Fig. 4.

Differential serum levels of five FPR ligands, including serum amyloid A (SAA), cathelicidin (LL-37), annexin A1 (ANXA1), lipoxin A4 (LXA4), and resolving D1 (RvD1), in COPD patients. a The COPD patients at presentation had significantly lower serum ANXA1 levels, which remained at low levels after 1-year medical treatment. Serum ANXA1 levels were b positively correlated with FPR2 expression on T helper cells, c positively correlated with FPR3 expression of natural killer cells, d negatively correlated with the percentage of M1 monocyte, and e positively correlated with the percentage of M2a monocyte. f The COPD patients with a history of more than 1 moderate exacerbation in the past 1 year had significantly lower serum ANXA1 levels as compared with that in those without the history or the healthy subjects. g Serum LXA4 levels showed significant reduction and h RvD1 showed elevation after 1-year medical treatment. *p < 0.01 for comparison between COPD patients with a specific phenotype and healthy non-smokers by ANOVA test. ^#p < 0.05 for comparison between COPD patients with and without s specific phenotype by ANOVA test