Presence Of Antiprothrombin Antibodies Research Articles

Lupus anticoagulant hypoprothrombinemia syndrome in Bence-Jones protein κ-type multiple myeloma patient with phosphatidylserine-dependent antiprothrombin antibody

Dear Editor, Approximately 2 % of multiple myeloma (MM) patients present with hemorrhage at diagnosis. However, hemorrhage due to abnormalities in the coagulation system is a rare complication [1, 2]. Although lupus anticoagulant (LA), which is infrequently reported to be in association with MM, is commonly a risk factor for arterial or venous thrombosis, bleeding tendencies in patients with LA are strongly related to a low prothrombin activity [3–6]. Acquired hypoprothrombinemia with LA, also called LA hypoprothrombinemia syndrome (LAHPS), is a rare disease which appears mostly in young females with systemic lupus erythematosus or in healthy children after viral infection and is usually associated with the presence of antiprothrombin antibodies [7]. We herein report the case of an 86-year-old male with Bence-Jones protein (BJP) κ-type MM who presented with hypoprothrombinemia and LA associated with antibodies directed to the phosphatidylserine–prothrombin complex (or phosphatidylserine-dependent antiprothrombin antibodies, aPS/PT). The patient was admitted with anemia and had no past history of bleeding disorders or thrombotic events. A urinalysis showed massive proteinuria (5.3 g/day), which was determined to be κ-type BJP using immunoelectrophoresis. Bone marrow aspiration showed proliferation of abnormal plasma cells. Computerized tomography showed hematomas in the bilateral gluteus maximus muscle and the supraclavicular area. Initial coagulation tests showed prolonged prothrombin time and activated partial thromboplastin time (aPTT) (Table 1). Reduced clotting activity of factors II (FII), VIII (FVIII), and IX (FIX) was noted in a pattern typical of that observed in previously reported cases of LAHPS [8, 9]. FVIII and FIX inhibitors were not detected. The prolonged aPTT with LA-sensitive aPTT reagent (PTT-LA Roche Diagnostics, Tokyo, Japan), which could not be corrected by mixing with normal plasma, suggested the presence of LA. The results were confirmed using the Staclot LA® assay, and the dilute Russell viper venom time test was used to confirm the presence of LA with the phospholipid-neutralizing LA test (Gradipore, Frenchs Forest, Australia). IgG/M anticardiolipin antibodies and IgG aPS/PT were negative, while strong positive IgM aPS/PT was detected, which was measured with ELISA using the phosphatidylserine–prothrombin complex as antigen immobilized on ELISA plates in the presence of CaCl2 [10]. Based on these findings, the patient was diagnosed as MM with LAHPS associated with aPS/PT and treated with melphalan and prednisolone (MP) therapy. The FII levels were observed to normalize after one cycle of MP therapy and the patient has remained in remission without any hemorrhage for 10 months. Table 1 Laboratory findings In our case, aPTT continued to be prolonged with reduced levels of FVIII and FIX in spite of normalizing the FII level after therapy. LA and IgM aPS/PT remained positive, although these values were improved, suggesting that the presence of LA might have an influence on coagulation tests after treatment. There are very rare reports showing the presence of aPS/PT in patients with LAHPS [9]. These reports describe the patients as having bleeding tendencies with mildly reduced FII levels, similar to that observed in our patient. However, in previously reported child cases of LAHPS, severe hemorrhage usually occurs when the FII levels are very low (under 10∼15 %). It is possible that other coagulation factors associated with aPS/PT in LAHPS might be present. A diagnosis of LAHPS should always be considered in MM patients with bleeding tendencies associated with LA, and aPS/PT detection should be performed in conjunction with LA tests.

Antiphosphatidylserine/Prothrombin Antibodies (aPS/PT) as Potential Markers of Antiphospholipid Syndrome

The antiphospholipid antibodies present in antiphospholipid syndrome (APS) are directed at a number of phospholipid-binding proteins: β2 glycoprotein I (β2GPI), prothrombin, and so on. Antibodies directed at β2GPI are accepted as a classification criterion for APS, while the presence of antiprothrombin antibodies is not. In the present article, we investigated the possible role of antiphosphatidylserine/prothrombin antibodies (aPS/PT) as marker of APS on a cohort of 295 individuals with APS (95 primary APS and 45 secondary APS) and APS-related diseases. We found aPS/PT to be highly associated with venous thrombosis (immunoglobulin G [IgG] aPS/PT odds ratio [OR], 7.44; 95% confidence interval [CI], 3.97-13.92 and IgM aPS/PT OR, 2.54; 95% CI, 1.35-4.77) and obstetric abnormalities (IgG aPS/PT OR, 2.37; 95% CI, 1.04-5.43), but not with arterial thrombosis. A very high degree of concordance between the concentration of aPS/PT and lupus anticoagulant activity was demonstrated. Therefore, we support the inclusion of aPS/PT determination as second-level assay to confirm APS classification.

The clinical significance of anti-prothrombin antibodies for risk assessment of thromboembolism in patients with lupus anticoagulant

IntroductionThromboembolism is a common manifestation of lupus anticoagulant (LA), however only a subgroup of LA-patients is affected by thrombosis. Study objective was to investigate whether anti-prothrombin antibodies can identify LA-patients at increased risk for thrombosis. Materials and MethodsIn total 79 patients, 50 with (42 men/8 women) and 29 without thrombosis (21 men/8 women), were investigated for their presence of anti-prothrombin IgG and IgM antibodies using assays from two different manufacturers (Aeskulisa=assay I, CoaChrom=assay II). ResultsThe prevalence of elevated levels of anti-prothrombin IgG, IgM as well as IgG and/or IgM antibodies was 66% [assayI] (36% [assayII]), 38% (24%) and 72% (50%) in patients with thrombosis and 55% (24%), 28% (28%) and 66% (41%) in patients without thrombosis, respectively. Neither anti-prothrombin IgG or IgM nor IgG and/or IgM antibodies were found to indicate an increased risk for thrombosis. In the subgroup of patients with arterial or venous thrombosis there was also no association between anti-prothrombin antibodies and thrombosis. The comparison of median levels of IgG and IgM anti-prothrombin antibodies between patients with and without thrombosis yielded a borderline statistically significant difference only for anti-prothrombin IgG antibodies by using assay II (p=0.033), all other comparisons were not statistically significant. ConclusionsIn conclusion, presence of anti-prothrombin antibodies was not associated with thromboembolism in LA-patients.

Antiphospholipid Syndrome With Anti-Prothrombin Autoantibodies in a Patient With an Axial-Flow Left Ventricular Assist Device

Autoantibodies to prothrombin, first described almost 50 years ago, are paradoxically associated with thrombosis. Described is an unusual case of fatal hypercoagulability in a patient with multiple arterial and venous thromboembolic complications despite intense anticoagulation while being bridged to transplantation with a left ventricular assist device. Serum analysis revealed the presence of prothrombin autoantibodies and high titers of anti-nuclear antibodies, and autopsy revealed pulmonary arteriolar vasculitis. These findings suggest an autoimmune basis for the presence of anti-prothrombin antibodies and the hypercoagulable state observed in the present case.

A study on associations between antiprothrombin antibodies, antiplasminogen antibodies and thrombosis

Anti-prothrombin antibodies are a frequent cause of lupus anticoagulant (LAC), a thrombotic risk factor. Prothrombin shares structural homology with plasminogen, a kringle protein with an important role in fibrinolysis. Cross-reactivity between antiprothrombin antibodies and plasminogen has been described. To study associations between LAC, IgG and IgM class antiprothrombin and antiplasminogen antibodies, plasminogen activity levels and thrombosis in selected patients with systemic autoimmune diseases. Patients included forty-six consecutive LAC-positive patients (29 with systemic lupus erythematosus (SLE); 33 with a thrombotic history), 38 patients without LAC (36 with SLE; seven with a history of thrombosis) and 40 healthy controls. In the total group of 84 patient samples, the prevalence of antiprothrombin and antiplasminogen antibodies was 30 and 38%, respectively. There was no significant relationship between the presence of these antibodies. In contrast to presence of antiplasminogen antibodies, presence of antiprothrombin antibodies was statistically significant related to thrombosis. Thirteen samples had antiprothrombin and antiplasminogen antibodies of similar isotype (IgG, n= 4; IgM, n= 9). Of these, all but one had LAC and 11/13 came from patients with a history of thrombosis. Simultaneous presence of IgM-class antiprothrombin and antiplasminogen antibodies had a significant association with thrombosis. Levels of plasminogen activity were similar in samples from healthy controls and patients (with or without antiplasminogen antibodies or thrombosis). Anti-prothrombin antibodies and antiplasminogen antibodies occur frequently in patients with systemic autoimmune disease. Anti-prothrombin antibodies, but not antiplasminogen antibodies are a risk factor for thrombosis. Anti-plasminogen are in most cases unrelated to antiprothrombin antibodies.

A Cross Sectional Study of Antiphospholipid-protein Antibodies in Patients with Venous Thromboembolism

To look for an association between venous thromboembolism (VTE) and antiphospholipid antibodies (aPL) in patients without Systemic Lupus Erythematosus (SLE) when implementing, beside conventional assays, new tests for aPL screening directed towards purified proteic targets. We conducted a cross-sectional, hospital-based study of consecutive unselected outpatients. We compared VTE+ patients to VTE- among 398 consecutive unselected outpatients referred for clinical suspicion of VTE. To detect aPL, the following ELISAs were performed: 1) a conventional standardized ELISA 2) an improved APA assay, 3) an anti-Beta2GPI ELISA, 4) an anti-Annexin V ELISA, 5) an anti-Prothrombin ELISA. We sought an association between VTE and aPL through a quantitative (t-test) and a qualitative comparison (chi-square test, according to the cut-off values set as the 95th percentile of aPL distribution). First we conducted an analysis of all patients. Then we stratified them into 2 subgroups, with or without a wellknown risk factor for VTE (prolonged immobilization >72h, surgery or trauma within the past three months, current malignancy). 61% of patients were classified as VTE-positive. Before stratification, we did not find any significant association between the VTE status and aPL. However, after stratification, in the subgroup without risk factors for VTE, the frequency of positive values as regards the anti Prothrombin antibodies detection was significantly higher in VTE+ patients (p = 0,04). The presence of anti Prothrombin antibodies might be an independent risk factor of VTE. However systematic screening for aPL in non SLE patients referred for VTE suspicion at the time of the thrombo-embolic event has little clinical relevance.

Pregnancy loss and autoantibodies against phospholipid-binding proteins

To evaluate the relationship between antibodies against beta 2-glycoprotein I or prothrombin and pregnancy losses in women with antiphospholipid antibodies. Women with antiphospholipid antibodies, (lupus anticoagulant and/or anticardiolipin antibodies), with (n = 41) and without (n = 61) a history of pregnancy loss were evaluated. Thirty-one out of the forty-one patients with pregnancy loss had early miscarriages (at less than 13 weeks) and ten patients had late miscarriages. Immunoglobulin (Ig)-G and IgM anti-beta 2-glycoprotein I and anti-prothrombin antibodies were measured by an enzyme-linked immunosorbent assay method. A significant association between pregnancy loss and positive IgM anti-beta 2-glycoprotein I antibodies was found (odds ratio 2.6; 95% confidence interval 1.03, 6.6; P = .043). Women with late pregnancy loss had higher levels of both IgG and IgM anti-beta 2-glycoprotein I antibodies compared with controls (P < .05). There was a good correlation between anticardiolipin and anti-beta 2-glycoprotein I antibodies levels (IgG: r = 0.75; IgM: r = 0.73). In contrast, there was no correlation between the levels of anticardiolipin or anti-beta2-glycoprotein I antibodies and the levels of anti-prothrombin antibodies. Furthermore, the presence of anti-prothrombin antibodies was not associated with a history of pregnancy loss. The result of our study shows that there is a relationship between the presence of IgM anti-beta 2-glycoprotein I and previous miscarriages in women with anti-phospholipid antibodies.