(HealthDay)—For unaffected relatives of systemic lupus erythematosus (SLE) patients, preclinical alterations in levels of soluble mediators may predict transition to disease, according to a study published in the March issue of Arthritis & Rheumatology.

Melissa E. Munroe, M.D., Ph.D., from the Oklahoma Medical Research Foundation in Oklahoma City, and colleagues examined factors associated with transition to classified in 409 previously identified blood of patients with SLE who had up to four American College of Rheumatology (ACR) classification criteria for SLE at baseline.

The researchers found that at the time of follow-up (mean, 6.4 years), 11 percent of unaffected relatives had transitioned to classified SLE. More lupus-associated autoantibody specificities and higher SLE-specific portion of the Connective Tissue Disease Screening Questionnaire (SLE-CSQ) scores at baseline (P < 0.0001) were seen for relatives who transitioned versus those who did not transition to classified SLE. Elevated baseline plasma levels of inflammatory mediators, including B lymphocyte stimulator, stem cell factor (SCF), and interferon-associated chemokines (P ≤ 0.02), were seen among relatives who developed SLE, with concurrent decreases in the levels of regulatory mediators, transforming growth factor β (TGFβ), and interleukin-10 (P ≤ 0.03). Significant and independent predictors of SLE transition included baseline SLE-CSQ scores or ACR scores and plasma levels of SCF and TGFβ, but not autoantibodies.

"Immune perturbations precede SLE classification and can help identify high-risk relatives for rheumatology referral and potential enrollment in prevention trials," the authors write.