Review on Effectiveness of Primary Prophylaxis in aPLs with and without Risk Factors for Thrombosis: Efficacy and Safety

Positive antiphospholipid antibodies: observation or treatment?

Antiphospholipid antibodies (APLAs) are  primarily directed toward phospholipid-binding proteins and are responsible for thrombotic events. APLAs include anti-β2Glycoprotein I (anti-β2GPI), anticardiolipin (anti-CL) antibodies, and lupus anticoagulant. These antibodies are typical markers of antiphospholipid syndrome (APS) and are a part of its diagnostic criteria. Many data underline the presence of APLAs in other rheumatic diseases (e.g., systemic lupus erythematosus, systemic sclerosis, Sjögren's syndrome, rheumatoid arthritis and Behçet's disease). However, they are also detected in patients with cancer, infection, and neurological disorders. Furthermore, healthy individuals may be carriers of APLAs. Chronic asymptomatic APLAs presence is most common in the elderly and subjects with chronic diseases (including malignancies). Specific kinds of APLAs are considered markers of oncological progression. These antibodies occur in 6% of pregnant women (without diagnosed APS) and are related to many pregnancy complications. Of worth, various types of APLAs are reported to have different prothrombotic properties. The risk of thrombotic events in APLA-positive but clinically naïve patients raises many questions in clinical practice. This manuscript analyses various clinical situations and consequences of the APLAs' presence, particularly in patients without diagnosed APS. The prevalence, etiology, molecular background, and prothrombotic properties of numerous APLAs are broadly discussed. The new management approach in different clinical conditions and organ complications is present in the context of recent recommendations. Discussed data underlines that adequate and timely introduced thromboprophylaxis can decrease the risk of thrombus formation and prevent increased morbidity.

Hydroxychloroquine and Covid-19: A Cellular and Molecular Biology Based Update

As the time for finding a definitive and safe cure as a vaccine for novel Corona Virus Disease 2019 (Covid-19) is still far, there is need to study in depth about the other potential drugs, which can save millions of lives due to Covid-19 pandemic. Right at the center of the debate is the use of drug "Hydroxychloroquine" as a prophylaxis as well as a treatment strategy against Covid-19 in conjunction with azithromycin. In this review, we will study the cellular and molecular aspects of hydroxychloroquine, which had driven its use in Covid-19 patients, as well as its chemistry and pharmacokinetics along with clinical trials going on worldwide using hydroxychloroquine against Covid-19.

Mechanisms of action of hydroxychloroquine and chloroquine: implications for rheumatology

Despite widespread clinical use of antimalarial drugs such as hydroxychloroquine and chloroquine in the treatment of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and other inflammatory rheumatic diseases, insights into the mechanism of action of these drugs are still emerging. Hydroxychloroquine and chloroquine are weak bases and have a characteristic 'deep' volume of distribution and a half-life of around 50 days. These drugs interfere with lysosomal activity and autophagy, interact with membrane stability and alter signalling pathways and transcriptional activity, which can result in inhibition of cytokine production and modulation of certain co-stimulatory molecules. These modes of action, together with the drug's chemical properties, might explain the clinical efficacy and well-known adverse effects (such as retinopathy) of these drugs. The unknown dose-response relationships of these drugs and the lack of definitions of the minimum dose needed for clinical efficacy and what doses are toxic pose challenges to clinical practice. Further challenges include patient non-adherence and possible context-dependent variations in blood drug levels. Available mechanistic data give insights into the immunomodulatory potency of hydroxychloroquine and provide the rationale to search for more potent and/or selective inhibitors.

Antiplatelet and anticoagulant agents for primary prevention of thrombosis in individuals with antiphospholipid antibodies

BACKGROUND

Antiphospholipid syndrome (APS) is an autoimmune disease characterised by the presence of antiphospholipid (aPL) antibodies that have prothrombotic activity. Antiphospholipid antibodies are associated with an increased risk of pregnancy complications (recurrent miscarriage, premature birth, intrauterine growth retardation) and thrombotic events (both arterial and venous). The most common thrombotic events include brain ischaemia (stroke or transient ischaemic attack) and deep vein thrombosis. To diagnose APS, the presence of aPL antibodies in two measurements and at least one thrombotic event or pregnancy complication are required. It is unclear if people with positive aPL antibodies but without any previous thrombotic events should receive primary antithrombotic prophylaxis.

OBJECTIVES

To assess the effects of antiplatelet or anticoagulant agents versus placebo or no intervention or other intervention on the development of thrombosis in people with aPL antibodies who have not had a thrombotic event. We did not address obstetric outcomes in this review as these have been thoroughly addressed by other Cochrane Reviews.

SEARCH METHODS

We searched the Cochrane Vascular Specialised Register (4 December 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (last search 29 November 2017), MEDLINE Ovid, Embase Ovid, CINAHL, and AMED (searched 4 December 2017), and trials registries (searched 29 November 2017). We also checked reference lists of included studies, systematic reviews, and practice guidelines, and contacted experts in the field.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any antiplatelet or anticoagulant agents, or their combinations, at any dose and mode of delivery with placebo, no intervention, or other intervention. We also included RCTs that compared antiplatelet or anticoagulant agents with each other or that compared two different doses of the same drug. We included studies performed in people of any age and with no history of thrombosis (as defined by APS Sapporo classification criteria or updated Sydney classification criteria), but with aPL antibodies confirmed on at last two separate measurements. The studies included both pregnant women who tested positive for aPL antibodies and had a history of recurrent obstetric complications, as well as non-pregnancy related cases with positive screening for antibodies, in accordance with the criteria mentioned above.

DATA COLLECTION AND ANALYSIS

Pairs of authors independently selected studies for inclusion, extracted data, and assessed the risk of bias for the included studies and quality of evidence using GRADE. Any discrepancies were resolved through discussion or by consulting a third review author when necessary. In addition, one review author checked all the extracted numerical data.

MAIN RESULTS

We included nine studies involving 1044 randomised participants. The studies took place in several countries and had different funding sources. No study was at low risk of bias in all domains. We classified all included studies as at unclear or high risk of bias in two or more domains. Seven included studies focused mainly on obstetric outcomes. One study included non-pregnancy-related cases, and one study included both pregnancy-related cases and other patients with positive results for aPL antibodies. The remaining studies concerned women with aPL antibodies and a history of pregnancy failure. Four studies compared anticoagulant with or without acetylsalicylic acid (ASA) versus ASA only and observed no clear difference in thrombosis risk (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.25 to 3.77; 4 studies; 493 participants; low-quality evidence). No major bleeding was reported, but minor bleeding risk (nasal bleeding, menorrhagia) was higher in the anticoagulant with ASA group as compared with ASA alone in one study (RR 22.45, 95% CI 1.34 to 374.81; 1 study; 164 participants; low-quality evidence). In one study ASA was compared with placebo, and there were no clear differences in thrombosis (RR 5.21, 95% CI 0.63 to 42.97; 1 study; 98 participants; low-quality evidence) or minor bleeding risk between the groups (RR 3.13, 95% CI 0.34 to 29.01; 1 study; 98 participants; low-quality evidence), and no major bleeding was observed. Two studies compared ASA with low molecular weight heparin (LMWH) versus placebo or intravenous immunoglobulin (IVIG), and no thrombotic events were observed in any of the groups. Moreover, there were no clear differences in the risk of bleeding requiring transfusion (RR 9.0, 95% CI 0.49 to 164.76; 1 study; 180 participants; moderate-quality evidence) or postpartum bleeding (RR 1.30, 95% CI 0.60 to 2.81; 1 study; 180 participants; moderate-quality evidence) between the groups. Two studies compared ASA with high-dose LMWH versus ASA with low-dose LMWF or unfractionated heparin (UFH); no thrombotic events or major bleeding was reported. Mortality and quality of life data were not reported for any of the comparisons.

AUTHORS' CONCLUSIONS

There is insufficient evidence to demonstrate benefit or harm of using anticoagulants with or without ASA versus ASA alone in people with aPL antibodies and a history of recurrent pregnancy loss and with no such history; ASA versus placebo in people with aPL antibodies; and ASA with LMWH versus placebo or IVIG, and ASA with high-dose LMWH versus ASA with low-dose LMWH or UFH, in women with aPL antibodies and a history of recurrent pregnancy loss, for the primary prevention of thrombotic events. In a mixed population of people with a history of previous pregnancy loss and without such a history treated with anticoagulant combined with ASA, the incidence of minor bleeding (nasal bleeding, menorrhagia) was increased when compared with ASA alone. Studies that are adequately powered and that focus mainly on thrombotic events are needed to draw any firm conclusions on the primary prevention of thrombotic events in people with antiphospholipid antibodies.

Efficacy of Different Treatment Regimens for Antiphospholipid Syndrome-related Recurrent Spontaneous Abortion

Background:

Antiphospholipid syndrome (APS)-related immune factors are considered as an important cause of recurrent spontaneous abortion (RSA). Anticoagulant and anti-inflammatory treatments are believed to effectively improve adverse pregnancy outcomes by affecting the abnormal autoimmune response of the maternal-fetal interface. The aim of this study was to observe the clinical characteristics and treatment outcomes of anticoagulant regimens and anti-inflammatory plus anticoagulation regimens for APS-related RSA.

Methods:

APS-related RSA cases from September 2011 to September 2016 at Peking University Third Hospital were retrospectively analyzed. The patients were assigned to study group (anti-inflammation plus anticoagulation) and control group (simple anticoagulation). The incidence of repeat abortion, the incidence of placental dysfunction, the gestational weeks of pregnancy, and the mean weight of the fetus were observed.

Results:

The pregnancy and neonatal outcome indicators of the repeat pregnancy loss rate (11.11% vs. 22.70%), placental dysfunction-related diseases (6.35% vs. 15.60%), the mean birth weight of infants born after 24 weeks gestation (3152.41 ± 844.67 g vs. 2765.76 ± 816.40 g), full-term delivery weight (3456.28 ± 419.79 g vs. 3076.18 ± 518.79 g), the proportions of low birth weight infants (12.70% vs. 21.98%), and small for gestational age (6.35% vs. 14.18%) differed significantly between the study and control groups (all P < 0.05). The incidence of preterm delivery, term delivery, and stillbirth was not significantly different between the two groups, and there was no significant difference between the study and control groups in gestational age at birth (37.6 ± 3.3 weeks vs. 36.9 ± 3.2 weeks; P > 0.05).

Conclusion:

The anti-inflammatory and anticoagulation regimen is more effective than the simple anticoagulation regimen in the treatment of APS recurrent abortion.