[Antibodies to N-homocysteinylated albumin in patients with systemic lupus erythematosus]

INTRODUCTION Hyperhomocysteinemia is known to predispose to atherosclerosis and occurs more commonly in patients with systemic lupus erythematosus (SLE) than in the general population. It has been shown that elevated plasma total homocysteine (tHcy) results in protein N-homocysteinylation and production o autoantibodies against N-homocysteinylated (N-Hcy) proteins. OBJECTIVES The aim of the study was to investigate whether anti-N-Hcy-albumin antibodies occur in patients with SLE and identify factors that determine these antibodies in such population. Patients and methods. In 50 subjects with SLE and 50 age- and sex-matched healthy controls, we determined serum IgG antibodies to N-Hcy-albumin using an in-house enzyme linked immunosorbent assay. RESULTS Patients had higher plasma tHcy and C-reactive protein (CRP) than controls, while serum folate and witamin B12 were lower in patients. Levels of anti-N-Hcy-albumin were higher in patients with SLE than in controls (medians: 0.31; vs. 0.19; p < 0.0001). In SLE patients, levels of anti- N-Hcy-albumin antibodies correlated with tHcy (r = 0.83; p