Role of serum calprotectin in diagnosis of inflammatory bowel diseases in patients with ankylosing spondylitis (preliminary results)

Abstract

Background. Patients with inflammatory bowel diseases (IBD) often have lesions of the musculoskeletal system, which is an extra-intestinal manifestation and mainly belongs to the group of seronegative spondyloarthritis (SPA). Ankylosing spondylitis (AS) is one of the main forms of diseases from the group of spondyloarthritis, associated with IBD. The frequency of AS in patients with IBD is of interest for elucidating the general pathophysiology of diseases. Colonoscopy is required to diagnose intestinal pathology. Colonoscopy in patients with AS to detect IBD, especially in the absence of intestinal symptoms, is very diffcult. Mainly for the diagnosis of IBD, the defnition of fecal calprotectin is used. Recently, there has been an interest in serum calprotectin, an increase in which is associated with a higher activity of the disease and is a marker of the intensity of inflammation in the intestine. However, there is currently no consensus on the clinical signifcance for serum calprotectin.The aim. To evaluate the role of serum calprotectin in diagnosis of inflammatory bowel disease in patients with ankylosing spondylitis.Materials and methods. In the analysis were included 50 patients with AS, fulflling the modifed New York criteria, among them were 36 (72%) men and 14 (28%) women, the mean age of patients was 42.5 ± 9.9, mean disease duration was 13.4 ± 8.7 years. All patients were examined with ESR, CRP, FC (range: 100–1800 µg/g), esophagogastroduodenoscopy, colonoscopy and quantitative analysis of the SC level using ELISA (Buhlmann MRP8/14 ELISA, range: 0.4–3.9 µg/ml).Results. All patients had a high disease activity, mean BASDAI was 5.3 ± 1.8, mean ASDAS CRP was 3.7 ± 1.01, mean ASDAS ESR was 3.6 ± 1.01. 78% patients had high FC level (more than 100 µg/g), while only 18% patients had an increase of SC level. IBD were diagnosed in 11 cases: 6 (12%) patients with CD and 5 (10%) patients with UC, in the remaining cases (78%) was no intestinal pathology. Only two patients with IBD had a high SC level. SC level was more correlated with ESR (r = 0.5) and CRP (r = 0.5) (p < 0.05) levels, than with FC level (r = 0.4) (p < 0.05).Conclusion. The results have shown that there was currently insuffcient data to assess the possibility of using SC in the diagnosis of IBD in patients with AS. There was a signifcant association between the SC, CRP and ESR, but not fecal calprotectin. Potentially SC may be more representative for systemic inflammation than intestinal inflammation.