Antiphospholipid Antibody Testing: Which Are Most Useful for Diagnosis?

Anti-Phosphatidylethanolamine and Anti-Phosphatidylserine Antibodies—Association with Renal Involvement, Atherosclerosis, Cardiovascular Manifestations, Raynaud Phenomenon and Disease Activity in Polish Patients with Systemic Lupus Erythematosus

Objective. To evaluate the association between anti-phosphatidylethanolamine (aPE) and anti-phosphatidylserine (aPS) antibodies and cardiovascular risk, organ involvement and disease activity in systemic lupus erythematosus (SLE) patients. Methods. We studied 93 SLE patients and 30 controls. We analyzed levels of anti-phospholipid antibodies, including aPS and aPE, the profiles of antinuclear, anti-neutrophil cytoplasmic (ANCA) and anti-endothelial antibodies, carotid intima-media thickness (cITM) and atherosclerotic plaque presence, ankle-brachial and high resistance indices, atherosclerotic risk factors, organ manifestations and treatment. Results. Levels of aPS and aPE were significantly higher in SLE patients in comparison with the controls (p = 0.038 and p = 0.044, respectively). aPS was associated with the risk of Raynaud’s phenomenon (p = 0.021) development. aPE increased the risk of renal involvement (p = 0.049), cerebral stroke (p = 0.050), high vlues of cIMT (p = 0.041) development as well as occurrence of selected serological markers associated with activity of the disease such as anti-double stranded DNA (p = 0.021). The long duration of regular smoking (p = 0.021) and the high number of cigarettes/day (p = 0.015) were significantly associated with the risk of aPE occurrence. Conclusions. Patients with aPS and aPE are at risk of vascular involvement. Especially the presence of aPE may significantly increase the risk of thrombotic complications development in SLE patients without classical serological markers of APS. Finally, aPE might be used as a marker of disease activity and risk of renal injury development in this patient group. The classical atherosclerotic markers including lipid indices play an important role in complex analysis of cardiovascular risk in lupus patients and enable to identify patients at the highest risk and implement effective preventive, diagnostic and therapeutic procedures.

Identification of rare anti-phospholipid/protein co-factor autoantibodies in patients with systemic lupus erythematosus

Lupus anticoagulant (LA) and beta2-glikoprotein I (b2GPI) dependent anti-cardiolipin (aCL) are part of the diagnostic criteria both of systemic lupus erythematosus (SLE) and anti-phospholipid syndrome (APS). Anti-phospholipid antibodies (aPL) may also bind to other phospholipids and/or protein co-factors. In the present study, besides aCL and anti-b2GPI, antibodies directed against phosphatidylserine, prothrombin (PT) and annexin V (aANX) were measured in 85 randomly selected SLE patients, 14 suffering from secondary APS. LA was detected by hemostasis tests. Correlations were determined between rare aPLs and clinical manifestations, including thrombotic events. Anti-cardiolipin IgG was positive in 14 patients, aCL IgM in 8, anti-b2GPI IgG in 4 and IgM in 5 patients. LA was detected in nine cases. Seven patients were positive for anti-phosphatidylserine (aPS) IgG, nine for aPS IgM, while anti-PT (aPT) IgG was positive in nine cases. aPT IgM and anti-aANX were negative in all patients. Correlation was found between aPS and aCL antibodies. The frequency and concentration of rare anti-phospholipid/co-factor antibodies was higher in patients with secondary APS. The presence of such rare aPLs cumulated in APS patients, their presence increased the frequency of thrombotic events in the entire study population, furthermore in patients positive for LA or aCL. Rare anti-phospholipid/co-factor antibodies were found in 12% of an un-selected lupus patient population. Their presence was more frequent in patients with secondary APS, and further increased the risk of thrombotic complications.

Anticardiolipin antibodies in patients with type 2 diabetes mellitus

BACKGROUND

There is controversy about an increased prevalence of antiphospholipid antibodies in diabetic patients. The possible implications are little known.

METHODS

We prospectively studied all consecutive outpatients with type 2 diabetes mellitus (DM) attended to in an Internal Medicine office. IgM and IgG anticardiolipin antibodies (ACA) were determined by standardized enzyme-linked immunoassay.

RESULTS

Fifty-six patients were included. Only one patient (1.8%) had a titer of IgM ACA higher than 15 MPL units and no patient had a titer of IgG ACA higher than 15 GPL units. Six patients (10.7%) had low IgM ACA titers (4-15 MPL units) and 18 patients (32.1%) had low IgG ACA titers (4-15 GPL units). There were no differences in the frequencies of a low IgM or IgG ACA titer or in the means of IgM and IgG ACA titers in patients with complicated and uncomplicated DM, with and without cardiovascular disease, with and without nephropathy, or with and without retinopathy.

CONCLUSIONS

Moderate to high ACA titers must be exceptional in patients with type 2 DM. Low ACA titers may occur in patients with type 2 DM. These low titers do not seem to be associated with complicated DM, cardiovascular disease, nephropathy or retinopathy.

Antiphospholipid syndrome in pediatrics

APS is recognized increasingly as a leading cause of vascular thrombosis in the pediatric population. With the obvious exception of pregnancy morbidity, most of the clinical features that may occur in adults with APS have been described also in children. Because the coincident prothrombotic factors that are common in adults have little or no impact in children, pediatric patients with APS constitute a suitable sample to investigate the relationship of aPL with the associated clinical manifestations, such as thrombocytopenia, hemolytic anemia, chorea, and livedo reticularis, and the specificities of aPL that are more linked to thrombosis. On the other hand, because of the high frequency of infectious processes in early life, children may have a greater prevalence of nonpathogenic and transient aPL. For these reasons, the diagnostic and therapeutic approach to APS in childhood may be different from that for adults. Because of the rarity of aPL-related thrombosis in children, the natural history and optimal management can be defined only through large, multicenter, controlled studies. A internet-based registry for pediatric patients with APS (Ped-APS Register) has been recently established as part of the activities of the Euro-aPL Forum and the Lupus Working Group of the Pediatric Rheumatology European Society. This registry is aimed to obtain information on APS in childhood, particularly regarding association of aPL with clinical manifestations, specificity of aPL, impact of treatment and long-term outcome (http://www.med.ub.es/MIMMUN/FORUM/PEDIATRIC.HTM).

How we diagnose and treat thrombotic manifestations of the antiphospholipid syndrome: a case-based review

Antiphospholipid antibodies including anticardiolipin antibodies, lupus anticoagulants, and anti–β2 glycoprotein-1–specific antibodies may identify patients at elevated risk of first or recurrent venous or arterial thromboembolism. Traditionally, published case series supplemented by anecdotal experience have formed the basis of management of patients with these autoantibodies. Over the past several years, studies have described the management of patients with key clinical manifestations of antiphospholipid antibodies, including patients with antiphospholipid antibody syndrome. As a result, evidence-based treatment recommendations are possible for selected patients with, or at risk of, thrombosis in the setting of antiphospholipid antibodies. Unfortunately, most patients encountered in clinical practice do not correspond directly with those enrolled in clinical trials. For such patients, treatment recommendations are based on experience, extrapolation, and less rigorous evidence. This article proposes 5 cases typical of those found in clinical practice and provides recommendations for therapy focused on a series of clinical questions. Whenever possible, the recommendations are based on evidence; however, in many cases, insufficient evidence exists, so the recommendation is experiential.