Primary versus secondary antiphospholipid syndrome: is this lupus or not?

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.

The impact of activated protein C resistance on the patency of arteriovenous grafts for hemodialysis access

INTRODUCTION

Vascular access is required for hemodialysis treatment. An effect of activated protein C resistance on access thrombosis rates has not yet been investigated. The aim of this study is to determine whether an activated protein C resistance is correlated with the patency of polytetrafluoroethylene arteriovenous grafts.

METHODS

The primary endpoint was the impact of activated protein C resistance; secondary endpoints were the influence of Factor V Leiden thrombophilia, homocysteine, ß2-glycoprotein antibodies, and other laboratory values on the assisted primary patency.

RESULTS

Forty-three grafts in 43 patients were included. The overall mean assisted primary patency was 18.4 months (±3.16 SE). Activated protein C resistance (p = 0.01) and ß2-glycoprotein antibodies (p = 0.018) had a significant influence on the assisted primary patency. The assisted primary patency for patients with low (<4) activated protein C resistance was 9.3 months compared to 24.8 of those with a high (≥4) activated protein C resistance. Patients with low (≤2.6) ß2-glycoprotein antibodies presented an assisted primary patency of 31.8 months whereas those with high (>2.6) ß2-glycoprotein antibodies showed 9.3 months. In all patients with a pathologic activated protein C resistance, a heterozygous or homozygous Factor V Leiden thrombophilia was detected.

CONCLUSIONS

This study identified low activated protein C resistance and high ß2-glycoprotein antibodies as risk factors for thrombosis in polytetrafluoroethylene arteriovenous grafts. A prospective study is needed to clarify if oral anticoagulation should be administered to all patients with a pathologic activated protein C resistance blood value and/or factor V Leiden mutation.

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

Primary antiphospholipid syndrome (PAPS) and antiphospholipid syndrome associated to lupus (SAPS) have several overlapping characteristics. As systemic manifestations are also reported in patients with PAPS, and as a subgroup of PAPS patients could evaluate to a SAPS, the differentiation between the two types of APS could be performed based on the clinical experience of the medical teams and is related to a variety of clinical, biological, histological and genetic features. Several data are available in the literature with respect to the identification of distinctive features between these two entities. However, there are some limitation in the interpretation of results issued from studies performed prior to updated Sydney criteria. Based on recent data, a certain number of features more frequent in one type of APS as compared to the other could be distinguished. The major differentiation between these two entities is genetical. New genetic data allowing the identification of specific subgroups of APS are ongoing.

Distinct antibody profile: a clue to primary antiphospholipid syndrome evolving into systemic lupus erythematosus?

We have performed a retrospective study to determine if patients with antiphospholipid syndrome that developed systemic lupus erythematosus (APS/SLE) had distinct clinical and/or serological features. All 80 primary APS (PAPS) patients followed up at our APS unit were included in the study and divided into two groups: 14 APS/SLE and 66 PAPS. Prior or at onset of lupus manifestations, six patients were uniformly negative for lupus and Sjögren autoantibodies, and the other eight patients had persistent positive. In the first year after diagnosis of SLE, three patients remained with negative antibodies, the other seven patients maintained the same antibodies, and four patients developed other antibodies. APS/SLE group had a significant lower mean age at PAPS diagnosis (26.0 ± 8.0 vs. 34.2 ± 11.9 years, p = 0.03) and a longer disease duration (14.0 ± 7.0 vs. 6.0 ± 5.0 years, p < 0.0001). The mean time for PAPS to develop SLE was 5.2 ± 4.3 years. The typical clinical and laboratorial findings of APS did not discriminate both groups of patients. At lupus onset, antinuclear antibodies were more frequently observed in those who evolved to SLE (100 vs. 51.5%, p = 0.0005). Anti-double-stranded DNA (dsDNA), anti-ribosomal P, anti-Ro/SS-A, anti-La/SS-B, and anti-U1RNP antibodies were exclusively found in the APS/SLE patients, whereas anti-Smith (Sm) antibodies were not detected in both groups. The detection of a distinct subgroup of lupus-associated autoantibody in PAPS patients seems to be a hint to overt SLE disease, particularly in those patients with young age at diagnosis.

Introducing polyautoimmunity: secondary autoimmune diseases no longer exist

Similar pathophysiological mechanisms within autoimmune diseases have stimulated searches for common genetic roots. Polyautoimmunity is defined as the presence of more than one autoimmune disease in a single patient. When three or more autoimmune diseases coexist, this condition is called multiple autoimmune syndrome (MAS). We analyzed the presence of polyautoimmunity in 1,083 patients belonging to four autoimmune disease cohorts. Polyautoimmunity was observed in 373 patients (34.4%). Autoimmune thyroid disease (AITD) and Sjögren's syndrome (SS) were the most frequent diseases encountered. Factors significantly associated with polyautoimmunity were female gender and familial autoimmunity. Through a systematic literature review, an updated search was done for all MAS cases (January 2006-September 2011). There were 142 articles retrieved corresponding to 226 cases. Next, we performed a clustering analysis in which AITD followed by systemic lupus erythematosus and SS were the most hierarchical diseases encountered. Our results indicate that coexistence of autoimmune diseases is not uncommon and follows a grouping pattern. Polyautoimmunity is the term proposed for this association of disorders, which encompasses the concept of a common origin for these diseases.

Anti-argonaute2 (Ago2/Su) and -Ro antibodies identified by immunoprecipitation in primary anti-phospholipid syndrome (PAPS)

OBJECTIVES

Primary anti-phospholipid syndrome (PAPS) is an autoimmune condition defined by anti-phospholipid antibodies (aPL) and thrombotic or obstetric events. Some PAPS can evolve into systemic lupus erythematosus (SLE) during follow-up. Few studies systematically examined lupus autoantibodies and their clinical significance in PAPS. The aim of our study is to analyze the clinical and laboratory correlations with lupus-related autoantibodies, detected by immunoprecipitation (IP), a technique not yet systematically applied to investigate autoantibodies in this condition.

METHODS

Sera from 52 PAPS patients were screened by indirect immunofluorescence (IIF) antinuclear antibodies (ANA), IP of ³⁵S-labeled K562 cell extract, and ELISA [anti-Argonaute2 (Ago2, Su), 60kRo, 52kRo, La, dsDNA)]. Anti-Ago2/Su positive sera were also tested for anti-GW bodies (GWBs) by IIF double staining, using rabbit anti-Rck/p54 serum.

RESULTS

First, 56% of PAPS patients (29/52) were ANA positive, mainly with speckled pattern. Anti-Ago2/Su antibodies were found in 13% (7/52), anti-Ro/SSA in 10% (5/52), anti-La in one case. The clinical profile of patients did not seem to be related to the presence of these antibody specificities. However, levels of IgG anti-β2 glycoprotein I antibodies were lower in anti-Ago2/Su positive patients (p = 0.02). None of anti-Ago2/Su or -Ro patients developed SLE during a 2-year follow-up. Ago2 is a key component of GWBs, however, only 1/7 anti-Ago2/Su serum showed a typical cytoplasmic GWBs staining.

CONCLUSIONS

Anti-Ago2/Su and -Ro antibodies are the two autoantibodies detected by IP in our PAPS cohort. Clarifying why Ago2/Su and Ro are specific targets of autoimmunity may help to understand the mechanisms of autoantibody production.

Antiphospholipid antibody syndrome and autoimmune diseases

The arbitrary division between antiphospholipid antibody syndrome and secondary antiphospholipid antibody syndrome has not proven useful. Antiphospholipid antibodies in the absence of antiphospholipid antibody syndrome often occur as epiphenomena in many autoimmune diseases. They are very common in systemic lupus erythematosus. Antiphospholipid antibody syndrome is a significant comorbidity in lupus but is uncommon in Sjögren's syndrome, rheumatoid arthritis, scleroderma, and systemic vasculitis. Evidence is growing that antiphospholipid antibodies may have a pathogenic role in pulmonary hypertension and accelerated atherosclerosis of autoimmune diseases.

Atypical movement disorders in antiphospholipid syndrome

Movement disorders have only rarely been reported in association with antiphospholipid syndrome (APS). In such cases, chorea is the most common disorder observed, with occasional reports of hemidystonia, Parkinsonism, and hemiballism. We report here on 3 cases of APS (3 women ages 16, 46, and 56 years) who presented with movement disorders, including tics, tremor, myoclonus, and a corticobasal syndrome, never or rarely reported in association with this disease. Mild executive dysfunction was observed in all 3 patients. We also report the successful treatment of two of these patients with mild oral anticoagulation (INR 2-3). Movement disorders in APS seem more clinically heterogeneous than previously thought. Oral anticoagulation should be considered in the treatment of movement disorders associated with APS.