Background/Purpose: Renal involvement in systemic sclerosis (SSc) includes scleroderma renal crisis as well as progressive organ fibrosis. Detection and management of these disease complications is challenging and there is a clinical need for biomarkers that reflect renal involvement. The immunoglobulin superfamily adhesion molecules ICAM-1 and VCAM-1 are upregulated in affected tissues in SSc and other connective tissue diseases. Serum levels of ICAM-1 and VCAM-1 have been elevated in previous studies, but in some instances this reflects the multi-organ burden of disease and organ-specific analysis may to be more robust.

Methods: We collected urine and serum from 80 SSc patients, with or without renal disease, and compared them with patients with CKD of other causes (n=10) and healthy controls (n=12). We used bead-based multiplex analysis to measure cell adhesion molecule concentrations.

Results were compared between groups by Kruskal-Wallis test. Results: 40 SSc patients had CKD defined by eGFR and urinalysis. Risk factors for renal involvement (SSc-CKD) included diffuse skin involvement and anti-RNA polymerase III antibodies. Serum concentrations of ICAM-1 or VCAM-1 did not differ significantly between SSc-CKD and the three control groups. Urine VCAM-1 concentrations were increased in SSc patients with renal involvement (mean VCAM-1:creatinine ratio 922, SD 953 versus 654, SD 708 for those without renal involvement) but this did not reach significance. Urine ICAM-1 was markedly upregulated in SSc-CKD (mean ICAM-1:creatinine ratio 1601, SD 1394 versus 806, SD 701 for SSc without renal involvement and 1307, SD 1211 for CKD of other causes, p<0.001)