Urinary Biomarkers Offer Insight Into SLE Activity, Long-Term Outcomes

Vascular cell adhesion molecule 1 (VCAM-1) and activated leukocyte cell adhesion molecule (ALCAM) appear to be useful urinary biomarkers of disease activity and long-term renal outcome among patients with systemic lupus erythematosus (SLE), according to findings of a new study.

The study included 111 women with SLE and 99 control subjects without lupus. The researchers measured renal activity using the renal domain of the British Isles Lupus Assessment Group (BILAG) index. They measured urine and plasma concentrations of soluble VCAM-1 and urinary soluble ALCAM using the enzyme-linked immunosorbent assay.

Urinary soluble VCAM-1/creatinine and urinary soluble ALCAM/creatinine ratios were higher among women with lupus compared with controls. The ratios were also higher among participants with active/low-active lupus nephritis compared with quiescent lupus nephritis. Compared with participants with nonrenal SLE, participants with nephritis history had higher ratios of urinary soluble ALCAM/creatinine.

Meanwhile, participants with urinary soluble VCAM-1/creatinine ratios in the 75th percentile or higher at baseline had a 23-fold increased risk of deterioration in estimated glomerular filtration rate by 25% or more during a 10-year follow-up. This was an outcome that went unpredicted by traditional markers including proteinuria, anti-double stranded DNA, and anti-C1q levels, the researchers reported. 

Consequently, the researchers advised high urinary soluble VCAM-1 levels may justify surveillance and renoprotective interventions.

“While high [urinary soluble] VCAM-1 levels appear to reflect SLE disease activity, [soluble] ALCAM might have particular importance in renal SLE,” the researchers concluded. “Both [urinary soluble] VCAM-1 and [urinary soluble] ALCAM showed ability to distinguish SLE patients with active renal involvement from patients with quiescent or no prior nephritis. High [urinary soluble] VCAM-1 levels may indicate patients at increased risk for long-term renal function loss.”

—Jolynn Tumolo

Reference:

Parodis I, Gokaraju S, Zickert A, et al. ALCAM and VCAM-1 as urine biomarkers of activity and long-term renal outcome in systemic lupus erythematosus. Rheumatology (Oxford). 2020;59(9):2237-2249. doi:10.1093/rheumatology/kez528