Potential value of collagen triple helix repeat containing-1 (CTHRC1) in systemic lupus erythematosus (SLE) patients with arthritis detected clinically or by musculoskeletal ultrasound

Abstract

Aim of the work

Is to measure collagen triple helix repeat containing 1 (CTHRC1) in systemic lupus erythematosus (SLE) patients and assessing its value as a marker of arthritis.

Patients and methods

This study included 44 female SLE patients and 44 matched healthy controls. All patients underwent hand and wrist Ultrasound (US) examination. Patients were divided into those with arthritis either clinically or sub-clinically by Ultrasound (A) and second one without arthritis. Serum level of CTHRC1 was measured using Enzyme linked immunosorbent assay. Disease activity was assessed using SLEDAI-2 K and joint activity using swollen to tender ratio (STR).

Results

Serum CTHRC1 level was significantly higher in patients compared to controls (52.3 ± 25.7 ng/ml and 14.5 ± 3.9 ng/ml respectively, p < 0.001). It was significantly higher in renal patients with nephritis and active arthritis by STR compared to those without (p = 0.04 and p = 0.003 respectively). Arthritis was detected in 68% of patients and they showed significantly higher CTHRC1 levels compared to those without (p = 0.037). Serum CTHRC1 showed positive significant correlation with STR (P = 0.007), CRP (p < 0.001), SLEDAI-2 K (p = 0.01) but not US findings. The STR showed significant association with CTHRC1 on regression analysis (p = 0.034). There was a fair ability for CTHRC1 to predict clinical and sub-clinical arthritis among SLE patients with sensitivity 56.7, specificity 85.7 at cut off value >55 ng/ml and area under curve 0.67.

Conclusion

Serum CTHRC1 level was significantly higher in SLE patients with nephritis and arthritis. It was significantly related to arthritis activity, inflammatory markers and disease activity. However, it showed fair performance for detecting arthritis.