Autoantibody Profile in Systemic Lupus Erythematosus Patients

Abstract

Systemic lupus erythematosus (SLE) is an autoimmune disease, in which the etiology is not well-understood; however, interactions between environmental and genetic factors in predisposed individuals have been recognized. As a consequence, immunological alternations occur and immune cells are involved, especially T and B lymphocytes that are activated to produce different immune components. Among these components are autoantibodies that react with self-antigens aside from non-self-antigens due to the proposed theory of molecular mimicry. Accordingly, the current study was designed to examine the profile of different autoantibodies in SLE patients by using the indirect membrane based enzyme immunoassay for the quantitative measurement of IgG class antibodies. Subjects: Sixty-four SLE patients (32 arthritis and 32 nephritis patients) and 32 healthy subjects (control) were enrolled in the study, and their sera were tested for anti-nucleosome, anti-histone, anti-smD1, anti-PCNA, anti-PO, anti-SS-A/Ro-60, anti-SS-A/Ro-52, anti-SS-B/La, anti-CENP, anti-SCI-70, anti-U1snRNP, anti-AMA-M2, anti-Jo-1, anti-PM-SCI, anti-Mi2 and anti-Ku autoantibodies in order to evaluate the autoimmunity status in SLE patients. Results: The sera of control subjects were negative for these antibodies; therefore, the comparisons were limited to the two groups of SLE patients; arthritis and nephritis. The highest percentage of seropositive arthritis patients was observed for anti-SS-A/Ro-60, anti-CENP and anti-U1snRNP antibodies (100.0%), while the lowest percentage was recorded for anti-Jo-1 antibody (15.6%). For nephritis patients, anti-U1snRNP antibody (87.5%) was also observed to have the highest percentage, and anti-Jo-1 antibody (3.1%) also recoded the lowest percentage. However, four autoantibodies (anti-PCNA, anti-SS-A/Ro-60, anti-SS-B/La and anti-CENP antibodies) showed different profiles in arthritis and nephritis SLE patients. They showed a significant increased percentage in arthritis patients compared to nephritis patients (anti-PCNA: 87.5 vs. 50.0%, p = 0.003; anti-SS-A/Ro-60: 100.0 vs. 81.2%, p = 0.02; anti-SS-B/La: 75.0 vs. 43.8%, p = 0.02; anti-CENP: 100.0 vs. 43.8%, p = 0.001). Conclusion: These findings suggest the diagnostic potential of autoantibodies as early markers for SLE development.