Asthma and risk of selective IgA deficiency or common variable immunodeficiency: a population-based case-control study.

OBJECTIVE: To determine the association between a history of asthma and a diagnosis of selective IgA deficiency (sIgAD)/common variable immunodeficiency (CVID). PATIENTS AND METHODS: This population-based case-control study included residents of Olmsted County, Minnesota, who met the Pan-American Group for Immunodeficiency/European Society for Immunodeficiencies diagnostic criteria for sIgAD/CVID between January 1, 1964, through December 31, 2008. Each case had 4 age- and sex-matched controls (2 from the community and 2 from a list of individuals who had undergone an immune work-up). We ascertained asthma status by applying predetermined criteria for asthma. RESULTS: We identified 39 cases: 26 (66.7%) had sIgAD and 13 (33.3%) had CVID. Of the 39 cases, 51.3% were men (n=20) and 97.1% were white (33 of 34 patients). The mean age at the index date (the time when criteria were met) of sIgAD/CVID was 34.2 years. Of the 39 cases, 9 (23.1%) had a history of asthma before the index date of sIgAD/CVID; of the 156 controls, 16 (10.3%) had a history of asthma before the index date (odds ratio, 2.77; 95% CI, 1.09-7.06; P=.03). A history of asthma (before or after the index date of sIgAD/CVID) was more prevalent in sIgAD/CVID cases (30.8%; n=12) than in matched controls (11.5%; n=18) (odds ratio, 3.57; 95% CI, 1.50-8.51; P=.01). CONCLUSION: Asthmatic patients are more likely to have a diagnosis of sIgAD/CVID than nonasthmatic individuals. This association may potentially account for the increased risks of bacterial infections in some individuals with asthma.

Assessment of the association between atopic conditions and tympanostomy tube placement in children.

This study assesses the relationship between otitis media and atopic conditions in children by comparing the incidence of tympanostomy tube placement between children with and without atopic conditions: asthma, allergic rhinitis, and atopic dermatitis. Study subjects were a cohort of 323 healthy children who participated in a study of vaccine response. All episodes of tympanostomy tube placement and physician diagnoses of allergic rhinitis and atopic dermatitis were collected through comprehensive medical record review. Asthma status was ascertained through application of established criteria. We compared incidence rates of tympanostomy tube placement between children with and without atopic conditions. We fitted data to a Poisson regression model to calculate relative risk ratios (RRs) and their corresponding 95% confidence intervals (95% CI). Three subjects were excluded who did not have parental authorization for using records for research. Of the remaining 320 subjects, 170 (53%) were male subjects, 268 (94%) were white, 124 (39%) were asthmatic patients, and 20 (6%) had tympanostomy tube placement. Children with asthma before the index date of tympanostomy tube placement were more likely to have tympanostomy tube placement compared with those without asthma (RR, 19.33; 95% CI, 11.41; 32.75; p < 0.001). We found a similar association between asthma ever (before or after index date) and the incidence of tympanostomy tube placement (RR, 1.53; 95% CI, 0.93-2.53; p = 0.095). This was true for children with allergic rhinitis compared with those without allergic rhinitis (RR, 1.70; 95% CI, 1.01-2.86; p = 0.007). Atopic dermatitis was not associated with the incidence of tympanostomy tube placement. Asthma or allergic rhinitis may be unrecognized risk factors for recurrent or persistent otitis media. However, given the small sample size of the study, a cohort study with a larger sample size is necessary.

Inflammatory bowel disease and asthma: a population-based, case-control study.

BACKGROUND: A few cross-sectional studies reported an increased risk of inflammatory bowel disease (IBD) among asthmatics. We conducted a population-based, case-control study that applied predetermined criteria for asthma and IBD to determine whether asthma, as a T-helper 2 (Th2) condition, reduces the risk of IBD, a Th1 condition. METHODS: This was a population-based, case-control study using criteria-based ascertainment for IBD and asthma. Subjects were all Rochester, Minnesota, residents who had developed IBD between 1964 and 1983 and their age- and gender-matched controls, using 1:1 matching. Controls were randomly selected from the community using the Rochester Epidemiology Project database and confirmed not to have IBD. All cases and controls were merged with the database comprising all Rochester residents with or without asthma between 1964 and 1983. RESULTS: Of the 231 IBD cases, 55% had ulcerative colitis and the remainder had Crohn's disease. Of these, 50.4% were male and 98.1% were Caucasians. The mean age at the time of IBD diagnosis was 33.8 years. Four cases (1.7%) had asthma prior to the index date of IBD, whereas two controls (0.9%) had asthma (unadjusted odds ratio [OR]: 3.0, 95% confidence interval [CI]: 0.31-28.84, P = 0.34). Similarly, 16 IBD cases (6.9%) had asthma ever while 12 controls (5.2%) had asthma ever (unadjusted OR: 1.4, 95% CI: 0.62-3.38, P = 0.40). CONCLUSIONS: Asthma as a Th2 condition does not reduce the risk of IBD as a Th1 condition. Because of the limitations of our study and others, the association between asthma and IBD needs to be further studied.