Fig. 2

ROC curve for total AGEs, sRAGE levels and Ages/sRAGE ratio. a AGEs and sRAGE showed a good capability to differentiate between IPF patients and fNSIP group (AUC = 0.879 and 0.801, respectively), whereas the AGEs/sRAGE ratio had higher predictable capability (AUC 0.987, CI = 0.959–1.000) to discriminate between both. b Comparing cHP and fNSIP, all the three indicators (AGEs, sRAGE levels and AGE/sRAGE ratio) showed AUC values quite good to be considered diagnostic tests (AGEs = 0.883, sRAGE = 0.887, Ratio = 0.882). Data were evaluated by ROC analyses; blood serum levels of AGE and sRAGE were considered as a continuous variable, and the diagnostic classification was accepted as a dichotomous variable