Worse lung function, more allergic sensitization but less blood eosinophilia in elderly patients with long-standing versus late-onset asthma

Background: Asthma in the elderly is usually considered homogeneous and non-atopic.

Objective: To compare clinical, functional and immunological features between elderly asthmatics with long-standing asthma (LSA) and those with late-onset asthma (LOA).

Methods: Eighty-two asthmatics older than 64 were included into LSA (asthma onset before age 40; n = 46) and LOA (asthma onset from 40 years of age on; n = 36) groups. Asthma treatment and comorbidities were recorded. All individuals underwent the asthma control questionnaire-7 (ACQ-7) and cognitive impairment screening (Mini-Mental State Examination). Inhaler technique was assessed by checklists; the Morisky Medication Adherence Scale-8 was used to assess adherence to treatment. Spirometry, skin prick tests (SPTs), induced sputum and blood eosinophil counts were performed.

Results: We found high frequencies of cognitive impairment, poor inhaler technique and low adherence to treatment in both groups, which had good disease control (ACQ-7 scores: 1.20 ± 0.74 versus 1.11 ± 0.89; p = 0.67, respectively). The LSA group had more severe airway obstruction (FEV₁(% predicted): 62.04 ± 19.50 versus 77.15 ± 18.74, p < 0.01; FEV₁/FVC: 0.59 ± 0.10 versus 0.69 ± 0.09, p < 0.01); higher frequency of positive SPTs (65.6% versus 18.8%, p = 0.001); and lower frequency of blood eosinophilia (45.7% versus 77.1%, p = 0.004) than the LOA group. No differences in sputum cell counts or inflammatory profiles were found between the groups. Ninety percent of the individuals studied had at least one feature of Type 2 asthma.

Conclusion: LSA and LOA phenotypes differ substantially. That should be accounted for in research and clinical practice grounds.