CRP and its subtypes have been known since 1930 as markers of acute inflammation such as following disease or injury. The measurement of chronic systemic inflammation is more difficult, because it involves lower levels of the biomarkers. So for example CRP levels increase by a factor of thousands when there is an infection, but in chronic systemic inflammation are elevated much more subtly. I don't know a great historical review but this "Nature Perspective" from 2019 seems pretty good:

https://zellavie.ch/wp-content/uploads/2020/06/Nature-Medici...