Fig 1.
Overview of available samples in the study.
UC: patients with ulcerative colitis; NC: normal controls. Abbreviations: UC: Ulcerative Colitis; NC: Normal Controls; ROC: Receiver operating characteristic; SJG; Scandinavian Journal of Gastroenterology.
Table 1.
Available samples and key metadata in the different analyses.
Fig 2.
Calprotectin was measured in 51 sets of 2 fecal samples collected within 1 week from each participant. Samples were extracted and run on both calprotectin assays. Values were then ln transformed. Panels A and B show scatterplots of the two samples for both assays. Dashed line is line of identity. Panels C and D show Bland-Altman plots of the same samples.
Fig 3.
One-hundred-eightysix samples measured with both assays. Panel A shows the raw data. Below 1000 there is a fairly linear correlation, but in the higher range the Calprest assay measures higher values than Calpro. After ln transformation of the raw data, a significant linear trend can be seen in panel B. Dashed line is line of identity.
Fig 4.
Analysis of 186 samples measured with both assays. The raw data in panel A shows shifting bias along the x-axis. This tendency is confirmed in the Bland-Altman plot of ln transformed raw data in panel B. Three sections with distinct bias pattern can be defined: calprotectin values <200; values in the interval 200–1000; and values >1000. Bland-Altman plots with mean bias and limits of agreement of each of these segments are presented in panel C.
Fig 5.
Prediction of endoscopic inflammatory activity. Panel A: Mucosal healing defined by Mayo endoscopic subscore (MES) = 0 by calprotectin (actual state: positives 42; negatives 62). Panel B: Significant inflammatory activity defined by MES 2–3 by calprotectin (actual state: positives 25; negatives 79). Panel C: Normalized mucosal TNF gene expression (<7500 copies/ug total RNA) by calprotectin (actual state: positives 27; negatives 69). Panel D: Normalized TNF gene expression (<7500 copies/ug total RNA) by the sum of calprotectin and MES (both standardized by ln transformation and division with the maximal scale value). For all plots: blue curve for Calprest; red curve for Calpro.