Accuracy of Helicobacter pylori serology in two peptic ulcer populations and in healthy controls

Figure 1 Receiver operating characteristic (ROC) curve for different cut-off values for H pylori IgG antibodies in vagotomized or medically treated peptic ulcer patients and in community controls. Cut-off values were 200, 300, 500, 600 and at intervals of 300 for IgG values above 600 to 4800. TRP = True positive rate (sensitivity), FPR = False positive rate (1-specificity). A: Cut-off 200; B: Cut-off 300; C: Cut-off 500.

Figure 2 Grade of inflammatory activity (no, mild, moderate, severe), grade of chronic gastritis (no, mild, moderate, severe) and semiquantitative numbers of H pylori (no, few = H pylori like organisms in 1-3 pits, some = H pylori like organisms in more than 3 pits but not all, many = H pylori like organisms in all pits) detected in gastric biopsies from 4 different biopsy sites (prepylorus, angulus, corpus and fundus) related to the mean value with 95% confidence intervals of IgG antibodies against H pylori in each category.

Figure 3 Subjects with peptic ulcer related to level of H pylori IgG antibodies. Frequencies are shown with 95% CI.