Specific strains of Streptococcus mutans, a pathogen of dental caries, in the tonsils, are associated with IgA nephropathy.

ABSTRACT: Streptococcus mutans is known to be a major causative agent of dental caries, and strains expressing the cell surface collagen-binding Cnm protein contribute to the development of several systemic diseases. A relationship between tonsillar immunity and glomerulonephritis has been recognized in IgA nephropathy (IgAN), and specific pathogens may have effects on tonsillar immunity (mucosal immunity). Here, we present findings showing a relationship between the presence of Cnm-positive S. mutans strains in the tonsils of IgAN patients and IgAN condition/pathogenesis. Analyses of tonsillar specimens obtained from patients with IgAN (n?=?61) and chronic tonsillitis (controls; n?=?40) showed that the Cnm protein-positive rate was significantly higher in IgAN patients. Among IgAN patients, the tonsillar Cnm-positive group (n?=?15) had a significantly higher proportion of patients with high urinary protein (>1.5?g/gCr) and lower serum albumin level than the Cnm-negative group (n?=?46). Additionally, Cnm protein and CD68, a common human macrophage marker, were shown to be merged in the tonsils of IgAN patients. These findings suggest that Cnm-positive S. mutans strains in the tonsils may be associated with severe IgAN.

SUBMITTER: Ito S 

PROVIDER: S-EPMC6934739 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature