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Abstract: SA-PO951

Cnm-Positive Streptococcus mutans, a Major Pathogen of Dental Caries, May Cause IgA Nephropathy via Tonsils

Session Information

Category: Glomerular Diseases

  • 1402 Glomerular Diseases: Clinical, Outcomes, and Trials


  • Misaki, Taro, Division of Nephrology, Seirei Hamamatsu General Hospital, Hamamatsu, Japan
  • Naka, Shuhei, Okayama Daigaku, Okayama, Okayama, Japan
  • Nagasawa, Yasuyuki, Hyogo Ika Daigaku, Nishinomiya, Hyogo, Japan
  • Matsuoka, Daiki, Okayama Daigaku, Okayama, Okayama, Japan
  • Ito, Seigo, Japan Self-Defense Iruma Hospital, Iruma, Japan
  • Matayoshi, Saaya, Osaka Daigaku, Suita, Osaka, Japan
  • Nomura, Ryota, Hiroshima Daigaku, Higashihiroshima, Hiroshima, Japan
  • Matsumoto-Nakano, Michiyo, Okayama Daigaku, Okayama, Okayama, Japan
  • Nakano, Kazuhiko, Osaka Daigaku, Suita, Osaka, Japan

The presence of Streptococcus mutans, a major pathogen of dental caries, expressing Cnm protein encoded by cnm in the oral cavity has been associated with the pathogenesis of IgA nephropathy (IgAN). Although tonsillectomy is applied for the treatment of IgAN, its effectiveness in the patients harboring cnm-positive S. mutans in the oral cavity is not clear.
This study aimed to investigate the effects of tonsillectomy on patients with IgAN who harbor cnm-positive S. mutans in the oral cavity.


The presence of cnm-positive S. mutans was analysed by polymerase chain reaction in saliva specimens from 117 patients with IgAN. The patient's history of tonsillectomy was examined, and they were divided into four groups based on the results of cnm-positive S. mutans detection and tonsillectomy history: group A (n=52) (tonsillectomy (-), cnm-positive S. mutans (-)); group B (n=35) (tonsillectomy (+), cnm-positive S. mutans (-)); group C (n=16) (tonsillectomy (-), cnm-positive S. mutans (+)), and group D (n=14) (tonsillectomy (+), cnm-positive S. mutans (+)). The subjects’ clinical parameters were analysed.


The proportion of patients with an estimated glomerular filtration rate <60 mL/min was significantly higher in group C than the other groups (p < 0.0083). The proportion of proteinuria 2+ or higher was significantly higher in group C than the other groups (p < 0.0083). In the cnm-positive S. mutans (+) groups, serum IgA was significantly lower in tonsillectomy group than in non-tonsillectomy group (266.9mg/dl vs 358.9mg/dl, p < 0.05).


These results suggest that the exacerbation of IgAN by cnm-positive S. mutans may be mediated by the tonsils and tonsillectomy may be effective in patients with IgAN who harbor cnm-positive S. mutans in the oral cavity.