Investigation of asymptomatic intestinal inflammation in ankylosing spondylitis patients by assessing the levels of fecal calprotectin

At the present time there are multiple evidences of coexisting subclinical intestinal inflammation in Ankylosing Spondylitis (AS) but its etiopathogenic and clinical significance is still unknown. Many researchers agree that there is a high prevelance of subclinical intestinal inflammation in AS. The frequency of subclinical inflammation is not definite because most of the patients are asymptomatic. Most of the researchers established intestinal inflammation with patients history or colonoscopic studies. The relationship between AS and intestinal inflammation is an interesting topic and can help to better understanding of the etiopathogenesis. Firstly we need a simple and reliable method to show that relationship.Fecal calprotectin (FC) is a recent and non-invasive test to identify intestinal inflammation. FC is a promising marker.Rheumatoid arthritis (RA) is an inflammatory rheumatic disease but intestinal inflammation is not connected with RA or non-inflammatory rheumatic diseases.On the other hand non-steroidal anti-inflammatory drugs (NSAID) use is known to cause intestinal inflammation.NSAID use is common in rheumatic diseases.In our study FC was accepted as a marker of intestinal inflammation. FC assay was used to determine asymptomatic intestinal inflammation in AS patients.Intestinal inflammation is not connected with RA or non-inflammatory rheumatic diseases. FC levels in both groups was assessed to identify the value of FC for intestinal inflammation. We compared FC levels with AS patients results.Also we asses the correlation between activation of the disease and the severity of intestinal inflammation. We asses the relationship of intestinal inflammation with rheumatic treatment and NSAID usage and compare our results with the literature.Our research included 97 AS patient fulfilling the modified New York Criteria, 48 RA patients fulfilling the American College of Rheumatology Criteria and 49 patients with non-inflammatory rheumatic diseases.AS group patients showed significantly higher positive FC test compared with RA group patients (p=0,016). AS group patients levels of FC were negatively associated with disease duration. Levels of FC were not associated with BASDAI, ESR, CRP, uveitis and peripheral arthritis. AS group patients on NSAID showed significantly higher FC compared with nonusers