Study finds previous removal of the tonsils and adenoids associated with 63% higher odds of pediatric-onset multiple sclerosis and a two-fold increase in annualized relapse rate
A history of adenotonsillectomy was associated with increased odds of developing pediatric-onset multiple sclerosis (POMS) and a higher annualized relapse rate among children with the disease, according to a study published in the Multiple Sclerosis Journal.
The researchers found that children with a previous history of adenoidectomy and/or tonsillectomy had 63% higher adjusted odds of POMS compared with pediatric controls. Among children already diagnosed with POMS who had longitudinal follow-up data, previous adenotonsillectomy was also associated with approximately twice the annualized clinical relapse rate.
The findings suggest a possible relationship between adenotonsillar tissue, immune regulation, Epstein-Barr virus (EBV), and MS development. However, the observational nature of the study means that the findings demonstrate an association and do not establish that adenotonsillectomy causes multiple sclerosis.
Study Included Children With and Without Pediatric-Onset MS
Researchers led by Gina Chang and colleagues recruited participants from 16 pediatric MS clinics between November 1, 2011, and July 1, 2017.
The case-control analysis included 359 children with POMS and 560 pediatric controls. The researchers collected clinical and demographic information, along with data on previous adenotonsillectomy, EBV serostatus, and the MS-associated genetic risk allele HLA-DRB1*15:01:01.
Multivariable logistic regression was used to examine the association between previous adenotonsillectomy and POMS risk while accounting for potential confounding factors.
Previous Adenotonsillectomy Associated With Higher POMS Odds
The analysis found that children with a history of adenotonsillectomy had significantly higher odds of POMS.
After adjustment for sex, ethnicity, maternal education, HLA-DRB1*15:01 status, body mass index, and anti-VCA-IgG serostatus, the adjusted odds ratio was 1.63 (95% CI, 1.01–2.64; P = 0.046).
This corresponds to a 63% increase in the odds of POMS among those with a history of adenotonsillectomy in the study population.
Adenotonsillectomy Also Associated With Higher Relapse Rate
Researchers additionally examined whether a history of adenotonsillectomy was associated with disease activity among children who already had POMS.
Longitudinal follow-up information was available for 239 POMS participants. After adjustment for age at disease onset, ethnicity, HLA-DRB1*15:01 status, anti-VCA-IgG serostatus, and disease-modifying therapy category, previous adenotonsillectomy was associated with a two-fold increase in annualized relapse rate.
The adjusted incidence rate ratio was 2.00 (95% CI, 1.15–3.48; P = 0.013). The association remained significant in a sensitivity analysis that excluded patients with less than three years of follow-up.
Researchers Investigate Possible Role of EBV and Immune Regulation
Epstein-Barr virus is considered an important environmental risk factor for multiple sclerosis. The tonsils and adenoids are lymphoid tissues that can serve as sites associated with EBV persistence and immune activity.
The researchers proposed that removal of these tissues could potentially influence immune regulation and MS susceptibility or disease activity. However, the study did not establish a causal mechanism, and there was no significant multiplicative interaction between anti-VCA-IgG serostatus and adenotonsillectomy history for either POMS risk or relapse rate.
Study Does Not Establish Adenotonsillectomy as a Cause of MS
The researchers emphasized that the findings should not be interpreted as evidence that adenotonsillectomy causes multiple sclerosis.
The study was observational and examined previous surgical history in relation to disease risk and activity. Although the statistical models adjusted for several potential confounding factors, other unmeasured factors could still contribute to the observed association.
Therefore, further research is required to determine whether the relationship reflects a causal biological mechanism, shared risk factors, or other factors associated with both adenotonsillectomy and MS.
Findings May Guide Future Neuroimmunology Research
The study adds to research examining the relationship between childhood immune-system exposures, EBV, and pediatric-onset multiple sclerosis.
The association between previous adenotonsillectomy and both POMS risk and relapse rate provides a basis for further investigation into how lymphoid tissue, immune regulation, and environmental factors may interact in MS.
Prospective studies will be needed to clarify the biological mechanisms and determine whether adenotonsillectomy itself has any causal role in the development or progression of pediatric-onset multiple sclerosis.
Important Highlights
- Previous adenotonsillectomy was associated with 63% higher adjusted odds of pediatric-onset multiple sclerosis.
- The case-control analysis included 359 POMS patients and 560 pediatric controls.
- Among 239 POMS patients with longitudinal follow-up, adenotonsillectomy was associated with a two-fold higher annualized relapse rate.
- The adjusted odds ratio for POMS was 1.63 (95% CI, 1.01–2.64; P = 0.046).
- The adjusted incidence rate ratio for annualized relapse was 2.00 (95% CI, 1.15–3.48; P = 0.013).
- The findings suggest a possible relationship involving EBV, adenotonsillar tissue, and immune regulation, but the study does not establish that adenotonsillectomy causes MS.
