The 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.

Antiphospholipid Syndrome and the Lungs

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterised by recurrent thromboembolic events (arterial or venous) and/or morbidity in pregnancy (fetal loss, premature birth, or recurrent embryonic losses) in the presence of laboratory evidence of antiphospholipid antibodies (aPL). APS is a multisystem disorder. Several lung manifestations may develop in patients with APS including pulmonary embolism (PE)/infarction; thromboembolic and non-thromboembolic pulmonary hypertension (PH) (pulmonary arterial hypertension); pulmonary microthrombosis; acute respiratory distress syndrome associated with catastrophic APS; diffuse alveolar haemorrhage; and pulmonary capillaritis. Postpartum syndrome and cryptogenic fibrosing alveolitis (CFA) can be associated with APS. Pulmonary manifestations are relatively rare but are more likely to be life-threatening compared with other complications of APS. Particularly in the presence of aPL, pulmonary manifestations should be suspected in any systemic lupus erythematosus patient with clinical findings such as chest pain, dyspnoea, tachypnoea, and haemoptysis. Early diagnosis and treatment of pulmonary manifestations in APS are essential for improving mortality rates in patients with this condition. The purpose of this review is to assess current evidence around the diagnosis, prognosis, and management of patients with common and rare pulmonary manifestations of APS.

DNA damage-inducible transcript 4 (DDIT4) mediates methamphetamine-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes

Methamphetamine (METH) is an amphetamine-like psychostimulant that is commonly abused. Previous studies have shown that METH can induce damages to the nervous system and recent studies suggest that METH can also cause adverse and potentially lethal effects on the cardiovascular system. Recently, we demonstrated that DNA damage-inducible transcript 4 (DDIT4) regulates METH-induced neurotoxicity. However, the role of DDIT4 in METH-induced cardiotoxicity remains unknown. We hypothesized that DDIT4 may mediate METH-induced autophagy and apoptosis in cardiomyocytes. To test the hypothesis, we examined DDIT4 protein expression in cardiomyocytes and in heart tissues of rats exposed to METH with Western blotting. We also determined the effects on METH-induced autophagy and apoptosis after silencing DDIT4 expression with synthetic siRNA with or without pretreatment of a mTOR inhibitor rapamycin in cardiomyocytes using Western blot analysis, fluorescence microscopy and TUNEL staining. Our results showed that METH exposure increased DDIT4 expression and decreased phosphorylation of mTOR that was accompanied with increased autophagy and apoptosis both in vitro and in vivo. These effects were normalized after silencing DDIT4. On the other hand, rapamycin promoted METH-induced autophagy and apoptosis in DDIT4 knockdown cardiomyocytes. These results suggest that DDIT4 mediates METH-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes.

Using a Contradictory Approach to Treat a Wound Induced by Hematoma in a Patient With Antiphospholipid Antibody Syndrome Using Negative Pressure Wound Therapy: Lessons Learnt

A 48-year-old woman with antiphospholipid syndrome (APS) had multiple skin necrosis caused by massive bleeding and hematoma collection at the right lower leg, left thigh, and abdomen. During the first month, we did surgical debridement every 2 to 3 days with meticulous coagulation and applied negative pressure wound therapy (NPWT). Then as the base showed initial granulation, we changed the NPWT every 4 days. NPWT was used with lower pressure and cyclic mode (-40 to -75 mm Hg) to minimize trauma and to reduce the possibility of bleeding from the wounds. After 2 months of NPWT treatment, all the wounds eventually healed with secondary intension despite the patient's condition with diabetes, hemodialysis, anticoagulant use, and corticosteroid therapy. This report supports the idea that if accompanied by conservative debridement with meticulous bleeding control, application of NPWT in low pressures and close monitoring of the patient, NPWT is possible to use even in wounds of patients with risk for bleeding.

Thrombocytopenia and thrombosis: a double-edged sword

Severe thrombocytopenia with bleeding associated with a life-threatening thrombotic manifestation in the setting of antiphospholipid syndrome is a major diagnostic and therapeutic challenge for the clinician. Hemorrhage is a less common complication than thrombosis in patients with APS, although severe thrombocytopenia can sometimes result in bleeding. There are no evidence-based guidelines regarding the management of a patient with severe thrombocytopenia associated with a major thrombotic manifestation. In this case report, we review the literature reporting the difficulties in management of such patient.

[Immunological aspects of the antiphospholipid syndrome]

Antiphospholipid antibodies constitute a group of heterogeneous antibodies, which mainly recognize complexes made of proteins and anionic phospholipids. The nature of these complexes is currently better defined, as well as known, the structure of the antiphospholipid antibodies owing to the analysis of the monoclonal forms of these antibodies which were also studied both in terms of their precise specificities and cross-reactivity. However, the origin of these autoantibodies is not clearly understood, as well as the possible link between antiphospholipid antibodies present in healthy individuals, and those observed in autoimmune diseases. Only a fraction of antiphospholipid antibodies are pathogenic and directly responsible for the clinical manifestations of the antiphospholipid syndrome, but there is, to date, no biological test able to accurately detect pathogenic antiphospholipid antibodies. The diverse mechanisms which link these autoantibodies to the occurrence of symptoms, mainly during obstetrical complications, are better understood, and suggest new therapeutic avenues.

Evidence for heterogeneity of the obstetric antiphospholipid syndrome: thrombosis can be critical for antiphospholipid-induced pregnancy loss

BACKGROUND

Antiphospholipid antibodies are associated with thrombosis and repeated pregnancy losses during the antiphospholipid syndrome. Several experimental findings indicate that purified antiphospholipid antibodies are directly responsible for inflammation-induced pregnancy losses, or for disruption of the annexin A5 shield at the trophoblastic interface. We previously showed that passive transfer of CIC15, a monoclonal antiphospholipid antibody binding to cardiolipin and annexin A5 that was isolated from a patient with primary antiphospholipid syndrome, induces fetal resorption in pregnant mice.

OBJECTIVES

To investigate the mechanisms of CIC15-induced pregnancy loss.

METHODS/RESULTS

We show that CIC15 induces fetal loss through a new mechanism that is probably related to procoagulant activity. The time course is different from those of previously described models, and histologic analysis shows that the placentas are devoid of any sign of inflammation but display some signs of thrombotic events. Despite these differences, the CIC15 and 'inflammatory' models share some similarities: lack of FcγRI/III dependency, and the efficacy of heparin in preventing fetal losses. However, this latter observation is here mostly attributable to anticoagulation rather than complement inhibition, because fondaparinux sodium and hirudin show similar efficiency. In vitro, CIC15 enhances cardiolipin-induced thrombin generation. Finally, using a combination of surface-sensitive methods, we show that, although it binds complexes of cardiolipin-annexin A5, CIC15 is not able to disrupt the two-dimensional ordered arrays of annexin A5.

CONCLUSIONS

This human monoclonal antibody is responsible for pregnancy loss through a new mechanism involving thrombosis. This mechanism adds to the heterogeneity of the obstetric antiphospholipid syndrome.

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.

Unravelling autoimmune pathogenesis by screening random peptide libraries with human sera

The incidence of autoimmunity is increasing worldwide. The long preclinical period of autoimmune disorders is characterised by an enhanced exposure over time of autoreactive T cells to an increased number of autoantigenic determinants and autoantibodies production. The discovery of novel autoimmune-disease related epitopes is a task that remains extremely challenging in order to establish predictive and preventive strategies of the disease onset. In this Opinion article we highlight the contribution of screening combinatorial random peptide libraries with patients sera in unravelling the etiopathogenesis of autoimmunity.