Distribution of two common idiotypes of anticardiolipin antibodies in sera of patients with primary antiphospholipid syndrome, systemic lupus erythematosus and monoclonal gammopathies

Management of Cardiovascular Complications in Antiphospholipid Syndrome: A Narrative Review with a Focus on Older Adults

Antiphospholipid syndrome (APS), also known as Hughes syndrome, is an acquired autoimmune and procoagulant condition that predisposes individuals to recurrent thrombotic events and obstetric complications. Central is the role of three types of antiphospholipid antibodies that target phospholipid-binding proteins: lupus anticoagulant (LAC), anti-β2-glycoprotein I (β2-GPI-Ab), and anti-cardiolipin (aCL). Together with clinical data, these antibodies are the diagnostic standard. However, the diagnosis of APS in older adults may be challenging and, in the diagnostic workup of thromboembolic complications, it is an underestimated etiology. The therapeutic management of APS requires distinguishing two groups with differential risks of thromboembolic complications. The standard therapy is based on low-dose aspirin in the low-risk group and vitamin K antagonists in the high-risk group. The value of direct oral anticoagulants is currently controversial. The potential role of monoclonal antibodies is investigated. For example, rituximab is currently recommended in catastrophic antiphospholipid antibody syndrome. Research is ongoing on other monoclonal antibodies, such as daratumumab and obinutuzumab. This narrative review illustrates the pathophysiological mechanisms of APS, with a particular emphasis on cardiovascular complications and their impact in older adults. This article also highlights advancements in the diagnosis, risk stratification, and management of APS.

Immunity, inflammation, and bipolar disorder: diagnostic and therapeutic implications

Bipolar disorder is now known to be associated not only with highly prevalent co-occurring psychiatric and substance use disorders but also with medical comorbidities, such as cardiovascular diseases, diabetes mellitus, obesity and thyroid dysfunction. Inflammatory disturbances repeatedly observed in bipolar disorder, can explain some of the comorbidity between bipolar disorder and medical disorder. This revised perspective of bipolar disorders should promote the development of therapeutic tools. Immuno-inflammatory dysfunction may well represent a significant component of the underlying pathophysiology of the disorder. We therefore propose to review the immuno-inflammatory hypothesis in bipolar disorder considering the co-occurence with autoimmune diseases, immunological and inflammatory markers, as well as immuno-genetic markers which could lead to personalized treatments.

Pathogenic natural anti-cardiolipin antibodies: the experience from monoclonal gammopathy

Anti-cardiolipin antibodies (ACA) were detected in 19% of sera from patients with monoclonal gammopathies (MG). ACA were purified from the sera of patients with MG. One of the IgG-ACA was found to be monospecific with high affinity for cardiolipin, and to carry a pathogenic ACA Id (1.10). Active immunization of naive BALB/c mice with the purified IgG-ACA was followed by production in the mice of sustained high titres of ACA, associated with prolonged activated partial thromboplastin time (APTT) (61 +/- 14s versus 31 +/- 2s in control mice; P < 0.001) and thrombocytopenia (468,000 +/- 224,000/mm3 versus 994,000 +/- 92,000/mm3 in controls; P < 0.001). The titres of other autoantibodies (e.g. anti-DNA, anti-histones), although being high after immunization, decreased rapidly and were undetected after 1 month following the boost injection. The mice immunized with the IgG-ACA exhibited low fecundity (36% of mice became pregnant versus 62% observed in the group immunized with control IgG). The pregnant mice had increased resorption rate (the equivalent of fetal loss in the human) of 52 +/- 8% (versus 5 +/- 4% in the control group). The mean (+/- s.d.) embryo and placental weights in mice with anti-phospholipid syndrome (APLS) were significantly lower compared with the mice injected with control IgG (682 +/- 304 mg and 102 +/- 12 mg versus 1303 +/- 105 mg and 145 +/- 8 mg, respectively; P < 0.001). Serum monoclonal immunoglobulins having autoantibody activity may be regarded as an expansion of clones producing natural autoantibodies. Our results confirm the pathogenic role of natural ACA in the pathogenesis of the anti-phospholipid syndrome.

Fish oil derivatives as a prophylaxis of recurrent miscarriage associated with antiphospholipid antibodies (APL): a pilot study

Since 1989, 22 patients with persistent antiphospholipid syndrome (PAPS) associated with recurrent miscarriage (defined as three or more miscarriages) were treated with fish oil, equivalent to 5.1 g eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at a ratio of 1.5 EPA to DHA. Twenty-two patients had 23 pregnancies (one patient had two pregnancies) over a period of 3 years. There was only one intrauterine fetal death at the 27th week associated with pre-eclampsia. Twenty-one pregnancies, 19 of which ended after the 37th week, produced a baby. Two pregnancies ended with cesarean section for pre-eclampsia at 30th and 35th week of gestation and one is ongoing at 32nd week. All babies are well. The weight at birth of babies delivered at term was always > 2500 g. These encouraging results favour a therapeutic role, without any adverse reaction, of fish oil to prevent recurrent miscarriage in PAPS.

Inhibitor(s) of natural anti-cardiolipin autoantibodies

IgG fractions were purified on Sepharose anti-human IgG column from eight sera of healthy donors, having no anti-cardiolipin (aCL) activity as measured by anti-cardiolipin ELISA assay (aCL-ELISA). All the IgG fractions, after elution with 4.9 M MgCl2, reacted with CL. The antigen-binding characteristics of the IgG fractions purified from normal human serum (NHS) were similar to those of IgG fractions purified from sera of four patients with the anti-phospholipid syndrome (APLS). Competition assay confirmed the specificity of the binding of the purified IgG fractions to CL. The same results have been achieved with IgG fractions purified on Sepharose Protein-A column. The binding to CL was completely inhibited by either whole NHS and sera from various animal species, or by beta 2-glycoprotein I (beta 2-GPI). Our results support the notion of the existence of both natural anti-CL antibodies and serum inhibitor(s) in sera of healthy individuals. It is conceivable that in part the pathogenesis of APLS entails defects in the natural inhibitors of aCL antibodies.

Induction of experimental primary and secondary antiphospholipid syndromes in naive mice

In the current series of experimental studies we show that anticardiolipin antibodies (ACA) are pathogenic: Infusion of serum ACA to the tail vein of naive mice induces experimental antiphospholipid syndrome (APLS) characterized by thrombocytopenia, prolonged aPTT, and recurrent fetal resorptions. Similar experimental APLS is induced by active immunization with serum as well as with natural human monoclonal ACA. APLS is also associated with low fecundity rate. The experimental APLS models were employed to demonstrate the efficacy of aspirin, low molecular heparin, and interleukin-3 preventing recurrent fetal loss. In another experiment, immunization with human monoclonal anti-DNA antibody was followed by the induction of APLS secondary to experimental systemic lupus erythematosus (SLE). In all studies, IgGs were found to be more pathogenic than IgMs ACA. These studies confirm the autoimmune nature of APLS.