IgM aCL Research Articles

The Clinical Performance of a New Chemiluminescent Immunoassay in Measuring Anti-β2 Glycoprotein 1 and Anti-Cardiolipin Antibodies.

BackgroundLaboratory criterion is needed for the classification of antiphospholipid syndrome (APS), which contain anticardiolipin antibodies (aCL) and anti-β2-glycoprotein 1 antibodies (aβ2GP1). They are commonly identified by enzyme-linked immunosorbent assay (ELISA), but lack standardized kits, resulting in substantial variations in the antibody positivity between different laboratories. The emergence of chemiluminescence automated BIO-FLASH may improve the situation.Material/MethodsWe selected 185 patients with APS, systemic lupus erythematosus (SLE), infertility, connective tissue disease (CTD), and other conditions in Peking University Third Hospital. We tested the aCL and aβ2GP1 levels by EUROIMMUN ELISA and 105 patients had at least one positive result for aCL and aβ2GP1, while the others had negative results. We retested them by chemiluminescence assay (CIA) and analyzed the result and compared the coincidence rate. The IgM levels were retested by AESKU ELISA. Data were analyzed using SPSS.ResultsOur result suggested that CIA had good performance for IgG isotype of aCL and aβ2GP1 in the coincidence rate. The positive coincidence rate of aCL IgM between CIA and EUROIMMUN ELISA was only 41.67%, but two ELISA kits showed good coincidence, CIA and AESKU ELISA had an obviously higher positive rate. CIA and AESKU had a higher coincidence than that of AESKU and EUROIMMUN in aβ2GP1-IgM.ConclusionsThe new automated CIA BIO-FLASH is suitable for detecting aCL and aβ2GP1 antibodies, especially IgG isotype, which may provide an alternative to time-consuming conventional ELISA method.

Assessment of diagnostic methods for the detection of anticardiolipin and anti-βeta2 glycoprotein I antibodies in patients under routine evaluation for antiphospholipid syndrome

BackgroundWe assessed the performance characteristics and correlations of the traditional enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassay (CIA) for detecting IgG and IgM antibodies to cardiolipin (aCL) and beta2 glycoprotein (anti-β2GPI) antibodies in patients under routine evaluation for APS. MethodsPatients (n = 216) referred to ARUP Laboratories for lupus anticoagulant (LAC) and/or aCL or anti-β2GPI IgG/IgM antibodies evaluation were assessed by ELISA and CIA methods. Diagnostic accuracies, correlations between methods and specific clinical manifestations in APS were investigated. ResultsThe areas under the curve (%) for APS using LAC with CIA (74, 95% CI: 65–82) or ELISA (70, 95% CI: 61–79) aPLs were comparable. The overall agreements and linear regression correlations between methods for aPL antibody of the same specificity were variable: aCL IgG 87.3%; R2 = 0.7491, aCL IgM 71.6%; R2 = 0.2656, anti-β2GPI IgG 77.2%; R2 = 0.7688 and anti-β2GPI IgM 81.7%; R2 = 0.3305. ConclusionsWith inclusion of LAC, the ELISA and CIA show comparable performance for the diagnosis of APS. However, correlations of APS-specific manifestations were dependent on method of detecting the aPL antibodies suggesting platforms may not be used interchangeable.

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.

Preconception antiphospholipid antibodies and risk of subsequent early pregnancy loss.

Objectives To prospectively estimate the association of preconception antiphospholipid antibodies (aPL) with subsequent pregnancy loss using a cohort design. aPL have been associated with recurrent early pregnancy loss (EPL) prior to 10 weeks in previous case-control studies. Prospective ascertainment of pregnancy loss is challenging, as most women do not seek care prior to EPL. Methods Secondary analysis of the Effects of Aspirin in Gestation and Reproduction trial of preconception low-dose aspirin. Preconception anticardiolipin (aCL) and anti-β2-glycoprotein-I (a-β2-I) were assessed in 1208 women with one or two prior pregnancy losses and no more than two prior live births. Comparison cohorts were defined by positive aPL (+aPL) or negative aPL (-aPL) status. All women were followed for six menstrual cycles while trying to conceive; if successful, they underwent an ultrasound at 6-7 weeks' gestation. EPL was defined as loss prior to 10 weeks' gestation; embryonic loss was loss after visualization of an embryo but prior to 10 weeks; clinical loss was any loss after visualization of an embryo (with or without fetal cardiac activity detected). Results In total, 14/1208 (1%) tested positive for +aPL. 786/1208 (65%) women had positive human chorionic gonadotropin during the study period, of which 9/786 (1%) had +aPL. Of the 786 pregnant women, 589 (75%) had live births and 24% had pregnancy losses. Women with +aPL experienced EPL at similar rates as women with -aPL, 44% vs 21% (aRR 2.4, 95% confidence interval (CI) 0.5-10.9). Embryonic loss was more common in women with +aCL IgM (aRR 4.8, 95% CI 1.0-23.0) and in women with two positive aPL. Clinical pregnancy loss was more common in women with positive a-β2-I IgM (50% vs 16.5%, aRR 3.7, 95% CI 1.3-10.8). Conclusion Positive levels of aPL are rare in women with one or two prior pregnancy losses and are not clearly associated with an increased rate of subsequent loss. Clinical trial registration The original source study was registered at ClinicalTrials.gov (#NCT00467363).

The lupus patient with positive rheumatoid factor.

Background Patients with systemic lupus erythematosus (SLE) may form clusters with clinical manifestations and autoantibodies. Objective The objective of this report is to study whether SLE patients with positive rheumatoid factor (RF) have a special clinical and/or serological profile. Methods A retrospective study of 467 SLE patients seen at a single rheumatology unit was conducted. Epidemiological data (age, gender, age at disease onset, ethnic background and tobacco use), clinical data (malar rash, photosensitivity, oral ulcers, discoid lesions, serositis, glomerulonephritis, convulsions, psychosis, hemolytic anemia, leukopenia, lymphocytopenia, arthritis and hypothyroidism) and serological profile (anti-dsDNA, anti-Ro/SS-A, anti-La/SS-B, anti-RNP, anti-Sm, IgG aCL, IgM aCL, lupus anticoagulant, direct Coombs and RF) were collected. Patients with positive and negative RF were compared. Results RF was found in 24.9% of the sample. In univariate analysis, RF was positively associated with butterfly rash ( p = 0.04), anti-Ro ( p = 0.03), anti-Sm antibodies ( p = 0.01) and hypothyroidism ( p = 0.01) and negatively associated with glomerulonephritis ( p = 0.003). Logistic regression showed that only glomerulonephritis ( p = 0.03; OR = 0.45; 95% CI = 0.21-0.93) and anti-Ro ( p = 0.009; OR = 2.3; 95% CI = 1.24-4.57) were independent associations. Conclusion In our sample RF was associated with protection from glomerulonephritis and with higher prevalence of anti-Ro antibodies.

A Successful Management of 29 year old Female with Left Central Retinal Artery Occlusion due to Manifestation of Primary Antiphospholipid Syndrome

Ocular involvement in Anti Phospolipid Syndrome (APS) includes a broad spectrum of manifestations from the anterior and posterior segment or the presence of neuro-ophthalmologic features. A female, 29 years old, came to ER handled by ophthalmology department, with chief complaint left visual loss suddenly since 4 hours before admission. Investigations revealed stable vital signs, VOD 20/20, VOS 1/300, funduscopy showedpale and cherry red spot on left retina, OCT revealed hyperreflective of left inner retinal layer, IgG aCL 51.7 U/mL (50.8 U/mL in OPD 3 months later), and the other examinations were within normal limit. Patient was diagnosed with Central Retinal Artery Occlusion due toPrimary Antiphospolipid syndrome. She was performed occular massage and anterior chamber paracintesis procedure, and given O2 6-8 lpm NRBM, Timolol 0.5% eye drop left eye bid, acetazolamide 250 mg bid, Kalium Slow Release 1 tab qd, Levofloxacine eye drop 1 drop/hour post surgery. After the result of IgM aCL available, we added warfarin 2 mg qd and aspirin 320 mg qd. Patient was discharged 2 days later as visual acuity improved with VOD 20/20 and VOS 0.5/60. Key words: Central retina artery occlusion, primary anti phospolipid syndrome, anti cardiolipin antibody

Novel enzyme immunoassay system for simultaneous detection of six subclasses of antiphospholipid antibodies for differential diagnosis of antiphospholipid syndrome.

: Antiphospholipid syndrome, which often complicates systemic lupus erythematosus (SLE), features high occurrence of arterial and/or venous thrombosis and recurrent fetal loss. However, which antibody subclass contributes to which clinical event remains uncertain. We newly developed an up-to-date enzyme immunoassay system using the AcuStar automated analyzer (Instrumentation Laboratory, Bedford, Massachusetts, USA) for parallel detection of six subclasses of antiphospholipid antibodies (aPLs): anticardiolipin antibodies (aCL) of IgG, IgM, and IgA and anti-β2-glycoprotein I antibodies (aβ2GPI) of IgG, IgM, and IgA. They were measured in 276 healthy volunteers and 138 patients with SLE: 45 with thromboembolic complications (29 arterial; 16 venous) and 93 without. Lupus anticoagulant activity in their plasma was measured according to the guidelines recommended by the Subcommittee on Lupus Anticoagulant/Phospholipid-Dependent Antibodies. aCL/β2GPI was measured with a standard ELISA kit commonly used in Japan. The positive results of IgG aCL, IgA aCL, and IgG aβ2GPI were closely associated with thromboembolic complications, whereas IgM aCL and IgM aβ2GPI were not. receiver operating characteristic analysis revealed that the accuracy of predicting thromboembolic complications based on the composite test results of the former three antibodies were obviously higher than by each alone. Regarding agreement with the test results of lupus anticoagulant activity, IgG aβ2GPI showed the closest match. Patients with SLE frequently possess various combinations of the six aPL subclasses, and this antibody spectrum is closely associated with thromboembolic events in these patients. This new automated enzyme immunoassay system allows simultaneous analysis of the profile of aPL subclasses for the differential diagnosis of antiphospholipid antibody syndrome in its early stage.

Dyslipidemia and its relationship with antiphospholipid antibodies in APS patients in North Kerala.

Antiphospholipid antibody syndrome (APS) is one of the most common acquired thrombophilic disorders resulting in arterial and venous thromboses. APS is a major cause for cerebrovascular accidents or stokes, myocardial infarction, venous thromboembolism and recurrent abortions/pregnancy losses especially in young patients. APS patients have an increased risk of atherosclerotic cardiovascular events. There are only two studies on lipid abnormalities in APS patients. None of them have studied the relationship between individual laboratory tests for APS and lipid profile abnormalities. Here we describe the significance of the relationship between various APS tests and lipid profile abnormalities in a subset of APS patients who presented with arterial thrombosis in a tertiary care hospital. The study was conducted at Government Medical College, which is a tertiary care referral hospital. All patients who presented to the medicine department with APS during a two-year period were studied. A patient was considered to be positive for anticardiolipin (aCL) antibody or anti-β2 glycoprotein (anti-β2G) if the titer was more than 15 IU/mL, and a high titer was considered to be more than 40 IU/mL for Immunoglobulin (lg) IgG and IgM isotypes. The fasting lipid profile was measured in all patients, and lipid profile abnormalities were defined with cutoffs of low-density lipoprotein (LDL) levels of >150 mg/dL, triglyceride (TG) levels of >150 mg/dL, and high-density lipoprotein (HDL) levels of <40 mg/dL. The relationship between lipid abnormalities and individual tests for APS, aCL IgG and IgM and anti-β2G IgG and IgM, were determined by statistical analysis. The study population included 77 APS patients, with 53% of patients between 20 and 40 years. The commonest abnormality in the lipid profile test was elevated TG levels of >150 mg/dL in 51.9% of the patients, followed by low HDL levels (<40 mg/dL) in 38.9% of the patients and high LDL levels (>150 mg/dL) in 40.2% of the patients. There was a statistically significant relationship between anti-β2G IgG levels and HDL and LDL levels, but not TG levels. Only LDL levels had a statistically significant relationship with aCL IgM levels. None of the lipid abnormalities had any statistically significant relationship with aCL IgG levels. This study highlights the importance of testing lipid profile abnormalities in APS patients and the existence of a statistically significant relationship between antiphospholipid antibody tests and lipid profile abnormalities.

A multicenter study to assess the reproducibility of antiphospholipid antibody results produced by an automated system

Background Inter-assay variability is a well-known problem in antiphospholipid antibody testing, because of the lack of standardization. Inter-laboratory reproducibility for the same assay is similarly important. Objectives Testing repeatability and reproducibility of HemosIL® AcuStar for anticardiolipin (aCL) and antiβ2-glycoprotein I antibodies (aβ2GPI) IgG and IgM. Patients/Methods In this observational study, out of 420 samples from the thrombophilia centers of Ghent and Geneva, 100 samples were randomly selected and successively analyzed in three centers: Ghent (C1, in duplicate for repeatability evaluation), Geneva (C2) and Frankfurt (C3). Results Results from 99 samples were available, including 25 from patients with antiphospholipid syndrome (APS) and 74 from non-APS patients. The intra-center repeatability expressed as intra-class correlation coefficient (ICC) was higher than 0.99 for each parameter. Differences between two measurements rarely exceeded 1 U mL-1 for values below 100 U mL-1 , except for aβ2GPI IgG, where differences varied from -4 to 4 U mL-1 . The inter-center ICCs were higher than 0.99, except for aCL IgM (ICC = 0.961). These ICCs remained high even when considering values below 100 U mL-1 (0.943, 0.964 and 0.977 for aCL IgG, aCL gM and aβ2GPI IgM, respectively), except for aβ2GPI IgG (ICC = 0.652). Qualitative comparison showed less than 5% discordant classification between centers, with somewhat more discordant results for aβ2GPI IgG. Conclusions In terms of discriminating properties, the HemosIL® AcuStar has excellent intra-center repeatability and a good inter-center reproducibility for aCL IgG, aCL IgM and aβ2GPI IgM. Some concern may arise for aβ2GPI IgG.

Solid Phase Immunoassay for the Detection of Anticardiolipin Antibodies.

The anticardiolipin (aCL) test was first developed in the 1980s and proved to be a valuable addition to the lupus anticoagulant assay for identifying patients with a disorder that came to be later known as the antiphospholipid syndrome (APS). Although the test has relatively poor specificity for APS diagnosis, particularly at low positive levels, it has continued to play a major role in the identification and management of these patients because of its high sensitivity and ability to be measured in both serum and plasma, and despite concomitant presence of anticoagulants normally given to APS patients. In this chapter we outline the procedure for producing essential assay components and for performing the aCL ELISA, which can be used to determine the presence of IgG, IgM and IgA aCL antibodies in human samples. We also provide general guidelines that will facilitate optimal performance of the aCL ELISA assay.

Clinical relevance of antiphospholipid antibodies in systemic sclerosis: A systematic review and meta-analysis.

To evaluate the clinical relevance of antiphospholipid antibodies (aPL) in systemic sclerosis (SSc). A systematic search of EMBASE and PubMed databases from January 1983 to July 2016 was carried out according to PRISMA guidelines whereas Peto׳s odds ratio (OR) for rare events was used for the meta-analysis. The pooled prevalence of participants positive for IgG and IgM anticardiolipin (aCL) antibodies was higher in SSc than controls (12.8% vs 1.6% and 7.8% vs 0.6%; p < 0.0001 for both) as was that of IgG and IgM anti-beta-2-glycoprotein-I antibodies (aβ2GPI) (6.1% vs 0.58%, p < 0.0001; 3.5% vs 0.3%, p = 0.001). The pooled prevalence of pulmonary arterial hypertension (PAH) was more common in SSc positive than negative patients for aCL (IgG/IgM combined) (26.5% vs 10.9%, p < 0.0001) whereas the pooled prevalence of renal disease (RD) was more common in IgG aCL positive than negative patients (36.3% vs 10.9%, p = 0.02). The pooled prevalence of thrombosis was higher in IgG aCL, IgM aCL, and IgM aβ2GPI positive than negative SSc patients (12.6% vs 1.4%, p < 0.0001), (15.1% vs 2.7%, p = 0.002) and (15% vs 0.78%, p = 0.009), respectively. The pooled prevalence of digital infarction/ischemia (DI) was higher in IgG aCL and IgM positive than negative SSc (52.8% vs 39.8%, p = 0.002) and (68.1% vs 29%, p = 0.07). A strong relationship exists between aCL and aβ2GPI of IgG/IgM isotype and SSc; patients positive for these antibodies are more likely to suffer from PAH, RD, thrombosis, and DI. However, data expressed as frequency of aPL positive patients rather than average antibody titers preclude further insight into the relevance of these assumptions.

Relevance of antiphospholipid antibodies in multiple sclerosis: A systematic review and meta analysis.

The relationship between antiphospholipid antibodies (aPL) and multiple sclerosis (MS) is unclear. To evaluate a link between aPL and MS. EMBASE and PubMed search to August 2016; Peto's odds ratio (OR) meta-analysis. The pooled prevalence of participants positive for IgG and IgM anticardiolipin (aCL) from 12 case-control studies was superior in MS than controls (6.8% vs 1.8%, p = 0.01 and 8.58% vs 2.18%, p = 0.001) with medium and high heterogeneities respectively (I2 = 48.55% and 68.13%). The pooled prevalence of participants positive for IgG anti-beta2glycoprotein-I (aβ2GPI) from seven case-control studies was lower in MS than controls (0.93% vs 4.02%) with high heterogeneity (I2 = 53.92%) though the pooled prevalence of participants positive for IgM aβ2GPI was similar (7.24% vs 6.13%) with high heterogeneity (I2 = 52.85%). Five cohorts compared IgG/IgM aCL and IgM aβ2GPI in stable/remission vs active/relapsing MS: the pooled prevalence of IgG aCL was similar in active/relapsing and stable/remission MS (19% vs 18.9%) but the pooled prevalence of IgM aCL was higher in active than in stable MS (36.9% vs 21%, p < 0.0001) as well as that of IgM β2GPI (40.5% vs 3.2%, p < 0.0001) with no heterogeneity. Data from case-control studies do not support a link between IgG/IgM aPL and MS. Data from cohort studies comparing active vs stable MS indicate a strong link between aPL of IgM isotype and active/relapsing MS but in the absence of aPL titres to comment upon this may either represent an epiphenomenon of active neuro-inflammation or natural autoantibodies devoid of pathogenic potential. Data expressed as frequency of aPL positive participants rather than average titres preclude further assumptions.

Simultaneous Quantification of Anticardiolipin IgG and IgM by Time Resolved Fluoroimmunoassay.

The autoimmune disease antiphospholipid syndrome (APS) is characterized by the presence of anticardiolipin antibodies (aCL), along with anti-β2-glycoprotein I (β2GPI) antibodies and lupus anticoagulant (LA). In this study, we developed a time-resolved fluoroimmunoassay (TRFIA) system for simultaneous quantification of aCL IgG and IgM. A 96-well microtiter plate precoated with the complex of cardiolipin from bovine heart and bovine β2GPI was incubated with the anticardiolipin IgG and IgM standard substance or serum, and the conjugate of Eu3+-labeled anti-human IgG and Sm3+-labeled anti-human IgM was pipetted to the wells to form a tipical double-antibody-sandwich immunoreactions; finally the fluorescent intensity of Eu3+ and Sm3+ was detected to reflect the quantity of anticardiolipin IgG and IgM. This assay showed a good relationship between fluorescence intensities and the concentration of anticardiolipin antibody(aCL) IgG and IgM, with a low-end sensitivity of 0.1 U/ml for IgG and 0.1 U/ml for IgM, respectively. The intra- and inter-assay coefficients of variation (CV) of the calibrators was 3.0% and 4.51% for IgG, and 2.76% and 4.45% for IgM. The average recovery was 100.38% for aCL IgG and 100.45% for aCL IgM. For serum samples, the results of our method showed a good correlation with those obtained with ELISA kit. Simultaneous detection of aCL-IgG and aCL-IgM in the same reaction well can optimize assay performance by avoiding potential influence of different reaction conditions-timing, and well-to-well difference in concentration and characteristics of cardiolipin antigen. The results of a combo aCL-IgG and aCL-IgM assay for the same sample are more consistent and more reliable. This dual-label time-resolved fluoroimmunoassay is sensitive for detecting aCL IgG and IgM across a wide concentration range with stable reagents and may assist in the clinical diagnosis of antiphospholipid syndrome.

A Clinical Approach for Defining the Threshold between Low and Medium Anti-Cardiolipin Antibody Levels for QUANTA Flash Assays.

The threshold between low and medium antibody levels for anticardiolipin (aCL) and anti-β2 glycoprotein I antibodies (aβ2GPI) for the diagnosis of antiphospholipid syndrome (APS) remains a matter of discussion. Our goal was to create a protocol for determining the low/medium antibody cut-off for aCL antibody methods based on a clinical approach, and utilize it to establish the clinically-relevant low/medium threshold for QUANTA Flash aCL chemiluminescent immunoassay (CIA) results. The study included 288 samples from patients with primary APS (n = 70), secondary APS (n = 42), suspected APS (n = 36), systemic lupus erythematosus (SLE) without APS (n = 96) and other connective tissue diseases (n = 44). All samples were tested for IgG and IgM aCL antibodies with QUANTA Flash CIA, along with traditional enzyme-linked immunosorbent assays (ELISAs) (QUANTA Lite). The assay specific low/medium threshold for QUANTA Flash aCL IgG and IgM assays (i.e., the equivalent of 40 GPL and MPL units) was established as 95 and 31 chemiluminescent units (CU), respectively, based on clinical performance and comparison to QUANTA Lite ELISAs. Agreement between CIA and ELISA assay results improved substantially when the platform-specific low/medium antibody threshold was used, as compared to agreement obtained on results generated with the assay cutoff: Cohen’s kappa increased from 0.85 to 0.91 for IgG aCL, and from 0.59 to 0.75 for IgM aCL results. This study describes a clinical approach for establishing the low/medium antibody threshold for aPL antibody assays, and successfully employs it to define 95 and 31 CU, respectively, as the low/medium cut point for QUANTA Flash aCL IgG and IgM results. This study can serve as a model for labs wishing to establish the appropriate low/medium aPL antibody threshold when implementing new aPL antibody assays.

Antiphospholipid antibodies and the risk of severe and non‐severe pre‐eclampsia: the NOHA case‐control study

pre-eclampsia (PEecl) can be defined as non-severe (NS-PEecl) or severe (S-PEecl). Our study aimed to determine the incidence of antiphospholipid antibodies (aPLs) in women with a past history of NS-PEecl or S-PEecl. This case-control study includes 195 control women, 199 NS-PEecl patients and 143 S-PEecl patients whose plasma samples were collected 6 months after their first delivery. Each plasma was tested for lupus anticoagulant (LA), anticardiolipin (aCL) and antiβ2GP1 antibodies, as well as antibodies against phosphatidylserine/prothrombin complex (aPS/PT) and domain I of the β2GP1. When compared with the control group no significant associations were found for the NS-PEecl group after adjustment of confounding variables. For the S-PEecl group, there was an association with antiβ2GP1 immunoglobulin G (IgG) (OR 16.91, 95% CI 3.71-77.06), as well as age, obesity, smoking and multiparity. Antiβ2GP1-domain I IgG was associated with aCL, antiβ2GP1 and aPS/PT IgG in the three groups. aPS/PT IgG was associated with aCL IgG, and aPS/PT IgM was associated with aCL and antiβ2GP1 IgM in the three groups. S-PEecl is a distinct entity from NS-PEecl and is mainly associated with the presence of antiβ2GP1 IgG. Antiβ2GP1 domain I correlates with other aPL IgG tests, and aPS/PT may be promising in patients for whom LA tests cannot be interpreted.

The Clinical Significance of Both IgM and IgG Anticardiolipin Antibodies in Non-Hodgkin’s Lymphoma

Background: Anticardiolipin (ACL) antibodies are associated with a wide variety of disorders including malignancies. The aim of this study was to investigate the prevalence and prognostic implication of ACL antibodies in patients with Non-Hodgkin’s lymphoma (NHL). Methods: Sixty-four patients with NHL were included in this study. Enzyme-linked immunosorbent assay kits were used to measure the concentrations of all IgM and IgG antibodies. Results: Antibodies (IgM, IgG) were found in 35.9% and 84.3% of patients respectively. The presence of elevated aCl IgM was correlated with relapse in NHL (P<0.001). Pretreatment serum levels of aCL IgG were significantly higher in patients with NHL (P<0.001), and significantly normalized in complete remission. Positive ACL IgG was also found in patients with relapse. A negative correlation was found between aCL antibodies (IgM, IgG) positivity and CD23 (P=0.037, P=0.003) respectively. Conclusion: Anticardiolipin antibodies are associated with lymphomas. Their determination is useful to predict treatment outcome or disease prognosis.

Association between antiphospholipid antibodies and all-cause mortality among end-stage renal disease patients with and without SLE: a retrospective cohort study.

To investigate the association between the presence of aPL and/or LA and all-cause mortality among end-stage renal disease (ESRD) patients with and without SLE. We included ESRD patients >18 years old followed at an urban tertiary care centre between 1 January 2006 and 31 January 2014 who had aPL measured at least once after initiating haemodialysis. All SLE patients met ACR/SLICC criteria. APL/LA+ was defined as aCL IgG or IgM >40 IU, anti-β2glycoprotein1 IgG or IgM >40 IU or LA+. Deaths as at 31 January 2014 were captured in the linked National Death Index data. Time to death was defined from the first aPL measurement. We included 34 SLE ESRD and 64 non-SLE ESRD patients; 30 patients died during the study period. SLE ESRD patients were younger [40.4 (12.5) vs 51.9 (18.1) years, P = 0.001] and more were women (88.2% vs 54.7%, P < 0.001) vs non-SLE ESRD patients. The frequency of aPL/LA+ was 24% in SLE and 13% in non-SLE ESRD (P = 0.16). Median (inter-quartile range) follow-up time was 1.6 (0.3-3.5) years in SLE and 1.4 (0.4-3.2) years in non-SLE, P = 0.74. The adjusted hazard ratio (HR) for all-cause mortality for SLE patients who were aPL/LA+ vs aPL/LA- was 9.93 (95% CI 1.33, 74.19); the adjusted HR for non-SLE aPL/LA+ vs aPL/LA- was 0.77 (95% CI 0.14, 4.29). SLE ESRD patients with aPL/LA+ had higher all-cause mortality risk than SLE ESRD patients without these antibodies, while the effects of aPL/LA on mortality were comparable among non-SLE ESRD patients.

Clinical utility of automated chemiluminescent antiphospholipid antibody assay

The threshold for clinically relevant levels of antiphospholipid (aPL) antibodies for the diagnosis of antiphospholipid syndrome (APS) remains a matter of debate. As new technologies for antibody detection are introduced, their performance characteristics must be clearly understood and compared to traditional assays. To assess the analytical performance and clinical utility of fully automated anticardiolipin (aCL) and anti-β2 glycoprotein I (aβ2GPI) chemiluminescent immunoassays (CIA) in comparison to the traditional ELISA tests. Samples from 220 autoimmune patients were studied (primary APS - 74; secondary APS - 47, systemic lupus erythematosus (SLE) without APS - 99). All samples were tested for IgG and IgM aCL and β2GPI antibodies using both CIA and ELISA, and for lupus anticoagulant (LAC). Good qualitative agreement and quantitative correlation were found between methods in regard to individual antibodies and their categories (profiles). All assays showed good clinical performance in APS, and strong correlation with APS-related clinical symptoms. Importance of determining individual laboratory 99 percentile values for a healthy population as normal cut-off values was shown. Additionally, based on a clinical approach, this study has established the low/medium threshold for QUANTA Flash aCL IgG and IgM assays. This study showed good clinical performance and strong correlation of the new automated CIA aPL assays with APS clinical symptoms. It also enabled us to determine the corresponding low/medium antibody threshold for the aCL antibody methods with different unit types.

STUDY ON RELATIONSHIP BETWEEN SERUM ANTI-CARDIOLIPIN ANTIBODIES AND BRAIN LESION VOLUMES, SEVERITY IN PATIENTS WITH ACUTE CEREBRAL INFARCTION

Objective: (1) To determine positive percentage and levels of serum anticardiolipin antibodies in patients with acute cerebral infarction. (2) To determine survey on relationship between serum anticardiolipin antibodies and brain lesion volumes, severity in these patients. Subjects and Methods: cross-sectional descriptive study, 68 patients with acute cerebral infarction at Hue Medical University Hospital. The quantitative analysis of serum IgM, IgG anticardiolipin (aCL) antibodies was performed by indirect ELISA technique. Data processing method according to usual medical statistics and SPSS 16.0. Results: The positive percentage of IgG aCL antibody was 20,6% and IgM aCL antibody was 7,4% in acute cerebral infarction patients. The average levels of the aCL-IgG (+) in acute cerebral infarction patients was 33,98 ± 29,42 GPL/mL and aCL-IgM (+) was 26,58 ±10,30 MPL/mL. There was a close correlation between aCL-IgG levels and brain lesion volumes (r = 0,709; p &lt;0,01) and close inverse correlation between aCL-IgG levels and Glasgow coma scale (r = -0,643; p &lt;0,01). There was an average correlation between aCL-IgM levels and brain lesion volumes (r = 0,407; p &lt;0,01); and average inverse correlation between aCL-IgM levels and Glasgow coma scale (r = -0,393; p &lt;0,01). Conclusion: levels of the aCL-IgG (+) was 33,98 ± 29,42 GPL/mL and aCL-IgM (+) was 26,58 ±10,30 MPL/mL in acute cerebral infarction patients. Serum aCL levels correlated to brain lesion volumes and severity of acute cerebral infarction patients. Key words: anti-cardiolipin, aCL, acute cerebral infarction

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

BackgroundCurrently, 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. MethodsThe 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. ResultsThe 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. ConclusionOur results suggest that FEIA is comparable to a home-made ELISA.