Prevalence and isotype distribution of antiphospholipid antibodies in Chilean patients with systemic lupus erythematosus (SLE)

IgG/IgM antiphospholipid antibodies present in the classification criteria for the antiphospholipid syndrome: a critical review of their association with thrombosis

Essentials The clinical value of IgM antibodies in thrombotic antiphospholipid syndrome (APS) is debated. By review of literature, we reconsidered the clinical value of IgM antibodies in thrombotic APS. More significant correlations with thrombosis were found for the IgG compared to IgM isotype. Unavailability of paired IgG/IgM results hampers evaluating the added value of IgM positivity. Click to hear Dr de Groot's perspective on antiphospholipid syndrome

SUMMARY

Background Despite the update of the classification criteria for the antiphospholipid syndrome (APS), difficulties persist in the identification of patients at risk for thrombosis. Current guidelines include assays detecting IgG/IgM anti-β2 -glycoprotein I and anti-cardiolipin antibodies, although the relevance of IgM antibodies has been debated. Objectives Through a review of the literature from 2001 to 2014, we aimed to formally establish the thrombotic risk stratification potential of IgM as compared with IgG anti-phospholipid antibodies (aPLs). Patients/methods One thousand two hundred and twenty-eight articles were selected by a computer-assisted search of the literature. Of the 177 studies that met our inclusion criteria, the clinical value of IgG/IgM aPLs was established through analysis of odds ratios for thrombosis or percentage of positives in the thrombotic population. Results/conclusions We clearly found more significant correlations with thrombosis for the IgG than for the IgM isotype. Nonetheless, in a minority of studies, significant associations with thrombosis were found for IgM but not IgG antibodies. The unavailability of paired results of IgG and IgM for each separate patient hampers evaluation of the added value of isolated IgM positivity. To fully take advantage of results obtained by future studies, we strongly encourage scientists to provide all studied information per patient. We planned a large multicenter study to investigate clinical associations of isolated/combined positivity for criteria/non-criteria aPLs. Importantly, because of the presence of non-pathogenic aPLs, quantitative assays are characterized by a high false-positivity rate. Optimization of functional assays, such as thrombin generation measuring the whole scheme of coagulation, may help to reduce APS-related morbidity and mortality.

The coexistence of antiphospholipid syndrome and systemic lupus erythematosus in Colombians

OBJECTIVES

To examine the prevalence and associated factors related to the coexistence of antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE) in a cohort of Colombian patients with SLE, and to discuss the coexistence of APS with other autoimmune diseases (ADs).

METHOD

A total of 376 patients with SLE were assessed for the presence of the following: 1) confirmed APS; 2) positivity for antiphospholipid (aPL) antibodies without a prior thromboembolic nor obstetric event; and 3) SLE patients without APS nor positivity for aPL antibodies. Comparisons between groups 1 and 3 were evaluated by bivariate and multivariate analysis.

RESULTS

Although the prevalence of aPL antibodies was 54%, APS was present in just 9.3% of SLE patients. In our series, besides cardiovascular disease (AOR 3.38, 95% CI 1.11-10.96, p = 0.035), pulmonary involvement (AOR 5.06, 95% CI 1.56-16.74, p = 0.007) and positivity for rheumatoid factor (AOR 4.68, 95%IC 1.63-14.98, p = 0.006) were factors significantly associated with APS-SLE. APS also may coexist with rheumatoid arthritis, Sjögren's syndrome, autoimmune thyroid diseases, systemic sclerosis, systemic vasculitis, dermatopolymyositis, primary biliary cirrhosis and autoimmune hepatitis.

CONCLUSIONS

APS is a systemic AD that may coexist with other ADs, the most common being SLE. Awareness of this polyautoimmunity should be addressed promptly to establish strategies for controlling modifiable risk factors in those patients.

Antibodies to β2-glycoprotein-I: Relation of anticardiolipin antibodies with clinical and laboratory parameters in patients with systemic lupus erythematosus

OBJECTIVES

There are controversial reports on the frequency of antiphospholipid antibodies (aPL) in patients with systemic lupus erythematosus (SLE). Thus, we aimed to determine the frequency and clinical importance of aPL isotypes in Turkish patients with SLE.

DESIGN AND METHODS

Fifty-nine patients with SLE and 41 healthy controls were included. Serum aPL levels were measured both in patients and healthy subjects by ELISA.

RESULTS

Fifteen of the patients with SLE had the antiphospholipid syndrome (APS) (25.4%). The percentage of anticardiolipin antibody (aCL)-positive SLE patients among all patients was 56%. At least one isotype of anti-beta(2)-glycoprotein I (beta(2)-GPI) antibody was positive in 83% of patients. The positivity rates of aCL and anti-beta(2)-GPI antibodies in patients with or without APS were higher than the healthy controls. There were positive correlations between isotypes of IgM aCL, IgG and IgM anti-beta(2)-GPI and manifestations of APS.

CONCLUSION

It seems that the isotypes of IgM aCL, IgG and IgM anti-beta(2)-GPI are correlated with manifestations of APS. They may play a role in pathogenesis and may be helpful in establishing the diagnosis.

Clinical manifestations and antiphosphatidylserine antibodies in patients with systemic lupus erythematosus: is there an association?

OBJECTIVE

Antiphospholipid antibodies are a group of heterogeneous autoantibodies which have been reported in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) in association with thrombosis, fetal loss, and thrombocytopenia. In this study, we aimed to reveal the prevalence and correlation of IgG, IgA, and IgM isotypes of antibodies to cardiolipin (aCL) and antiphosphatidylserine (aPS) with clinical and laboratory manifestations of SLE patients.

METHODS

Fifty-nine SLE patients and 41 healthy controls were included. Fifteen of patients (25.4%) had secondary APS. aCL and aPS antibody assays were performed by enzyme-linked immunosorbent assay.

RESULTS

All isotypes of aCL and aPS antibodies except IgG were higher in patients with or without APS than those in the healthy controls (p<0.001). The most significant associations were found among migraine and IgA aCL (p<0.001), livedo reticularis and both IgM aCL and IgM aPS (p<0.001), migraine and IgM aCL (p<0.01), pulmonary involvement and IgM aCL (p<0.01), migraine and IgA aPS (p<0.01), and both thrombosis and migraine with IgM aPS (p<0.01).

CONCLUSION

A relatively high prevalence of aCL and aPS antibodies was found in our SLE patients. It seems that isotypes of IgM aCL, IgM aPS, IgA aCL, and IgA aPS antibodies are correlated well with migraine and IgM aPS with thrombosis in SLE patients with secondary APS. The assessment of both IgM and IgA isotypes of aPS and aCL antibodies may be helpful in predicting these manifestations.

Ethnic and geographical variation in antiphospholipid (Hughes) syndrome

Investigation of the clinical epidemiology of the antiphospholipid syndrome (APS) is in its early stages. During the past 20 years, studies of antiphospholipid antibodies (aPL) and APS have been made in many countries and ethno-geographical groups. aPL appear to occur in all populations studied, with some variations noted in their frequency and in the clinical complications. Environmental and genetic factors contribute to ethnic variation and susceptibility to APS and thus inter-ethnic differences in disease patterns may be due to environmental or genetic factors, or both.

Antibodies and clinical features of the antiphospholipid syndrome as criteria for systemic lupus erythematosus

The antiphospholipid syndrome (APS) can occur as a primary diagnosis or as a prominent feature of other diseases, predominantly systemic lupus erythematosus (SLE). The 1982 revised criteria for SLE were published prior to many of the studies which have illuminated current understanding of the antiphospholipid syndrome and several current clinical criteria for SLE, when arising from thrombotic damage to different organ systems, could be attributed to APS, leading to some confusion about where the diagnoses of these two disorders should begin and end. Additionally, APS is a significant generalized risk factor for irreversible organ damage and overall mortality in SLE patients and genetic linkages to HLA in APS hold up whether the disorder is primary or linked to SLE. It is increasingly recognized that APS itself is a complex, heterogenous disorder, involving a spectrum of autoantibodies to phospholipid-binding proteins, many of which have known coagulation-regulating functions. Although the combination of more than one antiphospholipid-related antibody might indicate a more severe phenotype, it is not suggested here that additive criteria for the diagnosis of SLE be accumulated with more than one of these pathologically related autoantibodies. Patients with multiple criteria for APS should be considered to have severe APS but it would be recommended to restrict APS-attributed criteria for SLE to a maximal of two: one immunologic and one clinical. Thus people meeting the Sapporo criteria for APS could gain only a maximum of two criteria for SLE, regardless of how many autoantibodies were detected or how severe the clinical syndrome might be. This would allow manifestations of fullblown APS an appropriate impact towards the diagnosis of SLE without leading to a premature diagnosis of SLE for people who might better be considered to have moderate to severe primary APS.

Diagnosis of the antiphospholipid syndrome: How far to go?

The past decade has seen an evolution in the way that thrombophilic conditions are diagnosed and understood. This has largely evolved through the detection of single nucleotide polymorphisms in critical regulating proteins that are thought to confer significant structural-functional changes at key points in the coagulation cascade. The antiphospholipid syndrome (APS) is a complex hypercoagulable disorder that as yet defies the possibility of simple, predictive testing.