The Effect of Tonsillectomy on the Salivary Immune Factors: A Systematic Review and Meta-Analysis

Abstract

Background & objectives: The effect of tonsillectomy on the immune system is a controversial issue. The debate is largely based on contradictory findings in the literature. However, it is unlikely for tonsils to produce a negative systemic effect and it is more logical to think about a local effect that can be transient or long lasting. The aim of this systematic review is to analyze the observed changes in salivary immune factors following tonsillectomy and understand their clinical significance. Materials & methods: Systematic review of the English literature was performed using Medline, Embase and Cochrane. We used the terms tonsillectomy, adenotonsillectomy, humoral immunity, immune system, saliva in various combination to look for pertinent studies. We excluded duplicate publications, reviews and studies that did not analyze salivary immune factors. Results: Thirty four manuscripts studied the effect of tonsillectomy on the immune system. Only 9 of them (including 585 patients) looked at the effect on salivary immune factors. All studies analyzed the effect on salivary Immunoglobulin (Ig) A, four of them studied additional factors such as other salivary Ig’s, anti-microbial proteins (lactoferrin, peroxidases, lysozyme), anti-viral and anti-bacterial Ig’s. One study showed a significant decrease in salivary IgA, another showed a decrease in salivary IgG and a third showed a decrease in salivary IgM, lactoferrin and antimicrobial salivary IgG. Two studies had non-conclusive concerns regarding the observed changes in salivary immune factors, the third study recommended measuring salivary IgA pre and postoperatively. Only 11.1% of the studied patients had on the short term, a significant decrease in SecIgA level that can be attributed to tonsillectomy. Conclusion: Tonsillectomy does not seem in general to negatively affect the host’s salivary immune defenses. The concerns raised are based on a partial apparent down-regulation of the some of the salivary immune components. More longitudinal studies are needed to really understand the clinical effect of any observed change in the salivary immune system.