Cross‐reactive saliva IgA antibodies to oxidized LDL and periodontal pathogens in humans

• DOI: 10.1111/jcpe.12748
• Publication Date: 2017-05-26T09:52:41Z
• Authors: Ramin Akhi; Chunguang Wang; Mikael Kyrklund; Outi Kummu; Sini Pauliina Tur...; Kati Hyvärinen; Arja Kullaa; Tuula Salo; Pirkko J. Pussinen; Sohvi Hörkkö
• Keywords: Adult; Male; 0303 health sciences; Cross Reactions; Aggregatibacter actinomycetemcomitans; Healthy Volunteers; Immunoglobulin A; Lipoproteins, LDL; 03 medical and health sciences; Immunoglobulin M; Immunoglobulin G; Malondialdehyde; Luminescent Measurements; Humans; Female; Saliva; Porphyromonas gingivalis; Periodontal Diseases

AbstractAimOxidized low‐density lipoproteins (oxLDL) are formed as a result of lipid peroxidation and are highly immunogenic and proatherogenic. In this study, saliva antibodies binding to oxLDL, Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa) were characterized and their cross‐reactivity was evaluated.Materials and MethodsResting and stimulated saliva samples were collected from 36 healthy adults (mean age 26 years). Saliva IgA, IgG and IgM autoantibody levels to copper oxidized LDL (CuOx‐LDL) and malondialdehyde acetaldehyde‐modified LDL (MAA‐LDL) were determined with chemiluminescence immunoassay.ResultsSaliva IgA and IgG antibodies binding to MAA‐LDL and CuOx‐LDL were detected in all samples and they were associated with the saliva levels of IgA and IgG to P. gingivalis and A. actinomycetemcomitans. Competitive immunoassay showed that saliva antibodies to MAA‐LDL cross‐reacted specifically with P. gingivalis. The autoantibody levels to oxLDL in saliva were not associated with the autoantibody levels to oxLDL in plasma or with saliva apolipoprotein B 100 levels.ConclusionsSaliva contains IgA and IgG binding to oxLDL, which showed cross‐reactive properties with the periodontal pathogens Porphyromonas gingivalis (P.g). The data suggest that secretory IgA to P.g may participate in immune reactions involved in LDL oxidation through molecular mimicry.