POS0301 STRUCTURAL OUTCOMES IN THE SACROILIAC JOINT AFTER IXEKIZUMAB TREATMENT FOR 16 WEEKS IN PATIENTS WITH ACTIVE NON‑RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS STRATIFIED BY GENDER, HLA-B27, AND BASELINE MRI INFLAMMATION

Background

Ixekizumab (IXE) has demonstrated clinical efficacy in patients with active non-radiographic axial spondyloarthritis (nr-axSpA) together with significant repair of structural lesions in the sacroiliac joint (SIJ) on MRI. There is, however, a paucity of data as to which patients may be most responsive.

Objectives

We aimed to evaluate whether patients’ gender, HLA-B27 status, and presence of MRI inflammation impacted the effect of treatment with IXE versus placebo (PBO) on MRI structural lesions in the SIJ in patients with nr-axSpA.

Methods

Patients with active nr-axSpA, biologic-naïve (COAST-X, NCT02757352) were randomized 1:1:1 to ixekizumab 80 mg every 4 (Q4W) or 2 weeks (Q2W) or PBO. Structural lesions on SIJ MRI were assessed by the Spondyloarthritis Research Consortium of Canada (SPARCC) MRI SIJ structural score (SSS). Treatment comparisons used analysis of covariance based on observed cases. SPARCC SSS subgroup analyses were performed according to baseline gender, HLA-B27 status, and SPARCC MRI SIJ bone marrow oedema (BME) <4 and ≥4 subgroups, which reflects a definite MRI for inflammation in the SIJ typical of axSpA.

Results

Of 303 randomized patients, 266 patients (Q4W: n=85, Q2W: n=91, PBO: n=90) had an MRI scan at baseline and week 16. At baseline, SPARCC scores were consistently higher in males, and mostly higher in HLA-B27 and BME≥4 positive subgroups. Significant differences between patients treated with IXE versus PBO were observed for male patients, HLA-B27 positives, and those with baseline SPARCC BME ≥4. Numerically similar changes were observed in female patients, patients with negative HLA-B27, and patients with SPARCC BME<4, though not statistically significant.

Conclusion

Effects of IXE on structural repair are most evident in males, HLA-B27 positives, and patients with definite MRI inflammation at baseline.

Table 1.

MRI SIJ Structural Lesion Outcomes.

LesionAnalysisPBOIXE Q4WIXE Q2WMale (n=39)Female (n=51)Male (n=44)Female (n=41)Male (n=43)Female (n=48)ErosionBL mean5·1671·9803·5452·8173·5232·594LS mean CFB (SE)0·51 (0·20)-0·11 (0·17)-0·63 (0·18)-0·11 (0·19)-0·51 (0·18)-0·32 (0·17)P value vs PBONANAp<0·001p>0·99p<0·001p=0·37FatBL mean2·0510·9122·0911·2931·4650·677LS mean CFB (SE)-0·02 (0·09)-0·03 (0·08)0·29 (0·08)0·03 (0·08)0·21 (0·08)0·04 (0·08)P value vs PBONANAp=0·01p=0·65p=0·062p=0·51BackfillBL mean1·1540·1670·6630·4150·7910·323LS mean CFB (SE)-0·20 (0·13)0·01 (0·11)0·39 (0·12)0·01 (0·12)0·34 (0·12)0·14 (0·11)P value vs PBONANAp<0·001p>0·99p=0·002p=0·38LesionAnalysisHLA-B27+HLA-B27-HLA-B27+HLA-B27-HLA-B27+HLA-B27-(n=64)(n=25)(n=61)(n=23)(n=65)(n=26)ErosionBL mean3·8202·1003·4672·5433·5151·827LS mean CFB (SE)0·27 (0·15)-0·10 (0·24)-0·49 (0·15)-0·01 (0·25)-0·50 (0·15)-0·17 (0·24)P value vs PBONANAp<0·001p=0·79p<0·001p=0·84FatBL mean1·5781·0201·3282·7831·2850·462LS mean CFB (SE)-0·06 (0·06)-0·06 (0·10)0·22 (0·06)0·01 (0·10)0·13 (0·06)0·10 (0·10)P value vs PBONANAp=0·002p=0·65p=0·027p=0·25BackfillBL mean0·7420·2400·5420·5650·7620LS mean CFB (SE)-0·12 (0·10)0·01 (0·16)0·28 (0·10)0 (0·17)0·27 (0·10)0·16 (0·16)P value vs PBONANAp=0·005p=0·96p=0·005p=0·52LesionAnalysisBME ≥4BME <4BME ≥4BME <4BME ≥4BME <4(n=40)(n=50)(n=27)(n=58)(n=38)(n=53)ErosionBL mean4·8632·1605·3522·1905·2761·425LS mean CFB (SE)0·42 (0·19)-0·06 (0·17)-0·70 (0·23)-0·23 (0·16)-0·71 (0·20)-0·19 (0·17)P value vs PBONANAp<0·001p=0·47p<0·001p=0·57FatBL mean0·7751·9101·9261·6031·6710·604LS mean CFB (SE)-0·02 (0·08)-0·02 (0·07)0·54 (0·10)-0·01 (0·07)0·28 (0·08)0·01 (0·07)P value vs PBONANAp<0·001p=0·90p=0·013p=0·74BackfillBL mean0·7500·4701·0190·3280·7630·387LS mean CFB (SE)-0·21 (0·12)0·01 (0·11)0·41 (0·15)0·11 (0·10)0·49 (0·13)0·05 (0·11)P value vs PBONANAp=0·002p=0·52p<0·001p=0·80

CFB=change from BL. BL=baseline, LS=least squares.

Acknowledgements

Study was sponsored by Eli Lilly and Company

Disclosure of Interests

Walter P Maksymowych Speakers bureau: AbbVie, Janssen, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Boehringer Ingelheim, Celgene, Eli Lilly and Company, Galapagos, Janssen, Novartis, Pfizer, and UCB and is Chief Medical Officer of CARE Arthritis Ltd, Grant/research support from: AbbVie, Novartis, Pfizer, and UCB, Xenofon Baraliakos Grant/research support from: Abbvie, Amgen, BMS, Chugai, Galapagos, Gilead, Eli Lilly and Company, MSD, Novartis, Pfizer, Roche, Sandoz, and UCB, Robert G Lambert Consultant of: CARE Arthritis, Image Analysis Group, Parexel, and Pfizer, Robert B.M. Landewé Consultant of: AbbVie, Astra-Zeneca, Bristol Myers Squibb, Celgene, Eli Lilly and Company, Janssen, Gilead, Galapagos, Glaxo-Smith-Kline, Novartis, Pfizer, UCB, Grant/research support from: AbbVie, Novartis, Pfizer, and UCB; and is director of Imaging Rheumatology BV, which is a registered company under Dutch Law, David Sandoval Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Hilde Carlier Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Jeffrey Lisse Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Xiaoqi Li Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Maja Hojnik Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Mikkel Østergaard Speakers bureau: AbbVie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly and Company, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, Consultant of: AbbVie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly and Company, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, Grant/research support from: AbbVie, BMS, Merck, Celgene, and Novartis

Association between clinical specialty setting and disease management in patients with psoriatic arthritis: results from LOOP, a cross-sectional, multi-country, observational study

BACKGROUND

Psoriatic arthritis (PsA) is a chronic and debilitating disease that can be managed by different clinical specialists.

OBJECTIVES

The objective of the LOOP study was to evaluate the impact of clinical specialty setting on the time to diagnosis and treatment of patients with PsA. Clinical disease activity and disease burden were also compared between clinical settings.

METHODS

LOOP was a cross-sectional, multicentre, observational study conducted in 17 countries in Western and Eastern Europe, the Middle East, Latin America and Asia. Adult patients (≥18 years) with a suspected or established diagnosis of PsA who were routinely visiting a rheumatologist, dermatologist or non-rheumatology/non-dermatology physician were enrolled. All patients were assessed by both a rheumatologist and a dermatologist.

RESULTS

Of 1483 enrolled patients, a total of 1273 had a confirmed diagnosis of PsA. There was no significant difference in the median time from onset of inflammatory musculoskeletal symptoms to PsA diagnosis between patients enrolled by rheumatologists and dermatologists (6.0 vs. 3.9 months). However, the median time from diagnosis to first treatment with a conventional synthetic disease-modifying anti-rheumatic drug (csDMARD) was significantly shorter in the rheumatology setting compared with the dermatology setting (0 vs. 2.0 months; P < 0.001). In addition, disease activity was significantly higher in the dermatology setting compared with the rheumatology setting.

CONCLUSIONS

Differences in the management and clinical status of patients with PsA were observed between the rheumatology and dermatology settings. Importantly, median time from diagnosis to first csDMARD was significantly shorter in the rheumatology setting, and patients in the dermatology setting had higher disease activity. These data show the importance of improved collaboration between rheumatologists and dermatologists.

Parasympathetic nervous system dysfunction in primary Sjögren's syndrome

In the past sicca syndromes were attributed to destruction of glandular tissue. It is now thought that cytokines, autoantibodies, and parasympathetic nervous system dysfunction all have an important role in the xerostomia and xerophthalmia in Sjögren's syndrome.

Clinical presentations and vascular histopathology in autopsied patients with systemic lupus erythematosus and anticardiolipin antibodies

OBJECTIVE

To examine histomorphological and immunohistological changes in an autopsy series of systemic lupus erythematosus (SLE) patients with or without anticardiolipin antibodies (aCL).

METHODS

Fourteen SLE patients who died at our department from 1988 to 1996 were included. The patients' medical files were reviewed for the clinical history and the presence of IgG and IgM aCL. Autopsy samples of various organs, including regularly the kidneys, heart, brain and skin, were studied by standard histological methods and the direct immunofluorescence technique.

RESULTS

Thirteen of 14 (93%) autopsied SLE patients were persistently positive for IgG aCL and had common overt thrombotic complications and/or other clinical features related to the antiphospholipid syndrome. Their autopsy tissue samples showed frequent occlusive vascular changes such as bland thromboses, thrombotic microangiopathy (TMA) related changes and arterial intimalfibrous hyperplasia. The immune complex related vascular changes were mostly unremarkable and present mainly in low aCL positive patients, who also had more aggressive types of lupus glomerulonephritis (GN).

CONCLUSION

Increased IgG aCL were found in 13 out of 14 autopsied SLE patients who had predominant occlusive vascular histopathologic changes. The coincidence of bland thromboses with a characteristic TMA histopathology suggested two pathogenetic mechanisms associated with the presence of aCL, one related to abnormal coagulation and the other to endothelial cell injury. The extent of granular vascular immune deposits, typical of SLE, and the severity of lupus GN were inversely related to the aCL level.

Small vessel thrombosis without major thrombotic events in systemic lupus erythematosus patients with antiphospholipid syndrome

Antiphospholipid syndrome has been defined by the presence of antiphospholipid antibodies or lupus anticoagulant in association with certain clinical events, including recurrent arterial or venous thromboses and recurrent fetal loss. It comprises two separate clinical entities: simple, characterized by large vessel occlusions, and catastrophic, with multiple occlusive events predominantly affecting small vessels. Three patients with systemic lupus erythematosus and permanently increased IgG anticardiolipin antibody levels are being described. Only postmortem histopathological examination revealed microangiopathic thrombotic changes in different organs, which were clinically silent in early stages of the disease and misinterpreted later in its course because of a peculiar clinical picture. All patients presented features of catastrophic antiphospholipid syndrome in the final stage of the disease.

Target recognition of beta2-glycoprotein I (beta2GPI)-dependent anticardiolipin antibodies: evidence for involvement of the fourth domain of beta2GPI in antibody binding

Beta2-glycoprotein I (beta2GPI) is an absolute requirement for the binding of autoimmune anticardiolipin Abs (aCL) to cardiolipin (CL). We evaluated the target recognition of human beta2GPI by IgG derived from two patients with primary and two with secondary antiphospholipid syndrome. The total IgG serum fractions and beta2GPI affinity-purified IgGs were assessed by using various domain-deleted mutants (DM) of human beta2GPI (DMs: I-III, I-IV, II-V, III-V, IV-V, and V) and mouse mAbs against individual beta2GPI domains. The four IgGs bound slightly to CL in the absence of beta2GPI and showed increased binding in the beta2GPI presence. Following affinity purification of the IgGs on a beta2GPI column, reactivity toward CL was absent. DMs containing domain V inhibited the binding of biotinylated beta2GPI to CL. The addition to CL-coated plates of DM V, but not the other DMs, reduced the binding of all four IgGs. The anti-beta2GPI IgGs bound only to complete beta2GPI and DM I-IV coated on the plates. The binding to plate-adsorbed beta2GPI could be inhibited by complete beta2GPI and DM I-IV, the latter being a more efficient inhibitor. Further, the human anti-beta2GPI IgGs could compete with the binding to beta2GPI of Cof-21 mouse mAb (directed at domain IV), but not with the two other mouse mAbs. The results suggest that some "autoimmune:" beta2GPI-dependent anticardiolipin Abs recognize a beta2GPI target that is distinct from the CL-binding site in domain V. The target site for some antiphospholipid syndrome IgGs appear to reside in domain IV of beta2GPI.

Immunologic characterization and functional properties of murine antibodies raised against deleted mutants of human beta 2-glycoprotein I

beta 2-Glycoprotein I (beta 2GPI) is a 50 kDa molecule proposed as a principal target of 'autoimmune' antiphospholipid antibodies (aPL). We have used deleted mutants (DM) representing different domains of beta 2GPI (I-IV, IV-V and V) for immunization of naive mice and studied the characteristics of the respective murine IgG preparations in comparison with affinity-purified IgG from two patients with primary antiphospholipid syndrome. Immunization with beta 2GPI and with the DM produced anti-beta 2GPI antibodies, part of which reacted with negatively charged phospholipids (PL), whereas reactivity with cardiolipin was evident only in the IgG from mice immunized with beta 2GPI. These results are consistent with the presumption that aPL are induced following the in vivo association of beta 2GPI (used for immunization) with resident negatively charged PL. Accordingly, DM which either lack the PL binding site or aPL attachment locus did not elicit, upon immunization, antibodies reactive with PL. Further, murine anti-beta 2GPI IgG and human 'autoimmune' aPL were similar, albeit not identical, in terms of DM requirement for PL binding and charge dependency. Murine antibodies and human aPL, regardless of their binding characteristics, were found to bind significantly to platelets upon their activation with thrombin and to promote platelet activation. The results of the current study emphasize the dissimilarities between human 'autoimmune' aPL and murine anti-beta 2GPI. Thus, anti-beta 2GPI antibodies to different DM as well as human aPL are capable of binding and activating human platelets provided beta 2GPI is present.

Oxidized low-density lipoprotein (Ox-LDL) but not LDL aggravates the manifestations of experimental antiphospholipid syndrome (APS)

Ox-LDL is thought to play a major role in atherogenesis. The mechanisms mediating the deleterious influences of Ox-LDL include foam cell formation and cell cytotoxicity. The production of anti-Ox-LDL antibodies results in the formation of immune complexes which are taken up at enhanced rate by macrophages, leading to foam cell formation. APS is characterized by repeated venous and arterial thromboembolic phenomena, recurrent fetal loss and thrombocytopenia, associated with the presence of antibodies to negatively charged phospholipids (aPL) (i.e. cardiolipin, phosphatidylserine). Phospholipids bear structural resemblance to LDL, and several studies have indeed proved that aPL display cross-reactivity with anti-Ox-LDL antibodies. In this study we assessed the capacity of oxidized and native forms of LDL to aggravate the clinical picture of experimentally induced APS in naive mice. Mice were actively immunized intradermally with anticardiolipin antibodies and developed a clinical picture resembling APS in humans. Subsequently, the mice were infused with either Ox-LDL, native LDL or PBS, and similar regimens were applied to controls. APS mice infused with Ox-LDL were found to exhibit a significantly more severe form of the disease in comparison with native LDL- and PBS-infused mice, expressed by lower platelet counts (261,000/mm3, 535,000/mm3 and 455,000/mm3, respectively), longer activated partial thromboplastin time (aPTT) (99 +/- 12 s, 63 +/- 8 s and 74 +/- 8 s, respectively) and higher fetal resorption rates (72.7%, 34.4% and 32.6%, respectively). The results of this study show that Ox-LDL, compared with native LDL, aggravates the clinical manifestations of experimental APS and suggest that cross-reactivity of Ox-LDL with phospholipids may provide a pathogenic explanation for this effect.

Libman-Sacks endocarditis in the antiphospholipid syndrome: immunopathologic findings in deformed heart valves

OBJECTIVE

To examine the potential immunologic mechanism and involvement of antiphospholipid antibodies in the pathogenesis of heart valve lesions in patients with the antiphospholipid syndrome (APS).

METHODS

Immunoperoxidase and immunofluorescence staining methods were used to evaluate 13 heart valve specimens derived from eight patients with the APS, either primary or secondary to systemic lupus erythematosus. Primary antibodies to human immunoglobulins, complement components, serum albumin and a monoclonal anti-idiotypic antibody to human anticardiolipin antibodies (aCL) were employed. Various tissue specimens from a patient with the APS as well as deformed and normal valves from subjects without the APS were used as controls.

RESULTS

Linear subendothelial deposition consisting of immunoglobulins with complement components but not of a non-specific serum protein was found in deformed valves from patients with the APS. None of the control valves or tissues disclosed similar deposition. The same pattern and location of staining was obtained by the anti-idiotypic antibody to aCL. A significant amount of IgG immunoglobulins that bound to cardiolipin was eluted from a valve of a patient with secondary APS.

CONCLUSION

Deposits of immunoglobulins including aCL, and of complement components, are common in affected valves of patients with primary and secondary APS. Such deposits may be involved in the pathogenesis of valvular lesions.

Heart valve involvement (Libman-Sacks endocarditis) in the antiphospholipid syndrome

The antiphospholipid syndrome (APS) is defined by the presence of anti-phospholipid antibodies (aPLs) and venous or arterial thrombosis, recurrent pregnancy loss, or thrombocytopenia. The syndrome can be either primary or secondary to an underlying condition, most commonly systemic lupus erythematosus (SLE). Echocardiographic studies have disclosed heart valve abnormalities in about a third of patients with primary APS. SLE patients with aPLs have a higher prevalence of valvular involvement than those without these antibodies. Valvular lesions associated with aPLs occur as valve masses (nonbacterial vegetations) or thickening. These two morphological alterations can be combined and are thought to reflect the same pathological process. Both can be associated with valve dysfunction, although such association is much more common with the latter alteration. The predominant functional abnormality is regurgitation; stenosis is rare. The mitral valve is mainly affected, followed by the aortic valve. Valvular involvement usually does not cause clinical valvular disease. The presence of aPLs seems to further increase the risk for thromboembolic complications, mainly cerebrovascular, posed by valve lesions. Superadded bacterial endocarditis is rare but may be difficult to distinguish from pseudoinfective endocarditis. The current therapeutic guidelines are those for APS in general. Secondary antithrombotic prevention with long-term, high-intensity oral anticoagulation is advised. The efficacy of aspirin, either alone or in combination, is yet to be assessed. Corticosteroids are not beneficial and may even facilitate valve damage. Immunosuppressive agents should only be used for the treatment of an underlying condition. Current data suggest a role for aPLs in the pathogenesis of valvular lesions. aPLs may promote the formation of valve thrombi. These antibodies may also act by another mechanism, as indicated by the finding of subendothelial deposits of immunoglobulins, including anticardiolipin antibodies, and of colocalized complement components in deformed valves from patients with APS.

Anticardiolipin antibodies in infections are heterogenous in their dependency on beta 2-glycoprotein I: analysis of anticardiolipin antibodies in leprosy

We studied the effect of beta 2-GPI on binding of antibodies in sera from patients with leprosy and patients with the antiphospholipid syndrome (APS) to CL in enzyme-linked immunosorbent assays (ELISAs). Increased levels of IgG aCL were detected in 59 of 61 leprosy patients' sera by the standard aCL-ELISA in the presence of bovine beta 2-GPI and in 60 of the 61 leprosy patients' sera by the modified aCL-ELISA without beta 2-GPI. When tested by both aCL-ELISAs on the same plate, 10/31 leprosy sera and 9/10 APS sera bound better in the standard aCL-ELISA, 16/31 leprosy sera bound better in the modified aCL-ELISA and in five leprosy and one APS sera the difference was not significant. A dose-dependent enhancing effect of beta 2-GPI on the leprosy and APS sera binding to CL was confirmed using purified human beta 2-GPI. Enhanced binding was seen if beta 2-GPI was added either before or together with the test serum. In 11/61 leprosy sera increased levels of IgG antibodies against beta 2-GPI were found by ELISA. Leprosy anti-beta 2-GPI antibodies appear to be a separate antibody population recognizing only beta 2-GPI adsorbed on the ELISA plate. These results demonstrate heterogeneity of leprosy aCL with respect to their beta 2-GPI requirement for binding to CL.