The immunogenicity of seasonal and pandemic influenza vaccination in autoimmune inflammatory rheumatic patients-a 6-month follow-up prospective study.

INTRODUCTION: Influenza may cause severe complications in patients with autoimmune inflammatory rheumatic disease (AIRD), to whom vaccinations are especially recommended. However, AIRD patients require cautious scrutiny of immunogenicity as they might exhibit poor antibody response to vaccination, especially when taking immunomodulatory medications. AIM: The aim was to determine immunogenicity of seasonal and pandemic influenza vaccine in AIRD patients, its timeline/persistence, and influence of medications on immune response. METHODS: One hundred and thirty-seven AIRD and 54 healthy controls were vaccinated with trivalent seasonal influenza. After 3-5 weeks, 15 healthy controls and 93 AIRD were vaccinated with pandemic influenza vaccine, and 63 of patients were vaccinated a second time after 3-5 weeks. Sera were collected before vaccination, 18-90 days after each vaccination, and more than 180 days after the last vaccination. The immune response was measured using hemagglutination inhibition (HI) assay and IgG/IgA antibodies against influenza A/B with ELISA. RESULTS: Our findings indicate that following vaccination with seasonal influenza vaccine, seroprotection, seroresponse, and change in geometric mean titers (GMT) in AIRD patients was not compromised compared to healthy. Similarly, we report for pandemic influenza vaccination little added benefit of the second dose. We confirm lowest increase in HI titer in rituximab-treated AIRD compared to other medications. Vaccination largely tilts the balance from negative ELISA A IgG and IgA titers to positive titers in seasonal H1N1 seroresponsive AIRD patients and controls. A significant decrease in HI GMT and seroprotection was observed only in AIRD at > 180 days after vaccination highlighting an absent persistence of immunogenic response in AIRD patients. Due to high initial HI titers for influenza vaccine, we foresee their benefit in personalized medicine in the future. CONCLUSION: Influenza vaccination is immunologically active for AIRD, with little value of the second dose of the pandemic vaccine and further scrutiny on persistence of immune response to vaccine in AIRD is needed.

Autoantibodies against dsDNA measured with nonradioactive Farr assay-an alternative for routine laboratories.

Autoantibodies against dsDNA are utilized for the diagnosis and prognosis of SLE as they are highly specific and correlate with disease activity/renal involvement. However, different detection methods are used in routine diagnostic laboratories. Farr radioimmunoassay (Farr-RIA) has been designated as the preferred method, since it provides very specific and at the same time quantitative results, enabling follow-up of level variations over time. Using intercalating fluorescent dsDNA dye would enable all the benefits of Farr-RIA without the radioactive material and organic solvents. To develop a modified fluorescent Farr method (Farr-FIA) and compare it to the classical Farr-RIA in regard to laboratory parameters, as well as clinical utility. Assays were tested on sera of 70 SLE patients, 78 other autoimmune patients, and 145 healthy blood donors. DNA for Farr-FIA was isolated from healthy donor, for Farr-RIA, 14C-labeled dsDNA from E. coli was used and mixed with sera in borate-buffered saline, followed by precipitation with saturated ammonium sulfate solution and centrifugation. The supernatant (S) was separated from the precipitate (P), and content of dsDNA was measured with PicoGreen (Invitrogen) in Farr-FIA or radioactive isotope in scintillation solution in Farr-RIA. The results were calculated as a ratio (P-S)/(P+S). Farr-FIA has a diagnostic sensitivity of 53% and diagnostic specificity of 100% (ROC AUC 0.781). Good correlation and agreement were shown between Farr-RIA and Farr-FIA. Also, there is good correlation between Farr-FIA and SLEDAI, comparable to that of Farr-RIA. Farr-FIA differs from Farr-RIA in the changed detection system yielding comparable results and thus could represent a nonradioactive replacement for Farr-RIA.

Insight into inflammatory cell and cytokine profiles in adult IgA vasculitis.

Immunoglobulin A vasculitis (IgAV) is an immune complex, small vessel vasculitis with dominant IgA deposits in vessel walls, predominantly affecting the pediatric population. However, adults frequently have more severe gastrointestinal tract (GIT) and renal involvements as compared to children. Our aim was to study serological and cellular biomarkers to support clinicians in their diagnosis and the course of IgAV in adult patients. This cross-sectional study included 62 adult IgAV patients and 53 healthy blood donors (HBDs). Demographic and clinical data, as well as routine laboratory tests, were meticulously analyzed. Serum levels of IL-1ß, IL-2, IL-6, IL-8, IL-9, IL-10, IL-17A, IL-23, TNF-α and serum amyloid A (SAA) were measured. Percentages of neutrophils, lymphocytes, and monocytes with neutrophil expression of L-selectin and integrin αM were determined by flow cytometry. SAA (12-fold), IL-6 (3-fold), IL-8 (2-fold), and TNF-α (2-fold) were significantly elevated in sera of adult IgAV patients compared to HBDs. There was a 16% elevation in neutrophils in IgAV patients, with IgAV neutrophils showing significantly higher CD62L surface expression. IgAV patients with GIT involvement exhibited elevated numbers of leukocytes, neutrophils, and neutrophil/lymphocyte (NLR), but lower neutrophil CD11b expression, as compared to IgAV patients without GIT. IgAV patients exhibit a low-medium grade inflammatory, neutrophil-driven response. Patients with GIT can be distinguished by their elevated NLR.

Evaluating the utility of autoantibodies for disease activity and relapse in giant cell arteritis.

In patients with giant cell arteritis (GCA), autoantibodies against cytoskeletal elements, cardiolipin, neutrophil cytoplasmic antigens, ferritin, endothelial and smooth muscle cells have been reported, however no updated reviews are available evaluating their clinical utility. Methodology of detection is important, especially for quantitative assays, e.g. enzyme-linked immunoassays and multiplex beadbased immunoassays, while semiquantitative assays contribute valuable data on isoforms, epitope mapping and cellular localization. Most studies to date reporting on antiphospholipid antibodies in GCA have focused on anti-cardiolipin antibodies (aCL), while the highest prevalence of autoantibodies in GCA patients was reported for the anti-N-terminal peptides of the ferritin heavy chain (92%). Antineutrophil cytoplasmic antibodies were shown to be present in only a small percentage of GCA patients, decreasing after therapy, however in combination with aCL and antibodies against peptides of N-terminal ferritin heavy chain, they could represent an added value in detecting relapse in GCA patients.

Analysis of Drug Effects on Primary Human Coronary Artery Endothelial Cells Activated by Serum Amyloid A.

BACKGROUND: RA patients have a higher incidence of cardiovascular diseases compared to the general population. Serum amyloid A (SAA) is an acute-phase protein, upregulated in sera of RA patients. AIM: To determine the effects of medications on SAA-stimulated human coronary artery endothelial cells (HCAEC). METHODS: HCAEC were preincubated for 2 h with medications from sterile ampules (dexamethasone, methotrexate, certolizumab pegol, and etanercept), dissolved in medium (captopril) or DMSO (etoricoxib, rosiglitazone, meloxicam, fluvastatin, and diclofenac). Human recombinant apo-SAA was used to stimulate HCAEC at a final 1000 nM concentration for 24 hours. IL-6, IL-8, sVCAM-1, and PAI-1 were measured by ELISA. The number of viable cells was determined colorimetrically. RESULTS: SAA-stimulated levels of released IL-6, IL-8, and sVCAM-1 from HCAEC were significantly attenuated by methotrexate, fluvastatin, and etoricoxib. Both certolizumab pegol and etanercept significantly decreased PAI-1 by an average of 43%. Rosiglitazone significantly inhibited sVCAM-1 by 58%. CONCLUSION: We observed marked influence of fluvastatin on lowering cytokine production in SAA-activated HCAEC. Methotrexate showed strong beneficial effects for lowering released Il-6, IL-8, and sVCAM-1. Interesting duality was observed for NSAIDs, with meloxicam exhibiting opposite-trend effects from diclofenac and etoricoxib. This represents unique insight into specific responsiveness of inflammatory-driven HCAEC relevant to atherosclerosis.

A concise review of significantly modified serological biomarkers in giant cell arteritis, as detected by different methods.

Giant cell arteritis (GCA) is a primary systemic vasculitis present in subjects older than 50years with involvement of large- and medium-sized arteries. Early diagnosis for GCA is essential to prevent serious complications, such as permanent vision loss and/or cerebrovascular events. Elevated inflammatory cytokines, with acute phase and other proteins dominate large- and medium-sized arteries leading to stenosis or occlusion of arterial lumen. To date, there are no reliable serological markers for monitoring GCA. The review aims to provide concise overview of published GCA studies in order to: a) identify significantly changed serological biomarkers in GCA and compare the influences of techniques for marker evaluation and b) investigate most promising markers in GCA using analyte frequency and meta-analysis.

Oxidatively altered IgG with increased immunoreactivity to ß2-glycoprotein I and its peptide clusters influence human coronary artery endothelial cells.

Oxidative stress has been shown to play a role in modifying antibodies in favor of higher auto-immunoreactivity. We studied the immunoreactivity of oxidized IgG (oxIgG) to ß2-glycoprotein I (ß2GPI), six peptide sequences corresponding to amino acid clusters on its different domains, to determine their effects on human coronary artery endothelial cells (HCAEC). Human IgG was purified from seven donors, electro-oxidized and checked for immunoreactivity and avidity to ß2GPI and to peptides by ELISA. Conformational stability and antibody-antigen complex formation of oxIgG was analyzed by fluorescence spectroscopy and dynamic light scattering. Resting and activated sub-confluent HCAEC were stimulated with oxIgG or IgG. Secreted cytokines were measured by ELISA. Immunoreactivity of seven oxIgG samples increased to 7.5-fold against ß2GPI and to 3.8-fold against six peptides as compared to IgG. oxIgG showed low avidity "properties." Conformational changes and exposure of protein hydrophobic regions were confirmed by an elevation in fluorescence (2.4- to 5.0-fold) on bis-ANS dye binding to oxIgG. oxIgG significantly elevated the release of GROα and IL-8 in resting and activated states of HCAEC. Oxidation alters IgG in favor of autoreactivity toward whole ß2GPI and corresponding peptides on different domains of ß2GPI and could lead to dysfunction of arterial endothelium by upregulation of chemokines.

Immunoreactivity and avidity of IgG anti-ß2-glycoprotein I antibodies from patients with autoimmune diseases to different peptide clusters of ß2-glycoprotein I.

The pathogenicity of antibodies against ß2-glycoprotein I (anti-ß2GPI) depends on multiple factors such as subclass type, epitope binding and avidity. Due to their large heterogeneity, their impact on antiphospholipid syndrome (APS) onset is still not fully clarified. We studied the binding characteristics of IgG anti-ß2GPI with known avidity from sera of 201 autoimmune patients (87 with APS, 67 with APS associated with systemic lupus erythematosus (SLE), 47 with only SLE) to six ß2GPI peptides corresponding to amino acid clusters on domains I-II, II, III and III-IV by indirect ELISA and evaluated their association with clinical features of APS. Peptides A (LKTPRV; domain I-II), B (KDKATF; domain IV) and C (TLRVYK; domain III) were derived from a hexapeptide phage display library previously shown to react with pathogenic monoclonal anti-ß2GPI. Peptides D (NGPANSK; domain III), E (YNPLWFV; domain II) and F (KMDGNHP; domain III-IV) represent surface amino acid clusters on ß2GPI. The percentage of patients positive for peptides were observed as follows: 30.3% for peptide D, 28.90% for B, 25.9% for C, 24.9% for E, 24.4% for F and 10.0% for A. The anti-peptide antibodies in studied serum samples were predominantly of heterogeneous avidity, followed by law avidity anti-peptide antibodies, whereas only a few were of high avidity. Positive and negative correlations were found between several anti-peptide antibodies and the rate of thrombosis. Our results indicated diverse reactivity of IgG anti-ß2GPI to different epitopes on ß2GPI. Classification of IgG anti-ß2GPI into subgroups regarding epitope specificity and avidity could represent an additional tool in understanding their pathogenicity in APS.

Avidity of anti-ß2-glycoprotein I antibodies in patients with antiphospholipid syndrome.

Antibodies against ß(2)-glycoprotein I (anti-ß(2)GPI) are one of the hallmarks of the antiphospholipid syndrome (APS). However, they are heterogenic regarding their epitope specificity, pathogenic mechanisms and their avidity. In the current study we present some outstanding issues about avidity of anti-ß(2)GPI antibodies. Our results confirmed that high avidity anti-ß(2)GPI are associated with thrombosis and APS, while in low avidity anti-ß(2)GPI group non-APS (predominantly systemic lupus erythematosus) patients prevailed.

Antibodies to phosphatidylserine/prothrombin complex as an additional diagnostic marker of APS?

Antiprothrombin antibodies can be measured by ELISA using either a prothrombin/phosphatidylserine complex (aPS/PT) or prothrombin alone (aPT) as antigen. We aimed to compare the clinical features of autoimmune patients with avidity of aPS/PT and determine the diagnostic efficiency of aPS/PT and aPT for assessing antiphospholipid syndrome (APS). aPS/PT were of low (n = 9), heterogeneous (n = 31) and high (n = 8) avidity out of 48 cases. None of the samples with low avidity were positive in aPT ELISA. Among patients with heterogeneous or high avidity aPS/PT, there was a significantly greater number of patients with APS as compared to patients with low avidity (38/39 vs. 7/9; p < 0.05). No SLE patients had high avidity antiprothrombin antibodies.

Safety and efficacy of influenza vaccination in a prospective longitudinal study of 31 children with juvenile idiopathic arthritis.

OBJECTIVES: Influenza vaccination in children with rheumatic diseases is often recommended, but not frequently performed. Our aim was to assess the safety and efficacy of annual influenza vaccination in a longitudinal follow-up study of an unselected group of children with juvenile idiopathic arthritis (JIA). METHODS: Thirty-one children with stable JIA (10 boys, 21 girls, mean age 11.0 years) receiving various therapies and 14 children in a control group (10 boys, 4 girls, mean age 11.9 years) were vaccinated with the annual influenza vaccine Begrivac® 2008/2009. The children in both groups were followed for adverse events and infections 6 months after vaccination. Autoantibodies production and antibody titers against three vaccine viruses were determined in serial samples taken before, 1 and 6 months after vaccination. RESULTS: Eleven (35%) children with JIA and 5 (36%) children in the control group reported short-term adverse events. A JIA flare was observed one month after vaccination in 4 (13%) patients, and in the following five months in 7 (23%) patients. The response to vaccination after one month was significant in the control and study groups as a whole, but not in a subgroup of 4 children receiving anti-TNF-α therapy. After six months, no significant differences in the protective titers against vaccine viruses among the patient and control groups were observed. Changes in the mean values of autoantibodies after vaccination were found only for IgG aCL in the JIA group. CONCLUSIONS: No long-term adverse events were reported after influenza vaccination in JIA and control group. Thirty-five percent of children with JIA experienced flare of the disease after vaccination. Protective antibodies against at least 2 vaccine viruses 6 months after vaccination were detected in all patients.

Autoimmune response following influenza vaccination in patients with autoimmune inflammatory rheumatic disease.

Vaccines have undoubtedly brought overwhelming benefits to mankind and are considered safe and effective. Nevertheless, they can occasionally stimulate autoantibody production or even a recently defined syndrome known as autoimmune/inflammatory syndrome induced by adjuvants (ASIA). There is scarce data regarding autoimmune response after seasonal/influenza A (H1N1) vaccine in patients with autoimmune inflammatory rheumatic disease (AIRD). The objective of our study was therefore to determine autoimmune response in a large group of AIRD patients vaccinated against seasonal and/or H1N1 influenza. We conducted a prospective cohort study with a 6-month follow-up. Two-hundred and eighteen patients with AIRD (50 vaccinated against seasonal influenza, six against H1N1, 104 against both, 58 non-vaccinated controls) and 41 apparently healthy controls (nine vaccinated against seasonal influenza, three against H1N1, 18 against both, 11 non-vaccinated controls) were included. Blood samples were taken and screened for autoantibodies [antinuclear antibody (ANA), anti-extractable nuclear antigen (anti-ENA), anticardiolipin (aCL) IgG/IgM antibodies, anti-beta 2-glycoprotein I (anti-ß2GPI)] at inclusion in the study, before each vaccination, 1 month after the last vaccination and 6 months after inclusion. For non-vaccinated participants (patients and healthy controls) blood samples were taken at the time of inclusion in the study and 6 months later. We report that after the administration of seasonal/H1N1 vaccine there were mostly transient changes in autoantibody production in AIRD patients and in healthy participants. However, a small subset of patients, especially ANA-positive patients, had a tendency towards anti-ENA development. Although no convincing differences between the seasonal and H1N1 vaccines were observed, our results imply that there might be a slight tendency of the H1N1 vaccine towards aCL induction. Although seasonal and H1N1 vaccines are safe and effective, they also have the potential to induce autoantibodies in selected AIRD patients and healthy adults. Follow-up of such individuals is proposed and further research is needed.

The avidity of anti-beta2-glycoprotein I antibodies in patients with or without antiphospholipid syndrome: a collaborative study in the frame of the European forum on antiphospholipid antibodies.

OBJECTIVE: The objective of this study was to extend the findings of the preliminary study by measuring the avidity of IgG anti-ß2-glycoprotein I antibodies (anti-ß2-GPI) on a larger group of patients with primary or secondary antiphospholipid syndrome (APS) and anti-ß2-GPI positive patients without APS in the frame of the European Forum on antiphospholipid antibodies (aPL). METHODS: Serum from 137 patients with primary APS, APS associated with autoimmune diseases, and patients with autoimmune diseases other than APS from five EU rheumatology centres were tested for anti-ß2-GPI antibodies. The 109 patients who were sera positive for anti-ß2-GPI by the in-house anti-ß2-GPI enzyme-linked immunosorbent assay (ELISA) at the Immunology Laboratory, UMC Ljubljana were selected for further testing on avidity with chaotropic anti-ß2-GPI ELISA. RESULTS: High, low and heterogeneous avidity IgG anti-ß2-GPI was found in 32/109, 17/109 and 60/109 patients respectively. Significantly more patients with APS were in the high avidity than in the low avidity anti-ß2-GPI group, while the opposite was observed for non-APS (both p < 0.001). The most common clinical feature among patients with high avidity anti-ß2-GPI was thrombosis, mainly due to venous thrombosis (p < 0.01 and p < 0.001, versus low avidity anti-ß2-GPI group). CONCLUSION: Patients with or without APS had anti-ß2-GPI of high, low or heterogeneous avidity. High avidity anti-ß2-GPI was associated with thrombosis and APS, while in the low avidity anti-ß2-GPI group non-APS (predominantly SLE) patients prevailed. Determination of anti-ß2-GPI avidity should be considered in the analytical strategies for further differentiation of patients with anti-ß2-GPI antibodies.

An international multicentre-laboratory evaluation of a new assay to detect specifically lupus anticoagulants dependent on the presence of anti-beta2-glycoprotein autoantibodies.

BACKGROUND: Antiphospholipid syndrome (APS) is diagnosed by the simultaneous presence of vascular thrombosis and/or pregnancy morbidity and detection of antiphospholipid antibodies in plasma. OBJECTIVES: We have shown that prolongation of clotting time by anti-beta2-glycoprotein I (beta2GPI) antibodies correlates better with thrombosis than a positive classic lupus anticoagulant (LAC) assay in a single center study. To confirm or falsify this finding we have conducted a multicenter study. METHODS AND RESULTS: In 325 LAC-positive samples, we found that the beta2GPI-dependent LAC correlated 2.0 times better with thrombosis than the classic LAC assay. Although significant, this was a minimal improvement compared with the 'classic' LAC. It was published that calcium influences the behavior of anti-beta2GPI antibodies in coagulation assays. To investigate whether calcium plays a role in the present study, we divided the patient population into two groups: (i) blood was collected in 0.109 m sodium citrate and (ii) blood was drawn in 0.129 m sodium citrate as anticoagulant. We found that a positive result with the beta2GPI-dependent LAC assay correlated better with thrombosis [odds ratio (OR): 3.3, 95% confidence interval (CI) 1.9-5.8] when 0.109 m sodium citrate was used compared with 0.129 m sodium citrate (OR: 0.4, 95% CI 0.1-1.1). CONCLUSION: We were able to confirm in an international multicenter study that a positive result in a beta2GPI-dependent LAC assay correlates better with thrombosis than the classic LAC assay, but that the assay needs further study as it is sensitive to external factors such as the sodium citrate concentration used as anticoagulant in the test sample.

Autoimmune response following annual influenza vaccination in 92 apparently healthy adults.

OBJECTIVE: To evaluate the possibility of autoimmune responses following annual influenza vaccination in a large cohort of apparently healthy adults. METHODS: Autoantibodies including antinuclear antibodies (ANA), anticardiolipin antibodies (aCL), anti-beta(2)-glycoprotein I antibodies (anti-beta(2)-GPI), lupus anticoagulant (LA) and anti-extractable nuclear antigen antibodies (anti-ENA) were determined in 92 healthy adult subjects, staff at the University Children's Hospital Ljubljana. Blood samples were taken from each participant before the vaccination, 1 month and 6 months after the annual influenza vaccination. RESULTS: Before the influenza vaccination, 26% of participants were positive for ANA, 16% for aCL, 7% for anti-beta(2)-GPI, 2% for LA and 1% for anti-ENA. There were no statistically significant differences in the percentage of positive ANA, aCL, anti-beta(2)-GPI, LA and anti-ENA before, 1 month and 6 months after the vaccination. One month after the vaccination 24% of participants demonstrated changes in the levels of autoantibodies including 15% of participants with increased level of autoantibodies or appearance of new autoantibodies. Six months after the vaccination 26% of participants demonstrated changes in the levels of autoantibodies including 13% of participants with increased level of autoantibodies or appearance of new autoantibodies. Persistently elevated levels of autoantibodies were observed in 7 (8%) participants and 2 showed progressively increased levels of IgM aCL or IgA anti-beta(2)-GPI, respectively. Eleven participants had a transient increase in autoantibodies. DISCUSSION: Influenza vaccination in general did not alter the percentage of healthy adults with positive autoantibodies. Transiently or persistently increased levels of autoantibodies or appearance of new autoantibodies was demonstrated in up to 15% of apparently healthy adults after the influenza vaccination.

Autoimmune and proinflammatory activity of oxidized immunoglobulins.

AIMS: Oxidation reactions can modify protein activity or specificity. Recently, a novel redox-reactive family of autoantibodies was described, which indicated involvement of altered antibodies (beside altered antigens) into autoimmune reactions. The aim of our study was to determine the binding capacity alterations of electro-oxidized blood donors' IgGs, and to evaluate their effects on released proinflammatory interleukin 6 in HUVEC. RESULTS: We found out that 1.) Isolated blood donor IgGs bound after electro-oxidation to beta2-glycoprotein I, cardiolipin, citrullinated cyclic peptide and protein 3 by enzyme-linked immunosorbent assay, extractable nuclear antigens by counterimmuno-electrophoresis, and cell antigens by indirect immunofluorescence; 2.) Alterations in immunoreactivity of IgGs due to oxidation highly depend on electric current, time of exposure and the presence of antioxidants, 3.) Treatment of HUVEC with oxidized IgGs resulted in changed cell morphology, accompanied by an increase in released interleukin-6. CONCLUSIONS: Our data suggest repeatable transformation of antibodies present in the blood of healthy persons and patients. Inter-individual differences in chemical stability of antibodies, patient's antioxidant status, and the microenvironmental changes at the cellular level may influence the range of antibody alterations and their involvement in pathophysiological autoimmune processes.

Prevalence and clinical associations of anti-Ku antibodies in patients with systemic sclerosis: a European EUSTAR-initiated multi-centre case-control study.

OBJECTIVES: To determine the prevalence of anti-Ku antibodies in 625 patients with systemic sclerosis (SSc) from six European rheumatological centres and to evaluate their clinical and serological characteristics. METHODS: Sera of 625 consecutive patients with either limited cutaneous or diffuse cutaneous SSc were tested for antibodies to Ku antigen together with other extractable nuclear antigens by counterimmunoelectrophoresis. A case-control design with calculation of bootstrap 95% confidence intervals derived from anti-Ku negative control patients was used to evaluate clinical associations of anti-Ku antibodies. Sera from anti-Ku positive patients with SSc and a control group were additionally tested by immunofluorescence on Hep-2 cell substrates and line immunoassay. RESULTS: Anti-Ku antibodies were found in the sera of 14/625 (2.2%) patients with SSc. Of 14 anti-Ku positive patients with SSc, 10 had no other anti-extractable nuclear antigen (ENA) antibodies detected by counterimmunoelectrophoresis. Using a case-control study design, anti-Ku antibodies were significantly associated with musculoskeletal manifestations such as clinical markers of myositis, arthritis and joint contractures. In addition, a significant negative correlation of anti-Ku antibodies was found with vascular manifestation such as fingertip ulcers and teleangiectasias. There was a striking absence of anti-centromere antibodies as well as anti- polymyositis (PM)/scleroderma (Scl) antibodies in patients that were anti-Ku positive. As expected, anti-Scl70 and punctate nucleolar immunofluorescence patterns were present only in single cases. CONCLUSION: This is the largest cohort to date focusing on the prevalence of anti-Ku antibodies in patients with SSc. The case-control approach was able to demonstrate a clinically distinct subset of anti-Ku positive patients with SSc with only relative clinical differences in skeletal features. However, the notable exceptions were signs of myositis. This shows the importance of anti-Ku antibody detection for the prediction of this specific clinical subset.

Serum amyloid A in autoimmune thrombosis.

The objectives of this study were (1) to determine how levels of serum amyloid A (SAA), high sensitivity C-reactive protein (CRP) and interleukin-6 (IL-6) correlate to autoimmune diseases in patients with or without thrombosis, and (2) to discuss the parameters that influence the relative SAA values. SAA, CRP and IL-6 concentrations were determined by enzyme linked immunosorbent assay (ELISA). 84 patients with secondary antiphospholipid syndrome (SAPS), primary antiphospholipid syndrome (PAPS), systemic lupus erythematosus with antiphospholipid antibodies (SLE+aPL), SLE, venous thrombosis (VT), arterial thrombosis (AT) were compared to healthy donors (n=60). The percentages of patients above cut-off were highest in the SAPS, SLE and SLE+aPL groups. Significant differences were observed between healthy donors and inflammatory groups of patients (SAPS and SLE+aPL) in all three measured parameters. SAA and CRP were shown to be correlated to a greater extent in SAPS patients than SLE+aPL patients. In summary, this cross-sectional, retrospective, small study and accompanying clinical considerations limit the ability to make definite conclusions. SAA would not serve as a useful marker for venous, arterial thrombosis or PAPS (pro-coagulant events). It could however, be a good predictor of progression from a non-inflammatory thrombotic condition to an inflammatory one.

Changes in avidity and specificity of IgG during electro-oxidation. Relevance of binding of antibodies to beta2-GPI.

The immune response may be changed due to altered proteins or modifications of immunoglobulins, including oxidative processes. The susceptibility to oxidative modifications depends greatly on amino-acid moiety composition due to chemical characteristics (instability) of their side-chains. Initial steps of oxidation may change the specificity and avidity of immunoglobulins due to chemical alteration of the hypervariable region. The oxidation of antibodies increases the hydrophilic nature of the paratopes and makes them more susceptible for the binding to cationic surfaces even without the strong surface-to-surface fitting. The electro-oxidation of IgG significantly changes the immunoreactivity and specificity of IgG fractions, regardless of the initial immunoreactivity to a specific autoantigen also in healthy persons. Data are presented on changes in the immunoreactivity as well as the avidity of antibodies against beta2-glycoprotein I after being exposed to direct current. ELISA measurements showed increased reactivity of anti-beta2-glycoprotein I antibodies at the beginning and various, fluctuating results after prolonged exposure to electro-oxidation. Inter-individual differences in chemical stability of immunoglobulins and patient's antioxidative status may influence the range of their alterations and their impact on health/disease balance.