Oral Mucosal Immunity — ORE Part 1 MCQ

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ModerateDental Public Health & EpidemiologyOral Mucosal ImmunityORE Part 1

Which immunoglobulin is predominantly found in saliva and plays a key role in mucosal immunity of the oral cavity?

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Correct answer: B — Secretory IgA (sIgA)

Secretory IgA (sIgA) is the most abundant immunoglobulin in saliva and the primary mediator of oral mucosal immunity. It is actively synthesized by plasma cells in the stroma of salivary glands and transported across the epithelium by the polymeric Ig receptor, where it prevents microbial colonization and epithelial invasion. While IgG is also present in saliva, it is primarily derived from passive leakage via gingival crevicular fluid rather than active local production. IgM, IgE, and IgD are either absent or play no documented role in salivary/mucosal immunity of the oral cavity.

Reference: Proctor GB. Chewing stimulates secretion of human salivary secretory immunoglobulin A. J Dent Res. 2001;80(10):1909-1913. https://pubmed.ncbi.nlm.nih.gov/11379894/