Detection of antiphosphatidylserine/prothrombin antibodies and their potential diagnostic value.

Antiprothrombin antibodies, measured with phosphatidylserine/prothrombin complex (aPS/PT) ELISA, have been reported to be associated with antiphospholipid syndrome (APS). They are currently being evaluated as a potential classification criterion for this autoimmune disease, characterized by thromboses and obstetric complications. Given the present lack of clinically useful tests for the accurate diagnosis of APS, we aimed to evaluate in-house and commercial assays for determination of aPS/PT as a potential serological marker for APS. We screened 156 patients with systemic autoimmune diseases for antibodies against PS/PT, ß2-glycoprotein I, cardiolipin and for lupus anticoagulant activity. We demonstrated a high degree of concordance between the concentrations of aPS/PT measured with the in-house and commercial assays. Both assays performed comparably relating to the clinical manifestations of APS, such as arterial and venous thromboses and obstetric complications. IgG aPS/PT represented the strongest independent risk factor for the presence of obstetric complications, among all tested aPL. Both IgG and IgM aPS/PT were associated with venous thrombosis, but not with arterial thrombosis. Most importantly, the association between the presence of IgG/IgM aPS/PT and lupus anticoagulant activity was highly significant. Taken together, aPS/PT antibodies detected with the in-house or commercial ELISA represent a promising serological marker for APS and its subsets.

Stroke and antiphospholipid syndrome-antiphospholipid antibodies are a risk factor for an ischemic cerebrovascular event.

Testing for antiphospholipid antibodies could be an important part in determining the cause of a cerebrovascular event (CVE). Currently, it is also unknown whether antiphospholipid antibodies represent a risk factor for the development of a CVE and whether the selected therapy options are efficacious. So, this study aimed at (1) determining the frequency of patients experiencing a CVE and fulfilling the laboratory criterion for an antiphospholipid syndrome (APS), (2) investigating whether the persistent presence of antiphospholipid antibodies represented a risk factor for a CVE, and (3) focusing on the efficacy of the selected treatment strategy in the first year after the CVE. Eighty-nine patients with an acute CVE were prospectively followed for 1 year. At least two sera from each were tested for lupus anticoagulants, anticardiolipin, anti-ß2-glycoprotein I, anti-phosphatidylserine/prothrombin and anti-annexin V antibodies. Twenty out of eighty-nine (22%) of CVE patients fulfilled the criteria for APS (17/20 for definitive and 3 for probable APS). There was a significant association between persistently present antiphospholipid antibodies and the CVE (OR, 4.62). No statistically significant difference was found in the CVE recurrence rate between APS-CVE and non-APS-CVE patients being treated mainly with acetyl salicylic acid. Antiphospholipid antibodies represent an independent risk factor for a CVE. In the first year after the CVE, antiplatelet therapy seemed to be sufficient in secondary CVE thromboprophylaxis in most APS patients.

Neutralizing effects of anti-infliximab antibodies on synergistically-stimulated human coronary artery endothelial cells.

BACKGROUND AND AIMS: Patients with rheumatic diseases have an increased risk of atherosclerosis with up-regulated serum amyloid A (SAA), tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß), which were reported to activate human coronary artery endothelial cells (HCAEC). We aimed to investigate the effects of TNF-α inhibitor infliximab and anti-infliximab antibodies on the TNF-α/IL-1ß/SAA activated HCAEC. METHODS: HCAEC were incubated with TNF-α, IL-1ß, SAA, infliximab, anti-infliximab antibodies and their combinations. The protein levels of pro- and anti-atherogenic analytes were measured in supernatants using ELISA and multiplex assays, while mRNA expression was determined by RT-PCR. Anti-infliximab antibodies were purified from sera samples by affinity chromatography. RESULTS: IL-6, IL-8, GM-CSF and GRO-α were synergistically up-regulated in triple stimulation with TNF-α, IL-1ß and SAA, while their levels in solely SAA- or TNF-α-stimulated HCAEC did not increase. IL-1Ra, IL-1α, VCAM-1, MCP-1, IL-10 and IL-17A were increased, but no synergistic responses were observed in triple stimulation. Infliximab was effective in lowering the synergistic effect of IL-6, IL-8, GM-CSF and GRO-α in triple stimulation, while anti-infliximab antibodies restored the levels. The changes were confirmed at the mRNA expression level for IL-6, IL-8 and GM-CSF. CONCLUSIONS: Triple stimulation with TNF-α, IL-1ß and SAA synergistically elevated IL-6, IL-8, GM-CSF and GRO-α release in supernatants of HCAEC, with infliximab substantially inhibiting their levels. An isolated, enriched fraction of polyclonal anti-infliximab antibodies was capable of neutralizing infliximab, in the presence of TNF-α/IL-1ß/SAA. The long-term presence of anti-infliximab antibodies in the circulation of patients with chronic rheumatic diseases is potentially important for promoting the atherosclerotic process.

Added value of non-criteria antiphospholipid antibodies for antiphospholipid syndrome: lessons learned from year-long routine measurements.

The international classification criteria for definite antiphospholipid syndrome (APS) include three laboratory measurements: lupus anticoagulant (LA), IgG and IgM isotypes of anti-cardiolipin (aCL) and anti-ß2glycoprotein I antibodies (anti-ß2GPI). When persistently elevated, they are specific for APS; however, many patients that fulfil clinical criteria may exhibit negative serological results. These "seronegative" APS (SN-APS) are exposed to an increased thrombotic risk. The aims of our cross-sectional, retrospective study of consecutive autoimmune patients' samples were to evaluate the association of non-criteria antiphospholipid antibodies (aPL) with thrombosis and obstetric events, to calculate the risk score for adverse events and to assess the specific contribution of single aPL positivity in SN-APS. LA, aCL, anti-ß2GPI and anti-phosphatidylserine/prothrombin antibodies (aPS/PT) of IgG, IgM, and IgA isotypes were determined in sera of 323 patients with autoimmune disorders. Medical records of all patients were carefully analyzed. aCL, anti-ß2GPI and aPS/PT of IgG and IgA isotypes were significantly associated with thrombosis while none of the IgM aPL showed such association. aPS/PT of all isotypes, aCL and anti-ß2GPI of IgG and IgA isotype showed significant correlation to obstetric events. When considering results of aPS/PT ELISA, we could additionally identify 3% of thrombotic patients and 2% of obstetric patients. Thrombotic and obstetric risk scores were calculated showing significantly higher association to clinical events, as compared to evaluating individual risk factors. aPS/PT could represent an additional biomarker in SN-APS patients. IgA aPL are associated with thrombosis and obstetric complications. Risk scores accounting different aPL and conventional risk factors, better assesses risk for adverse event, as compared to evaluating individual factors alone.

Do Early Diagnosis and Glucocorticoid Treatment Decrease the Risk of Permanent Visual Loss and Early Relapses in Giant Cell Arteritis: A Prospective Longitudinal Study.

To determine the incidence of permanent visual loss (PVL) in giant cell arteritis (GCA) and the GCA relapse rate during glucocorticoid (GC) tapering.This prospective, longitudinal single secondary/tertiary rheumatology centre study was conducted between September 2011 and September 2014 in Slovenia. Predetermined clinical and laboratory tests were performed at 12, 24, 48, 96, and 144 weeks after diagnosis.Sixty-eight GCA patients (72.1% female), with a median (IQR) age of 73.2 (67.3-76.1) years and a symptom duration before the diagnosis of a median (IQR) 30 (14-70) days were included. Thirty-nine of 68 patients had symptoms for less than 31 days (14 (10-28) days-early GCA) and 29/68 for 31 days or longer (90 (60-120) days-late GCA). Four (5.9%) patients presented with PVL (1 early GCA). The median (IQR) follow-up was (IQR) 104 (53-126) weeks. GCA relapsed in 17/39 (43.6%) and 14/29 (48.3%) in early and late GCA, respectively. The median (IQR) time to the first relapse was 24.8 (13.6-46.5) weeks (early GCA 14 (13-34) weeks; late GCA 25 (22-48) weeks, P = 0.117), at the methyl-prednisolone dose of 6.0 (4.0-12.0) mg. The patients who relapsed had significantly higher levels of inflammation parameters at the baseline (including ESR, CRP, serum amyloid A, haptoglobin, and fibrinogen).An early GCA diagnosis and prompt GC treatment decreased the PVL rate in comparison to historic controls, but seem to have no impact on the frequency of relapses, which are predicted by the high baseline levels of the biomarkers of inflammation.

AA amyloidosis in a polyarteritis nodosa patient treated with tocilizumab.

Amyloid A (AA) (secondary) amyloidosis represents a severe complication of chronic inflammatory diseases. Since pathogenic mechanisms point to the central role of interleukin 6 (IL-6) in the process of amyloid AA generation, IL-6 blockade seems an attractive therapeutic option. We report a case of a patient with polyarteritis nodosa complicated by AA amyloidosis treated with tocilizumab.