Periodontitis in ischemic stroke: impact of Porphyromonas gingivalis on thrombus composition and ischemic stroke outcomes

Background: Periodontitis is associated with an increased risk of ischemic stroke, but the mechanisms underlying this association remain unclear. Objectives: Our objective was to determine whether Porphyromonas gingivalis (Pg), a periodontal bacterium, could be detected within thrombus aspirates, modify thrombus composition, and endovascular therapy responses. Methods: The presence of Pg gingipain in 175 consecutive thrombi from patients with large vessel occlusion stroke enrolled in the multicenter research cohort compoCLOT was investigated by immunostaining. Thrombus blood cell composition according to gingipain status was analyzed in a subset of 63 patients. Results: Pg gingipain immunostaining was positive in 33.7% of thrombi (95% CI, 26.7%40.8%). The percentage of near to complete reperfusion (modified Thrombolysis in Cerebral Infarction Score 2c/3) at the end of the procedure was lower in the Pg(pos) group than the Pg(neg) group (39.0% vs 57.8% respectively; adjusted odds ratio, 0.38; 95% CI, 0.19-0.77). At 3 months, 35.7% of patients in the Pg(pos) group had a favorable neurological outcome vs 49.5% in the Pg(neg )group (odds ratio, 0.65; 95% CI, 0.30-1.40). Quantitative analysis of a subset of 63 thrombi showed that neutrophil elastase content was significantly (P < .05) higher in Pg(pos) thrombi than in Pg(neg) thrombi. Conclusion: Our results indicate that intrathrombus Pg gingipain is associated with increased neutrophil content and resistance to endovascular therapy.