Added Value of Fecal Calprotectin to Support the Diagnosis of Spondyloarthropathies

The clinical utility of faecal calprotectin in patients with differentiated and undifferentiated spondyloarthritis: Relevance and clinical implications

“…26 In our study we found that the mean FCP level (g/g) was significantly higher in the SpA group when compared to USpA and to normal control subjects (p < 0.001). In accordance with our results, Kopylov et al 19 and Van Hoovels et al 27 reported significantly higher FCP levels in the SpA group versus the non-SpA group. Moreover in our study we demonstrated significantly higher FCP levels in UC and CD patients compared to other SpA subgroup of patients and USpA (p < 0.001).…”

“…The area under the curve did not differ significantly among assays, but there was a significant difference in sensitivity and specificity for SpA when the manufacturer's cut-offs of different assays were applied. 27 It appears that GIT inflammation may occur in patients with SpA including the clinically evident well differentiated IBD in the form of either CD or UC and that others display a subclinical gut inflammation despite the absence of signs and symptoms of IBD. Such subclinical gut inflammation in patients with SpA, is apparently driven by intestinal dysbiosis, dysregulating the intestinal epithelial barrier, especially in human leucocyte antigen (HLA-B27) positive patients.…”

“…An ROC analysis was performed in our study to reveal the most diagnostic performance levels for the different FCP assays in our studied groups of patients. When the manufacturer's cut-off (50 g/g) was applied, the sensitivity was 66.7%, specificity was 17.3%, positive predictive value (PPV) 39.3%, negative predictive 27 A ROC analysis was performed to reveal the diagnostic performance for the different FCP assays for SpA. The area under the curve did not differ significantly among assays, but there was a significant difference in sensitivity and specificity for SpA when the manufacturer's cut-offs of different assays were applied.…”

Dr. Seidman replies

“…We are pleased to note the interest that Van Hoovels and colleagues have for our SpACE Capsule study 1 , and read with interest their investigation of the clinical utility of assaying fecal calprotectin (FC) to assist in the diagnosis of spondyloarthritis (SpA) 2 . Rheumatologists traditionally proclaim that the extraarticular manifestations of SpA include inflammatory bowel disease (IBD) 3 .…”

“…Moreover, there are concerns regarding the potential to overdiagnose axial spondyloarthritis (axSpA). In the Van Hoovels study, the final diagnosis of SpA was based on expert opinion 2 . Recently, Ez-Zaitonie, et al 8 prospectively investigated whether patients presenting with chronic back pain (CBP) of short duration and many SpA features are uniformly diagnosed with axSpA by the rheumatologist, and to what extent fulfillment of the Assessment of Spondyloarthritis international Society (ASAS) axSpA criteria is associated with an axSpA diagnosis.…”