MPO and Sepsis: By immunohistochemistry and immunofluorescence methods, we found that myeloperoxidase expression significantly increased in sepsis on day 1 (Figures 2A, B), higher levels of CCL5 occurred at the plasma level as early as 12 h post-sepsis, and CCL5 mRNA levels increased in parallel with those in the muscularis (Figures 2C, D).