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.

Evaluation of phosphatidylserine-dependent antiprothrombin antibody testing for the diagnosis of antiphospholipid syndrome: results of an international multicentre study.

Objective A task force of scientists at the International Congress on Antiphospholipid Antibodies recognized that phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) might contribute to a better identification of antiphospholipid syndrome (APS). Accordingly, initial and replication retrospective, cross-sectional multicentre studies were conducted to ascertain the value of aPS/PT for APS diagnosis. Methods In the initial study (eight centres, seven countries), clinical/laboratory data were retrospectively collected. Serum/plasma samples were tested for IgG aPS/PT at Inova Diagnostics (Inova) using two ELISA kits. A replication study (five centres, five countries) was carried out afterwards. Results In the initial study ( n = 247), a moderate agreement between the IgG aPS/PT Inova and MBL ELISA kits was observed ( k = 0.598). IgG aPS/PT were more prevalent in APS patients (51%) than in those without (9%), OR 10.8, 95% CI (4.0-29.3), p < 0.0001. Sensitivity, specificity, positive (LR+) and negative (LR-) likelihood ratio of IgG aPS/PT for APS diagnosis were 51%, 91%, 5.9 and 0.5, respectively. In the replication study ( n = 214), a moderate/substantial agreement between the IgG aPS/PT results obtained with both ELISA kits was observed ( k = 0.630). IgG aPS/PT were more prevalent in APS patients (47%) than in those without (12%), OR 6.4, 95% CI (2.6-16), p < 0.0001. Sensitivity, specificity, LR + and LR- for APS diagnosis were 47%, 88%, 3.9 and 0.6, respectively. Conclusions IgG aPS/PT detection is an easily performed laboratory parameter that might contribute to a better and more complete identification of patients with APS.

Methotrexate reduces HbA1c concentration but does not produce chronic accumulation of ZMP in patients with rheumatoid or psoriatic arthritis.

OBJECTIVES: The mechanism by which methotrexate (MTX) improves glucose homeostasis in patients with rheumatoid (RA) and psoriatic arthritis (PsA) remains undetermined. Animal studies indicate a role for intracellular accumulation of 5-aminoimidazole-4-carboxamide-1-ß-d-ribofuranosyl 5'-monophosphate (ZMP) but this has not been directly demonstrated in humans. We explored whether accumulation of ZMP is associated with improvements in glucose homeostasis during MTX therapy. METHOD: MTX-naïve, non-diabetic RA (n = 16) and PsA (n = 10) patients received uninterrupted MTX treatment for 6 months. To evaluate whether ZMP accumulated during MTX therapy, we measured the concentration of ZMP in erythrocytes and the concentration of its dephosphorylated derivative 5-aminoimidazole-4-carboxamide-1-ß-d-ribofuranoside (AICAR) in urine using liquid chromatography mass spectrometry (LC-MS/MS). To assess glucose homeostasis, we determined the concentration of glycated haemoglobin (HbA1c) and homeostasis model assessment of insulin resistance [HOMA-IR: fasting glucose (mmol/L) × fasting insulin (µU/mL)/22.5]. RESULTS: Erythrocyte ZMP and urinary AICAR concentrations did not increase during 6 months of MTX therapy. HbA1c concentration was reduced from 5.80 ± 0.29% at baseline to 5.51 ± 0.32% at 6 months (p < 0.001), while HOMA-IR remained unaltered. Reduction in HbA1c concentration was not associated with increased ZMP or AICAR concentrations. CONCLUSIONS: MTX therapy probably does not produce a chronic increase in erythrocyte ZMP or urinary AICAR concentrations. Collectively, our data do not support the hypothesis that MTX improves glucose homeostasis through chronic accumulation of ZMP.

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.

Quantification of synovitis in the cranio-cervical region: dynamic contrast enhanced and diffusion weighted magnetic resonance imaging in early rheumatoid arthritis--a feasibility follow up study.

OBJECTIVE: To test the feasibility of dynamic contrast enhanced (DCEI) and diffusion weighted (DWI) magnetic resonance imaging (MRI) for quantifying synovitis of the cranio-cervical (C-C) region in patients with early rheumatoid arthritis (RA) and neck pain at the beginning and at a six month follow up. METHODS: 27 patients with duration of RA of less than 24 months and neck pain were studied with standard qualitative MRI evaluation and two quantitative MRI methods (DCEI and DWI) at the level of atlantoaxial joints. Rate of early enhancement (REE), enhancement gradient (Genh) and apparent diffusion coefficient (ADC) were extracted from DCEI and DWI data. MRI was coupled with clinical assessment and radiographic imaging. RESULTS: Using standard qualitative MRI evaluation, unequivocal active synovitis (grade 2 or 3 contrast enhancement) was proved in 16 (59%) patients at baseline and 14 (54%) at follow up. DCEI and DWI measurements confirmed active synovitis in 25 (93%) patients at baseline and 24 (92%) at follow up. Average REE, Genh and ADC values decreased during follow up, however the difference was not statistically significant (p>0.05). Both qualitative and quantitative MRI methods confirmed active inflammatory disease in the C-C region following therapy although all clinical criteria showed signs of improvement of the peripheral disease. CONCLUSIONS: The study proved the feasibility of DCEI and DWI MRI for quantifying synovitis of the C-C region in patients with early RA and neck pain. Both techniques can be used as additional method for evaluation of synovitis of the C-C region in RA.

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.

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.

Annexin A5 binding to giant phospholipid vesicles is differentially affected by anti-beta2-glycoprotein I and anti-annexin A5 antibodies.

OBJECTIVES: Anti-phospholipid antibodies have been recognized to play a role in vascular thrombosis and pregnancy morbidity. They were first thought to be directed to phospholipids, but it is now known that the majority of pathogenic antibodies recognizes epitopes on phospholipid-binding plasma proteins such as beta2-glycoprotein I (beta2GPI) or possibly also annexin A5 (ANXA5). The mechanism of their prothrombotic action is still not completely understood. The aim of the present study was to observe the effect of antibodies against ANXA5 (aANXA5) and antibodies against beta2GPI (abeta2GPI) on the binding of ANXA5 to the negatively charged phospholipid membrane. METHODS: Giant phospholipid vesicles (GPVs) were used as a simple model of the membrane surface. GPVs composed of phosphatidylserine and phosphatidylcholine were produced in an aqueous medium. A single GPV was transferred to the solution containing ANXA5 conjugated with Alexa Fluor 488 (FANXA5) and (i) aANXA5 or abeta2GPI and (ii) different concentrations of abeta2GPI together with beta2GPI. The emission of the fluorescent light from the GPV surface, as the result of FANXA5 binding, was measured. RESULTS: Beta2GPI together with abeta2GPI reduced the binding of FANXA5 to GPVs. On the contrary, aANXA5 enhanced the binding of ANXA5 to the GPV surface. CONCLUSIONS: Our results point to the competition between FANXA5 and complexes of beta2GPI-abeta2GPI for the same binding sites and therefore support the hypothesis of the disruption of the ANXA5 protective shield on procoagulant phospholipid surface. The influence of increased cell surface ANXA5 concentration in the presence of aANXA5 on coagulation needs to be further studied.

Ultrasonographic changes of major salivary glands in primary Sjogren's syndrome. Diagnostic value of a novel scoring system.

OBJECTIVES: To reveal typical ultrasonographic (US) changes in major salivary glands associated with Sjogren's syndrome (SS) and to determine the diagnostic value of a novel US scoring system. METHODS: In 218 consecutive patients with suspected SS, US of both parotid and submandibular salivary glands was performed besides the regular diagnostic procedure following the American-European Consensus Group criteria of 2002. Five US parameters were assessed: echogenicity, inhomogeneity, number of hypoechogenic areas, the hyperechogenic reflections and clearness of the borders of the salivary gland. The grades of these five parameters for all four salivary glands were summed. The final US score ranged from 0 to 48. RESULTS: SS was established in 68 patients. The remaining 150 subjects, in whom SS was not confirmed, constituted our control group. All five US parameters were significantly associated with SS. The patients with SS had significantly higher US scores than those not diagnosed with SS (P<0.01). Setting the cut-off US score at 17 resulted in the best ratio of specificity (98.7%) to sensitivity (58.8%). CONCLUSIONS: Well-defined US changes in the major salivary glands summarized in our novel scoring system were typical of SS patients. Advanced structural changes found on US imaging almost invariably represent SS salivary gland involvement.

Estimation of anticardiolipin antibodies, anti-beta2 glycoprotein I antibodies and lupus anticoagulant in a prospective longitudinal study of children with juvenile idiopathic arthritis.

OBJECTIVE: Anticardiolipin antibodies (aCL) have been frequently detected in juvenile idiopathic arthritis (JIA), but have not been associated with disease activity or clinical features of the antiphospholipid syndrome (APS). Our aim was to determine aCL and anti-beta2 glycoprotein I (anti-beta2GPI) antibody levels and lupus anticoagulant (LA) in serial samples from children with JIA and to investigate the clinical significance of these antibodies. METHODS: The values of aCL, anti-beta2GPI and LA were prospectively followed in 28 children with JIA from disease onset. aCL and anti-beta2GPI were assayed by an ELISA method. Two monoclonal beta2GPI-dependent aCL (HCAL and EY2C9) were used as calibrators. LA was determined by a modified dilute Russell viper venom time test. RESULTS: Thirteen (46.4%) children with JIA were already positive for aCL at their first referral to our center. During the follow-up, the frequency of aCL decreased from 46.4% to 28.6%; however, it remained significantly higher compared with healthy children. In contrast, for anti-beta2GPI the difference in the frequency between the children with JIA and healthy children was not statistically significant. Serial determination of aPL levels in JIA patients revealed frequent fluctuations. Positive aCL persisted over time in 6 (21.4%) children with JIA, 6 (21.4%) children were initially positive for aCL, but became later negative, and 3 (10.7%) children were initially negative for aCL and became later positive. Persistently positive anti-beta2GPI were observed during the follow-up only in one patient, while none of the patients was persistently positive for LA. No association between aCL, anti-beta2GPI or LA and disease activity could be established. No patient with positive aCL, anti-beta2GPI or LA showed any clinical feature of APS. CONCLUSION: The discrepancy between the presence of aCL and anti-beta2GPI might indicate that the production of aCL in JIA is associated with an infectious trigger. Furthermore, the low frequency of anti-beta2GPI and LA could explain the limited prothrombotic potential of aPL observed in JIA. However, we found a distinct group of JIA patients with persistently positive aCL, the clinical implications of which are at the present time unknown.

Anticardiolipin and anti-beta(2) glycoprotein I antibodies in sera of 61 apparently healthy children at regular preventive visits.

OBJECTIVES: To determine anticardiolipin (aCL) and anti-beta(2) glycoprotein I antibodies (anti-beta(2)GPI) in apparently healthy children and express the cut-off levels in concentrations of monoclonal antibodies, and to compare the mean values and frequencies of aCL and anti-beta(2)GPI in children with those in blood donors. METHODS: Blood samples were collected from 29 preschool children and 32 adolescents during their routine preventive follow-up visits. The control group consisted of 52 blood donors. aCL and anti-beta(2)GPI were assayed by an ELISA method. Two monoclonal beta(2)GPI-dependent aCL (HCAL and EY2C9) were used as calibrators. RESULTS: The estimated cut-off values for immunoglobulin G (IgG) and immunoglobulin M (IgM) aCL, expressed in concentrations of monoclonal antibodies and standardized international units (GPL/MPL units), were 13.9 ng/ml (7.6 GPL) and 33.1 ng/ml (3.3 MPL) for preschool children, 13.5 ng/ml (7.2 GPL) and 36.9 ng/ml (4.0 MPL) for adolescents, and 14.4 ng/ml (8.0 GPL) and 42.6 ng/ml (5.1 MPL) for blood donors. No statistically significant differences in the mean values for IgG and IgM aCL were found between the age groups. The mean value of IgA aCL was significantly higher in blood donors than in preschool children and adolescents (P<0.037 and P<0.025 respectively). Seven (11.4%) of 61 apparently healthy children had low positive values for aCL (IgG for all seven). The estimated cut-off values for IgG and IgM anti-beta(2)GPI were 4.2 and 13.1 ng/ml respectively for preschool children, 3.2 and 13.1 ng/ml for adolescents, and 2.9 and 20.5 ng/ml for blood donors. The mean value for IgG anti-beta(2)GPI was found to be higher in preschool children than in adolescents and blood donors (P<0.0001 and P<0.0001). The mean values for IgM and IgA anti-beta(2)GPI were higher in blood donors than in preschool children (IgM, P<0.007; IgA, P<0.0001) and adolescents (IgM, P<0.01; IgA, P<0.0001). Four (6.6%) of 61 apparently healthy children had positive values for anti-beta(2)GPI (two for IgG and two for IgA). CONCLUSIONS: This is the first report in which the cut-off values for aCL and anti-beta(2)GPI in children are expressed in concentrations of monoclonal antibodies. Low titres of aCL, which were identified frequently in apparently healthy children, were hypothesized to be the result of previous infections. The high mean value of IgG anti-beta(2)GPI observed in preschool children was an unexpected result of the study and might indicate a default response to nutritional exposure to beta(2)GPI in this age group.

Anti-beta2-glycoprotein I ELISA: methodology, determination of cut-off values in 434 healthy Caucasians and evaluation of monoclonal antibodies as possible international standards.

Antibodies against beta2-glycoprotein I are among the most commonly detected subset of antiphospholipid antibodies. The inter-laboratory comparability of results is hardly possible due to methodological differences, lack of international standards and different cut-off values. We evaluated an ELISA for the detection of anti-beta2-glycoprotein I using the analytical goals based on biological variations for similar analytes (immunoglobulins). By our ELISA we fulfilled the optimal (IgA, IgM) or minimal (IgG) analytical goals in long-term imprecision. The determination of cut-off values was based on the frequency distribution of results obtained on 434 healthy Caucasians. To aim at a better inter-laboratory comparability we tested two monoclonal antibodies as possible calibrators: HCAL (IgG) and EY2C9 (IgM). Binding properties determined by dilutional curves showed great similarities with polyclonal sera, used as in-house standards. Cut-off values were expressed by concentrations of IgG and IgM monoclonal antibodies (4.5 and 25.3 microg/l). Our study shows the possibility for a successful application of analytical goals based on biological variation even when data for a particular analyte are not available. The expression of cut-off values, obtained on a large scale Caucasian population, by the concentration of IgG and IgM monoclonal antibodies could make possible a more reliable inter-laboratory comparison of data.