Calprotectina fecal como biomarcador para a avaliação da cicatrização da mucosa em pacientes com retocolite ulcerativa idiopática

Abstract

In the follow-up of patients with idiopathic ulcerative colitis (UC), the ideal therapeutic target capable of modifying the course of the disease is the healing of the mucosa, even though there is still no consensus whether only endoscopic, histological remission or both. However, it is still necessary to perform colonoscopy or sigmoidoscopy, which are expensive, invasive and time-consuming procedures for repeated assessments of disease activity. Fecal calprotectin (FC) is a biomarker that is strongly associated with clinically active disease. However, it is not clear whether it is capable of definitively replacing these invasive methods in monitoring patients in clinical remission. As well as a cut off capable of predicting endoscopic and/or histological remission has not yet been defined. The objectives of this study were to study the association of FC in patients with UC in clinical remission with the Mayo endoscopic and Geboes histological activity scores and suggest a cut off for FC that best relates to endoscopic and histological remission and activity. Methods: cross-sectional study with prospective entry of patients with UC in clinical remission using the Simple Clinical Colitis Activity Index (SCCAI). All participants underwent colonoscopy or sigmoidoscopy with biopsies and FC measurement. Results: 114 patients with UC in clinical remission were selected and 34 patients were excluded because they did not meet all the inclusion criteria. Total of 80 patients included in the study. The FC showed no association with the SCCAI. FC concentrations were not significantly different between endoscopic sub scores when considering patients with disease in endoscopic remission compared with those with endoscopically active disease (P = 0.099). FC showed a significant association with the histological score (P <0.001). The area under the ROC curve of FC to distinguish histological remission activity was 0.806 (95% CI, 0.709-0.903). Considering the criterion of deep remission (combined endoscopic and histological scores), FC measurements showed a statistically significant difference between remission and activity (P = 0.025). The area under the ROC curve of the FC to distinguish deep remission activity was 0.741 (95% CI, 0.630-0.851). FC <100 μg/g showed correlation with endoscopic (sensitivity 81.5%), histological (sensitivity 91.7%) and profound (sensitivity 82.4%) remission, with negative predictive values (NPV) of 85.3% (95% CI = 69.9-93.6), 94.1% (95% CI = 80.9-98.4) and 82.4 (95% CI = 66.5-91.6), respectively . Conclusion: FC has a good association with histological activity and the cut off <100 μg/g can be used as an isolated and non-invasive method to predict histological remission in those patients in clinical remission. Values above 100 μg/g, due to the low association with activity indexes, should not be used as an isolated method for monitoring these patients.