
In an unlikely twist, two chronic health conditions have intersected to provide a protective benefit. A new study from the Yale School of Medicine in New Haven, Connecticut, suggests that people with asthma suffered less severe COVID-19 infections than those without the lung condition.
Considered the largest analyses to date of patients with chronic airway diseases and COVID-19, the study has found that while those with COPD were at a higher risk of severe infection during the first two waves of the pandemic, those with asthma showed better health outcomes than the general population. The study was published in the July 14 issue of The Journal of Allergy and Clinical Immunology
“Our findings suggest that there may be a mechanism intrinsic to having asthma that actually may allow these patients to handle the virus better than a healthy individual,” said Geoffrey Chupp, MD, professor of medicine (pulmonary, critical care, and sleep medicine) at Yale School of Medicine and principal investigator of the study. Dr. Chupp is also the director of the Yale Center for Asthma and Airways Disease.
The results are contrary to what researchers believed at the onset of the COVID-19 pandemic. At that time, public health officials warned that those with asthma might be especially vulnerable to the rapidly spreading respiratory virus. Current studies continue to support that patients of advanced age, obesity and diabetes are at risk for experiencing severe COVID-19 outcomes.
Although this study is promising, physicians continue to encourage those with chronic airway diseases like asthma and chronic obstructive pulmonary disease (COPD) to take extra precautions against COVID.
In 2020, Dr. Chupp admitted one of the first patients with asthma and COVID-19 into the intensive care unit at Yale New Haven Hospital.
“From the moment COVID hit, I was struggling to figure out what to say to my patients and how to counsel them about the risks of COVID-19," he said.
Surprisingly, Dr. Chupp noticed that his patients with asthma and COVID-19 tended to have successful recoveries post-infection. But there was little existing research to support what he was seeing in the clinic.
Dr. Chupp’s team used Yale’s electronic health record to identify more than 8,000 patients who were hospitalized with COVID-19 between March 2020 and April 2021. The researchers organized these patients into four groups based on their diagnostic codes: asthma, COPD, asthma plus COPD and no airway disease. For each of the groups, they used patient sequential organ failure assessment (SOFA) scores to track the severity of COVID-19 infection over the course of hospitalization and looked at mortality across cohorts. The team adjusted their analyses to account for factors known to influence COVID-19 outcomes including age, sex, comorbid diseases, and race and ethnicity.
The study found increased severity of COVID-19 in patients with COPD compared to the control group, but lessened severity in patients with asthma. Patients with both asthma and COPD experienced outcomes similar to those without a chronic airway disease.
The team also considered counts of eosinophils, white blood cells associated with allergic inflammation that can be associated with chronic lung disease. Their findings revealed that higher eosinophil counts and inflammation were significantly correlated with better health outcomes in all the patient groups, and especially for those with asthma. Intrigued, the researchers conducted a further analysis adjusting for eosinophil count and found that the improved outcomes in patients with asthma persisted. Thus, while this immune response may explain some of the improvement seen in this group, it does not tell the full story.
“Our work demonstrates that we need to precisely understand a patient’s underlying airway disease to properly educate them about the risks of severe COVID,” Dr. Chupp said. “That education includes distinguishing between asthma and COPD.”
Dr. Chupp hopes the study will inspire future exploration of the mechanisms underlying this boosted protection so that researchers may better understand how to help patients infected with SARS-CoV-2.
As a reminder, Dr. Chupp said all patients should seek medical advice if they begin experiencing COVID-19 symptoms and get vaccinated if they haven’t already.
“COVID is here to stay, and it’s going to continue to cause illness,” said Dr. Chupp. “So, it’s important for public health advisories to be specific about the risks for those with airway diseases.”