Antiphospholipid syndrome Schreiber, Karen; Sciascia, Savino; de Groot, Philip G ...
Nature reviews. Disease primers,
01/2018, Letnik:
4
Journal Article
Recenzirano
Odprti dostop
Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of antiphospholipid antibodies, such as lupus anticoagulant, anticardiolipin antibodies and anti-β2-glycoprotein ...1 antibodies. APS can present with a variety of clinical phenotypes, including thrombosis in the veins, arteries and microvasculature as well as obstetrical complications. The pathophysiological hallmark is thrombosis, but other factors such as complement activation might be important. Prevention of thrombotic manifestations associated with APS includes lifestyle changes and, in individuals at high risk, low-dose aspirin. Prevention and treatment of thrombotic events are dependent mainly on the use of vitamin K antagonists. Immunosuppression and anticomplement therapy have been used anecdotally but have not been adequately tested. Pregnancy morbidity includes unexplained recurrent early miscarriage, fetal death and late obstetrical manifestation such as pre-eclampsia, premature birth or fetal growth restriction associated with placental insufficiency. Current treatment to prevent obstetrical morbidity is based on low-dose aspirin and/or low-molecular-weight heparin and has improved pregnancy outcomes to achieve successful live birth in >70% of pregnancies. Although hydroxychloroquine and pravastatin might further improve pregnancy outcomes, prospective clinical trials are required to confirm these findings.
Objective
To develop new classification criteria for systemic lupus erythematosus (SLE) jointly supported by the European League Against Rheumatism (EULAR) and the American College of Rheumatology ...(ACR).
Methods
This international initiative had four phases. 1) Evaluation of antinuclear antibody (ANA) as an entry criterion through systematic review and meta‐regression of the literature and criteria generation through an international Delphi exercise, an early patient cohort, and a patient survey. 2) Criteria reduction by Delphi and nominal group technique exercises. 3) Criteria definition and weighting based on criterion performance and on results of a multi‐criteria decision analysis. 4) Refinement of weights and threshold scores in a new derivation cohort of 1,001 subjects and validation compared with previous criteria in a new validation cohort of 1,270 subjects.
Results
The 2019 EULAR/ACR classification criteria for SLE include positive ANA at least once as obligatory entry criterion; followed by additive weighted criteria grouped in 7 clinical (constitutional, hematologic, neuropsychiatric, mucocutaneous, serosal, musculoskeletal, renal) and 3 immunologic (antiphospholipid antibodies, complement proteins, SLE‐specific antibodies) domains, and weighted from 2 to 10. Patients accumulating ≥10 points are classified. In the validation cohort, the new criteria had a sensitivity of 96.1% and specificity of 93.4%, compared with 82.8% sensitivity and 93.4% specificity of the ACR 1997 and 96.7% sensitivity and 83.7% specificity of the Systemic Lupus International Collaborating Clinics 2012 criteria.
Conclusion
These new classification criteria were developed using rigorous methodology with multidisciplinary and international input, and have excellent sensitivity and specificity. Use of ANA entry criterion, hierarchically clustered, and weighted criteria reflects current thinking about SLE and provides an improved foundation for SLE research.
Video
Patients with COVID-19 are at high risk for thrombotic arterial and venous occlusions. Lung histopathology often reveals fibrin-based blockages in the small blood vessels of patients who succumb to ...the disease. Antiphospholipid syndrome is an acquired and potentially life-threatening thrombophilia in which patients develop pathogenic autoantibodies targeting phospholipids and phospholipid-binding proteins (aPL antibodies). Case series have recently detected aPL antibodies in patients with COVID-19. Here, we measured eight types of aPL antibodies in serum samples from 172 patients hospitalized with COVID-19. These aPL antibodies included anticardiolipin IgG, IgM, and IgA; anti-β
glycoprotein I IgG, IgM, and IgA; and anti-phosphatidylserine/prothrombin (aPS/PT) IgG and IgM. We detected aPS/PT IgG in 24% of serum samples, anticardiolipin IgM in 23% of samples, and aPS/PT IgM in 18% of samples. Antiphospholipid autoantibodies were present in 52% of serum samples using the manufacturer's threshold and in 30% using a more stringent cutoff (≥40 ELISA-specific units). Higher titers of aPL antibodies were associated with neutrophil hyperactivity, including the release of neutrophil extracellular traps (NETs), higher platelet counts, more severe respiratory disease, and lower clinical estimated glomerular filtration rate. Similar to IgG from patients with antiphospholipid syndrome, IgG fractions isolated from patients with COVID-19 promoted NET release from neutrophils isolated from healthy individuals. Furthermore, injection of IgG purified from COVID-19 patient serum into mice accelerated venous thrombosis in two mouse models. These findings suggest that half of patients hospitalized with COVID-19 become at least transiently positive for aPL antibodies and that these autoantibodies are potentially pathogenic.
Objective
Antiphospholipid antibodies (aPL) constitute a diagnostic criterion of systemic lupus erythematosus (SLE), and aPL have been functionally linked to liver disease in patients with SLE. Since ...the mechanistic target of rapamycin (mTOR) is a regulator of oxidative stress, a pathophysiologic process that contributes to the development of aPL, this study was undertaken in a mouse model of SLE to examine the involvement of liver mitochondria in lupus pathogenesis.
Methods
Mitochondria were isolated from lupus‐prone MRL/lpr, C57BL/6.lpr, and MRL mice, age‐matched autoimmunity‐resistant C57BL/6 mice as negative controls, and transaldolase‐deficient mice, a strain that exhibits oxidative stress in the liver. Electron transport chain (ETC) activity was assessed using measurements of oxygen consumption. ETC proteins, which are regulators of mitochondrial homeostasis, and the mTOR complexes mTORC1 and mTORC2 were examined by Western blotting. Anticardiolipin (aCL) and anti–β2‐glycoprotein I (anti‐β2GPI) autoantibodies were measured by enzyme‐linked immunosorbent assay in mice treated with rapamycin or mice treated with a solvent control.
Results
Mitochondrial oxygen consumption was increased in the livers of 4‐week‐old, disease‐free MRL/lpr mice relative to age‐matched controls. Levels of the mitophagy initiator dynamin‐related protein 1 (Drp1) were depleted while the activity of mTORC1 was increased in MRL/lpr mice. In turn, mTORC2 activity was decreased in MRL and MRL/lpr mice. In addition, levels of aCL and anti‐β2GPI were elevated preceding the development of nephritis in 4‐week‐old MRL, C57BL/6.lpr, and MRL/lpr mice. Transaldolase‐deficient mice showed increased oxygen consumption, depletion of Drp1, activation of mTORC1, and elevated expression of NADH:ubiquinone oxidoreductase core subunit S3 (NDUFS3), a pro‐oxidant subunit of ETC complex I, as well as increased production of aCL and anti‐β2GPI autoantibodies. Treatment with rapamycin selectively blocked mTORC1 activation, NDUFS3 expression, and aPL production both in transaldolase‐deficient mice and in lupus‐prone mice.
Conclusion
In lupus‐prone mice, mTORC1‐dependent mitochondrial dysfunction contributes to the generation of aPL, suggesting that such mechanisms may represent a treatment target in patients with SLE.
Background
High incidence of thrombosis in COVID‐19 patients indicates a hypercoagulable state. Hence, exploring the involvement of antiphospholipid antibodies (aPL) in these patients is of interest.
...Objectives
To illustrate the incidence of criteria (lupus anticoagulant LAC, anticardiolipin aCL immunoglobulin G IgG/IgM, antibeta2‐glycoprotein I antibodies aβ2GPI IgG/IgM) and noncriteria (anti‐phosphatidyl serine/prothrombin aPS/PT, aCL, and aβ2GPI IgA) aPL in a consecutive cohort of critically ill SARS‐CoV‐2 patients, their association with thrombosis, antibody profile and titers of aPL.
Patients/Methods
Thirty‐one consecutive confirmed COVID‐19 patients admitted to the intensive care unit were included. aPL were measured at one time point, with part of the aPL‐positive patients retested after 1 month.
Results
Sixteen patients were single LAC‐positive, two triple‐positive, one double‐positive, one single aCL, and three aCL IgG and LAC positive. Seven of nine thrombotic patients had at least one aPL. Sixteen of 22 patients without thrombosis were aPL positive, amongst them two triple positives. Nine of 10 retested LAC‐positive patients were negative on a second occasion, as well as the double‐positive patient. Seven patients were aPS/PT‐positive associated to LAC. Three patients were aCL and aβ2GPI IgA‐positive.
Conclusion
Our observations support the frequent single LAC positivity during (acute phase) observed in COVID‐19 infection; however, not clearly related to thrombotic complications. Triple aPL positivity and high aCL/aβ2GPI titers are rare. Repeat testing suggests aPL to be mostly transient. Further studies and international registration of aPL should improve understanding the role of aPL in thrombotic COVID‐19 patients.
Objective
Antiphospholipid Syndrome Alliance For Clinical Trials and International Networking (APS ACTION) is an international research network devoted to conducting well‐designed clinical trials in ...persistently antiphospholipid antibody (aPL)–positive patients. One of the first needs of APS ACTION was to know the true aPL frequency in patients with pregnancy morbidity (PM), stroke (ST), myocardial infarction (MI), and deep venous thrombosis (DVT).
Methods
The search for “aPL” and multiple keywords regarding the outcomes of interest was completed in PubMed. The median frequency for positive aPL tests (lupus anticoagulant, antibody against cardiolipin aCL, and antibody against β2‐glycoprotein I anti‐β2GPI) was calculated for each outcome and was used to estimate the overall aPL frequency.
Results
Based on the analysis of 120 full‐text papers, the overall aPL frequency was estimated as 6% for PM, 13.5% for ST, 11% for MI, and 9.5% for DVT. Limitations of the literature were that 60% of the papers were published before 2000, all 3 criteria aPL tests were performed in only 11% of the papers, 36% of papers used a low‐titer aCL cutoff, anti‐β2GPI cutoff was quite heterogeneous, aPL confirmation was performed in only one‐fifth of papers, and the study design was retrospective in nearly half of the papers.
Conclusion
It is difficult to determine the frequency of a “clinically significant aPL profile” in patients with aPL‐related clinical outcomes due to the lack of robust data. Our best estimates of the incidence of aPL‐associated events should be confirmed with appropriately designed population studies.
First described in the early 1980s, antiphospholipid syndrome (APS) is a unique form of acquired autoimmune thrombophilia in which patients present with clinical features of recurrent thrombosis and ...pregnancy morbidity and persistently test positive for the presence of antiphospholipid antibodies (aPL). At least one clinical (vascular thrombosis or pregnancy morbidity) and one lab-based (positive test result for lupus anticoagulant, anticardiolipin antibodies and/or anti-β2-glycoprotein 1 antibodies) criterion have to be met for a patient to be classified as having APS. However, the clinical spectrum of APS encompasses additional manifestations that can affect many organs and cannot be explained exclusively by patients being in a prothrombotic state; clinical manifestations not listed in the classification criteria (known as extra-criteria manifestations) include neurologic manifestations (chorea, myelitis and migraine), haematologic manifestations (thrombocytopenia and haemolytic anaemia), livedo reticularis, nephropathy and valvular heart disease. Increasingly, research interest has focused on the development of novel assays that might be more specific for APS than the current aPL tests. This Review focuses on the current classification criteria for APS, presenting the role of extra-criteria manifestations and lab-based tests. Diagnostic approaches to difficult cases, including so-called seronegative APS, are also discussed.
Objective
The primary objective of this study was to evaluate the safety of rituximab in antiphospholipid antibody (aPL)–positive patients with non‐criteria manifestations of antiphospholipid ...syndrome (APS). The secondary objectives were to evaluate the effect of rituximab on the aPL profile and to evaluate the efficacy of rituximab treatment for non‐criteria manifestations of APS.
Methods
In this 12‐month, phase II pilot study, adult aPL‐positive patients with thrombocytopenia, cardiac valve disease, skin ulcer, aPL nephropathy, and/or cognitive dysfunction received 2 doses of rituximab (1,000 mg) on days 1 and 15. Antiphospholipid antibody profiles and clinical outcome measures, which were categorized as complete response, partial response, no response, or recurrence, were analyzed at preset time points.
Results
Two of 19 patients experienced infusion reactions, resulting in early termination. Twelve serious adverse events and 49 nonserious adverse events were recorded. All patients who had positive results of lupus anticoagulant, anticardiolipin, and anti–β2‐glycoprotein I antibody tests at baseline had positive results at 24 weeks and 52 weeks. The numbers of patients with a complete response, a partial response, no response, and recurrence for the clinical outcome measures at 24 weeks were as follows: for thrombocytopenia, 1, 1, 2, and 0, respectively; for cardiac valve disease, 0, 0, 3, and not analyzed, respectively; for skin ulcer, 3, 1, 0, and 1, respectively; for aPL nephropathy, 0, 1, 0, and 0, respectively; and for cognitive dysfunction, 3, 1, 1, and not analyzed, respectively.
Conclusion
The results of this uncontrolled and nonrandomized pilot study suggest that the safety of rituximab in aPL‐positive patients is consistent with the safety profile of rituximab. Despite causing no substantial change in aPL profiles, rituximab may be effective in controlling some but not all non‐criteria manifestations of APS.
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