I can't remember which book I read it in, but no, it wasn't about the focal infection, but rather the inflammation markers. Inflammation changes blood chemistry (blood cell mix, the "stickiness," and other chemical markers) and there's good reason to believe there's no such thing as "local" inflammation when it's an internal organ (vs, say, a rash on your elbow). And like circulating hormones in response to a grievous injury, these changes can cause a cascade effect.