Carlos A. Núñez-Álvarez

Release of neutrophil extracellular traps by neutrophils stimulated with antiphospholipid antibodies: a newly identified mechanism of thrombosis in the antiphospholipid syndrome.

Antiphospholipid antibodies (aPL), especially those targeting β2‐glycoprotein I (β2GPI), are well known to activate endothelial cells, monocytes, and platelets, with prothrombotic implications. In contrast, the interaction of aPL with neutrophils has not been extensively studied. Neutrophil extracellular traps (NETs) have recently been recognized as an important activator of the coagulation cascade, as well as an integral component of arterial and venous thrombi. This study was undertaken to determine whether aPL activate neutrophils to release NETs, thereby predisposing to the arterial and venous thrombosis inherent in the antiphospholipid syndrome (APS).

Systemic lupus erythematosus risk factors for coronary artery calcifications

OBJECTIVE Premature atherosclerosis in patients with SLE is partially explained by traditional risk factors; therefore, we aimed to identify lupus-related risk factors for coronary artery calcifications. METHODS An inception cohort of 139 lupus patients (93% females) was screened for coronary artery calcifications using Multidetector CT, after 5.1 years of follow-up. Clinical and immunological variables and cardiovascular risk factors were assessed longitudinally. Also, 100 age- and sex-matched healthy subjects were studied. Correlates for calcifications were analysed in lupus patients, including levels of lipids and inflammatory molecules in samples obtained at enrolment, mid-term follow-up and at screening. RESULTS At enrolment, lupus patients were 27.2 (9.1) years of age and with a disease duration of 5.4 (3.8) months. Calcifications were detected in 7.2% of patients and 1% of controls [unadjusted odds ratio (OR) 7.7, 95% CI 1.05, 336.3, P = 0.02]. In lupus, calcifications were detected since the age of 23 years and from 3 years of diagnosis. Patients with calcifications were older, post-menopausal, and had higher levels of serum apolipoprotein B and Framingham risk scores (P < 0.05). Lupus-related factors identified included age at diagnosis, IgG aCLs, cumulative lupus activity, length of moderate/severe activity and cumulative dose of prednisone and CYC (P < 0.05). Use of anti-malarials was protective (P = 0.006). Logistic regression analysis showed as predictors of calcification: disease duration (OR 15.1, 95% CI 2.6, 87.2), age at enrolment (OR 8.5, 95% CI 1.7, 43.0) and SLEDAI 2000 update (SLEDAI-2K) mean area under the curve (OR 12.3, 95% CI 2.5, 61.8). Longitudinal analyses of lipids and inflammatory molecules did not differ between patients. CONCLUSIONS Disease activity is a potentially modifiable risk factor for coronary artery calcifications in SLE. Therefore, management of traditional risk factors plus tight control of lupus activity, including the use of anti-malarials, is recommended.

Assessment of myocardial fibrosis and microvascular damage in systemic sclerosis by magnetic resonance imaging and coronary angiotomography

OBJECTIVE Cardiac involvement in SSc is characterized by myocardial fibrosis, arrhythmias and pericarditis. Prevalence studies have shown variable results. The objective of this study was to determine the prevalence of cardiac involvement in SSc patients using the non-invasive, highly sensitive diagnostic methods of cardiac MRI and coronary angiotomography. METHODS We included 62 SSc patients and excluded those with heart disease prior to the onset of SSc, renal failure, diabetes mellitus, hyperlipidaemia, arterial hypertension, untreated thyroid disease, cor pulmonale, pregnancy or contraindications to performing cardiac MRI. All underwent clinical and laboratory evaluation, ECG, coronary angiotomography and cardiac MRI. RESULTS The prevalence of myocardial fibrosis was 45% and was higher in dcSSc (59%) than in lcSSc patients (33%; P = 0.04). The mean left ventricular ejection fraction (LVEF) was lower in patients with myocardial fibrosis (56%) than in those without fibrosis (63%; P = 0.0009); myocardial fibrosis on MRI was more frequent in the basal-septal segments of the LV. Seventy-nine per cent of patients had subendocardial perfusion defects and these were associated with higher ultrasensitive serum CRP values. There was no association of myocardial fibrosis or microvascular damage with atherosclerosis. CONCLUSION The prevalence of myocardial fibrosis on MRI attributable to SSc is 45%, is more frequent and severe in dcSSc patients, is associated with lower LVEF and affects mainly basal LV walls. Microvascular damage in SSc is common and is associated with elevated ultrasensitive CRP levels. Cardiac damage due to SSc is not associated with coronary artery disease.

Endothelial progenitor dysfunction associates with a type I interferon signature in primary antiphospholipid syndrome

Objectives Patients with antiphospholipid syndrome (APS) are at risk for subclinical endothelial injury, as well as accelerated atherosclerosis. In the related disease systemic lupus erythematosus, there is a well-established defect in circulating endothelial progenitors, which leads to an accrual of endothelial damage over time. This defect has been at least partially attributed to exaggerated expression of type I interferons (IFNs). We sought to determine whether these pathways are important in APS. Methods We studied 68 patients with primary APS. Endothelial progenitors were assessed by flow cytometry and functional assay. Type I IFN activity was determined by a well-accepted bioassay, while peripheral blood mononuclear cells were scored for expression of IFN-responsive genes. Results Endothelial progenitors from patients with APS demonstrated a marked defect in the ability to differentiate into endothelial cells, a phenotype which could be mimicked by treating control progenitors with APS sera. Elevated type I IFN activity was detected in the circulation of patients with APS (a finding that was then replicated in an independent cohort). While IgG depletion from APS sera did not rescue endothelial progenitor function, the dysfunction was successfully reversed by a type I IFN receptor-neutralising antibody. Conclusions We describe, for the first time to our knowledge, an IFN signature in primary APS and show that this promotes impaired endothelial progenitor function. This work opens the door to novel approaches that may mitigate vascular damage in APS, such as anti-IFN drugs.

Utility of the American-European Consensus Group and American College of Rheumatology Classification Criteria for Sjögren’s syndrome in patients with systemic autoimmune diseases in the clinical setting

OBJECTIVE The aim of this study was to evaluate the feasibility and performance of the American-European Consensus Group (AECG) and ACR Classification Criteria for SS in patients with systemic autoimmune diseases. METHODS Three hundred and fifty patients with primary SS, SLE, RA or scleroderma were randomly selected from our patient registry. Each patient was clinically diagnosed as probable/definitive SS or non-SS following a standardized evaluation including clinical symptoms and manifestations, confirmatory tests, fluorescein staining test, autoantibodies, lip biopsy and medical chart review. Using the clinical diagnosis as the gold standard, the degree of agreement with each criteria set and between the criteria sets was estimated. RESULTS One hundred fifty-four (44%) patients were diagnosed with SS. The AECG criteria were incomplete in 36 patients (10.3%) and the ACR criteria in 96 (27.4%; P < 0.001). Nevertheless, their ability to classify patients was almost identical, with a sensitivity of 61.6 vs 62.3 and a specificity of 94.3 vs 91.3, respectively. Either set of criteria was met by 123 patients (80%); 95 (61.7%) met the AECG criteria and 96 (62.3%) met the ACR criteria, but only 68 (44.2%) patients met both sets. The concordance rate between clinical diagnosis and AECG or ACR criteria was moderate (k statistic 0.58 and 0.55, respectively). Among 99 patients with definitive SS sensitivity was 83.3 vs 77.7 and specificity was 90.8 vs 85.6, respectively. A discrepancy between clinical diagnosis and criteria was seen in 59 patients (17%). CONCLUSION The feasibility of the SS AECG criteria is superior to that of the ACR criteria, however, their performance was similar among patients with systemic autoimmune diseases. A subset of SS patients is still missed by both criteria sets.

Utility of Interferon-α as a Biomarker in Central Neuropsychiatric Involvement in Systemic Lupus Erythematosus

Objective. To assess the utility of interferon-α (IFN-α) in serum and cerebrospinal fluid (CSF) as a biomarker of disease activity in central neuropsychiatric systemic lupus erythematosus (cNPSLE). Methods. Serum and CSF samples were drawn at hospitalization in 34 patients with cNPSLE, 16 surgical SLE, 4 primary neuropsychiatric conditions, and 25 with nonautoimmune conditions, except in 44 non-NPSLE patients in whom only serum was studied. Six months later, serum/CSF and serum samples were taken in 20 cNPSLE and 35 non-NPSLE patients, respectively. SLE activity was assessed at hospitalization, and 6 months later in cNPSLE and non-NPSLE patients. IFN-α was detected by Luminex technology. Results. The mean ± SD age of patients with cNPSLE was 31.4 ± 12.2 years, which was similar across the study groups (p = 0.46). Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) scores among cNPSLE, non-NPSLE, and SLE-surgical patients were 15.3 ± 8.2, 12.4 ± 8.2, and 3.8 ± 1.5, respectively. IFN-α levels in serum were higher in cNPSLE than in nonautoimmune patients (p = 0.02), but were similar to non-NPSLE and SLE-surgical groups. In CSF samples, IFN-α levels were higher in cNPSLE than in nonautoimmune patients (p = 0.03), and were nonsignificantly higher than in SLE-surgical and primary neuropsychiatric patients. Six months later, serum levels of IFN-α did not vary from baseline values despite a significant decrease in SLEDAI-2K score in cNPSLE and non-NPSLE patients. IFN-α levels in the CSF of patients with cNPSLE also remained stable. Among specific cNPSLE syndromes, CSF IFN-α levels were significantly higher among patients with acute confusional syndrome. Conclusion. IFN-α does not seem to represent a useful biomarker of cNPSLE syndromes; its utility in specific cNPSLE manifestations merits further investigation.

Venous and Arterial Thrombotic Events in Systemic Lupus Erythematosus.

Objective. The incidence of thrombosis in patients with systemic lupus erythematosus (SLE) is 25 to 50-fold higher than in the general population; we aimed to define the characteristics of venous thrombotic events (VTE) and arterial thrombotic events (ATE) to identify the patients at highest risk. Methods. The study included 219 patients with recent-onset SLE. At baseline, standardized medical history and laboratory tests were done. Followup visits occurred quarterly, and information about damage accrual, comorbidities, and cardiovascular risk factors was updated annually. Main outcome was development of TE after SLE diagnosis. Results. Thirty-five patients (16%) developed TE (27 VTE, 8 ATE) during 5.21 years of followup; incidence rate 31/1000 patient-years. Most events (57%) developed within the first year of diagnosis, and 69% were not associated with lupus anticoagulant (LAC), determined with 1 method. VTE developed earlier than ATE (2.0 vs 57.5 mos, p = 0.02). In the multivariate analysis, variables preceding VTE included cutaneous vasculitis, nephrotic syndrome, dose of prednisone, and LAC in combination with anti-RNP/Sm antibodies (p < 0.03). Patients with ATE were older (median age 44 vs 29 yrs, p = 0.04), smokers, and had hypertension, diabetes mellitus, dyslipidemia, at least 2 traditional risk factors, nephrotic syndrome, chronic damage, and a higher cumulative dose of prednisone (p < 0.05). LAC in combination with anti-RNP/Sm antibodies was associated with VTE and improved the accuracy for predicting it. Conclusion. Our study suggests that in SLE, VTE and ATE have different risk factors. Understanding these differences is helpful for identifying patients at highest risk. The use of LAC plus anti-RNP/Sm for predicting VTE deserves further study.

Pathogenic mechanisms of the anti-phospholipid antibodies ☆

Abstract The antiphospolipid syndrome (APS) is an autoimmune disease characterized by recurrent fetal loss, thrombotic events (arterial or venous) and hemocytopenic disorders associated to high titers of circulating aPL. Two variants of the APS have been described. Primary APS is a clinical entity without evidence of any other autoimmune disease and secondary APS is a clinical disorder mainly associated with Systemic Lupus Erithematosus (SLE). aPL are a widely group of immunoglobulins directed against different components or proteins factors. In 1990 three groups of researchers identified that β2GP-I is the mainly antigenic target of aPL in APS patients. There are evidences that show that more than one pathogenic mechanism is involved in the development of the APS. The best documented clinical manifestations associated with the APS are recurrent fetal loss and thrombotic disorders. The latter is based on observations in vivo in animal models and in vitro on the effects caused by aβ2GP-I antibodies from patients with APS or from animals which cause experimental APS. The objective of the present paper is to show the pathogenic mechanisms that participate in the development of the APS. We also presented evidence that shows that aβ2GP-I induces pro-inflammatory, pro-adhesive and pro-coagulant disorder.

Antiphospholipid Antibodies Promote the Release of Neutrophil Extracellular Traps: A New Mechanism of Thrombosis in the Antiphospholipid Syndrome

Antiphospholipid antibodies (aPL), especially those targeting β2‐glycoprotein I (β2GPI), are well known to activate endothelial cells, monocytes, and platelets, with prothrombotic implications. In contrast, the interaction of aPL with neutrophils has not been extensively studied. Neutrophil extracellular traps (NETs) have recently been recognized as an important activator of the coagulation cascade, as well as an integral component of arterial and venous thrombi. This study was undertaken to determine whether aPL activate neutrophils to release NETs, thereby predisposing to the arterial and venous thrombosis inherent in the antiphospholipid syndrome (APS).

Predicting Sjögren’s syndrome in patients with recent-onset SLE

OBJECTIVE To determine the prevalence of SS in a cohort of recent-onset SLE patients and evaluate the clinical and immunological variables that may identify SLE patients prone to develop SS. METHODS A total of 103 patients participating in a prospective cohort of recent-onset SLE were assessed for fulfilment of the American European Consensus Group criteria for SS using a three-phase approach: screening (European questionnaire, Schirmer-I test and wafer test), confirmation (fluorescein staining test, non-stimulated whole-salivary flow and anti-Ro/La antibodies) and lip biopsy. Anti-Ro/SSA and anti-La/SSB antibodies and RF were measured at entry into the cohort and at SS assessment. RESULTS Ninety-three females and 10 males were included. Mean age at lupus diagnosis was 25.9 ± 8.9 years, and lupus duration at SS assessment was 30.9 ± 9.1 years. SS was diagnosed in 19 (18.5%) patients, all female, and the patients were older at SLE diagnosis than patients without SS (30.8 ± 9.3 vs 24 ± 8.8 years, P = 0.004). Anti-Ro/SSA antibody was more common in SLE-SS patients (84% vs 55%, P = 0.02, LR + 1.53, 95% CI 1.14, 2.04). In the multivariate analysis, age ≥25 years and anti-Ro/SSA antibodies at SLE diagnosis were identified as predictors of SLE-SS, while the absence of anti-Ro/SSA, anti-La/SSB and RF seems to be protective (LR- 0.14, 95% CI 0.02, 0.95). CONCLUSION The overlap of SLE and SS occurs in almost one-fifth of SLE patients and presents early during its evolution. SLE onset at age ≥25 years plus the presence of anti-Ro/SSA antibody at diagnosis are useful predictors, while the absence of anti-Ro/SSA, anti-La/SSB and RF identifies patients at lowest risk.