Clinical associations of proinflammatory cytokines, oxidative biomarkers and vitamin D levels in systemic lupus erythematosus.

Background The abnormal biological activity of cytokines plays an important role in the pathophysiology of both systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). Several studies have highlighted the association of vitamin D and certain pro-inflammatory cytokines with disease activity in SLE. However, there are limited data on the association of vitamin D and antiphospholipid antibodies (aPL) with various proinflammatory biomarkers in these patients and their relative impact on clinical outcomes. Methods The serum levels of several aPL, 25-hydroxy-vitamin D, pro-inflammatory cytokines including IFNα, IL-1ß, IL-6, IL-8, IP10, sCD40L, TNFα and VEGF were measured in 312 SLE patients from the Jamaican ( n = 45) and Hopkins ( n = 267) lupus cohorts using commercial Milliplex and ELISA assays. Oxidized LDL/ß2glycoprotein antigenic complexes (oxLß2Ag) and their associated antibodies were also measured in the Jamaican cohort. Healthy controls for oxidative marker and cytokine testing were used. Results Abnormally low vitamin D levels were present in 61.4% and 73.3% of Hopkins and Jamaican SLE patients, respectively. Median concentrations of IP10, TNFα, sCD40L and VEGF were elevated in both cohorts, oxLß2Ag and IL-6 were elevated in the Jamaican cohort, and IFNα, IL-1ß and IL-8 were the same or lower in both cohorts compared to controls. IP10 and VEGF were independent predictors of disease activity, aPL, IP10 and IL-6 were independent predictors of thrombosis and IL-8, and low vitamin D were independent predictors of pregnancy morbidity despite there being no association of vitamin D with pro-inflammatory cytokines. Conclusions Our results indicate that aPL-mediated pro-inflammatory cytokine production is likely a major mechanism of thrombus development in SLE patients. We provide presumptive evidence of the role IL-8 and hypovitaminosis D play in obstetric pathology in SLE but further studies are required to characterize the subtle complexities of vitamin D's relationship with cytokine production and disease activity in these patients.

A unique antiphospholipid assay recognizing phospholipid mixture compared with criteria antiphospholipid immunoassays in lupus patients.

Background While essential for the classification of antiphospholipid syndrome (APS), anticardiolipin (aCL) assays lack specificity and anti-ß2glycoproteinI (anti-ß2GPI) assays lack sensitivity in this regard. Our aim was to perform a comparative analysis of the APhL ELISA assay (IgG/IgM) and criteria antiphospholipid (aPL) immunoassays in identifying APS-related clinical manifestations in a large group of patients with systemic lupus erythematosus (SLE). Methods Serum samples from 1178 patients from the Hopkins ( n = 543), LUMINA ( n = 588) and Jamaican SLE cohorts ( n = 47) were examined for IgG/IgM positivity in aCL (in-house), anti-ß2GPI (two commercial kits) and APhL (Louisville APL) ELISA assays. Correlation of assay positivity with clinical manifestations and sensitivity, specificity, positive and negative predictive values and likelihood ratios were evaluated. A case series analysis was also performed in patients for whom there was isolated positivity in the specific aPL assays. Results The prevalence of aCL positivity was 34.9%, anti-ß2GPI kit A was 22.6%, APhL was 11.5% and anti-ß2GPI kit B was 7.6% in the study population. Anti-ß2GPI kit B, aCL and APhL assays were correlated with venous thrombosis, while only APhL was significantly correlated with arterial thrombosis and consistently correlated with pregnancy-related morbidity. No significant correlations were noted for anti-ß2GPI kit A. Sensitivity was greatest for aCL assays followed by anti-ß2GPI kit A, APhL and anti-ß2GPI kit B, while specificity was greatest and equal for anti-ß2GPI kit B and APhL assays. Conclusions Overall, APhL antibodies, especially IgG, represent a promising biomarker for the classification of APS patients in the context of autoimmunity and in risk assessment with regards to pregnancy morbidity and thrombotic manifestations.

Effects of statins on proinflammatory/prothrombotic biomarkers and on disease activity scores in SLE patients: data from LUMINA (LXXVI), a multi-ethnic US cohort.

OBJECTIVES: We sought to determine the effect of statin therapy on the levels of proinflammatory/prothrombotic markers and disease activity scores in patients with SLE in a multi-ethnic, multi-centre cohort (LUMINA). METHODS: Plasma/serum samples from SLE patients placed on statins (n=21) therapy taken before and after at least 6 months of treatment were tested. Disease activity was assessed using SLAM-R scores. Interleukin (IL)-1ß, IL-6, IL-8, tumour necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF) and soluble CD40 ligand (sCD40L) levels were determined by a multiplex immunoassay. Soluble intercellular cell adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1 and anticardiolipin (aCL) antibodies were evaluated using ELISA assays while high sensitivity C-reactive protein (hsCRP) was assessed by nephelometry. Plasma/serum samples from frequency- matched healthy donors were used as controls. RESULTS: Levels of IL-6, VEGF, sCD40L and TNF-α were significantly elevated in SLE patients versus controls. Statin therapy resulted in a significant decrease in SLAM-R scores (p=0.0199) but no significant changes in biomarker levels were observed. There was no significant association of biomarkers with SLAM-R scores. CONCLUSIONS: Statin therapy resulted in significant clinical improvement in SLE patients, underscoring the use of statins in the treatment of SLE.

Evaluation of different immunoassays for the detection of antiphospholipid antibodies: report of a wet workshop during the 13th International Congress on Antiphospholipid Antibodies.

BACKGROUND: The performance and standardization of anticardiolipin (aCL) and anti-ß2 glycoprotein I antibodies (aß2GPI) tests for the confirmation of diagnosis of antiphospholipid syndrome (APS) remain a matter of debate and concern. We evaluated the performance of different ELISAs and other new immunoassays for the detection of aCL and aß2GPI in a wet workshop at the 13th International Congress on Antiphospholipid Antibodies in Galveston, TX (April 13th, 2010, APLA 2010). METHODS: Aliquots of 26 un-identified APS or persistently aPL positive serum samples and 21 controls (9 from healthy individuals and 5 from patients with infectious diseases and 7 with various autoimmune diseases) were distributed to all participants/groups. All serum samples were evaluated in various aCL and aß2GPI ELISAs, a chemiluminescent immunoassay, a fluoro-enzyme immunoassay, and in a multiplexed immunoassay system. Monoclonal and polyclonal calibrators were also evaluated. RESULTS: Although not all the assays reported the titers of aCL and aß2GPI in the same units, the correlation of positive titers among the assays was good. All aCL and aß2GPI tests showed excellent clinical sensitivities, specificities and positive predictive values and good agreement with respect to the levels of the IgG and IgM antibodies, regardless of assay type, or whether tests were done using automated or "manual" systems. CONCLUSIONS: New methodologies for the detection of aPL look promising and comparable to currently approved ELISA tests. This study provides evidence of progress of efforts of harmonization of tests used to detect aPL.

C6 knock-out mice are protected from thrombophilia mediated by antiphospholipid antibodies.

BACKGROUND: Complement activation plays a role in pathogenesis of the antiphospholipid syndrome (APS), but the involvement of the C5b-9 membrane attack complex (MAC) is unknown. Here we studied the effects of human polyclonal antiphospholipid (aPL) antibodies on thrombosis and tissue factor (TF) up-regulation in C6 deficient (C6(-/-)) mice. METHODS: C6(-/-) mice or the wild-type C3H/HeJ (C6(+/+)) mice were injected twice with IgG-APS (n = 2) or IgM-APS (n = 1) isolated from APS patients or with the corresponding control immunoglobulins (Igs) of normal human serum, (NHS) (IgG-NHS or IgM-NHS). Then, the sizes of induced thrombi in the femoral vein were determined 72 hours after the first injection. Tissue factor was determined in homogenates of carotid arteries and in peritoneal macrophages. RESULTS: Thrombus sizes were significantly larger in C6(+/+) treated with IgG-APS1 or with IgG-APS2 or with IgM-APS when compared with C6(+/+) mice treated with IgG-NHS or with IgM-NHS, respectively. The sizes of thrombi were significantly smaller in the C6(-/-) mice injected with IgG-APS1, IgG-APS2 or IgM-APS (p < 0.001), compared to their C6(+/+) counterparts showing an important abrogation of thrombus formation in mice lacking C6. The TF expression and activity in the C6(-/-) mice treated with IgG-APS or IgM-APS were diminished when compared to C3H/HeJ (C6(+/+)) mice treated with the same Igs. All mice injected with IgG-APS and IgM-APS had medium-high titers of anticardiolipin (aCL) and anti-ß(2)glycoprotein I (aß(2)GPI) antibodies. CONCLUSIONS: These data indicate that the C6 component of the complement system mediates aPL-thrombogenic effects, underscoring an important pathogenic mechanism and indicating the possibility of inhibiting complement to ameliorate APS-related manifestations.

Effect of hydroxychloroquine treatment on pro-inflammatory cytokines and disease activity in SLE patients: data from LUMINA (LXXV), a multiethnic US cohort.

OBJECTIVE: We sought to determine the effect of hydroxychloroquine therapy on the levels proinflammatory/prothrombotic markers and disease activity scores in patients with systemic lupus erythematosus (SLE) in a multiethnic, multi-center cohort (LUMINA). METHODS: Plasma/serum samples from SLE patients (n = 35) were evaluated at baseline and after hydroxychloroquine treatment. Disease activity was assessed using SLAM-R scores. Interferon (IFN)-α2, interleukin (IL)-1ß, IL-6, IL-8, inducible protein (IP)-10, monocyte chemotactic protein-1, tumor necrosis factor (TNF)-α and soluble CD40 ligand (sCD40L) levels were determined by a multiplex immunoassay. Anticardiolipin antibodies were evaluated using ELISA assays. Thirty-two frequency-matched plasma/serum samples from healthy donors were used as controls. RESULTS: Levels of IL-6, IP-10, sCD40L, IFN-α and TNF-α were significantly elevated in SLE patients versus controls. There was a positive but moderate correlation between SLAM-R scores at baseline and levels of IFN-α (p = 0.0546). Hydroxychloroquine therapy resulted in a significant decrease in SLAM-R scores (p = 0.0157), and the decrease in SLAM-R after hydroxychloroquine therapy strongly correlated with decreases in IFN-α (p = 0.0087). CONCLUSIONS: Hydroxychloroquine therapy resulted in significant clinical improvement in SLE patients, which strongly correlated with reductions in IFN-α levels. This indicates an important role for the inhibition of endogenous TLR activation in the action of hydroxychloroquine in SLE and provides additional evidence for the importance of type I interferons in the pathogenesis of SLE. This study underscores the use of hydroxychloroquine in the treatment of SLE.

Isolated elevation of IgA anti-beta2glycoprotein I antibodies with manifestations of antiphospholipid syndrome: a case series of five patients.

Current diagnostic classification criteria recommend elevated titres of anti-cardiolipin (aCL) and/or anti-beta(2)GPI antibody by ELISA IgG or IgM and/or lupus anticoagulant (LA) to confirm antiphospholipid syndrome (APS). Although IgA aPL antibodies have been shown to be pathogenic in animal models of APS, their clinical significance has remained elusive. We report four cases of exclusive IgA anti-beta(2)GPI antibody sero-positivity with concomitant clinical manifestations associated with APS. Four of the five patients were LA negative. 1) Thirty-eight-year-old African-American female with SLE presented with resolving digital ulcers. Serum IgA anti-beta(2)GPI antibody titres were 118.5 SAU (normal range: 0-20 SAU). 2) Twenty-seven-year-old African-American woman with SLE was evaluated for recent onset of severe headaches, unresponsive to analgesics and anti-migraine medications. MRI of the brain revealed hyper-intensities in the white matter in the frontal lobes. Serum IgA anti-beta(2)GPI antibody titres were 29.1 Standard A Units (SAU). 3) Thirty-two-year-old Hispanic female with history of two unexplained miscarriages and negative serologies for SLE. Serum IgA anti-beta(2)GPI antibody titres were 102.0 SAU. 4) Twenty-five-year-old white female with history of recent unexplained miscarriage in the 11th week of gestation and associated complaints of numbness and tingling in her hands. Her IgA anti-beta(2)GPI antibody titre was 62.0 SAU. 5) Twenty-five-year-old African-American woman with SLE, positive for anti-Ro antibodies with a history of ischemic fingers, a pregnancy loss and recent pregnancy complicated due to pre-eclampsia. Her LA was positive and her IgA anti-beta(2)GPI antibody titer was 186.0 SAU. This case series supports that elevated IgA anti-beta(2)GPI antibody titres may identify additional patients who have clinical features of APS but who do not meet current diagnostic criteria.

In vivo inhibition of antiphospholipid antibody-induced pathogenicity utilizing the antigenic target peptide domain I of beta2-glycoprotein I: proof of concept.

SUMMARY OBJECTIVES: In the antiphospholipid syndrome (APS), the immunodominant epitope for the majority of circulating pathogenic antiphospholipid antibodies (aPLs) is the N-terminal domain I (DI) of beta(2)-glycoprotein I. We have previously shown that recombinant DI inhibits the binding of aPLs in fluid phase to immobilized native antigen, and that this inhibition is greater with the DI(D8S/D9G) mutant and absent with the DI(R39S) mutant. Hence, we hypothesized that DI and DI(D8S/D9G) would inhibit aPL-induced pathogenicity in vivo. METHODS: C57BL/6 mice (n = 5, each group) were injected with purified IgG derived from APS patients (IgG-APS, 500 microg) or IgG from normal healthy serum (IgG-NHS) and either recombinant DI, DI(R39S), DI(D8S/D9G), or an irrelevant control peptide (at 10-40 microg). Outcome variables measured were femoral vein thrombus dynamics in treated and control groups following standardized vessel injury, expression of vascular cell adhesion molecule-1 (VCAM-1) on the aortic endothelial surface, and tissue factor (TF) activity in murine macrophages. RESULTS: IgG-APS significantly increased thrombus size as compared with IgG-NHS. The IgG-APS thrombus enhancement effect was abolished in mice pretreated with recombinant DI (P