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Abstract: FR-PO838

Aberrant Immune Response to Periodontopathic Microbiota in Patients with IgA Nephropathy

Session Information

Category: Glomerular Diseases

  • 1202 Glomerular Diseases: Immunology and Inflammation

Authors

  • Yamaguchi, Hiroki, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
  • Goto, Shin, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
  • Tsuchida, Masafumi, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
  • Watanabe, Hirofumi, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
  • Yamamoto, Suguru, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
  • Kaneko, Yoshikatsu, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
  • Narita, Ichiei, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
Background

Aberrant mucosal immune response is implicated in terms of the multi-hit theory of IgA nephropathy (IgAN) development, however, microbiota responsible for pathogenic IgA production in IgAN remained obscure. We have focused until now on roles of microbiome in tonsillar crypts, considering efficacy of tonsillectomy for the treatment of IgAN. To reveal distinct immune responses in IgAN patients, we studied the binding ability of serum IgA against anaerobic bacteria in tonsillar crypts and its relationship with galactose-deficient IgA1 (Gd-IgA1).

Methods

We enrolled 30 biopsy-proven IgAN patients treated with tonsillectomy. Seven recurrent tonsillitis patients who had no urine abnormalities as control. Serum of enrolled patients were fractionated with high-performance liquid chromatography, and the levels of Gd-IgA1 in each fraction were determined by ELISA using KM55 monoclonal antibody. Then, we quantified the binding of each fractionated IgA against bacteria anaerobically cultured from tissues of tonsillar crypts of IgAN patients (Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium intermedia, well known as periodontopathic bacteria, and Escherichia coli as control) using flowcytometry.

Results

The serum levels of Gd-IgA1 in IgAN patients were significantly higher than RT patients (P < 0.01). In fractionated serum, Gd-IgA1 levels in polymeric IgA fraction of IgAN patients were significantly higher than those of RT patients (P < 0.05), but not in monomeric IgA fraction. Polymeric IgA of IgAN patients were more bound to both Porphyromonas gingivalis and Prevotella intermedia than those of RT patients. The amounts of polymeric IgA bound to Porphyromonas gingivalis were significantly correlated with the levels of Gd-IgA1 in polymeric IgA fraction of IgAN patients (P < 0.01).

Conclusion

Patients with IgAN exhibit perturbed immune response against periodontopathic microbiota.