Treatment of the antiphospholipid syndrome with direct oral anticoagulantsPosition statement of German societies

The antiphospholipid-syndrome (APS) is one of the most severe forms of thrombophilia, which may not only lead to recurrent venous but also to arterial thromboembolic events (TE), and to severe pregnancy complications, respectively. APS is defined by clinical symptoms and specific laboratory findings: 1. Lupus anticoagulant (LA), 2. anticardiolipin-antibodies (ACA), and 3. β2-Glycoprotein I-antibodies (β2GPI-Ab). All test results have to be confirmed after at least 12 weeks. The thrombotic risk is highest, if all 3 test groups are positive. It must be pointed out that the presence of UFH, VKA or DOACs may lead to false positive LA-test results; the addition of a specific absorber after blood sampling may provide reliable results in the presence of DOACs. A prospective randomized controlled trial comparing warfarin and rivaroxaban (TRAPS-trial) including only high-risk patients with triple positive APS was terminated early because of an increased rate of TE in patients treated with rivaroxaban [19 %, mostly arterial, compared to 3 % with warfarin (HR 7.4;1.7-32.9)]. Subsequently, a warning letter was issued by the pharmaceutical manufacturers of DOACs, including a warning of DOAC use in APS-patients, particularly in triple-positive high-risk patients. Conclusions: 1. Clinical suspicion of APS requires careful diagnostic testing. Because of inadequate diagnostic workup, many patients may not even have an APS, and these patients could be adequately treated with a DOAC. 2. Patients with single or double positive antiphospholipid antibodies but without positive LA may have a comparably low thrombotic risk and may also be treated with a DOAC in venous TE - sufficient evidence for that conclusion is not yet available but is suggested by the results of meta-analyses. 3. Triple positive patients or those with APS who suffered from arterial thromboembolism have a very high recurrence risk of thrombosis; the TRAPS-Study shows that these patients should be treated with VKA instead of a DOAC.

Triple Antiphospholipid (aPL) Antibodies Positivity Is Associated With Pregnancy Complications in aPL Carriers: A Multicenter Study on 62 Pregnancies

Objective: Antiphospholipid antibodies (aPL) are risk factors for thrombosis and adverse pregnancy outcomes (APO). The management of the so called “aPL carriers” (subjects with aPL positivity without the clinical criteria manifestations of APS) is still undefined. This study aims at retrospectively evaluating the outcomes and the factors associated with APO and maternal complications in 62 pregnant aPL carriers.

Methods: Medical records of pregnant women regularly attending the Pregnancy Clinic of 3 Rheumatology centers from January 1994 to December 2015 were retrospectively evaluated. Patients with concomitant autoimmune diseases or other causes of pregnancy complications were excluded.

Results: An aPL-related event was recorded in 8 out of 62 patients (12.9%) during pregnancy: 2 thrombosis and 6 APO. At univariate analysis, factors associated with pregnancy complications were acquired risk factors (p:0.008), non-criteria aPL manifestations (p:0.024), lupus-like manifestations (p:0.013), and triple positive aPL profile (p:0.001). At multivariate analysis, only the association with a triple aPL profile was confirmed (p:0.01, OR 21.3, CI 95% 1.84–247). Patients with triple aPL positivity had a higher rate of pregnancy complications, despite they were more frequently receiving combined treatment of low dose aspirin (LDA) and low molecular weight heparin (LMWH) at prophylactic dose.

Conclusion: This study highlights the importance of risk stratification in pregnant aPL carriers, in terms of both immunologic and non-immunologic features. Combination treatment with LDA and LMWH did not prevent APO in some cases, especially in carriers of triple aPL positivity. Triple positive aPL carriers may deserve additional therapeutic strategies during pregnancy.

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.

INR Management of an Antiphospholipid Syndrome Patient With Point-of-Care INR Testing

Management of patients with antiphospholipid syndrome on warfarin therapy can be challenging. The international normalized ratio (INR) of patients with antiphospholipid syndrome can be falsely elevated. This elevation is thought to be reflective of the reaction of the antiphospholipid antibody with the thromboplastin used to measure the protime. This false elevation can be seen in both venipuncture and point-of-care results. This discrepancy is usually more apparent in patients with whose INR is tested using point of care. As a result, there is a preference for venipuncture INR testing in most patients with antiphospholipid syndrome requiring warfarin therapy. In our case, we highlight one patient who we correlated her venipuncture INR with point-of-care INR as well as a chromogenic factor X level in order to manage her INR by point-of-care INR testing.

Testosterone Therapy, Thrombophilia, Venous Thromboembolism, and Thrombotic Events

In our sequential studies of 67 and 21 patients, testosterone therapy (TT) interacted with thrombophilia⁻hypofibrinolysis, leading to venous thromboembolism (VTE). Compared to 111 VTE controls not taking TT (VTE-no TT), the 67 and 21 cases were more likely (p < 0.05 for all) to have Factor V Leiden (FVL) heterogeneity (24% and 33% vs. 12%), the lupus anticoagulant (14% and 33% vs. 4%), and high lipoprotein(a) (33% vs. 13%, n = 21). After a first VTE and continuing TT, 11 thrombophilic cases had a second VTE despite adequate anticoagulation, 6 of whom, still anticoagulated, had a third VTE. The greatest density of thrombotic events was at three months after starting TT, with a rapid decline by 10 months. From <1 to 8 months after starting TT, 65% of VTE occurred, which may reflect TT-induced depletion of susceptible thrombophilic patients, leaving a winnowed residual group with fewer VTE events despite the continuation of TT. Before starting TT, we suggest screening for FVL, lipoprotein(a), and the lupus anticoagulant to identify patients at increased VTE risk, with an adverse risk-to-benefit ratio for TT. We suggest that TT should not be started in patients with known thrombophilia⁻hypofibrinolysis, and should not be continued after a first VTE. When TT is given to patients with thrombophilia⁻hypofibrinolysis, VTE may occur and then recur despite adequate anticoagulation.

Prevalence and Significance of Non-conventional Antiphospholipid Antibodies in Patients With Clinical APS Criteria

Background: The biological diagnostics of antiphospholipid syndrome (APS) takes into account the persistent positivity for anticardiolipin and/or anti-β2GP1 antibodies and/or presence of lupus anticoagulant (LA). However, some non-conventional antiphospholipid antibodies have emerged that could help in the diagnosis of APS.

Objectives: To study the potential usefulness of non-conventional antiphospholipid antibodies in clinical practice.

Methods: Eighty-seven patients, aged from 15 to 92 years were included and classified in following groups: 41 patients positive for the conventional antibodies with clinical criterion of APS (31 with primary APS and 10 secondary), 17 seronegative APS (SNAPS) patients (i.e., persistent negativity for the conventional antibodies with a strong clinical suspicion of APS), 11 asymptomatic antiphospholipid antibodies carriers (i.e., persistent positivity for the conventional antibodies without clinical evidence of APS), and 18 patients presenting with a first thrombotic or obstetrical event. IgG and IgM were detected to the following antigens: phosphatidylserine/prothrombin (PS/PT) by ELISA, and phosphatidic acid, phosphatidyl-ethanolamine, phosphatidyl-glycerol, phosphatidyl-inositol, phosphatidylserine, annexin V, prothrombin by immunodot. Anti-β2GP1 IgA, and anti-β2GP1 domain 1 IgG were detected by chemiluminescence.

Results: Positivity for the non-conventional antibodies was correlated with APS severity; patients with catastrophic APS (CAPS) being positive for 10.7 (Median, Range: 5–14) non-conventional antibodies. 9/17 seronegative patients were positive for at least one of non-conventional antibodies. A study of non-supervised hierarchical clustering of all markers revealed that anti-PS/PT antibodies showed high correlation with the presence of LA. All patients with APS triple positivity (highest risk profile) exhibited also persistent positivity for anti-PS/PT antibodies.

Conclusions: Our data obtained from a prospective cohort constituted mainly by patients with primary APS, suggest that non-conventional APS antibodies may be useful for patients classified as SNAPS. They demonstrate the potential value of aPS/PT antibodies as a strong marker of APS. We propose that anti-PS/PT antibodies could be a surrogate APS biological marker of LA to classify in high-risk profile patients treated by direct oral anticoagulants (DOACs), in whom LA detection cannot be achieved.

Bilateral adrenal hemorrhage revealed antiphospholipid syndrome in a male patient: benefit from comprehensive treatment

BACKGROUND

Adrenal hemorrhage caused by antiphospholipid syndrome (APS) secondary to systemic lupus erythematosus (SLE) is very rare, especially in males.

REPORT

This study reports a 45-year-old male patient who presented with fatigue, loss of appetite, nausea, and vomiting for 2 months with a history of recurring epilepsy. On examination, he had low blood pressure (95/53 mmHg) and hyponatremia (117.9 mmol/L). His abdominal computed tomography (CT) scan showed bilateral diffusely enlarged adrenal hemorrhage. Laboratory studies revealed evidence of APS secondary to SLE. He remains well with adrenal lesions shrunken under the treatment of steroid, cyclophosphamide, hydroxychloroquine, warfarin, oxcarbazepine and entecavir.

CONCLUSION

This case is presented as a warning that the correct diagnosis of adrenal hemorrhage and appropriate treatment is needed, especially when complications set in.

Antiphosphatidylserine/prothrombin antibodies (aPS/PT) as potential diagnostic markers and risk predictors of venous thrombosis and obstetric complications in antiphospholipid syndrome

BACKGROUND

The aim of the study was to determine the prevalence and clinical associations of antiphosphatidylserine/prothrombin antibodies (aPS/PT) with thrombosis and pregnancy loss in Chinese patients with antiphospholipid syndrome (APS) and seronegative APS (SNAPS).

METHODS

One hundred and eighty six Chinese patients with APS (67 primary, 119 secondary), 48 with SNAPS, 176 disease controls (79 systemic lupus erythematosus [SLE], 29 Sjogren's syndrome [SS], 30 ankylosing spondylitis [AS], 38 rheumatoid arthritis [RA]) and 90 healthy donors were examined. IgG and IgM aPS/PT, IgG/IgM/IgA anticardiolipin (aCL) and IgG/IgM/IgA anti-β2-glycoprotein I (anti-β2GPI) antibodies were tested by ELISA.

RESULTS

One hundred and sixty (86.0%) of APS patients were positive for at least one aPS/PT isotype. One hundred and thirty five (72.6%) were positive for IgG aPS/PT, 124/186 (66.7%) positive for IgM aPS/PT and 99 (53.2%) positive for both. Approximately half of the SNAPS patients were positive for IgG and/or IgM aPS/PT. Highly significant associations between IgG aPS/PT and venous thrombotic events (odds ratio [OR]=6.72) and IgG/IgM aPS/PT and pregnancy loss (OR=9.44) were found. Levels of IgM aPS/PT were significantly different in APS patients with thrombotic manifestations and those with fetal loss (p=0.014). The association between IgG/IgM aPS/PT and lupus anticoagulant (LAC) was highly significant (p<0.001). When both were positive, the OR for APS was 101.6. Notably, 91.95% (80/87) of LAC-positive specimens were positive for IgG and/or IgM aPS/PT, suggesting aPS/PT is an effective option when LAC testing is not available.

CONCLUSIONS

Anti-PS/PT antibody assays demonstrated high diagnostic performance for Chinese patients with APS, detected some APS patients negative for criteria markers and may serve as potential risk predictors for venous thrombosis and obstetric complications.

Zonal cortical scarring and tubular thyroidization in kidney biopsies of patients with SLE-histologic indicator for antiphospholipid antibodies

Antiphospholipid antibody syndrome (APS) is an acquired prothrombotic autoimmune disease caused by the presence of antibodies against anionic phospholipids or plasma proteins bound to phospholipids on cell membranes. It can be a primary disease or secondary to other autoimmune diseases, most commonly systemic lupus erythematosus (SLE). Laboratory testing for antiphospholipid antibodies (aPL) may be only transiently positive, so APS could be missed until a catastrophic thrombotic episode or pregnancy morbidity occurs. In the kidneys, this manifests as thrombotic microangiopathy (TMA), and patients present with hypertensive urgency and acute kidney injury. However, APS may not always have a catastrophic presentation but instead a more smoldering course. Kidney biopsy may not show obvious active TMA lesions but rather only chronic injury in the form of zonal cortical scarring and tubular thyroidization. Still, it may warrant anticoagulation therapy. So it is important to recognize this pattern of injury in the biopsy. Herein, we retrospectively study the correlation between presence of this histologic feature in kidney biopsies of SLE patients and positive aPL testing results (anticardiolipin antibodies and/or lupus anticoagulant). Kidney biopsies of SLE patients from 2004 to 2015 ( n = 186) were screened for presence or absence of zonal cortical scarring. Their electronic medical records were reviewed for aPL results. Our study showed low sensitivity (33%) but higher positive predictive value (62%), specificity (89%) and negative predictive value (71%). This histologic finding is therefore not a sensitive screening tool, but if present, greatly increases the likelihood of underlying aPL. We want to emphasize that recognition of this histologic feature in the biopsies of SLE patients is important so as not to miss the opportunity to treat with anticoagulation therapy and possibly slow down the chronic renal damage.

Slicc damage index score in systemic lupus erythematosus patients and its associated factors

The aims of this study were to determine damage index in systemic lupus erythematosus (SLE) patients based on Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index (SDI) and to determine the laboratory and clinico-demographic factors affecting SDI.This is a retrospective cohort study of 94 SLE patients attending rheumatology clinics in 2 local hospitals in Kelantan, Malaysia. The patients were divided into 2 groups based on SDI score assigned by the attending physician, 0 (without damage) or ≥1 (with damage). Newly diagnosed SLE patients with disease duration less than 6 months were excluded.A total of 45 (47.9%) SLE patients showed damage by SDI score. Majority of the subjects had neuropsychiatric damages (21/94; 22.3%) followed by skin (12/94; 12.8%) and musculoskeletal (6/94; 6.4%) damage. SDI score was significantly associated with higher disease duration (6.2 ± 6.57 years vs 4.5 ± 3.7 years; P = .018), lower prednisolone dose (8.74 ± 10.89 mg vs 4.89 ± 3.81 mg; P < .001), hypertension (P = .007), and exposure to cyclophosphamide (P = .004). Hypertension (P = .020), exposure to cyclophosohamide (P = 0.013), and lower prednisolone dose (P = .023) were significantly associated with damage by multivariable analysis.Higher SDI score was significantly associated with exposure to cyclophosphamide, suggesting that lower cyclophosphamide doses or alternative therapeutic agents are recommended.

Obstetric antiphospholipid syndrome

The present clinical and laboratory classification criteria for antiphospholipid syndrome (APS) were established in Sydney, Australia, in 2006. In this review, we focus on the obstetric subset of APS (OAPS), defined by persistent positivity for antiphospholipid antibodies together with either early recurrent pregnancy loss, early fetal death, stillbirth or premature birth <34 gestational weeks due to pre-eclampsia, eclampsia and placental insufficiency. It is important to diagnose these cases since most women suffering from OAPS can, when given appropriate treatment, have successful pregnancies. Furthermore, patients with OAPS may, depending on the antibody profile, be at enhanced risk of thrombotic events later in life. We present an update on the present knowledge of possible underlying pathogenesis, risk factors and risk estimations for adverse pregnancy outcomes before and during pregnancy, current treatment concepts, and long-term outcomes for women with OAPS and their children.

Paired APTTs of low and high lupus anticoagulant sensitivity permit distinction from other abnormalities and achieve good lupus anticoagulant detection rates in conjunction with dRVVT

INTRODUCTION

A prolonged activated partial thromboplastin time (APTT) may be indicative of a specific or multiple factor deficiency, therapeutic anticoagulation, presence of a nonspecific factor inhibitor, or lupus anticoagulant (LA). Recently, pairing of the LA-sensitive APTT and standard APTT reagents, Cephen LS and Cephen, respectively, has been shown to be effective in LA detection. The present study aimed to evaluate the usefulness of this reagent pair for discriminating between causes of APTT elevation and the detection of LA in conjunction with dilute Russell's viper venom time (dRVVT).

METHODS

Plasma samples from 50 normal and 105 non-anticoagulated LA-positive patients in routine dRVVT and/or dilute APTT (dAPTT) via the percent correction formula were employed. Cephen LS/Cephen and dRVVT reagents LA1/LA2 were used to screen/confirm, respectively. Thirty-four symptomatic LA-negative, 25 warfarinised non-antiphospholipid syndrome, 6 coagulation inhibitors, 17 samples with hereditary elevated APTT, and 24 FVIII/IX/XI/XII and 17 FII/V/X artificial single deficiency plasmas were used.

RESULTS

Thirty-three samples out of 105 (31%) were LA-positive in Cephen LS/Cephen. The total percent positivity in Cephen LS/Cephen and LA1/LA2 pairs was 89.1% against samples with the routine dRVVT/dAPTT double positive. The percent corrections of Cephen LS/Cephen in the routine dAPTT/dRVVT positive group were significantly higher than those in all other groups.

CONCLUSIONS

The percent correction of the APTT reagent pair showed higher values in LA-positive samples. The combination will be useful with respect to differentiating LA from other abnormal samples and is effective in LA detection when paired with dRVVT.

Distinguishing lupus anticoagulants from factor VIII inhibitors in haemophilic and non-haemophilic patients

INTRODUCTION

Accurate diagnosis of an inhibitor, a neutralizing antibody to infused factor VIII (FVIII), is essential for appropriate management of haemophilia A (HA). Low-titre inhibitors may be difficult to diagnose due to high rates of false-positive inhibitor results in that range. Transient low-titre inhibitors and false-positive inhibitors may be due to the presence of a lupus anticoagulant (LA) or other non-specific antibodies. Fluorescence immunoassay (FLI) to detect antibodies to FVIII is a sensitive method to identify inhibitors in HA. Evaluations of antibody profiles by various groups have demonstrated that haemophilic inhibitors detected by Nijmegen-Bethesda (NBA) and chromogenic Bethesda (CBA) assays correlate with positivity for anti-FVIII immunoglobulin (Ig) G1 and G4.

AIM

This study sought to determine whether FLI could distinguish false-positive FVIII inhibitor results related to LAs from clinically relevant FVIII inhibitors in HA patients.

METHODS

Samples from haemophilic and non-haemophilic subjects were tested for LA, specific FVIII inhibitors by NBA and CBA, and anti-FVIII immunoglobulin profiles by FLI.

RESULTS

No samples from LA-positive non-haemophilic subjects were positive by FLI for anti-FVIII IgG4. Conversely, 91% of NBA-positive samples from haemophilia subjects were positive for anti-FVIII IgG4. Two of 11 haemophilia subjects had samples negative for anti-FVIII IgG4 and CBA, which likely represented LA rather than FVIII inhibitor presence.

CONCLUSIONS

Assessment of anti-FVIII profiles along with the CBA may be useful to distinguish a clinically relevant low-titre FVIII inhibitor from a transient LA in HA patients.

Bleeding complications and antithrombotic treatment in 264 pregnancies in antiphospholipid syndrome

Purpose The purpose of this study was to evaluate the safety of antithrombotic treatments prescribed during pregnancy in patients with antiphospholipid syndrome (APS). Methods This international, multicenter study included two cohorts of patients: a retrospective French cohort and a prospective US cohort (PROMISSE study). Inclusion criteria were (1) APS (Sydney criteria), (2) live pregnancy at 12 weeks of gestation (WG) with (3) follow-up data until six weeks post-partum. According to APS standard of care, patients were treated with aspirin and/or low-molecular weight heparin (LMWH) at prophylactic (pure obstetric APS) or therapeutic doses (history of thrombosis). Major bleeding was defined as abnormal blood loss during the pregnancy and/or post-partum period requiring intervention for hemostasis or transfusion, or during the peripartum period greater than 500 mL and/or requiring surgery or transfusion. Other bleeding events were classified as minor. Results Two hundred and sixty-four pregnancies (87 prospectively collected) in 204 patients were included (46% with history of thrombosis, 23% with associated systemic lupus). During pregnancy, treatment included LMWH ( n = 253; 96%) or low-dose aspirin ( n = 223; 84%), and 215 (81%) patients received both therapies. The live birth rate was 89% and 82% in the retrospective and prospective cohorts, respectively. Adverse pregnancy outcomes occurred in 28% of the retrospective cohort and in 40% of the prospective cohort. No maternal death was observed in either cohort. A combined total of 45 hemorrhagic events (25%) occurred in the retrospective cohort, but major bleeding was reported in only six pregnancies (3%). Neither heparin nor aspirin alone nor combined therapy increased the risk of hemorrhage. We also did not observe an increased rate of bleeding in the case of a short interval between last LMWH (less than 24 hours) or aspirin (less than five days) doses and delivery. Only emergency Caesarean section was significantly associated with an increased risk of bleeding (odds ratio (OR) 5.03 (1.41-17.96); p=.016). In the prospective cohort, only one minor bleeding event was reported (vaginal bleeding). Conclusion Our findings support the safety of antithrombotic therapy with aspirin and/or LMWH during pregnancy in high-risk women with APS, and highlight the need for better treatments to improve pregnancy outcomes in APS. PROMISSE Study ClinicalTrials.gov identifier: NCT00198068.

Spontaneous internal jugular vein thrombosis as primary presentation of antiphospholipid syndrome: case report

Introduction

Spontaneous and isolated internal jugular vein (IJV) thrombosis is a rare entity, and atypical localization for venous thromboembolism usually occurs after an oropharyngeal infection, cancer, central venous catheter, and ovarian hyperstimulation syndrome. This report describes a case of spontaneous IJV thrombosis leading to neck pain and swelling as a primary manifestation of antiphospholipid (Hughes) syndrome.

Case presentation

A 44-year-old male with no significant past medical history presented with a 1-week duration of right-sided painful neck swelling. Duplex ultrasound and computed tomography angiogram revealed right IJV thrombosis. Hematology studies were normal apart from positive lupus anticoagulant. The patient was managed conservatively with low molecular weight heparin, antibiotics, and close follow-up.

Conclusion

Acute spontaneous IJV thrombosis as a primary presentation of antiphospholipid syndrome is extremely uncommon. We should be aware of the possibility of this condition in the differential diagnosis and management, as long-term anticoagulation is needed.

Prolonged Activated Partial Thromboplastin Time and False-Positive Results for Fibrinogen and Fibrin Degradation Products in a B-Cell Lymphoma Patient

We report a unique case of a B-cell lymphoma patient in whom IgM monoclonal gammopathy resulted in a prolonged activated partial thromboplastin time (APTT) and false-positive results for fibrinogen and fibrin degradation products (FDPs). An 86-year-old man was referred to our hospital for further examination of abnormal cells in his peripheral blood. Laboratory data upon admission revealed an elevation of monoclonal IgM, presence of FDPs and marked prolongation of APTT (>180 s). Bone marrow examination revealed a predominant involvement of B lymphoma cells. In vitro examination revealed that IgM isolated from the patient's plasma had resulted in false-positive results for FDPs and APTT. Neither hemorrhagic nor thrombotic tendency was observed in this patient, suggesting that the abnormal coagulation data were due to interference by elevated monoclonal IgM levels.

Thrombophilia Caused by Beta2-Glycoprotein I Deficiency: In Vitro Study of a Rare Mutation in APOH Gene

This study aimed to explore the mechanism of a novel mutation (p.Lys38Glu) in apolipoprotein H (APOH) gene causing hereditary beta2-glycoprotein I (β2GPI) deficiency and thrombosis in a proband with thrombophilia. The plasma level of β2GPI was measured by ELISA and Western blotting, and anti-β2GPI antibody by ELISA. Lupus anticoagulant (LA) was assayed using the dilute Russell viper venom time. Deficiency of the major natural anticoagulants including protein C (PC), protein S (PS), antithrombin (AT) and thrombomodulin (TM) was excluded from the proband. A mutation analysis was performed by amplification and sequencing of the APOH gene. Wild type and mutant (c.112A>G) APOH expression plasmids were constructed and transfected into HEK293T cells. The results showed that the thrombin generation capacity of the proband was higher than that of the other family members. Missense mutation p.Lys38Glu in APOH gene and LA coexisted in the proband. The mutation led to β2GPI deficiency and thrombosis by impairing the protein production and inhibiting the platelet aggregation. It was concluded that the recurrent thrombosis of the proband is associated with the coexistence of p.Lys38Glu mutation in APOH gene and LA in plasma.

Antiphospholipid syndrome, "the best prophet of the future"

The antiphospholipid syndrome (APS) is an autoimmune disorder characterized by the occurrence of venous and arterial thromboses, often multiple, and obstetric-related adverse events in the presence of antiphospholipid antibodies (aPL). APS, first described in 1983, as thrombosis, abortion and cerebral disease, is nowadays recognised as a systemic disease with a wide constellation of clinical manifestations related to acute and chronic vascular lesions. The presence of aPL is the serological hallmark of APS representing a heterogeneous population of autoantibodies with many antigenic specificities directed to phospholipid-binding proteins, either alone or in combination with phospholipids. Many assays have been developed for aPL detection. Particularly, anticardiolipin antibodies, anti-β2-glycoprotein I antibodies and lupus anticoagulant are essential tools for APS diagnosis. The cumulative evidence indicates that aPL are pathogenic autoantibodies binding to target cells and promoting thrombosis and pregnancy complications through a wide range of pathological mechanisms not yet fully understood. Finally, the recognition of the important role of aPL to assess the individual risk of thrombosis or pregnancy complications has expanded the concept of aPL, and currently aPL profile is regarded as a major risk factor for clinical thrombotic events.

An Evaluation of Hemostatic Abnormalities in Patients With Hemophilia According to the Activated Partial Thromboplastin Time Waveform

The usefulness of the waveform of activated partial thromboplastin time (APTT) in various diseases has been evaluated in recent years. The APTT waveform was examined in patients with hemophilia and patients positive for lupus anticoagulant (LA). The correlation with the FVIII activity was highest for the height of acceleration peak. The peak time of acceleration, velocity, and ½ fibrin formation, and the width of acceleration and velocity were significantly long and the height of acceleration was significantly low in patients with hemophilia. The height of velocity was significantly low in patients with hemophilia with inhibitor. There were no significant differences in the APTT waveform between patients with hemophilia and patients with LA, but the peak of acceleration and ½ fibrin formation were significantly longer and the height of acceleration and velocity were significantly lower in patients with hemophilia with inhibitor than in the patients with LA. Wave changes in the APTT were observed in all 22 patients positive for LA, while a biphasic waveform was observed in patients with hemophilia with FVIII activity <10.0%. The APTT waveform is useful for the analysis of hemostatic abnormalities in patients with hemophilia.

[Transient detection of lupus anticoagulant in acute phase of Kawasaki disease]

  In Kawasaki disease (KD), endothelial damage and an elevation in coagulant factors provoke thrombosis. Lupus anticoagulant (LA) is strongly associated with the risk of thrombosis in patients with antiphospholipid syndrome; however, there has been no report of positive LA in KD patients. A previously healthy, 2-year-old boy was admitted due to fever, bilateral conjunctivitis, redness of the lips, and unilateral cervical lymphadenopathy. Typical Kawasaki disease was diagnosed on day 5 of illness. Adenovirus antigens were detected in his stool. After the KD symptoms were successfully treated with intravenous immunoglobulin, his activated partial thromboplastin time (APTT) increased to 88 seconds at eight days of illness. The cross-mixing test showed an inhibition pattern, and the presence of LA was proved using diluted Russell's viper venom time. APPT elongation improved due to continued low dose aspirin therapy without thromboembolisms. The possibility of contamination by LA was low because six other patients treated with the same immunoglobulin lot showed no APTT elongation. We speculated that KD-related infections led to the presence of LA, which may have triggered the thrombosis. Further accumulation of data is warranted to elucidate the role of LA in KD patients.

Newly developed dilute Russell's viper venom reagents for lupus anticoagulant detection with improved specificity

Background Dilute Russell's viper venom time (dRVVT) is indispensible in lupus anticoagulant (LA) detection yet commercial reagents from different suppliers perform variably, no gold standard assays exist and therapeutic anticoagulation interference is problematic. Objective The objective of this study was to compare a new formulation dRVVT with two currently available dRVVTs. Materials and methods Life Diagnostics (LD) dRVVT and Stago PTT-LA were routinely used for lupus anticoagulant detection, plus Taipan snake venom time/ecarin time (TSVT/ET) for patients on warfarin or rivaroxaban. Siemens dRVVT and the new HYPHEN BioMed (HBM) dRVVT were tested with 193 patient samples. Group 1, 59 non-anticoagulated patients (NAPs) LA-positive in LD dRVVT; Group 2, 15 PTT-LA-positive/dRVVT-negative NAPs; Group 3, 24 LA-positive warfarinized patients; Group 4, 13 patients on rivaroxaban; Group 5, 62 LA-negative thrombotic NAPs; Group 6, 20 warfarinized, non-antiphospholipid syndrome patients. Results Accepting that the Life Diagnostics reagents were acting as a pseudo-gold standard, Siemens dRVVT detected 56/59, (95%) Group 1 LA and HBM dRVVT 46/59, (76%), one each from Group 2, and Siemens dRVVT detected one in Group 5. The lower HBM dRVVT detection rate mainly concerned weaker LA, where between-reagent concordance is problematic. All Group 3 patients appeared LA-positive in undiluted plasma with Siemens dRVVT, as did 16/24 (67%) with HBM dRVVT but the fewer LA-positives in mixing tests better mapped to clear LA-positives with LD dRVVT. LD and Siemens dRVVTs exhibited 87% and 95% false-positivity for Group 6 whilst HBM dRVVT had none. Increasing the cut-off improved accuracy. Applying higher cut-offs improved accuracy in Group 4 patients. Conclusion HBM dRVVT exhibited improved specificity, mainly due to less interference by anticoagulation, but reduced sensitivity, compared to the other dRVVTs employed.

Lupus anticoagulant mixing tests for multiple reagents are more sensitive if interpreted with a mixing test-specific cut-off than index of circulating anticoagulant

BACKGROUND

Lupus anticoagulant (LA) is classified in the antibody family that is recognized as antiphospholipid antibodies. Guidelines for LA detection recommend mixing test interpretation with either a mixing test specific cut-off (MTC) or index of circulating anticoagulant (ICA). We previously evidenced that MTC was superior to ICA in detecting the in vitro inhibition of LA with a single dilute APTT (activated partial thromboplastin time) and dRVVT (diluted Russell's viper venom time) pairing.

OBJECTIVES

The objective in the present study was to compare the LA diagnostic effectiveness of MTC and ICA by multiple APTT and dRVVT reagents.

METHODS

One hundred-five samples from non-anticoagulated patients positive for LA in the dilute APTT (dAPTT) and dRVVT reagent pairing employed for diagnostic examination were performed by undiluted and in a 1:1 mix with normal pooled plasma with four additional APTT reagents and another dRVVT reagent (dRVVT B).

RESULTS

Frequencies of MTC and ICA positivity were determined from samples LA positive in undiluted plasma. MTC positivity in mixing test were 63%, 77%, 80%, 84%, 46%, 81%, and 72% in 4 APTT, dAPTT and 2 dRVVT, respectively. ICA positivity were 47%, 67%, 58%, 54%, 42%, 47%, and 29%, respectively. There were no samples of ICA-positive/MTC-negative with any reagent.

CONCLUSIONS

The data indicate that MTC is superior to ICA for LA detection in mixing tests in multiple reagents and reagent types. Although mixing tests may make weak LA samples appear negative, the efficacy of LA detection can be improved by the method to interpret the results.

Antiphospholipid antibodies and non-thrombotic manifestations of systemic lupus erythematosus

Objectives The aim of this study was to investigate the association between antiphospholipid antibodies and non-thrombotic and non-gestational manifestations of systemic lupus erythematosus. Methods Systemic lupus erythematosus patients with persistently positive antiphospholipid antibodies or lupus anticoagulant were identified and grouped as systemic lupus erythematosus with antiphospholipid syndrome (SLE-APS), systemic lupus erythematosus with positive antiphospholipid antibodies/lupus anticoagulant without antiphospholipid syndrome (SLE-aPL), and systemic lupus erythematosus with negative aPLs (SLE-No aPL). Groups were compared in terms of non-thrombotic systemic lupus erythematosus manifestations and laboratory features retrospectively. Results A total of 150 systemic lupus erythematosus patients, 26 with SLE-APS, 25 with SLE-aPL, and 99 with SLE-No aPL, were identified. Livedo reticularis, neurologic involvement, and thrombocytopenia were more common in antiphospholipid antibody positive systemic lupus erythematosus cases. Malar rash, arthritis, and pleuritis were more common in the SLE-No aPL, SLE-APS, and SLE-aPL groups, respectively. Positivity rates and titers of specific antiphospholipid antibodies did not differ between the SLE-APS and SLE-aPL groups. Conclusions Presence of antiphospholipid syndrome or persistent antiphospholipid antibodies may be related to non-thrombotic and non-gestational systemic lupus erythematosus manifestations. Patients with systemic lupus erythematosus plus antiphospholipid syndrome and persistent antiphospholipid antibodies without antiphospholipid syndrome also differ in terms of systemic lupus erythematosus manifestations.