Antiphospholipid syndrome

Critical Limb Ischemia Secondary to Antiphospholipid Syndrome in a Pediatric Patient: Case Report and Review

BACKGROUND

Antiphospholipid syndrome (APS) is a condition that manifests as venous or arterial thrombosis, as well as complications of pregnancy. APS affecting primarily the arteries is less common when compared to venous complications. We present a case of arterial occlusion resulting in critical limb ischemia (CLI) in a pediatric patient.

METHODS

A 14-year old boy presented with worsening right lower extremity pain and ulcerative lesions of his foot. Laboratory analysis revealed a diagnosis of APS. This case report and review of the literature expands our understanding of arterial manifestations of APS in the pediatric patient.

RESULTS

The patient was discovered to have proximal occlusion of the superficial femoral artery (SFA), the distal popliteal artery, the anterior tibial artery at the mid-calf, and the posterior tibial artery at the ankle. He underwent a common femoral artery to above-knee-popliteal artery bypass with reversed greater saphenous graft. Follow up after over one-year demonstrated an ABI of 1.0 and no evidence of stenosis in the bypass graft on duplex ultrasound (DUS).

CONCLUSIONS

APS is a complex syndrome with a variety of clinical presentations. This case highlights arterial manifestations of APS and reviews the expanding literature to guide improved patient outcomes.

Prevention of Stroke in Rheumatoid Arthritis

The risk of cerebrovascular disease is increased among rheumatoid arthritis (RA) patients and remains an underserved area of medical need. Only a minor proportion of RA patients achieve suitable stroke prevention. Classical cardiovascular risk factors appear to be under-diagnosed and undertreated among patients with RA. Reducing the inflammatory burden is also necessary to lower the cardiovascular risk. An adequate control of disease activity and cerebrovascular risk assessment using national guidelines should be recommended for all patients with RA. For patients with a documented history of cerebrovascular or cardiovascular risk factors, smoking cessation and corticosteroids and non-steroidal anti-inflammatory drugs at the lowest dose possible are crucial. Risk score models should be adapted for patients with RA by introducing a 1.5 multiplication factor, and their results interpreted to appropriately direct clinical care. Statins, angiotensin-converting enzyme inhibitors, and angiotensin-II receptor blockers are preferred treatment options. Biologic and non-biologic disease-modifying anti-rheumatic drugs should be initiated early to mitigate the necessity of symptom control drugs and to achieve early alleviation of the inflammatory state. Early control can improve vascular compliance, decrease atherosclerosis, improve overall lipid and metabolic profiles, and reduce the incidence of heart disease that may lead to atrial fibrillation. In patients with significant cervical spine involvement, early intervention and improved disease control are necessary and may prevent further mechanical vascular injury.

Effect of hydroxychloroquine on antiphospholipid antibody-induced changes in first trimester trophoblast function

PROBLEM

Women with antiphospholipid syndrome (APS) are at risk for pregnancy complications. Antiphospholipid antibodies (aPL) alter trophoblast function by triggering an inflammatory cytokine response; modulating angiogenic factor secretion; and inhibiting migration. While patients with APS are often treated with hydroxychloroquine (HCQ), its effect on trophoblast function is poorly understood.

METHOD OF STUDY

A human first trimester trophoblast cell line was treated with or without antihuman β2GPI mAbs in the presence or absence of HCQ. Supernatants were analyzed by ELISA. Cell migration was measured using a colormetric assay.

RESULTS

Antiphospholipid antibodies-induced trophoblast IL-8, IL-1 β, PlGF, and sEndoglin secretion were not altered by HCQ. aPL-induced inhibition of trophoblast migration was partially reversed by HCQ, even though HCQ significantly increased secretion of pro-migratory IL-6 to greater than baseline. aPL-induced upregulation of TIMP2 appears to inhibit trophoblast migration; the inability of HCQ to prevent aPL-induced TIMP2 may explain why migration was only partially restored.

CONCLUSION

Hydroxychloroquine reversed the aPL-inhibition of trophoblast IL-6 secretion and partially limited aPL-inhibition of cell migration. Thus, some form of combination therapy that includes HCQ may be beneficial to pregnant APS patients.

Venous and arterial thrombosis: Two aspects of the same disease?

An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice.

Clinical manifestations and outcomes of antithrombotic treatment of the Tan Tock Seng Hospital Singapore antiphospholipid syndrome cohort

To examine the clinical manifestations, intensity of oral anticoagulation and outcomes in the prevention of recurrent thromboses in patients with antiphospholipid syndrome (APS) in a tertiary rheumatology centre in Singapore. Retrospective case review of consecutive patients with APS attending a rheumatology clinic from 1st January 2004 to 31st December 2005. There were 59 (44%) patients with definite APS and 75 (56%) with probable APS. Systemic lupus erythematosus (SLE) was the most common cause of secondary APS. Hypertension and hyperlipidaemia were the most common cardiovascular comorbidities. The most common manifestations were haematological (thrombocytopaenia and haemolytic anaemia), neurological (seizure, headache) and pulmonary hypertension. Among those with definite APS, there were similar proportions with arterial and venous thromboses. Recurrent thromboses occurred in 14 (23.7%) patient with definite APS receiving warfarin, comprising 14 (73.7%) episodes of arterial and 5 (26.3%) episodes of venous thromboses. Recurrent arterial thromboses occurred at international normalized ratio (INR) of <2 in 5 (35.7%), INR 2–3 in 6 (42.9%), INR > 3 in 3 (21.4%) episodes, respectively. Recurrent venous thromboses occurred at INR < 2 in 4 (80.0%) and INR > 3 in 1 (20.0%) episode, respectively. Twenty-eight episodes of bleeding occurred in 21 (35.6%) patients, the majority (78.6%) being minor bleeding. Two-thirds of all major bleeds occurred at INR ≥ 3. Venous and arterial thromboses were equally common in our patients with definite APS, although recurrent thromboses were more common in the arterial circulation. Target INR > 3 was associated with lower rates of recurrent arterial thromboses but higher rates of major and recurrent bleeding. Target INR ≥ 2 appeared to be sufficient to prevent recurrent venous thromboses.

Antiphospholipid antibodies in rheumatoid arthritis: identifying the dominoes

Antiphospholipid antibodies (aPL) occur in a variety of autoimmune, malignant, and infectious diseases, with or without the thrombotic or obstetric sequelae that characterize the antiphospholipid syndrome. Although many studies have focused on the clinical implications of aPL in systemic lupus erythematosus, few have specifically addressed the questions facing rheumatologists caring for rheumatoid arthritis patients who are concomitantly positive for aPL. Such a clinical scenario requires current knowledge of antiphospholipid syndrome diagnosis criteria, test reliability, conditions causing temporal positivity of aPL, and treatment risks and benefits. Recently researched factors possibly integral to rheumatoid arthritis's increased morbidity and mortality and related to aPL include oxidatively modified low-density lipoprotein antibodies, homocysteine, annexins, infectious agents, beta estradiol, and specific gene polymorphisms. This review presents current scientific research addressing the pathophysiologic mechanisms and clinical implications of aPL in rheumatoid arthritis.

New developments in lupus-associated antiphospholipid syndrome

Systemic lupus erythematosus is the disease in which the antiphospholipid syndrome was first described more than 20 years ago and which is the most frequent underlying disorder in secondary antiphospholipid syndrome. With respect to pathogenic concepts and treatment, the subjects of this review, no clear distinction between primary and secondary antiphospholipid syndrome can be made.

Links between arterial and venous disease

An increasing body of evidence suggests the likelihood of a link between arterial and venous disease. According to the results of recent studies, atherosclerosis and venous thromboembolism (VTE) share common risk factors, including age, obesity, diabetes mellitus and metabolic syndrome. Atherosclerosis has the potential to promote the development of thrombotic disorders in the venous system. Another scenario assumes that the two clinical conditions are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Several recent studies have consistently shown that patients with VTE of unknown origin are at a higher risk of cardiovascular diseases, including atherosclerotic complications, than patients with secondary VTE and matched control individuals. Future studies are needed to clarify the nature of this association, to assess its extent and to evaluate its implications for clinical practice.

Venous thromboembolism and atherosclerosis: is there a link?

After the initial demonstration provided 4 years ago by a case-control study in the New England Journal of Medicine, numerous investigations have addressed the association between venous and arterial thrombotic disorders. According to the results of recent studies, the two conditions are likely to share common risk factors, including age, obesity, cigarette smoking, diabetes mellitus, arterial hypertension, hyperlipemia and metabolic syndrome. The nature of this association is unclear. On the one hand, atherosclerosis has the potential to promote the development of thrombotic disorders in the venous system. On the other hand, the two clinical conditions can be simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Based on the results of two population-based studies carried out in the USA, atherosclerosis is unlikely to constitute a risk factor for venous thromboembolic (VTE) disorders. Several recent studies have consistently shown that subjects with VTE of unknown origin are at a higher risk of subsequent arterial cardiovascular events than subjects with secondary VTE and matched control individuals. In conclusion, the separate nature of arterial and venous disorders has been challenged. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice.

Who should be tested for thrombophilia?

PURPOSE OF REVIEW

The purpose of this review is to identify on the basis of available data and expert opinions who would benefit most from screening for thrombophilia.

RECENT FINDINGS

Recent studies have clearly defined the risk of venous thromboembolism in members of families with inherited thrombophilia. Meta-analyses have shown the role of the most common thrombophilic conditions in increasing the risk of recurrent venous thromboembolism in carriers. Screening for thrombophilia in venous thromboembolism patients might help identify those at higher risk of recurrences even though it is unclear how this information can be of use in modifying their management. Thrombophilia seems to play a role in early fetal losses as also shown in women at their first intended pregnancy, which makes it interesting to screen women after only one bad pregnancy outcome.

SUMMARY

Screening for thrombophilia can be performed particularly in young patients with venous thromboembolism. Carriers of inherited thrombophilia are at increased risk of venous thromboembolism recurrences. Screening families of venous thromboembolism patients with thrombophilia allows the identification of still asymptomatic carriers who may benefit from thromboprophylaxis. This may be true of women in fertile age belonging to thrombophilic families. In thrombophilic women with pregnancy complications prophylaxis may be offered to prevent recurrences.

Immunoprophylaxis against mother-to-child transmission of HIV-1

The authors discuss a new study in PLoS Medicine that examines whether human anti-HIV monoclonal antibodies might be useful in South Africa for preventing mother-to-child transmission of subtype C HIV viruses.

Drug-induced phospholipidosis: issues and future directions

Numerous drugs containing a cationic amphiphilic structure are capable of inducing phospholipidosis in cells under conditions of in vivo administration or ex vivo incubation. The principal characteristics of this condition include the reversible accumulation of polar phospholipids in association with the development of unicentric or multicentric lamellated bodies within cells. There is an abundance of data providing an understanding of potential mechanisms for the induction of phospholipidosis; however, the process is likely to be complex and may differ from one drug to another. The functional consequences of the presence of this condition on cellular or tissue function are not well understood. The general consensus is that the condition is an adaptive response rather than a toxicological manifestation; however, additional studies to examine this question are needed. Until this issue is resolved, concerns about phospholipidosis will continue to exist at regulatory agencies. Procedures for the screening of potential phospholipogenic candidate compounds are available. In contrast, a clear need exists for the identification of valid biomarkers to assess the development of phospholipidosis in preclinical and clinical studies.