Elevated lupus risk seen in allergic rhinitis patients
Patients with allergic rhinitis may risk developing systemic lupus erythematosus (SLE), according to the results of a systematic review and meta-analysis.
Researchers pooled data from eight relevant articles, of which seven were case control and one was a cohort study. The total population comprised 3,326,171 participants.
In a random-effect model, the risk of developing SLE was 40-percent higher in the presence of allergic rhinitis (odds ratio, 1.36, 95 percent confidence interval, 1.08–1.72). There was high heterogeneity observed among the included studies (I2, 80 percent), and the funnel plot indicated no publication bias.
While unclear, the mechanism by which allergic rhinitis patients are at risk of SLE possibly relates to the pathogenesis of the two diseases. Both allergic and autoimmune diseases entail immune dysregulation and increased inflammatory mediators. For instance, IgE, which is a known mediator in allergic rhinitis, may help activating both type 1 and type 2 helper T cells and contribute to chronic inflammation and amplification of autoantibody production and therefore trigger the development of SLE later in life. [Autoimmun Rev 2016;15:487-491; Curr Allergy Asthma Rep 2011;11:378-387]
The “hygiene hypothesis” may also apply to the current observation, such that the lower incidence of infections and colonization of certain microorganism as a result of good hygiene may contribute to the increased risk of both allergic rhinitis and SLE. [Clin Exp Immunol 2010;160:1-9]
Finally, it is also possible that the genetic polymorphism of HLAB gene may cause immune dysregulation and loss of self-tolerance, making the carriers more susceptible to both allergic rhinitis and SLE. [J Allergy Clin Immunol 2017;140:771-781]
Additional experimental and translational studies are needed to better understand the pathogenesis of both allergic and autoimmune disorders.