Tonsils play an important role in our immune system. Tonsils are a pair of lymphoid tissues located at the rear of the throat and function as the first defence against bacteria and virus. The underlying component of B cells in the germinal centers of the tonsil is activated when a pathogen is present.
Studies show that the pre-existing antigen-specific IgA antibodies in the nasopharynx declined sharply after adenotonsillectomy (surgical removal of the adenoids and tonsils) in children, suggesting that the tonsils are important for generating mucosal immunity. Moreover, recently been noted that besides thymus tonsils are the reservoir of T cells.
It is thus possible that removing tonsils may lead to future dysfunction of the immune system. Swedish study tested the hypothesis that individuals with tonsillectomy face an increased incidence of autoimmune diseases in their later life. All individuals who underwent a tonsillectomy in Sweden during 1997-2012 were included and explored systematically their subsequent risk of 33 autoimmune diseases. In Sweden, patients with autoimmune diseases are normally diagnosed by two doctors: 1) at a primary health care center and 2) a specialist in the hospital. This can guarantee high accuracy of this study as compared to studies that use self-reported questionnaires.
179 875 individuals received a tonsillectomy between 1997 and 2012 in Sweden. The median age at operation was nine years old. Hypertrophy of tonsils and adenoids (59%) was the most common underlying diseases, followed by chronic tonsillitis and adenoiditis (26.7%) and sleep disordered breathing (3.5%).
From the total of 33 specific autoimmune diseases were examined in this study; 16 of them showed an increased incidence, whereas none of them showed a decreased incidence. A total of 5357 patients were subsequently diagnosed with autoimmune diseases after the tonsillectomy, giving an overall Standardized incidence ratios (SIR) of 1.34. The risk of autoimmune diseases was not different for men and women, with an exception of Hashimoto/hypothyroidism and Sjogren’ssyndrome. SIR for Hashimoto thyroiditis for male is 1.99 and for female 1.50.
The risk of autoimmune diseases was further analysed by the underlying indications of tonsillectomy. The overall risk of autoimmune diseases was 1.36 for chronic tonsillitis and adenoiditis, 1.27 for hypertrophy of tonsils and adenoids, 1.34 for sleep disordered breathing, and 1.50 for other indications. For specific diseases, the incidence of Hashimoto/hypothyroidism and rheumatoid arthritis was increased after tonsillectomy due to all indications. Some diseases, such as Crohn’s disease, Graves’/hyperthyroidism, Hashimoto/hypothyroidism, psoriasis, and rheumatoid arthritis, showed an increased incidence after tonsillectomy at different ages.
Immune dysfunction due to tonsillectomy may partly explain the association between tonsillectomy and autoimmune diseases. As recent evidence suggests tonsils might be the reservoir of T cells outside of thymus. However, future studies are needed to further explain the underlying mechanisms.
Have you had your tonsils removed? If yes, let us know below if you see any relation between tonsillectomy and the occurance of your autoimmune condition?
Bitar, M. A., Dowli, A., & Mourad, M. (2015). The effect of tonsillectomy on the immune system: A systematic review and meta-analysis. International Journal of Pediatric Otorhinolaryngology, 79(8), 1184-1191. doi:10.1016/j.ijporl.2015.05.016
Ji, J., Sundquist, J., & Sundquist, K. (2016). Tonsillectomy associated with an increased risk of autoimmune diseases: A national cohort study. Journal of Autoimmunity, 72, 1-7. doi:10.1016/j.jaut.2016.06.007
Leavy, O. (2012). Tonsils turn out T cells too. Nature Reviews Immunology, 12, 232. doi:10.1038/nri3196