Transgenerational occurrence of allergic disease and autoimmunity: general practice-based epidemiological research

Corresponding with the T helper cell type 1/T helper cell type 2 hypothesis, autoimmune and allergic diseases are considered pathologically distinct and mutually exclusive conditions. Co-occurrence of autoimmune disorders and allergy within patients, however, has been reported. Transgenerational co-occurrence of autoimmune and allergic disease has been less often described and may differ from the intra-patient results.

To test the hypothesis that autoimmune disorders in parents are a risk factor for the development of an allergic disease in their offspring.

Prospectively registered (by academic general practitioners) International Classifications of Primary Care (ICPC) for diagnoses of autoimmune disorders and allergy within families were evaluated (n=5,604 families) by performing multiple logistic regression analyses.

The presence of any ICPC-encoded autoimmune disorder in fathers appeared to be associated with an increased risk in their eldest children of developing an allergy (odds ratio (OR) 1.4, 95% CI 1.042 to 1.794). Psoriasis in fathers was particularly shown to be of influence (OR 1.5, 95% CI 1.061 to 2.117) and, although any ICPC-encoded autoimmune disease in mothers was found not to be of significance, the combined international code for registering rheumatoid arthritis/ankylosing spondylitis in mothers was OR 1.7 (95% CI 1.031 to 2.852).

The occurrence of ICPC-encoded autoimmune disorders in parents, especially psoriasis and rheumatoid arthritis/ankylosing spondylitis, significantly increases the occurrence of allergic disease in their children. After validation in follow-up research in a larger sample, these results may lead to the inclusion of 'parental autoimmune condition' as a risk factor in the general practitioner's diagnostics of allergic disease.