Endoscopy was not performed in our study. The key issue for the clinician is to evaluate whether MI is present or not. In clinical practice, the patient population is more heterogeneous, presenting with different levels of symptoms and disease activity. These publications have studied homogeneous patient groups (only UC or CD, only active or inactive disease). The median CV in this study was 40%, and the sample from the first bowel movement in the morning obtained the highest f-calprotectin value in only one-third of the cases. studied f-calprotectin variability in 18 UC patients, the majority having extensive colitis and severe disease activity, providing faeces samples from up to four bowel movements from the same day. Because f-calprotectin increased with increasing interval between the bowel movements, the authors found it more appropriate to analyse samples from the first bowel movement of the day. Most f-calprotectin values were though high and the differences of minor clinical importance in two-thirds of the patients. The authors found large intra-individual variability both during the day (median CV 52%) and from one day to the next (median CV 40.8%). have studied f-calprotectin diurnal and day-to-day variability in 18 UC patients with active disease verified by endoscopy. However, a similar study found low day-to-day variability in clinically quiescent CD. Significant day-to-day variability of f-calprotectin in CD patients with mild to moderate clinical disease activity has previously been described. In this study, we found high intra-individual f-calprotectin variability within IBD patients, demonstrated by a high CV (mean 39.4%) from three samples obtained from bowel movements morning – evening – morning. The laboratory technician informed that one sample (number 7) seemed heterogeneous and was difficult to extract. In Figure 5, we present f-calprotectin results from all four extraction methods used in the group of 19 patients providing both conventional faeces sample and home extracted faeces samples. Figure 4 demonstrates the distribution of f-calprotectin results from the 10 Calex extracts compared to the reference method. The Roche device was used as reference method. We further evaluated how the Calex device performed in loose and watery faeces samples.
Passing Bablok regression equation using extraction with Roche device as method x and Calex device as method y, resulted in a slope of 1.19 (95% CI 1.00–1.51) and an intercept of 1.89 (95% CI 14.58–28.07). Figure 3(b) demonstrates a difference plot of the two extraction methods. Spearman’s rank correlation coefficient was 0.95 ( p 5 0.001). Figure 3(a) shows the correlation between f-calprotectin values from the 50 first morning samples extracted with Roche device and Calex device performed by a laboratory technician. Cut-off level 259 m g/g is chosen from our previous work. Table 2 shows the reliability of detecting MI from day to day, and from morning to evening, calculated by kappa statistics. Although intra-individual variation in f-calprotectin levels occurs, neither the diurnal variation ( p 1⁄4 0.78) nor day-to-day variation ( p 1⁄4 0.096) was significant. Figure 2 shows scatterplots of the f-calprotectin values from the first morning sample compared with the second morning sample (Figure 2a) and the evening sample (Figure 2b). The mean CV of the morning – evening – morning f-calprotectin samples from each patient was 39.4% (95% CI 31.1%–47.7%). The mean CV of the duplicated f-calprotectin analyses was 3.4% (95% confidence interval (CI) 2.5%–4.5%).
Baseline characteristics of included patients are presented in Table 1. From the remaining 19 sets of samples, we evaluated feasibility of home-based extraction.
Three patients did not receive a conclusive diagnosis of IBD and were excluded.
In the second part of the study, 22 patients provided two faeces samples from the same bowel movement one sampled with the Calex device and one conventional sampling tube. The analysis therefore included 50 patients with complete set of samples. Thirty-one patients failed to return some of or all of the samples and were excluded. A total of 81 patients were included in this first part of the study. From these samples we evaluated the intra-individual f- calprotectin variability and performed method comparison for laboratory use of the Calex device. first part of the study included patients providing faeces samples taken morning – evening – morning.
0 kommentar(er)
