Israel Medical Association Journal

Abstract

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by multisystem involvement due to immune dysregulation. Neuropsychiatric systemic lupus erythematosus (NPSLE) includes neurological syndromes involving the central, peripheral and autonomic nervous system, as well as psychiatric syndromes observed in patients with SLE in which other causes have been excluded. The pathogenesis of NPSLE has been attributed to many different mechanisms. In particular, autoantibody-mediated vasculopathy seems to play a major role in the pathogenesis of the clinical features. Several autoantibody specificities have been reported in the serum and cerebrospinal fluid of NPSLE patients. Recently, we demonstrated an association between serum anti-endothelial antibodies (AECA) and psychosis or depression in SLE patients, strengthening the notion of a possible role of this class of autoantibodies in the pathogenesis of the disease. The study of these autoantibodies could be a useful diagnostic and prognostic tool in patients with NPSLE.

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by disturbance of the innate and adaptive immune systems with the production of autoantibodies by stimulated B lymphocytes. The BLyS protein (B lymphocyte stimulator) is secreted mainly by monocytes and activated T cells and is responsible for the proliferation, maturation and survival of B cells.

Objectivs: To study sera BLyS level and its clinical significance in Israeli lupus patients over time.

Methods: The study population included 41 lupus patients (8 males, 33 females; mean age 35.56 ± 15.35 years) and 50 healthy controls. The patients were followed for 5.02 ± 1.95 years. We tested 221 lupus sera (mean 5.4 samples/patient) and 50 normal sera for BLyS levels by a capture ELISA. Disease activity was determined by the SLEDAI score.

Results: Sera BLyS levels were significantly higher in SLE patients than in controls (3.37 ± 3.73 vs. 0.32 ± 0.96 ng/ml, P < 0.05). BLyS levels were high in at least one sera sample in 80.5% of the patients but were normal in all sera in the control group. There was no correlation between sera BLyS and anti-ds-DNA autoantibody levels. BLyS levels fluctuated over time in sera of lupus patients with no significant correlation to disease activity.

Conclusions: Most of our lupus patients had high sera BLyS levels, suggesting a role for BLyS in the pathogenesis and course of SLE. Our results support the current novel approach of targeting BLyS (neutralization by antibodies or soluble receptors) in the treatment of active lupus patients.