Association of antiphospholipid antibodies with active digital ulceration in systemic sclerosis

The predictive value of anti-IFI16 antibodies for the development or persistence of digital ulcers in systemic sclerosis

To evaluate the association of anti-IFI16 antibodies with peripheral vasculopathy and the predictive value of anti-IFI16 antibodies for the development or persistence of digital ulcers (DPDU) in SSc. A total of 42 SSc patients and 42 age- and sex-matched healthy controls were enrolled. Anti-IFI16 antibodies were examined by ELISA. Nailfold videocapillaroscopy (NVC) and power Doppler ultrasound (PDUS) were used to assess the micro- and macro-vascular involvement in SSc. All patients were followed up for 6 months to evaluate DPDU. Potential risk factors for DPDU were analyzed by a Firth's penalized logistic regression model. Of the 42 SSc patients enrolled, 19.05% patients were positive for anti-IFI16 antibodies, compared to a significantly low positivity rate of 4.76% in healthy controls (p < 0.001). SSc patients who were positive for anti-IFI16 antibodies manifested higher ulnar artery resistance index than anti-IFI16 negative patients (p = 0.018). Within a 6-month follow-up, 14 (33.3%) patients suffered from DPDU, and the prevalence of anti-IFI16 antibodies in patients with DPDU was 42.9%, remarkably higher than 7.1% in those without DPDU (p = 0.012). Additionally, patients with DPDU were more likely to have digital ulcers (DUs) at enrollment and manifest lower finger pulp blood flow, lower ulnar artery (UA) flow velocity, lower UA resistance index, and higher UA resistance index at baseline in comparison to patients without DPDU. Multivariate analysis further identified DUs at enrollment (OR 5.81; 95% CI 1.09-30.86; p = 0.046) and the positivity of anti-IFI16 antibody (OR 8.64; 95% CI 1.05-70.87; p = 0.045) as independent risk factors for DPDU. Presence of anti-IFI16 antibody is associated with higher UA resistance index in SSc. Multivariate analysis further identified anti-IFI16 antibody as a predictive marker for DPDU in SSc. Key Points • SSc patients who were positive for anti-IFI16 antibodies manifested higher ulnar artery resistance at baseline. • The prevalence of anti-IFI16 antibodies in patients with DPDU during the 6-month follow-up was remarkably higher than those without DPDU. • Multivariate analysis identified DUs at enrollment and anti-IFI16 antibody positivity as independent risk factors for DPDU. • Anti-IFI16 antibody is associated with peripheral vasculopathy in SSc. Multivariate analysis further identified anti-IFI16 as a predictive biomarker for the development of DUs.

Autoantibodies as putative biomarkers and triggers of cell dysfunctions in systemic sclerosis

PURPOSE OF REVIEW

Antinuclear autoantibodies represent a serological hallmark of systemic sclerosis (SSc), with anticentromere, antitopoisomerase-I, and anti-RNA polymerase III antibodies routinely assessed for diagnosis, clinical subset classification, and prognosis. In addition, an increasing number of autoantibodies have been demonstrated to play a pathogenic role by mediating different SSc manifestations. This review aims to give an overview on autoantibodies as putative biomarkers in SSc and discuss their possible pathogenic role as triggers of cell dysfunctions.

RECENT FINDINGS

Over the years, different autoantibodies have been proposed as biomarkers aiding in diagnosis, disease subtype classification, disease progression prediction, organ involvement, as well as in understanding treatment response. Increasing literature also indicates functional autoantibodies as direct contributors to SSc pathogenesis by exerting agonistic or antagonistic activities on their specific cognate targets.

SUMMARY

In SSc, search and validation of novel autoantibodies with higher diagnostic specificity and more accurate predictive values are increasingly needed for early diagnosis and specific follow-up, and to define the best therapeutic option according to different disease subsets. Moreover, since autoantibodies are also emerging as functional pathogenic players, a better unraveling of their possible pathomechanisms becomes essential to identify new targets and develop promising therapeutic agents able to neutralize their effects.

History of pre-eclampsia does not appear to be a risk factor for vascular phenotype in women with systemic sclerosis

BACKGROUND

Vascular phenotype is associated with a poor prognosis in systemic sclerosis (SSc). The identification of its risk factors could facilitate its early detection.

OBJECTIVES

To explore risk factors for a vascular phenotype of SSc, among them a history of pre-eclampsia.

METHODS

This observational multicentre case-control study enrolled adult women fulfilling European Alliance of Associations for Rheumatology 2013 diagnosis criteria for SSc and having a pregnancy history≥6 months before SSc diagnosis in 14 French hospital-based recruiting centres from July 2020 to July 2022. Cases had specific vascular complications of SSc defined as history of digital ischaemic ulcers, pulmonary arterial hypertension, specific cardiac involvement or renal crisis. Women with SSc were included during their annual follow-up visit and filled in a self-administered questionnaire about pregnancy. A case report form was completed by their physician, reporting data on medical history, physical examination, clinical investigations and current medication. The main outcome was the presence/absence of a personal history of pre-eclampsia before SSc diagnosis, according to the validated pre-eclampsia questionnaire.

RESULTS

378 women were included: 129 cases with a vascular phenotype and 249 matched controls. A history of pre-eclampsia was reported in 5 (3.9%) cases and 12 (4.8%) controls and was not associated with a vascular phenotype (OR=0.96, 95% CI 0.28 to 3.34, p=0.9). Besides, Rodnan skin score and disease duration≥5 years were risk factors for vascular phenotype.

CONCLUSIONS

In women with SSc and a pregnancy history≥6 months before SSc, a history of pre-eclampsia is not associated with a vascular phenotype.

Understanding the value of non-specific abnormal capillary dilations in presence of Raynaud's phenomenon: a detailed capillaroscopic analysis

BACKGROUND

Nailfold videocapillaroscopy (NVC) non-specific abnormalities may be present in subjects with isolated Raynaud's phenomenon (RP) before the potential transition to systemic sclerosis (SSc) specific microvascular alterations ('scleroderma pattern'). This study aims to investigate NVC non-specific abnormalities, notably capillary dilations, in RP patients, as possible forerunners of the 'scleroderma pattern'.

METHODS

A 10-year retrospective NVC-based investigation evaluated 55 RP patients sorted into 3 sex-matched and age-matched groups according to clinical evolution: 18 later developing SSc (cases), 19 later developing other connective tissue disease and 18 maintaining primary RP at long-term follow-up (controls). All patients had a basal NVC showing non-specific abnormalities, namely non-specific &gt;30 µm dilated capillaries (30-50 μm diameter). Sequential NVCs were longitudinally evaluated using current standardised approach. Statistical analysis assessed the risk for developing a 'scleroderma pattern'.

RESULTS

Significantly larger capillary diameters were observed in cases versus controls both at basal NVC and during follow-up NVC (p=&lt;0.05 to &lt;0.001). Interestingly, controls showed stable NVC non-specific abnormalities over the study follow-up. The number of &gt;30 µm dilated capillaries/mm at basal NVC was the strongest single predictor of 'scleroderma pattern' evolution with 24% increased risk per each dilated capillary (OR 1.24, 95% CI 1.17,1.32). Additionally, a tree-based analysis suggested the efferent (venous) diameter of the most dilated capillary on basal NVCas a variable of interest to identify patients maintaining primary RP.

CONCLUSION

This is the first study to describe an NVC 'prescleroderma signature' to potentially identify RP patients later developing a 'scleroderma pattern'.

Autoantibodies as Biomarker and Therapeutic Target in Systemic Sclerosis

Systemic sclerosis (SSc) is a rare connective tissue disorder characterized by immune dysregulation evoking the pathophysiological triad of inflammation, fibrosis and vasculopathy. In SSc, several alterations in the B-cell compartment have been described, leading to polyclonal B-cell hyperreactivity, hypergammaglobulinemia and autoantibody production. Autoreactive B cells and autoantibodies promote and maintain pathologic mechanisms. In addition, autoantibodies in SSc are important biomarkers for predicting clinical phenotype and disease progression. Autoreactive B cells and autoantibodies represent potentially promising targets for therapeutic approaches including B-cell-targeting therapies, as well as strategies for unselective and selective removal of autoantibodies. In this review, we present mechanisms of the innate immune system leading to the generation of autoantibodies, alterations of the B-cell compartment in SSc, autoantibodies as biomarkers and autoantibody-mediated pathologies in SSc as well as potential therapeutic approaches to target these.

Endothelial Dysfunction in Systemic Lupus Erythematosus and Systemic Sclerosis: A Common Trigger for Different Microvascular Diseases

This review describes the complex interplay between inflammation, vasculopathy and fibrosis that involve the heart and peripheral small vessels, leading to endothelial stiffness, vascular damage, and early aging in patients with systemic lupus erythematosus and systemic sclerosis, which represents two different models of vascular dysfunction among systemic autoimmune diseases. In fact, despite the fact that diagnostic methods and therapies have been significantly improved in the last years, affected patients show an excess of cardiovascular mortality if compared with the general population. In addition, we provide a complete overview on the new techniques which are used for the evaluation of endothelial dysfunction in a preclinical phase, which could represent a new approach in the assessment of cardiovascular risk in these patients.

Screening for Pulmonary Hypertension in Systemic Sclerosis-A Primer for Cardio-Rheumatology Clinics

Systemic sclerosis (SSc) is a rare disease, with unfavorable clinical course and prognosis, characterized by progressive multisystemic involvement. SSc associated pulmonary hypertension (SSc-PAH) and interstitial lung disease (ILD) are the most important factors for morbi-mortality in these patients, being responsible for more than 60% of total deaths. Though pulmonary arterial hypertension (PAH) is the dominant subtype seen in SSc, PH secondary to ILD, left-heart pathology, and pulmonary veno-occlusive disease (PVOD) are also possible occurrences. Initial evaluation of a SSc case is complex and should be performed with a multidisciplinary approach. Early detection of SSc-PAH is imperative, given the fact that new and effective medications are available and early treatment was shown to improve outcomes. Therefore, screening algorithms must be used adequately and in a cost-effective manner. Sensitivity and negative predictive value (NPV) are the most important performance measures in a screening test. Several algorithms were developed in the last decade (e.g., DETECT and ASIG) and demonstrated higher efficiency when compared to older algorithms. The present manuscript details the risk factors for SSc-PAH and includes a critical description of current detection algorithms, as a primer for clinicians working in the field of cardio-rheumatology.

Antiphospholipid Antibodies in Inflammatory and Autoimmune Rheumatic and Musculoskeletal Diseases Beyond Lupus: A Systematic Review of the Available Evidence

Background

The diagnosis of antiphospholipid syndrome (APS) requires the presence of thrombosis and/or recurrent miscarriages along with one or more anti-phospholipid antibodies (aPL). The role of aPL has been largely investigated in systemic lupus erythematosus (SLE) with minimal data on other autoimmune rheumatic diseases. In this review, we aim to assess the prevalence of aPL in patients with inflammatory and autoimmune rheumatic and musculoskeletal diseases (RMDs) other than SLE, and their association with thrombosis.

Results

A total of 20 studies, including 3242 patients, measured aPL in different inflammatory and autoimmune RMDs. The overall median percentage of aPL-positive patients was 14.05% (from 0 to 57.5%). For systemic sclerosis (SSc) patients, the median positivity was 14.05% for aPL, with IgG aCL being detected in up to 35.48% of all SSc aPL-positive patients. Only six studies (30%) performed an antibody confirmation test after 12 weeks, with the median prevalence being 10.88% (from 0 to 29.79%). Only six studies also assessed the number of double or triple aPL-positive patients. A total of eight (40%) studies including 1071 patients investigated the association between aPL and thrombotic events, namely five for SSc, one for SS, one for ANCA associated vasculitides (AAV), and one for RA. A median of 18.75% (7.69–71.43%) of aPL-positive patients experienced an arterial event in comparison to a median of 13.66% (7.69–31.25%) who underwent venous thrombotic event. Taking into consideration only the studies that performed a confirmation test, a median value of 34.36% (12.9–71.43%) of aPL-positive patients underwent an arterial event and a median value of 16.32% (9.68–25%) of aPL-positive patients underwent a venous event.

Conclusions

Anti-phospholipid antibodies can be detected in up to a third of patients with inflammatory and autoimmune RMDs, especially in SSc. However, there was a large heterogeneity among the retrieved studies. Available data supporting a general screening for aPL in all inflammatory and autoimmune RMDs are still insufficient. Screening for aPL in selected scenarios (e.g., pregnancy planning) could be considered.

Anti-phospholipid syndrome leading to digital ischaemia and rare organ complications in systemic sclerosis and related disorders

Antiphospholipid syndrome (APS) is an acquired, autoimmune thrombophilia that can occur as a primary disorder (with no associated disease) or secondary to infection, medication usage and autoimmune rheumatic diseases (ARDs). The association between APS and systemic lupus erythematosus (SLE) is well established, and practicing rheumatologists check for APS antibodies in the routine assessment of SLE, particularly if clinical features such as thrombotic events or pregnancy loss are present. APS secondary to systemic sclerosis (SSc)-related disorders is less widely recognised and easily overlooked. We describe 5 cases that highlight the varied breadth of clinical manifestations of APS in the context of SSc and related disorders. These cases range from uncomplicated Raynaud's phenomenon, digital ulceration/necrosis, critical digital ischaemia/gangrene and rare internal organ complications of APS in SSc-spectrum disorders. To our knowledge, our cases include the first reported case of secondary APS contributing to digital necrosis in the context of RACAND syndrome (Raynaud's phenomenon, anti-centromere antibodies and necrosis of the digits) and the first reported case of secondary APS in SSc causing posterior reversible encephalopathy syndrome (PRES). The case series is accompanied by a comprehensive review of the literature relevant to each case. Rheumatologists should be alert to the possibility of APS in SSc-spectrum disorders and should routinely check APS antibodies in all patients at diagnosis, and again later in the disease course if new features emerge that could indicate the presence of thrombotic events or other recognised APS manifestations. Key points • APS should be considered in all patients with digital ischaemic symptoms. • APS may be an important driver of SSc-related digital ulceration/necrosis. • Identification of SSc-associated APS opens up new therapeutic options for acute management and secondary prevention.