The of COPD: or balancing repair (yang) and inflammation (yin)

Ancient Chinese scholars believed there were two natural, complementary and contradictory forces in our universe: yin and yang (or in simplified Chinese ![Graphic][1] , in traditional Chinese ![Graphic][2] , and in pinyin (standard Mandarin romanisation) yīnyáng). Yin represents the female, negative aspects, darkness, softness, moisture, night-time, even numbers, and docility. Yang represents the male, positive aspects, brightness, hardness, dryness, day-time, odd numbers, and dominance. Yin and yang are continually in a state of flux and always looking for a balance point. One moves, the other responds. Ancient scholars therefore treated this phenomenon as a natural universal law. In this issue of the European Respiratory Journal ( ERJ ), Man et al. 1 hypothesise that a ratio of fibronectin to C-reactive protein (CRP) is a more suitable tool than each separated biomarker to assess the prognosis of chronic obstructive pulmonary disease (COPD). Using the Lung Health Study III data 2, they updated (and improved on) their previous research on CRP only 3. It appears that in this well-described group of mild-to-moderate COPD patients, the relationship of the log transformed ratio of fibronectin to CRP (both in ug·mL−1) and mortality is L shaped, … [1]: /embed/inline-graphic-2.gif [2]: /embed/inline-graphic-3.gif