The following is a summary of “Novel Biomarker of Collagen Degradation Can Identify Patients Affected With Both Axial Spondyloarthritis and Crohn’s Disease” published in the  December 2022  Issue of Rheumatology By Nielsen, et al.

Axial spondyloarthritis (axSpA) is characterized by chronic inflammatory arthritis, and it is common for Crohn’s disease (CD) to coexist with axSpA. With the hope of identifying patients with CD-axSpA, researchers studied the relationship between indicators of collagen degradation in healthy controls(HCs) and patients with axSpA, CD, and CD and axSpA overlap (CD-axSpA). Patients with axSpA who fulfilled Assessment of Spondyloarthritis international Society criteria (n = 13), had biopsy-proven CD (n=14), had CD-axSpA (n=10), and HCs (n=11) undergoing standard-of-care colonoscopies were included in the study.

Plasma samples were analyzed for the presence of the collagen biomarkers C3M, C4M, C6M, and C10C, which are specific to types III, IV, VI, and X collagen.  The age-adjusted analysis of covariance (ANCOVA), area under the receiver-operator characteristic (AUROC) curve analysis, and Spearman correlation were used for statistical analysis. Patients with CD-axSpA overlap exhibited elevated C4M compared to those with axSpA, CD, and HCs (all P<0.001). Patients with CD-axSpA overlap could be completely distinguished from those with HC, axSpA, and CD using C4M, as demonstrated by the area under the curve (AUC) equal to 1.00 (P<0.001). 

There were no significant variations between the patient groups in terms of C3M, C6M, and C10C. There was no association between collagen biomarkers and C-reactive protein, the Bath Ankylosing Spondylitis Disease Activity Index, the Simple Clinical Colitis Activity Index, or the Harvey-Bradshaw Index. C4M assessed excessive collagen breakdown and epithelium turnover, and it was clear that patients with CD-axSpA overlap were completely distinct from those with axSpA, CD, or HCs. Patients experiencing both characteristics may be identified and treated more effectively with this biomarker.