Obesity May Decrease Action of Asthma Drug
Obese patients do not respond as well as non-obese patients to omalizumab.
Asthma is an inflammatory disease that affects the respiratory system. The WHO has estimated that more than 339 million people around the world have asthma, and asthma is the most prevalent chronic disease in children. It is thought that a mixture of environmental and genetic factors cause asthma. Asthma is mainly characterized by chronic inflammation of the bronchi and bronchioles, causing the airways to become constricted thus making it harder to breathe.
The symptoms of asthma:
- Chest tightness
- Wheezing
- Breathing problems
- Persistent cough
There is no cure for asthma. The patients may try to avoid potential triggers like pollutants and allergens, and inhalers containing corticosteroids or long-acting beta-agonists are commonly used to treat asthmatic patients.
Omalizumab is also used by asthmatic patients. It is an antibody-based drug used to block IgE binding to the IgE receptor. IgE has a significant role in the pathophysiology of asthma, and therefore, omalizumab is used to inhibit the action of IgE in the body. This drug is commonly given to patients with uncontrolled asthma. However, some patients do not respond well to omalizumab. The researchers wanted to know why not!
In a study led by Chao Gu, patients with uncontrolled moderate-to-severe asthma were given omalizumab to manage their asthma. The patients in this study were given the appropriate dosage of omalizumab depending on their body weight and IgE levels.
The researchers found that obesity may have influenced the responsiveness to omalizumab, as most of the asthmatic patients that responded well to omalizumab were not obese(BMI less than 30). Whereas, the individuals that did not respond well to the treatment were mainly obese (BMI more than 30), and these differences were statistically significant. These results do not come as a surprise, as obesity can significantly enhance the risk of developing asthma and also reduces the responsiveness to many other asthma drugs too.
Interestingly, the BMI of the obese individuals was strongly associated with the levels of CCR4+ CM CD4+ T cells and type-2 innate lymphoid cells. The researchers believe these cells may have a role in the pathophysiology of asthma in obese patients and may answer why obese patients do not respond as well as non-obese patients to omalizumab.
