGY CLIN IMMUNOL , 127 (3), 654-660.