Incidence of thromboembolic events in asymptomatic carriers of IgA anti ß2 glycoprotein-I antibodies

Abstract

BackgroundThe antiphospholipid syndrome (APS) is defined by simultaneous presence of vascular clinical events and antiphospholipid antibodies (aPL). The aPL considered as diagnostics are lupus anticoagulant and antibodies anticardiolipin (aCL) and anti-ß2 glycoprotein-I (aB2GP1). During recent years, IgA aB2GP1 antibodies have been associated with thrombotic events both in patients positive, and mainly negative for other aPL, however its value as a pro-thrombotic risk-factor in asymptomatic patients has not been well defined.ObjectiveTo test the role of IgA anti B2GP1 as a risk factor for the development of APS-events (thrombosis or pregnancy morbidity) in asymptomatic population with a 5-year follow-up.Methods244 patients isolated positive for anti-beta2-glycoprotein I IgA (Group-1 study) and 221 negative patients (Group-2 control) were studied. All the patients were negative for IgG and IgM aCL.ResultsDuring the follow-up, 45 patients (9.7%) had APS-events, 38 positive for IgA-aB2GP1 and 7 negative (15.6% vs 3.2%, p<0.001).The incidence rate of APS-events was 3.1% per year in IgA-aB2GP1 positive patients and 0.6% per year in the control group. Arterial thrombosis were the most frequent APS-events (N = 25, 55%) and were mainly observed in Group-1 patients (21 vs 4, p = 0.001). Multivariate analysis were shown as independent risk-factors for the development of APS-events, age, sex (men) and presence of IgA-aB2GP1 (odds ratio 5.25, 95% CI 2.24 to 12.32).ConclusionThe presence of IgA-aB2GP1 in people with no history of APS-events is the main independent risk factor for the development of these types of events, mainly arterial thrombosis.

Seronegative antiphospholipid syndrome: refining the value of “non-criteria” antibodies for diagnosis and clinical management

“…33,35 Thus, a case-control study including 244 asymptomatic patients screened for aPL and positive only for IgA aβ2GPI and 221 negative patients followed for five years showed that the presence of IgA aβ2GPI was associated with an increased risk for developing clinical thrombotic APS events (OR 5.15; P<0.001). 36 Although attractive, these data were not confirmed by another study evaluating the presence of IgA aβ2GPI antibodies in SN-APS. 25 Based on this evidence, it is not clear whether testing for IgA aCL and IgA aβ2GPI antibodies in addition to the routine tests may improve thrombotic risk stratification.…”

Immunoglobulin A Isotype of Antiphospholipid Antibodies Does Not Provide Added Value for the Diagnosis of Antiphospholipid Syndrome in a Chinese Population

“…However, a recent study has revealed the opposite conclusion that IgA–aPL is associated with thrombosis and obstetric complications ( 10 ). Some other previous studies also have mentioned the robust association between IgA–aPL and thrombosis ( 13 , 39 – 42 ) and that even IgA–aβ 2 GPI can be used as an independent risk factor for the development of APS-related events ( 13 ) and should be included as a consensus criterion for the diagnosis of APS ( 43 ). These controversial conclusions can mainly be attributed to differences in the included criteria of the study population, ethnic distribution, or statistical methods of the study.…”

“…In addition, the detection of IgA–aPL does not increase the diagnostic sensitivity of APS ( 20 ) or help diagnose patients with APS-associated SLE ( 21 ). Furthermore, the incidence rate of patients with isolated IgA–aPL who experience APS events has been reported to be as low as 3.1% per year ( 13 ). Indeed, IgA–aPL is usually accompanied with the IgG/IgM isotype, but the follow-up evidence in patients with isolated IgA–aPL is insufficient.…”

Immune Complexes of Beta-2-Glycoprotein I and IgA Antiphospholipid Antibodies Identify Patients With Elevated Risk of Thrombosis and Early Mortality After Heart Transplantation

“…The high prevalence of aPL (first "hit") in patients with end-stage renal disease or severe heart failure, together with their exposure to transplant surgery (a well-known "second hit"), triggers that a high percentage of these patients will have thrombotic events after transplantation. To perform a similar study with patients of the general population, where the prevalence of aPL is ∼2% and the incidence of events/year in aPL carriers is 3% (30)(31)(32)(33), it would be necessary to follow-up ∼40,000 individuals for 1 year.…”