The relationship of serum vitamins A, D, E and LL-37 levels with allergic status, tonsillar virus detection and immune response

<div><p>Background</p><p>Tonsils have an active role in immune defence and inducing and maintaining tolerance to allergens. Vitamins A, D, and E, and antimicrobial peptide LL-37 may have immunomodulatory effects. We studied how their serum levels were associated with allergy status, intratonsillar/nasopharyngeal virus detection and intratonsillar expression of T cell- and innate immune response-specific cytokines, transcription factors and type I/II/III interferons in patients undergoing tonsillectomy.</p><p>Methods</p><p>110 elective tonsillectomy patients participated. Serum levels of vitamins A, 25(OH)D, and E, LL-37 and allergen-specific IgE as well as nasopharyngeal/intratonsillar respiratory viruses were analyzed. The mRNA expression of IFN-α, IFN-β, IFN-γ, IL-10, IL-13, IL-17, IL-28, IL-29, IL-37, TGF-β, FOXP3, GATA3, RORC2 and Tbet in tonsils were analyzed by quantitative RT-PCR.</p><p>Results</p><p>The median age of the patients was 16 years (range 3–60), 28% of subjects had atopy, and 57% carried ≥1 respiratory virus in nasopharynx. Detection of viruses decreased by age. Higher vitamin A levels showed borderline significance with less viral detection (<i>P</i> = 0.056). Higher 25(OH)D was associated with less allergic rhinitis and atopy (<i>P</i> < 0.05) and higher vitamin E with less self-reported allergy (<i>P</i> < 0.05). In gene expression analyses, 25(OH)D was associated with higher IL-37, vitamin A with higher IFN-γ and vitamin E with less IL-28 (<i>P</i> < 0.05). LL-37 was associated with less FOXP3, RORC2 and IL-17 in tonsils (<i>P</i> < 0.05).</p><p>Conclusions</p><p>Vitamin D and E levels were associated with less allergic disorders. Vitamin A was linked to antiviral and vitamin D with anti-inflammatory activity. LL-37 and was linked to T regulatory cell effects.</p>