Chapter 2 Epidemiology of the Antiphospholipid Syndrome

Acute Coronary Syndromes in Antiphospholipid Syndrome-above Suspicion: A Systematic Review

Antiphospholipid syndrome(APS) is an autoimmune disorder characterized clinically by vascular thrombosis and/or pregnancy morbidity, associated with persistently elevated titers of antiphospholipid antibodies on at least two measurements over 12 weeks apart. In this study, we conducted a systematic review of the literature utilizing the Pubmed platform, in order to acquire clinical information about acute coronary syndromes in patients with APS. The obtained articles were reviewed in order to register the clinical characteristics, the rate of occurrence, the prognosis and the therapeutic approach of these patients. APS should be considered in young patients with acute myocardial infarction, even in patients with normal coronary arteries. The pharmaceutical approach is mainly based on the vitamin K antagonists, and in certain occasions aspirin, without any definite guidelines on the subject. Further randomized clinical trials are imperative for a better understanding of the particular characteristics of this group of patients, so that a more complete therapeutic approach to be obtained.

Role of Direct Oral Anticoagulation Agents as Thromboprophylaxis in Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is an autoimmune disorder that causes venous, arterial and small-vessel thrombosis, pregnancy loss, and premature birth. Cardiac valvular disease, renal thrombotic microangiopathy, thrombocytopenia, hemolytic anemia, and cognitive impairment are some of its other clinical symptoms. Antiphospholipid antibodies cause endothelial cells, monocytes, and platelets to become activated, as well as an increase in tissue factor and thromboxane A2. Complement activation might play a key function in pathogenesis. Long-term oral anticoagulation is used to treat thrombosis, and individuals having arterial episodes should be treated quickly. Patients with systemic lupus erythematosus (SLE), as well as those with solely obstetric antiphospholipid syndrome, should get primary thromboprophylaxis. Obstetric care is based on a combination of medical and obstetric high-risk management, as well as aspirin and heparin therapy. Possible supplementary therapy for this condition is hydroxychloroquine. Statins, rituximab, and novel anticoagulant medicines are all potential future treatments for non-pregnant individuals with antiphospholipid syndrome. We aim to review the role of direct-acting oral anticoagulants (DOACs) as thromboprophylactic drugs in the treatment of APS in this article. The treatment of venous thromboembolism has been transformed by a new class of DOACs. These drugs, such as rivaroxaban, function by inhibiting factor Xa directly. Not only do they have known anticoagulant actions, but they also obviate the need for dosage monitoring and modification, in contrast to warfarin. We conducted an exhaustive literature search of PubMed/MEDLINE and Google Scholar Indexes using the keywords "Antiphospholipid syndrome," "thromboprophylaxis," and "oral anticoagulants" up to September 2021. We found that DOACs have been shown to be non-inferior to warfarin in a variety of anticoagulation situations in a number of high-powered clinical studies. In many hypercoagulable conditions such as APS, DOACs are quickly establishing themselves as first-line therapy. This article is focused on comprehensively reviewing the mechanism of action of DOACs, their role as thromboprophylactic drugs, risks and complications of DOACs, and comparing their efficacy with the standard treatment protocol and warfarin.

Venous thromboembolism in people living with HIV infection (PWH)

The risk of venous thromboembolism (VTE) and of recurrent VTE remain elevated in people living with HIV compared to controls still with contemporary antiretroviral therapy (ART). The pathophysiology of VTE in HIV is multi factorial and includes an interplay among traditional risk factors, HIV-specific factors, behavioral factors, exposure to ART and other therapies, coinfections, and co-morbidities.

Catastrophic Antiphospholipid Syndrome in Immune Thrombocytopenic Purpura - Beyond Tenuous Concomitance!

Significance of antiphospholipid antibodies in immune thrombocytopenic purpura is debatable and pose a diagnostic and therapeutic dilemma. Catastrophic antiphospholipid syndrome is a rare life-threatening entity, occurring in patients with antiphospholipid syndrome, usually after a triggering event. We describe an adult lady of chronic immune thrombocytopenic purpura (in remission) with antiphospholipid antibodies, who presented with rapidly progressive renal failure and had primary antiphospholipid syndrome nephropathy. The index manuscript titled exemplifies the fact that although the presence of APLA in ITP is known, however, management in the absence of clinical event remains debatable and may carry a future risk of thrombotic event/s mandating close monitoring with a high index of suspicion.

The antiphospholipid syndrome: from pathophysiology to treatment

Antiphospholipid antibody syndrome (APS) is an autoimmune acquired thrombophilia characterized by recurrent thrombosis and pregnancy morbidity in the presence of antiphospholipid antibodies (aPL). APS can be primary, if it occurs in the absence of any underlying disease, or secondary, if it is associated with another autoimmune disorder, most commonly systemic lupus erythematosus. The exact pathogenetic mechanism of APS is unknown, but different, not mutually exclusive, models have been proposed to explain how anti-PL autoantibodies might lead to thrombosis and pregnancy morbidity. Diagnosis of APS requires that a patient has both a clinical manifestation (arterial or venous thrombosis and/or pregnancy morbidity) and persistently positive aPL, but the clinical spectrum of the disease encompasses additional manifestations which may affect every organ and cannot be explained exclusively by a prothrombotic state. Treatment for aPL-positive patients is based on the patient's clinical status, presence of an underlying autoimmune disease, and history of thrombotic events. In case of aPL positivity without previous thrombotic events, the treatment is mainly focused on reduction of additional vascular risk factors, while treatment of patients with definite APS is based on long-term anticoagulation. Pregnancy complications are usually managed with low-dose aspirin in association with low molecular weight heparin. Refractory forms of APS could benefit from adding hydroxychloroquine and/or intravenous immunoglobulin to anticoagulation therapy. Promising novel treatments include anti-B cell monoclonal antibodies, new-generation anticoagulants, and complement cascade inhibitors. The objective of this review paper is to summarize the recent literature on APS from pathogenesis to current therapeutic options.

Systemic Lupus Erythematosus and Antiphospholipid Syndrome

Antiphospholipid syndrome is an autoimmune disorder defined as association of vascular thrombosis and/or pregnancy complications with presence of antiphospholipid antibodies (lupus anticoagulant, anticardiolipin and anti-β2 glycoprotein I). It is the most common cause of acquired thrombophilia, and can occur as an independent entity or in relation with other diseases, especially systemic lupus erythematosus. Presence of antiphospholipid syndrome in systemic lupus erythematosus is additional vaso occlusive factor in already present inflammation, bringing further risk for thrombotic events. Clinical and serological manifestations of antiphospholipid syndrome and systemic lupus erythematosus are very similar, so possible connection for these two autoimmune disorders is assumed.

Antiphospholipid antibodies and cerebellar ataxia: a clinical analysis and literature review

BACKGROUND

Although it has been established that antiphospholipid antibodies (APAbs) bind to and modulate the signaling of cerebellar neurons in vitro, the clinical correlation between increased APAbs and cerebellar ataxia has rarely been investigated.

METHODS

We reviewed 10 patients presenting with cerebellar ataxia with increased blood APAbs from our database along with 3 APAb-associated cerebellar ataxia patients in the literature.

RESULTS

Of these 10 patients, 4 exhibited a subacute onset of progressive ataxia, and there were no significant structural changes in their brains that appeared to be responsible for the symptoms. Another 6 showed a chronic course of ataxia, and shared similar morphological changes that included symmetrical lesions in bilateral hemispheres, periventricular lucency and central and temporal atrophy of varying severity; the cerebellum was spared. The predominant APAbs for subacute and chronic ataxia were the anti-beta2-glycoprotein I antibody and anticardiolipin antibody, respectively. Cancer was found in 1 patient with subacute ataxia and in 4 with chronic ataxia. The removal of the cancer, the plasmapheresis and immunosuppressive therapy successfully abolished the ataxia and increased APAb levels in all 5 patients.

CONCLUSIONS

The relation between APAbs and nonvascular neurological disorders, such as cerebellar ataxia, should be further studied. APAbs may mediate neurological deficits via different mechanisms such as structural damage or functional neurotoxicity. Clinically, the examination of blood APAb levels is recommended for patients with cerebellar ataxia without a determined cause, and the further survey of systemic cancers in the case of APAb positivity is also recommended. Finally, plasmapheresis is a reasonable and effective treatment for APAb-associated cerebellar ataxia.

Anti-cardiolipin and anti-beta 2-glycoprotein I antibodies in celiac disease

AIMS

To determine the frequency of anti-cardiolipin (aCL) and anti-β2-glycoprotein I antibodies (aβ2GPI) in celiac disease (CD) patients.

PATIENTS AND METHODS

Sixty-three untreated CD patients and 40 healthy blood donors (HBD) were studied. IgG, IgA and IgM aCL and aβ2GPI were detected by Elisa.

RESULTS

The frequency of antiphospholipid antibodies (aPL) (aCL and/or aβ2GPI) was significantly higher in CD patients (12 out of 63) than in HBD (two out of 40) (19% vs 5%, P=0.04). Six CD patients out of 63 (9.5%) and one HBD out of 40 (2.5%) had aCL. Ten CD patients (15.9%) and two HBD (5%) had aβ2GPI. Only aβ2GPI-IgA was significantly more frequent in CD patients than in HBD (14.3% vs 2.5%, P=0.048). In CD patients, aβ2GPI-IgA (nine out of 63) was significantly more frequent (14.3%) than aβ2GPI-IgG (1.6%) and IgM (1.6%) (P=0.008). In CD patients, the frequency of aCL-IgA and IgM was 6.3% (four out of 63) and aCL-IgG were not detected. Simultaneous presence of positive antibodies was found in four CD patients: one patient had four aPL, one had three aPL and two had two aPL. The four patients who had aCL-IgA had also aβ2GPI-IgA and three of them had a titer higher than 50 units. Among nine patients with aβ2GPI-IgA, four had a titer higher than 100 units. The highest titers were found in adults.

CONCLUSIONS

aPL and particularly aβ2GPI-IgA are frequent in CD. The significance of these antibodies has to be determined.