Multiparametric Analysis of Connective Tissue Disease Specific Autoantibodies Using a Spot Immunoassay.

BACKGROUND: Based on advances over several decades, a significant number of autoantibodies are aiding the diagnosis, differential diagnosis and even prognostic estimates of patients with connective tissue diseases (CTD). Based on cost and time constraints, multiplex assays are used more and more in routine practice. Here we describe the evaluation results of a novel spot immunoassay (SeraSpot® ANA) for multiplex analysis of the main CTD specific autoantibodies, which is based on autoantigens immobilized on microtitration plates. METHODS: For evaluation of the ANA spot immunoassay, comprising dsDNA, histone, nucleosome, Scl-70, U1-RNP (mixture of U1-RNP-A, C, and 70k), Sm (SmD), RibP (P0), Ro52/TRIM21, Ro60, La/SS-B, CENP-B, Jo-1, PM/ Scl-100, and Ku as target antigens, sera of 489 patients with systemic autoimmune rheumatic disease (SARD), sera of 54 patients with herpes virus infections, and sera of 202 apparently healthy individuals (AHI) were tested. RESULTS: The concordance between the SeraSpot and EIA results of disease specific autoantibodies (AABs) was high (94 - 97% for CENP-B, Jo-1, Scl-70, Sm, La, Ro52 and Ro60 antibodies) to moderate (86.7% for dsDNA antibodies), and no major differences in the frequency of these AABs in patients with CTD were observed. In SLE patients, the SeraSpot results of dsDNA antibodies correlate better with CLIFT results and HEp-2 cell pattern than the EIA results. The diagnostic specificities of SLE, SSc, SjS, and myositis specific AABs are very high (96.5 - 100%) compared to apparently healthy individuals, but lower with regard to serological differentiation of the SARD entities (86.6 - 99.1%). However, very high positive likelihood ratios (10 up to infinite) could be obtained by disease specific AAB profiles. CONCLUSIONS: The SeraSpot® ANA assay allows the detection of 14 AAB specificities used for the diagnosis and dif-ferentiation of CTD in one approach. Although the concordance between the SeraSpot® assay and EIA is moderate for most of the tested AAB specificities, defined AAB profiles are suitable for the correct diagnosis of the CTD entities. If time matters, the authors suggest the parallel employment of immunofluorescence on HEp-2 cells and the SeraSpot® ANA assay for screening and specific AAB determination of patients with suspected CTD.

[Survey of rheumatologists in Saxony, Saxony-Anhalt and Thuringia regarding the occupational situation and activities in further education: no way out of the undersupply of rheumatological care]. / Befragung von Rheumatologen in Sachsen, Sachsen-Anhalt und Thüringen zu Weiterbildungstätigkeit und beruflicher Situation: Kein Ausweg aus der rheumatologischen Unterversorgung.

INTRODUCTION: Many regions in the middle of Germany have a deficit in specialized rheumatological care. A survey was undertaken to investigate whether the regional capacities for rheumatological advanced training are sufficient to provide an adequate number of rheumatologists in the future. METHODS: All 91 rheumatologists registered in Saxony, Saxony-Anhalt and Thuringia received a questionnaire that was sent back by 66% of the recipients (23 responses from Saxony, 19 from Saxony-Anhalt, 18 from Thuringia). Of the rheumatologists 41 were in private practice, 19 worked in an inpatient department and the mean duration of professional activity was 18 years. RESULTS: Over the last decade the number of patients treated by rheumatologists in private practices increased from 1200 to 1500 per quarter year (p < 0.001), whereas the number of first consultations rose from 100 to 130 per quarter year (p = 0.06). The waiting time for a first consultation rose from 8 to 11 weeks (p = 0.01), 32% of the responders indicated that the conditions for outpatient treatment had either improved or had remained constant during the last 10 years, whereas 60% reported a mild or marked deterioration and 48% stated that the number of rheumatologists had decreased within the same time frame. Only 20% indicated that they had a definite successor in the practice after retirement. All inpatient departments also had an outpatient office. During the last 10 years, the number of consultations per quarter year decreased from 1100 to 700 (not significant), while the waiting time doubled from 6 to 12 weeks (rounded mean). Of the rheumatologists in private practice eight are currently entitled to provide advanced education in rheumatology, with a median training period of 18 months; however, none of the responding physicians had actually brought assistant doctors to the final examination during the last decade and only one prospective rheumatologist was currently completing training in a private practice setting. Only 6 out of 12 inpatient rheumatological facilities are entitled to educate rheumatologists over the whole training period, 5 facilities were not involved in training at all and 7 indicated that they lacked applications for rheumatology training. During the last 10 years, 37 rheumatologists completed the training of which 18 went into private practice, 8 worked as general practitioners and 29 remained in the region of their initial training. CONCLUSION: Given the increase in the number of outpatients served, the volume of training activities in rheumatology is hardly sufficient to improve the deficit of rheumatological care in the middle of Germany.

Rituximab therapy in patients with refractory dermatomyositis or polymyositis: differential effects in a real-life population.

OBJECTIVES: While a double-blind trial has not met its endpoint, rituximab (RTX) is still seen as useful in refractory DM and PM. In this study we analysed the charts of all patients receiving RTX for myositis in our institutions for objective outcome parameters. METHODS: In a retrospective way, the charts of all patients with PM or DM who received RTX were analysed for glucocorticoid dose, creatine phosphokinase (CPK) and lung function tests, as well as for serious adverse events. RESULTS: A total of 19 patients were identified, 1 of whom died from aspiration pneumonia 3 weeks after the first RTX infusion. The charts of 18 patients (13 PM, 5 DM) could be further analysed. In addition to the fatal pneumonia, six more severe infections were seen. One patient developed hypogammaglobulinaemia. Two patients had mild infusion reactions. Under RTX, both CPK and daily prednisolone dose were reduced by week 18. Six of eight patients with alveolitis improved under RTX. Overall, 9 of 13 PM patients responded. Six of the responders and two patients without documented response, all anti-synthetase syndrome patients, were re-treated. In contrast, all five DM patients responded and none required re-treatment. CONCLUSION: In a real-life population of patients with severe, refractory PM or DM, objective improvement was seen in the majority of patients with regard to CPK and lung function tests, and glucocorticoids could be reduced. In contrast to the subgroup with DM, where one cycle of RTX appeared sufficient, patients with anti-synthetase syndromes commonly experienced flares necessitating RTX re-treatment. Infections are of concern.

Defective removal of ribonucleotides from DNA promotes systemic autoimmunity.

Genome integrity is continuously challenged by the DNA damage that arises during normal cell metabolism. Biallelic mutations in the genes encoding the genome surveillance enzyme ribonuclease H2 (RNase H2) cause Aicardi-Goutières syndrome (AGS), a pediatric disorder that shares features with the autoimmune disease systemic lupus erythematosus (SLE). Here we determined that heterozygous parents of AGS patients exhibit an intermediate autoimmune phenotype and demonstrated a genetic association between rare RNASEH2 sequence variants and SLE. Evaluation of patient cells revealed that SLE- and AGS-associated mutations impair RNase H2 function and result in accumulation of ribonucleotides in genomic DNA. The ensuing chronic low level of DNA damage triggered a DNA damage response characterized by constitutive p53 phosphorylation and senescence. Patient fibroblasts exhibited constitutive upregulation of IFN-stimulated genes and an enhanced type I IFN response to the immunostimulatory nucleic acid polyinosinic:polycytidylic acid and UV light irradiation, linking RNase H2 deficiency to potentiation of innate immune signaling. Moreover, UV-induced cyclobutane pyrimidine dimer formation was markedly enhanced in ribonucleotide-containing DNA, providing a mechanism for photosensitivity in RNase H2-associated SLE. Collectively, our findings implicate RNase H2 in the pathogenesis of SLE and suggest a role of DNA damage-associated pathways in the initiation of autoimmunity.

Mutation and citrullination modifies vimentin to a novel autoantigen for rheumatoid arthritis.

OBJECTIVE: Modification of antigens represents a trigger for the generation of autoantibodies. In the pathogenesis of rheumatoid arthritis (RA), citrullination of proteins has been shown to be a critical process, and the determination of antibodies against citrullinated antigens has been a diagnostic milestone. We undertook this study to determine whether antibodies to mutated and citrullinated vimentin (MCV) could serve as a diagnostic and prognostic marker for RA. METHODS: We identified novel isoforms of human MCV in the synovial fluid of RA patients. The significance of these disease-related modifications was investigated by the analysis of autoantibody reactivities. In a group of 1,151 RA patients, the diagnostic significance and the prognostic value of an anti-MCV enzyme-linked immunosorbent assay (ELISA) were compared with that of an anti-cyclic citrullinated peptide (anti-CCP) ELISA. RESULTS: In RA, sensitivities of 82% and 72% were calculated for the anti-MCV and anti-CCP assays, respectively. The specificity of both assays was comparable (98% and 96%, respectively). In followup analyses of 16 RA patients with moderate disease activity (mean Disease Activity Score in 28 joints [DAS28] of 2.72) and 26 RA patients with active disease (mean DAS28 of 5.07), disease stratification of RA was possible using the anti-MCV assay (P = 0.0084). A significant correlation of anti-MCV antibodies with the DAS28 was documented (r = 0.5334, P = 0.0003), in 42 RA patients (n = 427 antibody determinations at different time points). CONCLUSION: Antigenic properties of vimentin were determined by mutation and citrullination. Anti-MCV antibodies are a novel diagnostic marker for RA. Furthermore, they may allow monitoring and-if confirmed in even larger series of patients-stratification of disease.