When calcium, creatinine and CRP were added into the logistic regression analysis with IL-6 and HGF, calcium was also able to predict severe AP independently (P = 0.023), as were IL-6 (P = 0.025) and HGF (P = 0.027), but creatinine (P = 0.86) and CRP (P = 0.45) were not. Here, IL6 is linked to alkaline phosphatase measurement.