Association of anti-NR2 and U1RNP antibodies with neurotoxic inflammatory mediators in cerebrospinal fluid from patients with neuropsychiatric systemic lupus erythematosus.

BACKGROUND: Autoantibodies (auto Abs) and inflammatory mediators (IMs) in cerebrospinal fluid (CSF) may be involved in the pathogenesis of neuropsychiatric systemic lupus erythematosus (NPSLE). It is suggested that anti-N-methyl D-aspartate receptor NR2 subunit (NR2) Ab can develop NP manifestation after blood-brain barrier (BBB) abruption. We also reported the association between NPSLE and CSF anti-U1RNP Ab. In the present study, combined effects of CSF anti-NR2 and anti-U1RNP Abs on IMs in patients with NPSLE were examined. METHODS: CSF samples were collected from 69 patients with NPSLE and 13 non-NPSLE controls. CSF anti-NR2 and anti-U1RNP Abs were determined using ELISA. Levels of IL-6, IL-8, and monokine induced by IFN-γ (MIG) in CSF were measured by quantitative multiplex cytokine analysis. RESULTS: CSF IL-6 levels were higher in CSF anti-NR2-positive than in CSF anti-NR2-negative patients (p = 0.003) and non-NPSLE controls (p = 0.015) and were positively correlated with anti-NR2 titer (r = 0.42). CSF IL-8 levels were higher in CSF anti-U1RNP-positive than in CSF anti-U1RNP-negative patients (p = 0.041). CSF MIG levels were more elevated in CSF anti-NR2-positive (p = 0.043) and anti-U1RNP-positive patients (p = 0.029) than in non-NPSLE controls. Additionally, in double positive (DP; both anti-NR2 and U1RNP Ab positive) group, CSF IL-6 and MIG levels were significantly higher than in the double negative (DN; both anti-NR2 and U1RNP Ab negative) group. However, combined effect of both Abs on IM elevation and clinical manifestation was not clear. CONCLUSIONS: CSF anti-NR2 and anti-U1RNP Abs have different effects on the elevation of CSF IM levels in patients with NPSLE. Additional effect of anti-U1RNP Abs on anti-NR2 Ab-mediated NP manifestation, however, was not recognized in our study.

Predicting factors for disappearance of anti-mutated citrullinated vimentin antibodies in sera of patients with rheumatoid arthritis.

Objectives: We aimed to determine the predicting factors for disappearance of anti-mutated citrullinated vimentin antibody (anti-MCV Ab) in sera from rheumatoid arthritis (RA) patients.Methods: In 2013, 95 RA patients whose Disease Activity Score with erythrocyte sedimentation rate were moderate to severe (DAS28-ESR ≥3.2) at baseline were enrolled. Titers of anti-MCV Ab and anti-cyclic citrullinated peptide (anti-CCP) Ab for 2013 and 2014 were measured. The association of anti-MCV disappearance with disease activity, treatment, interstitial lung disease (ILD), and serum markers of ILD were retrospectively examined. Predicting factors of anti-MCV disappearance were determined by multivariable analysis.Results: While anti-CCP positivity rate did not change during the year, anti-MCV Ab changed from positive to negative in 18 patients (=19.0%). Continuous biological disease-modifying anti-rheumatic drug use, prednisolone dose (≥5.0 mg daily), and low KL-6 level (<191 U/mL) were determined as predicting factors of anti-MCV disappearance by multivariable analysis. In our cohort, anti-MCV Ab disappearance was not linked to clinical and radiological improvement.Conclusion: Different from anti-CCP Ab, anti-MCV Ab in sera from RA patients can disappear in a year. Some predicting factors for such negative seroconversion were found, whereas clinical significance of anti-MCV Ab disappearance was undetermined.