Pittsburgh Researchers Find Chemical Implicated in Asthma and Allergy Also Tied to Common Cold

PITTSBURGH -- A medication currently approved for the treatment of asthma and allergies may provide unprecedented relief for the common cold and its complications, according to a study published this week in the Annals of Allergy, Asthma and Immunology by researchers at Allegheny General Hospital (AGH) and Children's Hospital in Pittsburgh.

Funded by the National Institutes of Health and led by AGH allergic disease specialist Deborah Gentile, MD, the study documented elevations of a chemical called leukotriene in patients with common colds caused by three separate viruses. Leukotrienes are metabolic agents produced by the body during episodes of inflammation or swelling and are associated with the trademark upper respiratory symptoms of asthma and allergies, such as nasal congestion, runny nose, itchy eyes, postnasal drip, wheezing and coughing.

To assess the role of leukotrienes in the pathology of the common cold, Gentile and colleagues David P. Skoner, MD, director of the AGH Center for Allergy, Asthma and Immunology and Philip Fireman, MD, of Children's Hospital of Pittsburgh, intranasally inoculated 66 healthy adults with a strain of either Influenza A (Flu), Rhinovirus (RV) or Respiratory Syncytial Virus (RSV). Nasal lavage samples were collected, symptoms were recorded and expelled nasal secretions were weighed before and then daily following virus exposure. Lavage samples were submitted for viral culture and tested for leukotriene.

Results of the study showed that all subjects became infected and following infection, each participant experienced significant increases in leukotriene levels. There was also a direct association between leukotriene levels and the development of illness.

Though not evaluated in the study, an FDA-approved drug that blocks the proliferation of leukotrienes, called montelukast, and provides substantial symptom relief for asthma and allergy patients, could potentially do the same for victims of the common cold, Gentile said.

"Because there are so many different strains of viruses that precipitate common colds, the quest to find effective agents to treat the condition has been elusive. The results of our study suggest that leukotrienes may be the therapeutic common denominator we have been looking for, " Gentile added.

"As in the case of allergen exposure and certain asthmatic triggers, infection with respiratory viral pathogens appears to induce the production of leukotrienes, causing inflammation that is expressed as upper respiratory tract symptoms. Given that, it is reasonable to assume that a leukotriene antagonist medication like montelukast has tremendous potential for subduing or even preventing cold symptoms. If our follow-up studies validate that, the impact from a public health perspective could be dramatic," Gentile said.

It is estimated by the National Institute of Allergy and Infectious Disease that in the course of any given year, Americans will suffer approximately 1 billion colds. A 1996 study by the National Center for Health Statistics documented 62 million cases of the common cold for which medical attention was sought in the U.S., 45 million days of restricted activity and 22 million days lost from school. While adults average about two to four colds a year, children suffer six to 10.

Although in most patients common colds are self-limited, they can lead to more serious complications, including the development of middle ear and sinus infections and exacerbation of asthmatic conditions.

Gentile and Skoner are in the process of planning two follow-up studies that will be conducted during the upcoming cold season to test the effectiveness of montelukast for the common cold. The first study will determine whether treatment with montelukast decreases symptoms and runny nose in adults with the cold. The second will examine whether the treatment decreases short and long term wheezing in infants hospitalized with a severe respiratory infection caused by RSV.

Source: West Penn Allegheny Health System