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of asthma could be caused by lupus pulmonary involvement; however, there is insufficient evidence that asthma is a result of lupus interstitial pneumonitis or pleuritis. To the best of our knowledge, a restrictive functional defect was observed in lupus pneumonitis, interstitial pulmonary fibrosis, and pleural effusion, which differed from an obstructive functional defect in asthma (7). Therefore, SLE plays an extremely important role in the development of asthma. With increasing age, other risk factors also contribute to the incidence of asthma, and the relative risk of asthma consequently decreases. Adult-onset asthma is believed to be an underestimated issue, affecting approximately 4–8% of patients older than 65 years (8). A review article by Eagan and coworkers reported that the pooled estimated incidence of adult asthma from general population cohort studies was 59 and 44 per 10,000 person-years in women and men, respectively (9). These findings were close to the incidence found in our non-SLE elderly groups. We believe a small proportion of cases are misclassified as asthma; however, these contributions should be equivalent in the two cohorts. In conclusion, the incidence of asthma may increase in patients with SLE with increasing age, and the data clearly demonstrate that IRR decreases inversely with increasing age. n