Circulating suPAR in Relation to Renal and Cardiovascular Involvement in Systemic Lupus Erythematosus: A Pilot Study

Soluble urokinase plasminogen activator receptor (suPAR) is an inflammatory biomarker associated with immune activation, endothelial dysfunction, and chronic inflammation. Increasing evidence suggests that suPAR may be involved in renal and cardiovascular injury and may reflect cumulative organ damage in systemic lupus erythematosus (SLE). Serum suPAR levels were measured in patients with SLE and healthy controls. Within the SLE cohort, suPAR levels were further evaluated according to the presence or absence of organ involvement. In this pilot study, serum suPAR levels were significantly higher in patients with SLE than in healthy controls. Within the SLE cohort, patients with renal involvement and those with reduced renal function had higher suPAR levels than their respective comparison groups. Similarly, patients with cardiovascular involvement showed significantly higher suPAR levels than SLE patients without cardiovascular involvement and healthy controls. However, serum suPAR levels were not significantly correlated with estimated glomerular filtration rate. Circulating suPAR levels are elevated in SLE and may be particularly associated with renal and cardiovascular involvement. These findings support the potential role of suPAR as a biomarker of cardiorenal involvement in SLE, although its relationship with renal function and clinical outcomes requires validation in larger prospective cohorts.