Stability of Type 2 Inflammation in a 12-Year Adult-Onset Asthma Follow-Up Study

To assess the stability of T2 inflammation and clinical features associated with high or low T2 markers in adult-onset asthma.

Seinäjoki Adult Asthma Study is a 12-year follow-up study including 256 patients diagnosed with new-onset adult asthma. Patients were grouped according to T2 marker status at baseline when steroid-naïve and at the 12-year follow-up after long-term inhaled corticosteroid (ICS) treatment. High T2 markers were defined at diagnosis by ≥1 of the following: blood eosinophils ≥0.30×10⁹/L or positive SPT, and at follow-up by ≥1 of the following: blood eosinophils ≥0.30×10⁹/L, FeNO ≥25 ppb, or specific IgE ≥0.3 ISU.

At diagnosis, 109 patients (66.5%) had high and 55 (33.5%) low T2 markers. Low T2 marker patients were older, had higher BMI, and higher Airway Questionnaire 20 scores. High T2 marker patients had greater reversibility of forced expiratory volume in 1 second. At follow-up, baseline low T2 marker patients had more comorbidities, non-respiratory medications and lower Asthma Control Test scores. Of patients, 76% remained in the low T2 marker group and 24% transitioned to the high T2 marker group; those who transitioned had higher BMI. Sixty-eight percent remained in the high T2 marker group and 32% transitioned to the low T2 marker group; those who transitioned were older, had more comorbidities, and more non-respiratory medications. No significant differences were observed between patients who transitioned and those remaining stable regarding lung function, asthma severity, control, exacerbations, or ICS use.

T2 high and low markers of adult-onset asthma are largely stable over time. However, differences in comorbidities, non-respiratory medication, age, and BMI distinguish the groups significantly.