The histological changes in cardiovascular syphilis are primarily driven by the immune response to the Treponema pallidum bacterium. The infection triggers a chronic inflammatory response, which leads to the recruitment of immune cells to the site of infection. Over time, this persistent inflammation causes significant tissue damage and scarring. Another important factor is the direct invasion of the blood vessel walls by the spirochetes. This can further exacerbate the inflammatory response and contribute to the structural changes observed in the affected vessels.
