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Background: This article provides an overview of modern serological diagnostic testing for rheumatoid arthritis (RA) involving the detection of antibodies against citrullinated peptides/proteins (ACPA). Recommendations are also given for differential diagnosis and sequential testing in rheumatoid arthritis, with a view toward improving early diagnosis so that irreparable joint damage can be avoided. Methods: Selective literature research, with consideration of the authors' own publications. Results: Two different, adequately evaluated testing systems, involving the detection of anti-CCP antibodies and of anti-MCV antibodies, are now commercially available and enable routine, relatively highly specific diagnostic testing for RA. Two point-of-care-tests (POCT) for the early diagnosis of RA constitute the latest development in serologic diagnostic testing. Conclusions: The two ACPA assays now on the market are equally useful for the diagnosis of rheumatoid arthritis. The correlation between RA disease activity and stratification with ACPA has only been demonstrable to date through the detection of anti-MCV antibodies. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Sjögren's syndrome (SS) is characterized by autoimmune infiltration and focal accumulation of lymphocytes in the exocrine glands, with a predominance of CD4-positive T cells. Since these histologic findings are nonspecific, determination of clinical and serologic abnormalities contribute to the diagnosis. The aim of this study was to identify a novel, disease-specific, immunologically relevant marker for SS. METHODS: To analyze disease-related and tissue-specific expression of candidate markers, we examined biopsied minor salivary glands and peripheral blood mononuclear cells from patients with primary and secondary SS (n = 26) as well as from patients with sicca symptoms without autoimmune sialadenitis (n = 15). Expression of the Th1/Th2-related chemokines CCL3 (macrophage inflammatory protein 1alpha) and CCL2 (monocyte chemoattractant protein 1), CXCL7 (neutrophil-activating peptide 2 [NAP-2]), interleukin-1beta, inducible costimulator, and the proteasome subunits alpha3 (C9) and beta5i (LMP7) was analyzed at the messenger RNA (mRNA) level using real-time polymerase chain reaction techniques. Immunohistochemical analysis was used to identify the beta5i (LMP7)-expressing cell populations in minor salivary glands. RESULTS: The expression profiles revealed a significant up-regulation of beta5i (LMP7) exclusively in the salivary glands of SS patients. Immunohistochemistry confirmed expression of the immunoproteasome subunit beta5i (LMP7) within the acinar and ductal epithelial cells. No significant difference in the distinct histologic focus scores was evident for the expression of the markers investigated. In the peripheral blood compartment, the expression of CXCL7 was up-regulated both in primary and in secondary SS. CONCLUSION: Tissue-specific up-regulation of beta5i (LMP7) mRNA was shown to be characteristic of SS, indicating a disease-specific modulation of the proteasome system. Expression of beta5i (LMP7) represents an independent parameter that can be used in addition to the focus score to distinguish SS in biopsied labial salivary glands. [ABSTRACT FROM AUTHOR]

Aims Inflammatory and immune activation and body wasting are important features of end-stage chronic heart failure. It is not known whether restoration of cardiac output by assist device implantation can improve these abnormalities.Methods We studied 48 patients (39 males; age 45±2 years) with NYHA class IV heart failure. All patients underwent ventricular assist device implantation for end-stage heart failure as a bridge to cardiac transplantation. Plasma levels of tumour necrosis factor α, and its receptors, interleukin-6, elastase, activated complement, and soluble CD14 receptors were measured at the time of operation and in survivors at 1 week (n=46), 40 days (n=35) and 90 days (n=26). Follow-up was for a minimum of 1 year.Results One-year survival was 35% (95% CI: 22–49%). Body mass index was the only predictor of survival (body mass index >25 (n=16); survival 63 (39–86)%; body mass index <25 (n=32); survival 22 (7·5–36)%: P=0·003). Tumour necrosis factor α fell from 9·66±1·33pg.ml−1to 4·2±1·0 at 1 week (P=0·008), but returned to pre-operative levels at 90 days. Interleukin-6, activated complement and elastase fell progressively to 40 days, but were rising at 90 days. There was no change in tumour necrosis factor receptor. There was a gradual rise in CD14 (3·99±0·15μg.ml−1at baseline, 5·02±0·39 at 90 days, P=0·006). After surgery, body weight fell from 80±2 to 73±2kg by 1 month (P<0·001) and to 72±2kg at 90 days.Conclusions Ventricular assist device implantation results in a short-term fall in tumour necrosis factor α and interleukin-6, but no change in CD14 or tumour necrosis factor receptor, suggesting that the pathophysiological process resulting in inflammation was not altered by left ventricular assist device implantation. Low body mass index is related to poor outcome after assist device implantation, and no weight gain. [ABSTRACT FROM PUBLISHER]

Background Leptin, a product of theobgene, is known to increase energy expenditure. Given that chronic heart failure is a hypercatabolic state, we sought to determine whether congestive heart failure involves elevations in plasma leptin levels. Since leptin secretion is up-regulated by insulin, we also explored whether in congestive heart failure, a hyperinsulinaemic state, plasma leptin levels relate to plasma insulin levels.Methods Male patients with weight-stable congestive heart failure (n=25, aged 55·5±2·0, mean±SEM, body mass index=27·4±0·8, radionuclide left ventricular ejection fraction=29·3±3·0%) and 18 controls, matched for age, sex and body fat (dual energy X-ray absorp-tiometry), underwent measurement of fasting plasma leptin (radioimmunoassay) and insulin levels.Results Compared to controls, patients with congestive heart failure had higher plasma leptin [8·12 (−1·12,+1·31) vs 4·48 (−0·61,+0·70) ng.ml−1, mean±asymmetrical SEM,P=0·003], 41·5% higher plasma leptin per percent body fat mass (P<0·001), and higher fasting insulin levels [67·8 (−11·1,+13·3) vs 32·9 (−5·7,+6·9) pmol.l−1,P=0·010]. In the congestive heart failure group, plasma leptin correlated with total body fat (r=0·66) and fasting insulin (r=0·68) (bothP<0·001). In multivariate regression analyses of the congestive heart failure group, fasting insulin (standardized coefficient=0·41,P=0·011) emerged as a predictor of plasma leptin levels, independent of total body fat (standardized coefficient=0·73,P=0·002, R2=0·66,P<0·001).Conclusions Plasma leptin levels are raised in patients with congestive heart failure. The observation of a positive relationship between plasma leptin and insulin concentrations suggests that the insulin–leptin axis may be related to the increased energy expenditure observed in patients with congestive heart failure. [ABSTRACT FROM PUBLISHER]

Introduction: Visual evaluation of indirect immunofluorescence (IIF) on human epithelial-2 cells is the routine method for screening for antinuclear antibodies (ANA) in connective tissue diseases. Since visual IIF is time-consuming and subjective, automated IIF processors have been developed to offer standardised, valid and cost-efficient IIF assays., Objective: The aim of this study was to determine the diagnostic reliability of 2 widely used IIF processors (Aklides, Medipan GmbH and Helios, Aesku Diagnostics) under real-life laboratory working conditions., Methods: ANA were determined in samples from patients with suspected autoimmune rheumatic disease (n=1008) using both automated IIF processors and compared with the results obtained by visual interpretation. The performance of IIF processors to discriminate positive from negative samples, pattern recognition and end point titre prediction were evaluated., Results: The IIF processors showed moderate agreement with visual interpretation in discriminating positive from negative ANA samples (κ values: Aklides 0.494; Helios 0.415). The sensitivity/specificity was 89%/59% for Aklides and 87%/54% for Helios. However, both processors correctly identified 99% of definitely positive samples (titre ≥1:320). Aklides correctly identified 43% of fluorescence patterns and its light intensity values showed good correlation (Spearman's ρ=0.680) with visually obtained titres., Conclusions: Automated IIF determination under real-life laboratory working conditions remains a challenge. Owing to their high sensitivity at clinically relevant ANA titres, automated IIF processors can already support but not totally replace visual IIF., Competing Interests: Competing interests: None declared.

Introduction: Antibodies against mutated citrullinated vimentin (AMCV) represent a useful diagnostic marker with correlation to disease activity in patients with rheumatoid arthritis (RA). Since seropositivity for citrullinated autoantibodies was predictive for response to B-cell depleting therapy (BCDT) with rituximab (RTX), we investigated whether differences in antibody fine reactivity and immunoglobulin (Ig) isotype kinetics among AMCV-positive patients could provide additional information about outcome., Methods: A total of 50 AMCV IgG-positive RA patients (RTX responders (RRs) n = 37 and non-responders (NRRs) n = 13) were analyzed for reactivity against MCV epitopes and co-existent AMCV isotypes IgM and IgA. Antibody titers were determined by enzyme-linked immunosorbent assay at baseline and 24 weeks after the first cycle of RTX, and compared to kinetics of rheumatoid factor (RF) and antibodies against cyclic citrullinated peptide (ACCP)., Results: Recognized MCV epitopes by AMCV IgG of RRs and NRRs showed similar baseline patterns, with reducing reactivity in RRs and unchanged or even expanding reactivity in NRRs upon RTX treatment. At baseline, RRs were more frequently negative for AMCV subtypes, especially for IgA (68%), compared to NRRs (31%). Being AMCV IgA-negative at baseline indicated a good treatment response to RTX (negative predictive value = 0.86). Co-existence of AMCV IgA and IgG with stable titers upon treatment were associated with poorer responses to RTX. Furthermore, reductions of AMCV IgA levels upon RTX correlated with the improvement of 28-joint Disease Activity Score (DAS28). In comparison, subtypes of RF and ACCP were not of additional value for prediction of RTX response., Conclusions: Restrictive IgG seropositivity against MCV with treatment-associated decline in fine reactivity and titers was predictive for response to RTX. Double-positivity for AMCV IgG and IgA was associated with failure to respond to BCDT, suggesting a pathogenetic and less sensitive IgA-producing B-cell subset in NRRs.

Objectives: Antibodies against citrullinated antigens (ACPA) represent one rheumatoid arthritis (RA) classification criteria. Recently, mutated and citrullinated vimentin (MCV), containing approx. 45 potentially citrullinated sites, was characterised as another modified autoantigenic RA target. Therefore, we wanted to screen, select and validate predominant MCV autoantigenic epitopes (called here MCE) as possible new diagnostic targets., Methods: MCV-derived peptides with citrullinated sites were screened in healthy controls and patients. Based on this, twelve selected MCE were used for validation of ACPA isotypes (IgA/IgG/IgM) with ELISA in early RA (ERA, <12 months) and established RA (>12 months) Russian patients. Sensitivity of MCE reactivity was compared to commercially available ELISAs for anti-CCP IgG, anti-MCV IgG, and anti-RF IgA/IgM/IgG., Results: Anti-MCE IgG/IgA//IgM antibodies were observed in 64.1%, 23.1%, and 15.4% ERA, and 63.9%, 26.7%, and 13.1% established RA patients, respectively. Anti-MCV IgG was present in 64.1% ERA and 55.0% RA patients. Furthermore, anti-CCP IgG and RF IgG/IgA/IgM were detectable in up to 76.9%, 71.8%, 71.8%, and 38.5% ERA, and 80.1%, 72.3%, 67.5%, and 43.0% RA patients. Anti-CCP IgG single positivity was observed in 7.7% ERA and 6.3% RA patients. Only one RA patient was anti-MCE single positive., Conclusions: MCV autoantigenic epitopes were emulated by cyclic citrullinated MCV-derived peptides and recognised by all autoantibody-Ig subclasses in RA. Tested MCE were recognized more frequently by IgG as the original MCV antigen. High antibody prevalence against CCP epitopes suggests a strong CCP-linkage to RA pathogenesis in the investigated Russian cohort.