The importance of measuring anticardiolipin antibodies

The (non-)sense of detecting anti-cardiolipin and anti-β2glycoprotein I IgM antibodies in the antiphospholipid syndrome

BACKGROUND

The antiphospholipid syndrome (APS) is characterized by thrombosis and/or pregnancy morbidity with the persistent presence of lupus anticoagulant (LAC), anti-cardiolipin (aCL) and/or anti-β2glycoprotein I (aβ2GPI) antibodies of the immunoglobulin G/immunoglobulin M (IgG/IgM) isotype. However, the role of aCL and aβ2GPI IgM as a serologic marker in APS is debated.

OBJECTIVES

We aimed to assess the diagnostic and clinical value of IgM antiphospholipid antibodies (aPL) in APS within the classification criteria.

PATIENTS/METHODS

Our multicenter study comprised 1008 patients, including APS patients and controls. Anti-CL and aβ2GPI IgG and IgM antibodies were detected with four commercially available solid phase assays.

RESULTS

Positivity for aCL and/or aβ2GPI antibodies was significantly correlated with thrombosis and pregnancy morbidity, independent of the isotype and solid phase assay. Higher odds ratios were obtained for IgG compared to IgM positivity. Isolated IgM was rare in thrombotic APS, but more frequent in obstetric APS, ranging from 3.5% to 5.4% and 5.7% to 12.3%, respectively, dependent on the solid phase assay. In a multivariate logistic regression analysis of aPL, IgM positivity was found to be associated with pregnancy morbidity. However, detection of IgM was not independently associated with thrombosis. Combined positivity for LAC, IgG, and IgM was highly associated with thrombosis and pregnancy morbidity.

CONCLUSIONS

Our data support testing for aCL and aβ2GPI IgM in women suspected of obstetric APS. However, no added value was found for testing IgM in patients suspected of thrombotic APS. Still, IgM aPL might be useful as a second-line test to improve thrombotic risk stratification.

The association between antiphospholipid antibodies and late fetal loss: A systematic review and meta-analysis

INTRODUCTION

Antiphospholipid syndrome is a chronic autoimmune disease with a high prevalence in females. Published data have identified that antiphospholipid antibodies (APLA) of antiphospholipid syndrome are risk factors for poor pregnancy outcomes, such as recurrent spontaneous abortion, intrauterine growth restriction and preeclampsia. However, the association between APLA and late fetal loss is not fully understood and remains controversial. The aim of this study is to identify and analyze the recent publications to better understand the association between APLA and late fetal loss.

MATERIAL AND METHODS

The literature was searched on 31 January 2019 using Ovid, Medline, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) to evaluate the association between APLA and late fetal loss, with articles published before January 2019, according to the PRISMA statement. Without imposing regional restrictions, referenced articles were selected. Quality assessment was conducted independently by two reviewers, based on the Newcastle-Ottawa scale. For the meta-analysis, we used odds ratios (random effects model). The between-study heterogeneity was assessed by Q test. Publication bias was assessed by funnel plots.

RESULTS

Nineteen studies (with 10 265 cases) were included in the final analysis. The odds ratio (OR) for the late fetal loss with lupus anticoagulant was 5.02 (95% confidence interval [CI] 2.14-7.89). Seven included studies reported that lupus anticoagulant had a statistically significant association with late fetal loss. The results did not show a statistically significant association between anticardiolipin antibodies and late fetal loss. The pooled odds ratio for the association of anticardiolipin antibodies with late fetal loss was 3.47 (95% CI 0.68-6.26). However, we did find the relation between anticardiolipin antibodies and late fetal loss among cohort studies (OR 2.27, 95% CI 1.20-3.44). Anti-beta2 glycoprotein 1 antibodies (β2GP1) showed a significant association with late fetal loss (OR 3.13, 95% CI 0.75-5.50).

CONCLUSIONS

Lupus anticoagulant is strongly associated with late fetal loss in antiphospholipid syndrome patients. However, the association between anticardiolipin antibodies and late fetal loss is inconsistent. There are currently insufficient data to support a significant relation between β2GP1 and late fetal loss.

Catastrophic antiphospholipid syndrome mimicking a malignant pancreatic tumour – a case report

Abstract

The catastrophic antiphospholipid syndrome is characterised by rapid onset thromboses, often resistant to conventional anticoagulant treatment, and resulting in life threatening multiple organ dysfunction. The diagnosis of catastrophic antiphospholipid syndrome may be difficult, predominantly due to its frequently atypical presentation. We report a case of a 35-year-old female who presented with a pancreatic tumour and extensive thromboses. Following a storm of ischemic events due to thrombotic occlusions in spite of therapeutic heparin dose, the suspicion of catastrophic antiphospholipid syndrome emerged. The patient was successfully treated with anticoagulants, immunuglobulins, plasmapheresis and rituximab. The present report shows that the use of the diluted Russell’s viper venom time can be helpful in providing additional information on the lupus anticoagulans antibody status, allowing careful monitoring of lupus anticoagulans conversion and hence response to therapy.

Evaluation of new commercial enzyme-linked immunosorbent assay kits in the laboratory diagnosis of antiphospholipid syndrome in view of the revised classification criteria of the antiphospholipid syndrome

Amendments to the Sapporo criteria for the diagnosis of the antiphospholipid syndrome (APS) have recently be published and include testing for the presence of IgG and IgM beta2-glycoprotein I (beta(2)GPI) antibodies. The Asserachrom Antiphospholipid antibodies line (Diagnostica Stago) with a monoclonal based standardisation, was evaluated in a Lupus anticoagulant (LAC) positive (n = 138) and a LAC negative (n = 134) populations. The ELISA line consists of the Asserachrom APA Screen, the Asserachrom APA IgG,M and the Asserachrom anti-beta(2)GPI IgG and IgM. Anti-prothrombin antibodies (APT), not being included in the updated laboratory criteria, have been tested by the Asserachrom anti-prothrombin IgG,M. Imprecision characteristics showed coefficients of variation (CV) ranging from 4.9% to 13.9%. Cut-off values were calculated with the 99 percentile. The Asserachrom APA Screen showed 1,5% false positive and 0,7% false negative results in correlation with the Asserachrom APA IgG,M. 14.7% of the patients were positive for beta2GPI antibodies, 30,0% of them showed a negative Asserachrom APA Screen. beta(2)GPI antibodies may be the only test positive in a minority of patients, so the Asserachrom APA Screen and the Asserachrom anti-beta(2)GPI IgG and IgM should be performed in parallel when APS is suspected. LAC and APA assays, however, remain essential in the laboratory diagnosis of APS.