Measurement of autoantibodies using multiplex methodology in patients with systemic lupus erythematosus.

Autoantibodies are central to the diagnosis and assessment of systemic lupus erythematosus (SLE). A recent technique for the measurement of autoantibodies utilizes addressable laser bead immunoassay technology (BioPlex 2200) which permits the simultaneous detection of multiple autoantibodies and improved efficiency due to the shorter time to perform the assay and low volume of test samples and reagents. In the current study we have compared this technique to more traditional measures of autoantibody detection. The clinical and laboratory data and stored serum samples from the enrollment visit into a long-term lupus registry at a single academic medical center were used. Sera were examined for a panel of autoantibodies using the BioPlex ANA screen. The results were compared to the historical data on autoantibody profiles using indirect immunofluorescence (IIF) and ELISA. The association with global and organ specific SLE disease activity (nephritis) was also examined. The study consisted of 192 patients who were predominantly female (87%) and Caucasian (91%) with mean disease duration of 8.8 years. The frequency of ANA and anti-dsDNA by IIF and ELISA was 81.3% and 46.6% respectively and was higher than that found with BioPlex (75.5% and 31.8%). The latter detected a higher proportion of patients with autoantibodies to Sm (7.5% vs 16.7%), RNP (21.8% vs 24.0%), Ro (37.4% vs 41.7) and La (13.9% vs 23.4%). Overall agreement between assays varied between 71.4% and 92.5%. Additional autoantibodies identified by BioPlex were anti-chromatin antibodies which were similar in frequency to anti-dsDNA antibodies (33.9% and 31.8% respectively). There was a low frequency of anti-ribosomal P (6.8%), anti-Scl-70 (5.2%), anti-centromere B (3.7%) and anti-Jo-1 (0.5%). Several autoantibodies revealed significant associations with SLEDAI scores but in a multivariate analysis the only autoantibodies that approached statistical significance were anti-Sm (p=0.094) measured by ELISA and anti-dsDNA (p=0.082) measured by BioPlex. There was no association between any of the autoantibodies regardless of the method of detection and cumulative organ damage scores. Fifty-three patients (27.6%) had lupus nephritis of which 17 (32%) had active nephritis at the time of autoantibody determination. There was no significant association between a positive ANA (IIF) and any autoantibodies detected by ELISA with either the cumulative occurrence of lupus nephritis or active nephritis. In contrast, there was an association between BioPlex detected anti-dsDNA with the cumulative occurrence of nephritis (p=0.074) which reached statistical significance with active nephritis at the time of antibody testing (p=0.012). This was confirmed by multivariate analysis (p=0.047). These results suggest reasonable agreement between the detection of lupus autoantibodies by ELISA and BioPlex. The latter demonstrated a better correlation with lupus nephritis.

Hanly JG ，Thompson K ，McCurdy G ，Fougere L ，Theriault C ，Wilton K ... -  《-》

BioPlex 2200 multiplexed system: simultaneous detection of anti-dsDNA and anti-chromatin antibodies in patients with systemic lupus erythematosus.

Bardin N ，Desplat-Jego S ，Daniel L ，Jourde Chiche N ，Sanmarco M ... -  《-》

Evaluation of the BioPlex 2200 ANA screen: analysis of 510 healthy subjects: incidence of natural/predictive autoantibodies.

Shovman O ，Gilburd B ，Barzilai O ，Shinar E ，Larida B ，Zandman-Goddard G ，Binder SR ，Shoenfeld Y ... -  《ANNALS OF THE NEW YORK ACADEMY OF SCIENCES》

Comparison between multiplex assays for autoantibody detection in systemic lupus erythematosus.

The performance of immunoassays for the detection of autoantibodies is of critical importance to the diagnosis and assessment of patients with systemic lupus erythematosus (SLE). Our objective was to compare 3 multiplexed assays for measurement of multiple autoantibodies and their association with global disease activity, active nephritis and cumulative organ damage in systemic lupus erythematosus (SLE). Stored sera, clinical and laboratory data from the enrollment visit of a long-term lupus registry were used. Autoantibodies were measured using the BioPlex 2200 ANA screen (Bio-Rad), QuantaPlex ENA8 (INOVA Diagnostics) and recomLine ANA/ENA (Mikrogen). The analytes included dsDNA, chromatin, ribosomal P protein, SS-A/Ro60, Ro52, SS-B/La, Sm, U1-RNP, centromere B, topoisomerase 1 and Jo-1 (histidyl tRNA synthetase). Global SLE disease activity was measured by the SLE disease activity index (SLEDAI) and cumulative organ damage by the SLICC/ACR damage index (SDI). One hundred ninety two patients (87% female; 91% Caucasian; mean disease duration 8.8years) were studied. Agreement between the 3 assays varied from 70% to 99% (Cohen's kappa: 0.04-0.88). There were significant associations between SLEDAI scores (excluding anti-dsDNA) and ANA (INOVA, Mikrogen), anti-dsDNA (Bio-Rad, Mikrogen), anti-chromatin (Bio-Rad, INOVA), anti-Ro (Mikrogen), anti-Sm and anti-U1-RNP (all 3 immunoassays) (p=0.002-0.05). Concurrent lupus nephritis was associated with anti-dsDNA (Bio-Rad (p=0.017) or Bio-Rad and Mikrogen together (p=0.015)). There was no significant association between autoantibodies and SDI scores. The overall agreement between assays for the detection of autoantibodies was reasonable. The greatest discordance (70-83%) occurred with those autoantibodies most strongly associated with global SLE disease activity (ANA, anti-dsDNA, anti-chromatin and anti-Sm). Furthermore, there were differences between assays in their associations with global SLE disease activity and lupus nephritis.

Hanly JG ，Su L ，Farewell V ，Fritzler MJ ... -  《-》

Anti-nucleosome antibodies as a disease marker in systemic lupus erythematosus and its correlation with disease activity and other autoantibodies.

Pradhan VD ，Patwardhan MM ，Ghosh K 《-》