Background:Self-reactive antibodies are a characteristic of systemic lupus erythematosus [SLE]. These autoantibodies may attack any organ or tissue in the body causing organ failure. One class of anti-DNA antibodies, known as anti-DNA/N-methyl-D-aspartate receptor 2 [anti-DNA/NR2] antibodies, also interacts with the NR2 subunit [anti-NR2] of N-methyl-D-aspartate receptors [NMDARs]. Research suggests that anti-NMDAR antibodies contribute to the pathophysiology of SLE-related emotional and cognitive dysfunction.Objective:The goal of this study was to evaluate the prevalence and severity of systemic lupus erythematosus in individuals with anti-DNA/N-methyl-D-aspartate receptor 2 [NR2] antibodies.Methodology: 60 SLE patients and 30 healthy controls had serum samples taken. Anti-NR2 antibodies in the serum were tested using an ELISA kit.Results: The average serum anti-NR2 antibody level in SLE patients was 34.10 ng/ml, whereas the level in healthy controls was only 11.60 ng/ml with a statistically significant difference [P<0.001].Serum anti-NR2 can significantlydiscriminate between SLE patients and healthy subjects, with diagnostic ability at best cut off value 13.26 ng/ml with high sensitivity and specificity.Conclusion:Serum anti-NR2 can be used as a new biomarker for SLE.