Prevalence of Anticardiolipin Antibodies in Patient Cohorts with Distinct Clinical Manifestations of the Antiphospholipid Syndrome

Long-term evaluation of temporomandibular disorders in association with cytokine and autoantibody status in young women

Temporomandibular disorders (TMD) is a chronic pain disease affecting 4-60% of general population. Its suggested etiology includes mechanical overloading to related structures, psychosocial factors, and genetic vulnerability. However, its pathogenesis is yet to be fully understood, especially in cases with a higher level of pain and more associated comorbidities. Recently chronic systemic inflammation and possible autoimmunity has been indicated in several pain conditions as the underlying mechanism of chronicity but this aspect has not been rigorously investigated in TMD. This article focuses on analyzing the levels of cytokines, chemokines, autoantibodies and nonspecific inflammatory markers and comparing their levels according to pain severity and duration in 66 female TMD patients in their 20 s and investigating their association with clinical indices of TMD and comorbidities. The high pain disability group showed decreased range of jaw function and more pain on palpation of capsule areas compared to the low pain disability group. Comorbidities such as anxiety and sleep disturbance were also significantly more prevalent. The level of IL-8 and IgG were significantly higher in the high pain disability group. IL-2, -8, -13, IFN- γ, RANTES, PGE2, and thrombopoietin levels showed a significant effect on indices reflecting jaw function, generalized pain intensity, and health related quality of life. Such results imply that longer pain duration and higher pain intensity is associated with higher levels of systemic inflammation suggesting the possible role of immunologic disturbance as an underlying factor of chronic TMD pain and warranting further investigation for its consideration in diagnosis and treatment.

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.

Revisiting the Phadia/EliA cut-off values for anticardiolipin and anti-β2-glycoprotein I antibodies: a systematic evaluation according to the guidelines

Background Phadia/EliA fluorescence enzyme immunoassays are widely used automated assays for anticardiolipin (aCL) and anti-β2-glycoprotein I (aβ2GPI) antibodies. To date, cut-off values for these assays have not been evaluated systematically and the evidence behind manufacturer's recommended cut-off values is not clear. Objective To determine Phadia/EliA cut-off values for antiphospholipid antibodies (aPL) according to the procedures suggested by guidelines. Methods A total of 266 blood donors (135 females and 131 males) were included. The pre-handling and analysis of the samples were performed according to the International Society on Thrombosis and Hemostasis (ISTH) guideline for solid phase aPL assays. Cut-off values and corresponding 90% confidence intervals (CI) for each antibody were established and outliers were handled according to the Clinical and Laboratory Standards Institute (CLSI) guideline for reference intervals. Samples from 377 consecutive patients, referred to our thrombophilia center with evidence of thrombosis or pregnancy morbidity were included for aPL testing. Results The in-house 99th (97.5th) percentile cut-off values were 11 (8.7), 12 (6.9) 8.5 (5.0) AU/mL for aβ2GPI IgG, IgM and IgA, and 21 (13) GPL-U/mL and 41 (25) MPL-U/mL for aCL IgG and IgM, respectively. The prevalence of positive results (%) defined by these cut-off values in patients with evidence of thrombosis or pregnancy morbidity was 9.5 (12.2), 1.6 (2.9), and 7.0 (9.9), and 0.8 (3.8) for aβ2GPI IgG, IgM, and aCL IgG and IgM respectively. The use of in-house 99th percentile cut-off values compared to the manufacturer suggested cut-off values resulted in 1 and 39 fewer samples for aβ2GPI and aCL to be classified as positive for aPL, respectively. Conclusions We present Phadia/EliA cut-off values with 90% CI for aPL determined systematically according to the ISTH and CLSI guidelines. These values are different from values previously determined, suggesting variation of aPLs in different populations. Our findings indicate the need for each laboratory to determine/validate assay specific cut-off values for aPL.

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.

A contribution to detection of anticardiolipin and anti-β2glycoprotein I antibodies: Comparison between a home-made ELISA and a fluorescence enzyme immunoassay

BACKGROUND

Currently, ELISA for detection of anticardiolipin (aCL) and anti-β2glycoprotein I (anti-β2GPI) antibodies is not standardized. Recently, few studies have compared the performance of ELISA with that of fluorescence enzyme immunoassay (FEIA), but they have produced debatable results. The aim of this investigation was to compare ELISA with FEIA results in detecting aCL and anti-β2GPI antibodies.

METHODS

The study cohort included 94 primary antiphospholipid syndrome (PAPS) patients, 65 subjects with the clinical criteria for PAPS classification but ELISA negative for the laboratory criteria and 165 control subjects. Serum IgG/IgM aCL/anti-β2GPI antibodies were determined using FEIA-EliA™ and a home-made ELISA.

RESULTS

The sensitivities of the two methods were similar with the exception of IgM aCL which was found to be significantly higher in the PAPS patients using the ELISA method, even if IgM aCL was detected at a low level by both techniques. The two assays had a comparable specificity, a high/significant agreement and a significant correlation between the antibody levels. FEIA testing uncovered no significant prevalence of any antiphospholipid (aPL) antibody in the ELISA negative patients.

CONCLUSION

Our results suggest that FEIA is comparable to a home-made ELISA.

The estimated frequency of antiphospholipid antibodies in young adults with cerebrovascular events: a systematic review

BACKGROUND

Around 10% of all thrombotic cerebrovascular events (CVE) occur in young population and in a large proportion of those the trigger remains undetermined. Antiphospholipid antibodies (aPL) are recognised risk factors for ischaemic stroke and recurrent thrombotic events; however, the frequency of aPL in young people with CVE is still an unresolved issue.

OBJECTIVES

To estimate the frequency of aPL in young adults with CVE and to determine whether aPL-positive young individuals are at greater risk of CVE when compared with individuals without aPL by systematically reviewing the literature.

METHODS

Medline reports published between 1970 and 2013 investigating the presence of aPL in young patients (<50 years old) with CVE were included. The median frequency for positive aPL, including lupus anticoagulant, anticardiolipin antibodies (aCL) and antibodies against β2Glycoprotein I (anti-β2GPI), was calculated for stroke and transient ischaemic attacks.

FINDINGS

This systematic review is based on available data from 5217 patients and controls from 43 studies analysing the frequency of aPL in young patients with CVE. The overall aPL frequency was estimated as 17.4% (range 5%-56%) for any CVE, 17.2% (range 2%-56%) for stroke and 11.7% (range 2%-45%) for transient ischaemic attack (TIA). The presence of aPL increased the risk for CVE by 5.48-fold (95% CI 4.42 to 6.79). Based on available data, the frequency of aPL in young patients with CVE can be estimated at 17%, rising up to 22% for aCL in patients with stroke. The presence of aPL seems to confer a fivefold higher risk for stroke or TIA when compared with controls. However, variability in test reproducibility and cut-off definition still represent an important methodological limitation for the current diagnostic testing for aPL. These observations should be confirmed by appropriately designed population studies.

Patients with antineutrophil cytoplasmic antibodies associated vasculitis in remission are hypercoagulable

OBJECTIVES

The risk of venous thromboembolism (VTE) is increased in patients with antineutrophil cytoplasmic antibodies (ANCA) associated vasculitides (AAV) as compared to healthy subjects. The mechanisms underlying this increased occurrence of VTE are not completely understood. We hypothesize that AAV patients in remission are more procoagulant than healthy controls.

METHODS

Patients with AAV in remission and no VTE for the last 6 months were included. Patients with severe renal impairment (serum creatinine > 250 μmol/l) were excluded. Age and sex matched healthy controls were included. The endogenous thrombin potential (ETP) was determined together with hemostatic variables: fibrinogen, D-dimers, factor VIII (FVIII), tissue factor pathway inhibitor (TFPI), protein C, and free protein S.

RESULTS

Thirty-one patients were included. In 27 patients not taking anticoagulants, ETP was measured and found to be elevated: 137.1% as compared to a median of 90.0% for healthy controls (p < 0.01). Fibrinogen and D-dimer levels were not elevated in patients (median 3.5 g/l and 279 μg/l, respectively). FVIII and TFPI levels were also significantly increased in patients as compared to healthy controls (159% vs 137%; 122.5% vs 101%, respectively), whereas protein C and free protein S levels were not elevated (126.5% vs 118.6% and 124.6% vs 118.3%, respectively).

CONCLUSION

Patients with AAV in remission are more procoagulant than healthy controls, as indicated by an increased ETP. The increased FVIII level measured in these patients suggests persistence of endothelial activation and/or dysfunction. This endothelial dysfunction may cause a continuous low-grade procoagulant state.