Calprotectin in patients with axial spondyloarthritis: Clinical features, disease activity and imaging

Aim of the work

The aim of the current study was to examine both serum and fecal calprotectin (sCal and fCal) levels in patients with axial spondyloarthritis (axSpA) and to evaluate their potential relations to clinical features, disease activity and imaging.

Patients and methods

This study included 40 axSpA patients and 18 controls. Disease activity using AS disease activity score (ASDAS), sacroiliac joints radiography and magnetic resonance imaging (MRI) were assessed. sCal and fCal were measured.

Results

The axSpA patients were 57.5 % males, with a mean age of 39.8±11.5 years and a median disease duration (IQR) of 4.5 (1.7–11.5) years. The median sCal and fCal levels were significantly higher in axSpA patients compared to controls (p< 0.001). There were no differences in median sCal and fCal levels in axSpA patients concerning demographic data, HLA-B27, extra-articular manifestations, intestinal symptoms and biologics treatment (p> 0.05). A significant increase in median sCal and fCal levels along with the increase in clinical disease activity grade was found (p< 0.0001 and p= 0.003, respectively). Both sCal and fCal were significantly correlating with each other (p= 0.003), with ASDAS score (p= 0.003 and p= 0.01, respectively) and negatively with hemoglobin (p= 0.01 and p= 0.009, respectively). An increase in median sCal levels was observed along with the increase in grade severity of sacroiliitis on MRI (p= 0.06).

Conclusion

Serum and fecal calprotectin levels were significantly increased in axSpA patients and associated with disease activity. Both were having good specificity and sensitivity as potential diagnostic biomarkers for the disease.