CXCL8 and alkaline phosphatase measurement: Numerous studies have revealed the types of substances that are elevated in the PAAF of SAP patients and in the animal model of AP [23], including adipokines [24]; proteases [25, 26]; cytokines, such as interleukin (IL)-1β [27], IL-6 [28] and IL-8 [29]; and lipid metabolites, such as TG and FFA [5, 7, 30, 31].