CD79A and gingivitis: Pussinen et al. (2007) have shown that periodontal pathogen Porphyromonas gingivalis may particularly associate with stroke by showing in their material that IgA-seropositive men to this bacterium had an OR of 3.31 (1.31–8.40) for stroke.[25] Microbiology of gingivitis, however, is different.[26]