Primary antiphospholipid syndrome and antiphospholipid syndrome associated to systemic lupus: Are they different entities?

The prevalence and incidence of thrombotic primary antiphospholipid syndrome in adults aged 18-49 years: A population-based study in a mountain community in northern Italy

OBJECTIVE

To estimate prevalence and incidence of thrombotic Primary Antiphospholipid Syndrome (PAPS) in the general population aged 18-49 years.

METHODS

The study was carried out in Valtrompia, a valley in northern Italy, in 2011-2015. The identification of PAPS cases leveraged three integrated sources: 1) Rheumatology Unit at the University Hospital; 2) General Practitioners; 3) hospital discharge codes of patients admitted for thrombotic events.

RESULTS

Prevalence and incidence were estimated as 22.9 (95% C.I. 11.4-41.0) and 5.0 (2.6-8.7) cases per 100,000 individuals, respectively. The estimates were 28.3 and 4.8, and 17.2 and 5.1 in males and females, respectively. The type of disease onset was mainly of arterial type in men and venous in women.

CONCLUSIONS

Thrombotic PAPS was found to be a rare disease in this population-based study. Prevalence and incidence were not significantly different between males and females aged 18-49 years, but a different type of onset was observed.

The impact of antiphospholipid antibodies/antiphospholipid syndrome on systemic lupus erythematosus

aPLs are a major determinant of the increased cardiovascular risk in patients with SLE. They adversely affect clinical manifestations, damage accrual and prognosis. Apart from the antibodies included in the 2006 revised classification criteria for APS, other non-classical aPLs might help in identifying SLE patients at increased risk of thrombotic events. The best studied are IgA anti-β2-glycoprotein I, anti-domain I β2-glycoprotein I and aPS-PT. Major organ involvement includes kidney and neuropsychiatric systems. aPL/APS severely impacts pregnancy outcomes. Due to increased thrombotic risk, these patients require aggressive cardiovascular risk factor control. Primary prophylaxis is based on low-dose aspirin in high-risk patients. Warfarin is the gold-standard drug for secondary prophylaxis.

High-throughput sequencing technology facilitates the discovery of novel biomarkers for antiphospholipid syndrome

Antiphospholipid syndrome (APS) is characterized by arterial and venous thrombosis and/or morbid pregnancy, accompanied by persistent antiphospholipid antibody (aPL) positivity. However, due to the complex pathogenesis of APS and the large individual differences in the expression of aPL profiles of patients, the problem of APS diagnosis, prognosis judgment, and risk assessment may not be solved only from the antibody level. It is necessary to use new technologies and multiple dimensions to explore novel APS biomarkers. The application of next-generation sequencing (NGS) technology in diseases with a high incidence of somatic mutations, such as genetic diseases and tumors, has been very mature. Thus, we try to know the research and application progress of APS by NGS technology from genome, transcriptome, epigenome and other aspects. This review will describe the related research of NGS technology in APS and provide more reference for the deep understanding of APS-related screening markers and disease pathogenesis.

Ocular retinal findings in asymptomatic patients with antiphospholipid syndrome secondary to systemic lupus erythematosus

The objective is to perform a multimodal ophthalmological evaluation, including optical coherence angiography (OCTA), asymptomatic APS secondary to SLE (APS/SLE), and compare to SLE patients and control group (CG). We performed a complete structural/functional ophthalmological evaluation using OCTA/microperimetry exam in all participants. One hundred fifty eyes/75 asymptomatic subjects [APS/SLE (n = 25), SLE (n = 25), and CG (n = 25)] were included. Ophthalmologic abnormalities occurred in 9 (36%) APS/SLE, 11 (44%) SLE, and none of CG (p < 0.001). The most common retinal finding was Drusen-like deposits (DLDs) exclusively in APS/SLE and SLE (16% vs. 24%, p = 0.75) whereas severe changes occurred solely in APS/SLE [2 paracentral acute middle maculopathy (PAMM) and 1 homonymous quadrantanopsia]. A trend of higher frequency of antiphospholipid antibody (aPL) triple positivity (100% vs. 16%, p = 0.05) and higher mean values of adjusted Global Antiphospholipid Syndrome Score (aGAPSS) (14 ± 0 vs. 9.69 ± 3.44, p = 0.09) was observed in APS/SLE with PAMM vs. those without this complication. We identified that ophthalmologic retinal abnormalities occurred in more than 1/4 of asymptomatic APS/SLE and SLE. DLDs are the most frequent with similar frequencies in both conditions whereas PAMM occurred exclusively in APS/SLE patients. The possible association of the latter condition with aPL triple positivity and high aGAPSS suggests these two conditions may underlie the retinal maculopathy. Our findings in asymptomatic patients reinforce the need for early surveillance in these patients. Key Points • Retinal abnormalities occur in more than 1/4 of asymptomatic APS/SLE and SLE patients. • The occurrence of PAMM is possibly associated with APS and DLDs with SLE. • Presence of aPL triple positivity and high aGAPSS seem to be risk factors for PAMM.

Reduced circulating Tregs and positive pANCA were robustly associated with the occurrence of antiphospholipid syndrome in patients with systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is a typical chronic immune disorder with clinical heterogeneity. The systemic abnormal immune response not only challenges the diagnosis and treatment of the disease itself but also the secondary antiphospholipid syndrome (APS), characterized by recurrent arterial or venous thrombosis, recurrent spontaneous abortion, or stillbirth. Clinical interest has primarily focused on primary APS's pathological and clinical features. However, differences in clinical features and laboratory indicators between SLE with or without APS are still lacking, especially differences between circulating lymphocytes, which are critical in the pathogenesis of SLE and its complications.

METHODS

In this retrospective study, we collected and analyzed clinical characteristics, general laboratory indicators, immunological indicators, and circulating lymphocyte subsets of SLE with or without APS.

RESULTS

Systemic lupus erythematosus with APS (SLE-APS) had elevated SLEDAI scores, hospitalization costs and time, and frequencies of central nervous system symptoms and spontaneous abortion compared with those without APS. SLE-APS had higher positive anti-Cardiolipin antibodies, anti-β2 Glycoprotein 1 antibodies, and perinuclear antineutrophil cytoplasmic antibody (pANCA) than none-APS patients. Compared with healthy controls (HCs), the circulating lymphocyte subsets were altered to some extent in all patients, especially in patients with SLE-APS. Reduced Tregs and positive pANCA were independent risk factors for SLE secondary APS.

CONCLUSION

The present study revealed a robust association between APS secondary to SLE and reduced Tregs and positive pANCA, which provides essential information regarding the diagnosis and therapeutic possibilities of APS secondary to SLE.

Predictors and Interrelationship of Patient-Reported Outcomes in Antiphospholipid Syndrome: A Cross-Sectional Study

OBJECTIVE

This study assessed patient-reported outcomes (PROs) in individuals with persistently positive antiphospholipid antibodies (aPL) to better understand how living with aPL may affect their quality of life.

METHODS

Patients completed Patient-Reported Outcomes Measurement Information System Physical Function (PF) and Cognitive Function (CF) Short Forms as well as the pain intensity (PI) rating (scale of 1-10). Patients were characterized for demographics, clinical manifestations of antiphospholipid syndrome (APS), cardiovascular risk factors, laboratory test results, and medication usage. Multivariate modeling was done via linear regression.

RESULTS

Of 139 patients, 89 had primary APS, 21 had secondary APS, and 29 had persistent aPL without meeting clinical criteria for APS. The average T scores (±SD) for PF and CF were 45.4 ± 9.2 and 48.6 ± 11.6, respectively; the average for PI was 3.0 ± 2.6. Approximately half of the patients (47%) endorsed at least mild impairment in PF (T score < 45). Mean PF, CF, and PI did not differ between diagnostic groups. Individuals who endorsed more impairment on one measure also tended to endorse more impairment on another (Pearson r = 0.43-0.59). In the multivariate models, age, smoking, pain medications, and serotonergic medications were associated with impairment in at least one PRO domain. The Damage Index for APS was significantly correlated with both PF and CF.

CONCLUSION

Individuals living with APS endorsed more impairment in PF (and potentially CF) than expected for the general population. The relationship between certain medications and PROs warrants further study, as does the longitudinal trajectory of these and other PROs.

Soluble LILRA3 is aberrantly expressed in antiphospholipid syndrome (APS) and is a potential marker of thrombotic APS

OBJECTIVE

Leucocyte immunoglobulin-like receptor A3 (LILRA3) belongs to a family of leucocyte receptors. Our previous study reported LILRA3 transcripts were markedly upregulated in neutrophils from patients with APS. We undertook this study to investigate clinical implications of LILRA3 in APS and its potential role in APS-associated thrombosis.

METHODS

Two independent cohorts were studied. The first consisted of 294 APS patients, 48 asymptomatic aPL carriers and 150 healthy controls (HCs) from Peking University People's Hospital. The second included 99 APS patients, 25 aPL carriers and 40 HCs from United States APS centres. Serum or plasma concentrations of LILRA3 and MPO-DNA complexes were measured. Additionally, 35 patients with thrombotic APS (tAPS) were evaluated to determine potential effects of immunosuppressive therapy on serum concentrations of LILRA3 and MPO-DNA complexes.

RESULTS

Both positivity and serum concentration of LILRA3 were significantly increased in APS patients, especially in those with tAPS. LILRA3-positive tAPS patients displayed more severe thrombotic manifestations. Serum LILRA3 was positively correlated with MPO-DNA complexes in LILRA3-positive tAPS. After immunosuppressive treatment, LILRA3 and MPO-DNA complexes were consistently decreased in tAPS patients. Key findings from the Peking cohort were confirmed in the United States cohort.

CONCLUSION

Our study provides first evidence that LILRA3 is aberrantly expressed in APS, especially in patients with tAPS. Serum LILRA3 correlated with MPO-DNA complexes, and the two indices were consistently decreased in tAPS patients after treatment. LILRA3 may play a role in thrombosis of APS and may serve as a biomarker and/or therapeutic target in tAPS.

Relationship Between Gender Differences and Clinical Outcome in Patients With the Antiphospholipid Syndrome

Antiphospholipid syndrome (APS), characterized by artherial and/or venous thrombosis, pregnancy morbidity and “antiphospholipid” antibodies (aPLs), is more common in women than in men, with a female to male ratio of about 3.5:1. Only few studies have investigated the clinical differences between male and female patients with APS. Therefore, this study was aimed to analyze the differences of clinical manifestations and laboratory tests, at diagnosis, between female and male APS patients and the clinical outcome. We enrolled 191 consecutive APS patients (125 with primary APS, PAPS, and 66 with secondary APS, SAPS) with a female predominant ratio of approximately 3:1 (142 vs 49). The prevalence of PAPS was higher in males than females (p<0.001). The analysis of aPL profile revealed that high IgM anti-cardiolipin (aCL) and high-medium IgG aCL titers were more frequent in males. In thrombotic APS peripheral arterial thrombosis was more common in male than female patients (p=0.049), as well as myocardial infarction (p=0.031). Multivariate analysis to correct for cardiovascular risk factors, high titer of aPLs and triple positivity for aPLs, revealed that the odds ratio for myocardial infarction in male was 3.77. Thus, APS may be considered as a disease in which serological (IgM titer) and clinical profiles are influenced by gender.

Association between interferon-I producing plasmacytoid dendritic cells and thrombotic antiphospholipid syndrome

Background: Thrombotic risk in antiphospholipid syndrome (APS) is conferred by the association of antiphospholipid (aPL) antibodies (first hit) with additional pro-coagulant stimulus (second hit), such as inflammation. Among inflammatory responses, the production of large amounts of interferon (IFN)-I by plasmacytoid dendritic cells (pDCs) is at the basis of the pathophysiology of systemic autoimmune disorders, which raises the hypothesis that this mechanism could also be associated with vascular manifestations of APS. Purpose: Here, we determined the association of pDCs and IFN-I production with thrombotic APS. Research design: Patients with thrombotic primary (t-PAPS) and secondary APS (t-SAPS), asymptomatic aPL carriers and individuals without thrombosis (controls) were included. Data collection and analysis: Circulating pDCs and IFN-α intracellular expression (in the presence or not of oligodeoxynucleotides (CP) stimulus) were quantified by flow cytometry. The expression of five IFN-I inducing genes: ISG15, OASL, Ly6E, MX1, and OAS1 in mononuclear cells was determined by qPCR. Between-group differences were evaluated using chi-square or Kruskal-Wallis tests. Results: A total of 50 patients with t-PAPS, 50 patients with t-SAPS, 20 aPL carriers, and 50 individuals without thrombosis (controls) were included. Intracellular expression of IFN-α was increased after CPG stimulation in both t-SAPS (1.56%; IQR 1.07-2.02) and t-PAPS (0.96%; IQR 0.55-1.24), when compared to aPL carriers (0.71%; IQR 0.42-0.93) and controls (0.48%; IQR 0.24-0.78; p < .0001). ISG15, OASL, Ly6E, MX1, and OAS1 mRNA expressions were higher in t-SAPS (but not in t-PAPS) than in aPL carriers and controls. The expression of proteins and mRNA related to IFN-I response was similar between the triple aPL-positive profile and other aPL profiles. Conclusion: Our results indicate an association of IFN-I response and t-APS. Since IFN-I expression was not increased in aPL carriers or associated with a higher-risk aPL profile, this mechanism does not appear to be related to the presence of aPL alone. IFN-I response could possibly constitute a complementary mechanism for triggering clinical manifestations in APS.

Hypercoagulability Evaluation in Antiphospholipid Syndrome without Anticoagulation Treatment with Thrombin Generation Assay: A Preliminary Study

Antiphospholipid syndrome (APS) is associated with thrombotic events (tAPS) and/or obstetrical morbidity (oAPS), with persisting antiphospholipid antibodies (aPL). Despite an update of aPL in 2006, several patients had typical clinical events without the classical biological criteria. The aim of our study was to evaluate the hypercoagulability state with both thrombin generation (TG) profiles and activated protein C resistance (aPCR) in different types of APS. Methods: We retrospectively included 41 patients with Sydney criteria classification (tAPS, oAPS) and no clinical manifestation of APS with persistent aPL (biological APS). A thrombin generation assay was performed with a Fluoroskan Ascent fluorometer in platelet-poor plasma (PPP). Activated protein C resistance was measured as a ratio: ETP_+aPC/ETP_-aPC × 100. Results: Thrombotic APS and oAPS had an increase of global thrombin generation (ETP_control = 808 nM.min (756–853) vs. 1265 nM.min (956–1741) and 1863 nM.min (1434–2080), respectively) (Peak_control = 78 nM (74–86) vs. 153 nM (109–215) and 254 nM.min (232–289), respectively). Biological APS had only a lag time increase (T_control = 4.89 ± 1.65 min vs. 13.6 ± 3.9 min). An increased aPCR was observed in tAPS (52.7 ± 16.4%), oAPS (64.1 ± 14.6%) as compared to the control group (27.2 ± 13.8%). Conclusion: Our data suggest an increase of thrombin generation in thrombotic and obstetrical APS and no hypercoagulable states in patients with biological APS. The study of a prospective and a larger controlled cohort could determine the TGA useful for APS monitoring and could confirm an aPCR evaluation in PPP.

Risk of Systemic Lupus Erythematosus in Patients With Anti-phospholipid Syndrome: A Population-Based Study

Objective: To investigate the association between anti-phospholipid syndrome (APS) and the risk of newly diagnosed systemic lupus erythematosus (SLE). Methods: We used 2003-2013 data derived from Taiwan's National Health Insurance Research Database to conduct this nationwide, population-based. We identified AS patients newly diagnosed between 2005 to 2013 as the study group and applied age-sex matched (1:20) and propensity score-matched (PSM) (1:2) non-SLE individuals as controls. The association between APS and risk of incident SLE was determined by calculating hazard ratios (HRs) with 95% confidence intervals (CIs) using Cox proportional hazard regression analysis. Results: We identified 1,245 patients with APS as well as 24,900 age- and sex-matched non-APS controls and 727 APS patients as well as 1,454 PSM non-APS controls. We found that the risk for incident SLE in the APS group was 80.70 times higher than the non-APS group, and the association remained robust after PSM (HR, 28.55; 95% CI, 11.49-70.91). The increased risk for SLE in patients with APS mainly existed within 5 years after the diagnosis of APS. The sensitivity analyses found that the risk for SLE in patients with APS was consistent excluding patients with ITP/AIHA and using distinct definitions of SLE. Conclusion: The present population-based study revealed a robust association between SLE risk and recent APS and highlights the need for vigilance of SLE-associated symptoms in patients who had been diagnosed with APS.

B cells in primary antiphospholipid syndrome: Review and remaining challenges

It is now widely accepted that antiphospholipid antibodies (aPL) have direct pathogenic effects and that B cells, notably through aPL production, play a key role in the development of antiphospholipid syndrome (APS). Recent findings strengthened the implication of B cells with the description of specific B cell phenotype abnormalities and inborn errors of immunity involving B cell signaling in APS patients. In addition, it has been shown in preclinical models that cross-reactivity between APS autoantigens and mimotopes expressed by human gut commensals can lead to B cell tolerance breakdown and are sufficient for APS development. However, B cell targeting therapies are surprisingly not as effective as expected in APS compared to other autoimmune diseases. Elucidation of the B cell tolerance breakdown mechanisms in APS patients may help to develop and guide the use of novel therapeutic agents that target B cells or specific immune pathway.

Childhood-onset systemic lupus erythematosus-related antiphospholipid syndrome: A multicenter study with 1519 patients

OBJECTIVE

To assess childhood-onset systemic lupus erythematosus-related antiphospholipid syndrome(cSLE-APS) in a large Brazilian population.

METHODS

A retrospective observational cohort study was carried-out in 27 Pediatric Rheumatology university centers, including 1519 cSLE patients.

RESULTS

cSLE-APS was observed in 67/1519 (4%) and was diagnosed at disease onset in 39/67 (58%). The median disease duration was 4.9 (0-17) years. Thrombosis recurrences were evidenced in 18/67 (27%) cSLE-APS patients. The most frequent thrombosis sites in cSLE-APS patients were: venous thrombosis in 40/67 (60%), especially deep vein thrombosis in 29/40 (72%); arterial thrombosis in 35/67 (52%), particularly stroke; small vessels thrombosis in 9/67 (13%) and mixed thrombosis in 3/67 (4%). Pregnancy morbidity was observed in 1/67 (1%). Non-thrombotic manifestation associated to cSLE-APS occurred in 21/67 (31%), mainly livedo reticularis in 14/67 (21%), valvar thickening in 4/67 (6%) and valvar vegetations not related to infections in 2/67 (3%). None of them had catastrophic APS. Further analysis demonstrated that the median of SLICC/ACR-DI [1(0-5) vs. 0(0-7),p < 0.0001] was significantly higher in cSLE-APS patients compared to cSLE without APS. The frequencies of cerebrovascular disease (40% vs. 1%,p < 0.0001), polyneuropathy (9% vs. 1%,p < 0.0001), SLICC/ACR-DI ≥1 (57% vs. 27%, p < 0.0001) and intravenous cyclophosphamide use (59% vs. 37%, p < 0.0001) were significantly higher in the former group.

CONCLUSIONS

Our large multicenter study demonstrated that cSLE-APS was a rare condition, occurring during disease course with a high accrual damage. Central and peripheral neuropsychiatric involvements were distinctive features of this autoimmune thrombosis.

Prevalence, outcome and management of patients with SLE and secondary antiphospholipid antibody syndrome after aPL seroconversion

Objective

The withdrawal of oral anticoagulation (OAC) in patients with SLE and secondary aPL syndrome (SAPS) who become seronegative has not been clearly investigated to date. Our aim was to evaluate the prevalence of aPL seroconversion and the prognosis of SLE patients with SAPS who withdrew OAC after aPL negativization.

Methods

We retrospectively analysed data of all SLE patients (ACR criteria) with SAPS (Sydney criteria) prospectively followed-up in our clinic. aPL seroconversion was defined as negativization of lupus anticoagulant, aCL, and anti-β2glycoprotein-1 antibodies on two or more consecutive measurements, at least 12 weeks apart. OAC discontinuation was defined as the definitive withdrawal of all anticoagulants.

Results

Fifty-five out of 513 (10.7%) SLE patients had vascular SAPS. Sixteen patients (29.1%) became aPL seronegative during follow-up. Immunosuppressive therapy predicted aPL negativization (odds ratio 5.211, 95%CI 1.341, 20.243), whereas APS diagnosis prior to that of SLE (odds ratio 0.078, 95%CI 0.008, 0.799) and triple-positive profile (odds ratio 0.264, 95%CI 0.115, 0.609) were negative predictors of aPL negativization. OAC was discontinued in 13/55 patients (23.6%), after a median follow-up of 45 months (range 1–276) from aPL seroconversion. SLE-related modifiable risk factors for thrombosis were observed in 10/13 patients (77%) at the time of the thrombotic event. No thrombotic recurrences were observed during a mean follow-up time of 44 (19) months from OAC discontinuation.

Conclusions

Our results suggest that OAC can be safely discontinued in SLE patients who became persistently seronegative for aPL, at least when aPL-related thrombotic events occurred in presence of other thrombotic risk factors.

Profiling of non-criteria antiphospholipid antibodies in patients with SLE: differentiation of thrombotic SLE patients and risk of recurrence of thrombosis

To reveal the clinical significance of criteria and non-criteria antiphospholipid antibodies detected by line immunoassay in comparison with ELISA, systemic lupus erythematosus patients with and without thrombotic events were investigated. Thus, 107 systemic lupus erythematosus patients (48% with deep vein thrombosis or/and arterial thrombosis) and 120 healthy donors were enrolled. Serum antiphospholipid antibodies were detected by ELISA (Orgentec Diagnostika, Germany) and line immunoassay (GA Generic Assays, Germany). Lupus anticoagulant and IgG to cardiolipin and β2GPI but not IgM as well as triple positivity by ELISA and line immunoassay were linked with thrombosis in systemic lupus erythematosus. IgG to phosphatidylinositol and phosphatidylserine by line immunoassay showed significantly higher levels in systemic lupus erythematosus with deep vein thrombosis/arterial thrombosis than without and were independent risk factors for deep vein thrombosis (odds ratio 3.9, 95% confidence interval 1.1, 13.2) and arterial thrombosis (odds ratio 5.1, 95% confidence interval 1.3, 19.8) as well as thrombosis (odds ratio 3.6, 95% confidence interval 1.1, 11.3) and recurrence thereof (odds ratio 6.9, 95% confidence interval 2.1, 22.6), respectively. The occurrence of >4 IgG antiphospholipid antibodies by line immunoassay was an independent risk factor for thrombosis (odds ratio 10.9, 95% confidence interval 1.2, 101.5), arterial thrombosis (odds ratio 14.6, 95% confidence interval 2.5, 86.3), deep vein thrombosis (odds ratio 5.8, 95% confidence interval 1.0, 32.4) and recurrence of thrombosis (odds ratio 35.9, 95% confidence interval 3.8, 342.8). Line immunoassay is a promising multiplex test for the simultaneous detection of criteria and non-criteria antiphospholipid antibodies. Profiling of antiphospholipid antibodies by line immunoassay can differentiate systemic lupus erythematosus patients with thrombosis from systemic lupus erythematosus patients without and assess the risk for thrombosis and recurrence thereof.

One-decade study of distinct features, morbidity and mortality of systemic lupus erythematosus (an update on systemic lupus erythematosus in the Fars Province of Iran)

OBJECTIVE

The objective of this article is to investigate the distinct features, morbidity and mortality of systemic lupus erythematosus (SLE) patients registered in rheumatology tertiary centers of Shiraz University of Medical Sciences from 2008 to 2018.

METHOD

A cross-sectional study was conducted on registered patients by reviewing their medical records. The clinical presentations were classified based on each organ's distinct involvement.

RESULT

Data of 1322 patients with a mean age of 40 at the time of the study were reviewed. The most common primary manifestation of the disease was arthralgia (37.5%), and the most common clinical presentation in course of the disease was skin involvement (61.8%). The most common cause of hospital admission was disease flare (27.8% (108/388)), and mortality was mainly due to pulmonary complications (27.5% (8/29)). Patients who had hypothyroidism had statistically significantly lower rates of constitutional symptoms (p = 0.006), gastrointestinal involvement (p = 0.024), hypertension (p = 0.002), headache (p = 0.019), depression (p = 0.049) and anemia (p = 0.014). Patients who presented with malar rash and photosensitivity in their course of disease were detected to have statistically significantly lower ages of disease onset (p = 0.013 and 0.003, respectively).

CONCLUSION

This study is an update to an epidemiologic study conducted in 2008 in the south of Iran. By comparing results between the two studies, we have tried to investigate the change in morbidity and mortality of SLE during these years.

Antiphospholipid syndrome's genetic and epigenetic aspects

Studies on last genetic and epigenetic predisposition to APS are summarized. It is well known that genetic predisposition is in HLA system (DR4 and DRw53) and that lupus anticoagulant (LA) and anticardiolipin antibodies (aCL) are both associated with the same HLA antigens. Other genes, outside the MHC, give their contribution to the development of this autoimmune syndrome, such as IRF5, STAT4 and those related to inherited thrombophilia - factor V Leiden and G20210A prothrombin polymorphisms. Finally, post-transcriptional modifications of anti-beta2GPI antibodies could be implicated too. The most important discovery of last years is that altered microRNAs' expression is linked to autoimmunity, thrombosis, early atherosclerosis, and oxidative stress in APS.

Characteristics of pregnancy complications and treatment in obstetric antiphospholipid syndrome in China

OBJECTIVES

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by obstetric complications and thrombotic events associated with antiphospholipid antibodies (aPL). We aimed to compare the clinical characteristics and treatment of primary APS (PAPS) and secondary APS (systemic lupus erythematosus-APS, SAPS) patients and investigate risk factors associated with obstetric complications in Shanghai, China.

METHODS

We retrospectively collected and analyzed the data of obstetric APS (OAPS) patients from 2000 to 2017 in the APS-Shanghai (APS-SH) database.

RESULTS

One hundred eighty OAPS patients with a total of 450 pregnancies were included in this study. Two hundred twenty-one (49.11%) pregnancies resulted in miscarriage, and 161 (35.77%) pregnancies resulted in intrauterine death. In our cohort, when women were treated, 57 out of 66 pregnancies resulted in live births (86%). Of the 9 treated patients who failed to have live births, 3 had intrauterine deaths, 3 had fetal growth restriction, 2 had pneumorrhagia of the newborn, and 1 had a miscarriage. OAPS patients were divided into two groups: PAPS and SAPS. More SAPS patients than PAPS patients used glucocorticoids (GCs) and hydroxychloroquine (both p < 0.001). However, there was no significant difference in the GC dosage between SAPS and PAPS patients (p = 0.188). Lupus anticoagulant (LAC) and IgG aβ2GPI were risk factors for miscarriage (odds ratio (OR) = 2.398, 95% confidence interval (CI) = 1.276-4.505, p = 0.002; OR = 2.907, 95% CI = 1.558-5.405, p = 0.001, respectively) and intrauterine death (OR = 2.439, 95% CI = 1.299-4.580, p = 0.006; OR = 2.060, 95% CI = 1.089-3.897, p = 0.026, respectively).

CONCLUSIONS

The live birth rate of OAPS patients in Shanghai was 86%. Even if OAPS patients were treated, pregnancy complications could occur, and these patients might need further second-line treatment. Key Points • This is the first study to report data on Chinese OAPS patients. The live birth rate was 86%. • Lupus anticoagulant and IgG aβ2GPI were risk factors for miscarriage and intrauterine death in our cohort. • Despite active treatment, 9 patients had obstetric complications. Therefore, further second-line treatment is still needed.

Alarmin HMGB1 and Soluble RAGE as New Tools to Evaluate the Risk Stratification in Patients With the Antiphospholipid Syndrome

Antiphospholipid antibody syndrome (APS) is a systemic autoimmune disease characterized by arterial and/or venous thrombosis, pregnancy morbidity in the presence of circulating “anti-phospholipid antibodies” (aPL). One of the main target antigens of aPL is β₂-glycoprotein I (β₂-GPI). APS may occur as a primary syndrome or associated with Systemic Lupus Erythematosus (SLE). High Mobility Group Box 1 (HMGB1) is a nuclear non-histone protein which is secreted from different type of cells during activation and/or cell death and may act as a proinflammatory mediator through ligation to its receptors, including RAGE. There is accumulating evidence that HMGB1 contributes to the pathogenesis of inflammatory and autoimmune diseases, especially SLE. In a previous study we demonstrated increased serum levels of HMGB1 in both primary and secondary APS patients. In this work we analyzed: (i) in vitro whether anti-β₂-GPI antibodies from APS patients may induce both a HMGB1 cellular relocation by activation of its putative receptor RAGE in platelets and monocytes and, (ii) ex vivo, serum levels of HMGB1/soluble RAGE (sRAGE) in APS patients and their possible correlation with clinical manifestations. Platelets and monocytes from healthy donors were incubated with affinity purified anti-β₂-GPI antibodies. HMGB1 and RAGE expression were analyzed by Western Blot. Sera from 60 consecutive APS patients (primary or secondary), diagnosed according to the Sydney Classification Criteria, were enrolled. As a control, 30 matched healthy subjects were studied. Serum levels of HMGB1 and sRAGE were analyzed by Western Blot. In vitro results showed that anti-β₂-GPI antibodies were able to induce RAGE activation and HMGB1 cellular relocation in both monocytes and platelets. HMGB1 and sRAGE serum levels were significantly increased in APS patients in comparison with healthy subjects (p<0.0001). Interestingly, APS patients with spontaneous recurrent abortion showed significantly higher levels of sRAGE; moreover, in APS patients a direct correlation between serum levels of HMGB1 and disease duration was detected. Our observations suggest that anti-β₂-GPI antibodies may trigger RAGE activation and HMGB1 cellular relocation during APS. Monitoring these molecules serum levels may represent an useful tool to evaluate the pathogenesis and risk stratification of clinical manifestations in APS.

Altered Th17/Treg Ratio in Peripheral Blood of Systemic Lupus Erythematosus but Not Primary Antiphospholipid Syndrome

Introduction: The role of the immune response in the pathogenesis of antiphospholipid syndrome (APS) remains elusive. It is possible that differences in the frequencies of Th17 cells and/or defects in the immunoregulatory mechanisms are involved in the pathogenesis of APS. Our aim was to determine the peripheral blood Th cells phenotype and the circulating cytokine profile in patients with primary APS (pAPS) and compare it with systemic lupus erythemathosus (SLE) as disease control group.

Methods: The frequencies of circulating regulatory T cells (Tregs) were determined in PBMCs from 36 patients with pAPS by flow cytometry. As control groups we included 21 age- and gender-matched healthy controls (HC) and 11 patients with SLE. The suppressive capacity of Tregs was evaluated in vitro by coculture assay. On the other hand, intracellular cytokine production was assessed in Th1, Th2, and Th17 cells and circulating IL-6, IL-10, and IL-35 were measured by Cytometric Bead Array and ELISA. The quantification of Th master gene expression levels was performed by real time quantitative PCR.

Results: pAPS patients and SLE patients did not show differences in the percentage or number of Tregs compared to HC. The suppressive capacity of Tregs was also similar in the three study group. Instead, we found higher FoxP3·mRNA expression levels in pAPS patients and HC than SLE patients. Regarding the Th17 response, patients with pAPS and HC showed a significantly lower frequency of circulating Th17 cells than SLE. However, no differences were observed in the Th1 response between patients and controls. Thus, increased Th17/Th1 and Th17/Treg ratios were found in SLE patients but not in pAPS patients. pAPS and SLE patients had higher serum IL-6 levels than HC but there was not difference between both disease groups. Besides, a significant increase in the immunosuppressive cytokine levels was observed only in pAPS as compared to HC.

Conclusions: Our data demonstrate an increased inflammatory profile of peripheral blood CD4⁺ T cells from SLE as compared with pAPS mostly due to an increased Th17 response. In conclusion, there seems not to be a direct pathogenic role for Th cells in pAPS but in SLE.

Low molecular weight heparin monotherapy for recurrent abortion with antiphospholipid system: A protocol of a systematic review

BACKGROUND

Previous clinical studies reported low molecular weight heparin (LMWH) monotherpay has been utilized for the treatment of recurrent abortion (RCA) with antiphospholipid system (APS). However, its efficacy is still inconclusive. This systematic review aims to assess its efficacy and safety for patients with RCA and APS.

METHODS

A systematic literature search for article up to February 2019 will be conducted in 9 databases: Cochrane Library, EMBASE, MEDILINE, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, VIP Information, and Wanfang Data. Inclusion criteria are randomized control trials of LMWH monotherpay for patients with RCA and APS. The Cochrane risk of bias tool will be used to evaluate the methodological quality for each qualified study. The summary results will be showed by using fixed-effects and random-effects models for pooling the data based on the heterogeneity of included studies.

RESULTS

This systematic review will assess the clinical efficacy and safety of LMWH monotherpay in treating RCA with APS. The primary outcome is pregnancy loss. The secondary outcomes include frequency of preterm delivery, live birth rates, maternal and fetal complications, as well as adverse events.

CONCLUSION

The findings of this study will summarize the present evidence to judge whether LMWH monotherpay is an effective therapy for patients with RCA and APS.

DISSEMINATION AND ETHICS

The findings of this study will be published by through peer-reviewed journals. This study does not needs ethic documents, because it will not analyze individual patient data.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019121064.