Is the determination of anti‐beta2 glycoprotein I antibodies useful in patients with venous thromboembolism without the antiphospholipid syndrome?

Anti-beta2-glycoprotein I (beta2GPI) antibodies are frequently found in patients with lupus anticoagulant (LA). To investigate the prevalence of antibeta2GPI antibodies and their clinical impact in patients with a history of venous thromboembolism (VTE) without LA/anticardiolipin antibodies (ACA), we studied 503 patients [128 (36.2%) men, median age 41 years (interquartile range, IQR 28-54 years)] with previous thrombosis. A group of 113 individuals without VTE [43 (38.1%) men, age 46.7 years (IQR 38-52 years)] served as a control group. Among 418 patients without LA/ACA, anti-beta2GPI-IgG levels were elevated in seven (1.7%), -IgM in 15 (3.6%) and -IgA in 14 (3.3%) cases; in 58 patients with ACA, anti-beta2GPI-IgG levels were elevated in two (3.4%), six (10.3%) and three (5.2%), and in 27 with LA, they were elevated in 18 (66.7%), 19 (70.4%) and 10 (37%) respectively. Thus, the prevalence of elevated anti-beta2GPI antibodies was not increased in patients without LA/ACA but was strongly associated with LA. Patients without ACA/LA who had a recurrent event did not have higher prevalence of elevated anti-beta2GPI-IgG, -IgM or -IgA antibodies than those without a recurrent event. Thus, elevated antibeta2GPI antibodies are not likely to be a predictor of recurrent events in patients without LA. We conclude that determination of anti-beta2GPI antibodies does not improve the clinical management of patients with a history of VTE without LA/ACA.     

The contribution of inherited and acquired thrombophilic defects, alone or combined with antiphospholipid antibodies, to venous and arterial thromboembolism in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is associated with an increased risk of venous (VTE) and arterial thromboembolism (ATE). Lupus anticoagulant (LA) and anticardiolipin antibodies (ACAs) are established risk factors. We assessed the contribution of deficiencies of antithrombin, protein C, total protein S, factor V Leiden, the prothrombin G20210A mutation and APC resistance, either alone or in various combinations with LA and/or ACAs, to the thrombotic risk in a cohort of 144 consecutive patients with SLE. Median follow-up was 12.7 years. VTE had occurred in 10% and ATE in 11% of patients. LA,ACAs, factor V Leiden, and the prothrombin mutation were identified as risk factors for VTE. Annual incidences of VTE were 2.01 (0.74-4.37) in patients with one of these disorders and 3.05 (0.63-8.93) in patients with 2 disorders. The risk of VTE was 20- and 30-fold higher, respectively, compared with the normal population. In contrast with LA and ACAs, thrombophilic disorders did not influence the risk of ATE. In conclusion, factor V Leiden and the prothrombin mutation contribute to the risk of VTE in patients with SLE, and potentiate this risk when one of these thrombophilic defects are combined with LA and/or ACAs.     

Detection of lupus anticoagulant identifies patients with autoimmune haemolytic anaemia at increased risk for venous thromboembolism

Venous thromboembolism (VTE) is a well-recognized complication of autoimmune haemolytic anaemia (AIHA), and is a major cause of morbidity and mortality in this disorder. However, the incidence, pathogenesis and risk-factors for VTE in AIHA remain poorly defined. Lupus anticoagulants (LA) and anticardiolipin (ACA) antibodies are autoantibodies directed against epitopes on prothrombin or beta2 glycoprotein I (beta2-GPI). Both LA and ACA (together called antiphospholipid antibodies, APLA) are associated with VTE. We have prospectively studied the occurrence of VTE and APLA in 30 patients with AIHA. VTE was objectively documented in eight (27%) patients. APLA were detected in 19 (63%) patients with AIHA, of whom nine (30%) had a LA and 17 (57%) ACA. Seven patients had both LA and ACA. Among the eight patients with VTE, LA was detected in five (63%) and ACA in four (50%). There was a statistically significant association between presence of LA and occurrence of VTE (RR: 7.50, 95% CI: 1.25-45.2, P = 0.03). VTE is a frequent and life-threatening complication of AIHA. Detection of the lupus anticoagulant in patients with AIHA identifies individuals at significantly increased risk for VTE. Future studies should address the role of prophylactic anticoagulation in patients with AIHA.     

Antiphospholipid antibodies and venous thromboembolism

The clinical relevance of antiphospholipid antibodies (APLA) in patients without systemic lupus erythematosus who have venous thromboembolism (VTE) in unknown. Limited evidence suggests that there is an association between the presence of APLA and both initial and recurrent episodes of VTE and that patients with APLA and VTE are resistant to warfarin therapy. Unselected patients with a first episode of clinically suspected deep vein thrombosis or pulmonary embolism were evaluated with objective tests for VTE and with laboratory tests for APLA; the latter included tests for the lupus anticoagulant (LA) and anticardiolipin antibodies (ACLA). Patients with VTE were treated with anticoagulant therapy and observed during and after discontinuation of anticoagulants for symptomatic recurrence of VTE. There was a strong association between LA and VTE (odds ratio, 9.4; 95% confidence interval [CI], 2.1 to 46.2) and 9 to 65 (14%; 95% CI, 7% to 25%) patients with VTE had LA. There was no association between the presence of ACLA and VTE (odds ratio, 0.7; 95%CI, 0.3 to 1.7) because of the high frequency of positive ACLA assays in patients without VTE. None of the 16 patients with VTE and APLA developed recurrent VTE while receiving warfarin therapy. There was no difference in rates of recurrent VTE in patients with or without APLA after anticoagulant therapy was discontinued. The strong association between LA and VTE suggests that testing for LA in patients with VTE is useful. The measurement of ACLA in patients with VTE has no clinical usefulness because the results are abnormal in a high proportion of patients without VTE. Although the presence of APLA in patients with VTE was not associated with resistance to a conventional intensity of warfarin or an increased risk of recurrent VTE after discontinuation of warfarin, a larger study should address these issues in a subgroup of patients with VTE and LA.     

A Study of Anti Beta-2 Glycoprotein I and Anti-Prothrombin Antibodies in Patients with Unexplained Recurrent Pregnancy Losses

To compare the levels of IgG and IgM anti beta-2 glycoprotein I antibodies and IgG and IgM anti prothrombin antibodies among women with unexplained recurrent pregnancy losses and women with at least 2 live issues. To compare the prevalence of newer anti beta-2 glycoprotein I & anti prothrombin antibodies with conventional Lupus anticoagulant & anticardiolipin antibodies. 50 women with recurrent pregnancy losses & 50 matched controls were evaluated for the presence of: Lupus anticoagulant—screened by LA sensitive aPTT& DRVV and confirmatory Staclot Assay. ELISA kits were used for detecting IgG & IgM anticardiolipin, anti beta-2 glycoprotein I & anti prothrombin antibodies. 11/50 (22 %) women in study group and none in control group had circulating antiphospholipid antibodies. 2 cases (4 %) had lupus anticoagulant. 1 case (2 %) had anticardiolipin antibody & 6 cases (12 %) were positive for anti beta-2 Glycoprotein I antibody (p value = 0.027). 3 cases (6 %) had anti prothrombin antibody. All were mutually exclusive except for one. Women with recurrent pregnancy losses should be tested for anti beta-2 Glycoprotein I antibodies & anti prothrombin antibodies in addition to conventional lupus anticoagulant and anticardiolipin antibodies. This approach can decrease the incidence of SNAP (seronegative antiphospholipid syndrome) cases while establishing the true prevalence of antiphospholipid syndrome.     

Anti β2 glycoprotein I antibodies: detection and association with thrombosis

Summary. It has been demonstrated that antiphospholipid antibodies (aPL) recognize epitopes formed by anionic phospholipids and protein cofactors. β₂ glycoprotein I (β₂GPI) is accepted as the cofactor of anticardiolipin antibodies (aCL). In the present study we explored the presence and clinical associations of anti β₂GPI antibodies of IgG isotype (aβ₂GPI-IgG), measured by ELISA. We studied sera from 169 patients with aCL and/or lupus anticoagulant (LA), including 52 patients with systemic lupus erythematosus and 49 with primary antiphospholipid syndrome (PAPS). We found 31.9% positive sera for aβGPI-IgG in the whole population and 48.6% in the aCL-IgG(+) group. There was a good correlation between the titre of aCL-IgG and the optical density for aβGPI-IgG ( r = 0.69, P <0.01). The presence of aβ₂GPI-IgG was associated with the presence of aCL-IgG ( P <0.0001) and LA ( P <0.0005). However, none of 23 LA (+) patients without aCL had aβ₂GPI-IgG.
We found a statistically significant association between the presence of aβ₂GPI-IgG and a history of venous thromboembolism (VTE) in our patients ( P <0.005). This association was observed in PAPS ( P <0.05) but not in secondary antiphospholipid syndrome (SAPS).
Our study confirms that some aPL(+) sera react with β₂GPI in special experimental conditions. In addition, the presence of these antibodies is associated with a history of VTE.     

ANTIPHOSPHOLIPID ANTIBODIES IN PAEDIATRIC SYSTEMIC LUPUS ERYTHEMATOSUS, JUVENILE CHRONIC ARTHRITIS AND OVERLAP SYNDROMES: SLE PATIENTS WITH BOTH LUPUS ANTICOAGULANT AND HIGH-TITRE ANTICARDIOLIPIN ANTIBODIES ARE AT RISK FOR CLINICAL MANIFESTATIONS RELATED TO THE ANTIPHOSPHOLIPID SYNDROME

Antiphospholipid antibodies (APA) are often associated withsevere clinical manifestations, especially in the setting ofsystemic lupus erythematosus (SLE). Here we have investigatedthe prevalence of anticardiolipin antibodies (aCL) and lupusanticoagulant (LA) in paediatric patients affected with SLE,JCA and overlap syndromes (OS) and correlated the presence ofaCL and LA with clinical features. aCL were assayed by enzyme-limitedimmunoassay; LA was determined by activated partial thromboplastintime and the kaolin clotting time test. aCL and LA assays wereperformed in parallel on at least two occasions over a 7–30-monthfollow-up. Fifteen out of nineteen (79%) SLE patients had aCLand 8/19 (42%) had LA. Six SLE patients displayed manifestationsthat were APA-related: deep venous thromboses, autoimmune haemolyticanaemia, pulmonary hypertension, neurological alterations. Fiveout of six symptomatic patients had both LA and high-titre aCL.In contrast, JCA and OS patients had usually low-titre aCL,no detectable LA and no APA-related manifestations. aCL persistedat high titre over time in SLE patients, but was only transientlydetected in JCA and OS patients. This study shows that the simultaneouspositivity for LA and high-titre aCL allows the identificationof paediatric SLE patients who are at risk not only for thrombosis,but also for other APA-related clinical features. KEY WORDS: Anticardiolipin antibodies, Lupus anticoagulant, Childhood systemic lupus erythematosus, Juvenile chronic arthritis, Overlap syndromes     

Anti-prothrombin antibodies combined with lupus anti-coagulant activity is an essential risk factor for venous thromboembolism in patients with systemic lupus erythematosus

Anti-prothrombin antibodies (anti-prothrombin) and anti-beta2-glycoprotein I antibodies (anti-beta2-GP I) are the most common and characterized anti-phospholipid antibodies (aPL) detected using specific enzyme-linked immunosorbent assay (ELISA) systems. Recently, lupus anti-coagulant (LA) activity detected by a phospholipid-dependent coagulation assay was reported to be associated with anti-prothrombin and/or anti-beta2-GP I. Here we show that the co-existence of IgG anti-prothrombin and LA activity might be an essential risk factor for venous thromboembolism (VTE) in patients with systemic lupus erythematosus (SLE). We examined not only the levels of antibodies to prothrombin and anti-beta2-GP I (both IgG and IgM isotypes) using an ELISA system, but also LA activity detected using both diluted Russell's viper venom time (dRVVT) and STACLOT LA test in 124 patients with SLE. The SLE patients were divided into four groups according to the results of ELISA and LA assay results for each aPL: group A, ELISA+ and LA+ group B, ELISA+ and LA-; group C, ELISA- and LA+ group D, ELISA- and LA-. Regarding IgG anti-prothrombin, the prevalence of VTE was significantly higher in group A (16/35 cases, 45.7%, P < 0.001, Fisher's exact probability test) than in the other groups (B, 2/30, 6.7%; C, 1/22, 4.5%; D, 1/37, 2.7%). With respect to IgM anti-prothrombin and IgG or IgM anti-beta2-GP I, the prevalence of VTE was higher in both groups A and C than in group D, but no statistical difference in prevalence was found between groups A and C. Multivariate logistic regression analysis of risk factors for VTE confirmed that the co-existence of IgG anti-prothrombin and LA activity was the only significant risk factor for VTE (odds ratio, 19.13; 95% confidence intervals, 4.74-77.18).     

Pathogenetic factors underlying juvenile deep vein thrombosis (DVT) in Indians.

The role of hereditary antithrombotic protein defects in juvenile deep vein thrombosis (DVT) was evaluated. Fifty six young patients (age <45 yr) with doppler-proven DVT were investigated for the presence of resistance to activated protein C (APC-R), lupus anticoagulant (LA), anticardiolipin antibodies and deficiencies of protein C, protein S, ATIII activities. Fifty nine normal healthy individuals served as controls. APC-R was observed to be the commonest defect underlying the Indian DVT as seen in 39.2% of patients followed by elevated ACA (5.3%), PAI (2.8%), presence of LA (2.8%) and reduced ATIII levels (2.8%). None of the subjects had protein C or S deficiency. APC-R was associated with ATIII deficiency in one case, and elevated ACA in two cases. In two subjects, APC-R was associated with elevated PAI levels. Patients with more than one prothrombotic factor had a higher prevalence of pulmonary thromboembolism, suggesting that the thrombogenic potential of APC-R is enhanced by the presence of coexisting hereditary or acquired prothrombotic defect.     

Clinical spectrum of males with primary antiphospholipid syndrome and systemic lupus erythematosus: a comparative study of 73 patients

The objective of this study was to compare the clinical findings, laboratory data, functional outcome and chronic damage in male patients with primary antiphospholipid syndrome (PAPS) and systemic lupus erythematosus (SLE). We studied 29 male patients with PAPS and 44 with SLE. Clinical findings, laboratory data, lupus damage index (SLICC/ACR DI), and functional outcome in PAPS, were analysed in each group. The mean age at diagnosis was 29.8 +/- 10.4 years in patients with PAPS and 26 +/- 10.1 years in SLE patients. The duration of disease was 4.5 +/- 2.6 versus 5.2 +/- 3.8 years in patients with PAPS and SLE, respectively (P = NS). In patients with PAPS the most frequent clinical manifestations were venous thrombosis, thrombocytopenia, and pulmonary thromboembolism. Patients with SLE had joint, skin and renal involvement more frequently than those with PAPS (P = 0.0001). All PAPS patients had anticardiolipin antibodies (aCL), and 14 patients (48%) had lupus anticoagulant (LA). All SLE patients had antinuclear antibodies (ANAs). Anti-dsDNA antibodies were positive in 39% of SLE patients. Five patients died: one with 'catastrophic' APS and four with SLE. SLICC/ACR-DI score in SLE patients was 1.9 (SD = 1). In PAPS patients poor functional outcome was due to myocardial infarction, pulmonary thromboembolism, stroke and mesenteric thrombosis. Lupus nephritis was the principal organ damage in SLE. In conclusion, in male patients with PAPS and SLE, the clinical manifestations were significantly different. Arterial thrombosis was the major cause of functional impairment and permanent organ damage in PAPS. Renal involvement was the major cause of chronic damage in SLE.     

Inhibition of annexin V binding to cardiolipin and thrombin generation in an unselected population with venous thrombosis

OBJECTIVE: To examine the effect on annexin V binding to cardiolipin (CL) and in vitro thrombin generation by plasma samples from an unselected population of patients with confirmed venous thrombosis and matched controls. The prevalence of autoimmune antiphospholipid antibodies (aPL) was also determined. METHODS: A total of 111 patients who presented to a single emergency room with symptoms suggestive of venous thromboembolic (VTE) disease were studied. In 34 patients the diagnosis of lower limb deep venous thrombosis (DVT) and/or pulmonary embolus (PE) was confirmed (VTE+ group). In the remaining 77 patients the diagnostic workup was negative (VTE- group). Plasma samples were collected prior to the initiation of anticoagulation and examined for IgG anticardiolipin (aCL), IgG anti-beta2-glycoprotein I (GPI), and IgG anti-prothrombin (aPT antibodies) by ELISA. In addition, the effect of individual patient and control plasma samples on annexin V binding to CL and on in vitro thrombin generation was determined by a competitive ELISA and a chromogenic assay, respectively. RESULTS: The prevalence and levels of IgG aCL, anti-beta2-GPI, and aPT antibodies were similar in the VTE+ and VTE- groups. However, plasma samples from the VTE+ group caused a significant inhibition of in vitro thrombin generation (mean +/- SD Z score: -0.66 +/- 0.97 vs 0.26 +/- 1.46; p < 0.001) and a concurrent but less impressive inhibition of annexin V binding to CL (mean +/- SD Z score: -2.53 +/- 1.44 vs -2.05 +/- 1.61; p = 0.123). Upon analyzing a panel of clinical and laboratory variables, only age and inhibition of thrombin generation were significantly associated with VTE disease. CONCLUSION: Our findings suggest that subtle abnormalities in annexin V physiology may contribute to the procoagulant state in patients with idiopathic venous thrombosis.     

Prevalence of inherited thrombophilia in young thrombosis patients from the East Bohemian region.

Venous thromboembolism is a multifactorial disease that is defined by multiple interactions between genetic and environmental components. Inherited thrombophilia may result in a hypercoagulable state that causes an increased tendency to thrombosis. We assessed the prevalence of factor V Leiden, factor II 20210A, antithrombin III, protein C and protein S deficiency, and the presence of antiphospholipid syndrome among 325 thrombosis patients from the East Bohemian region with a first episode of thrombosis under the age of 45 years. The average age of the first thrombotic event was 34 years (age range, 14-45 years). These data are not known yet from this part of the Czech Republic. Factor V Leiden was found in 40%, factor II 20210A in 6%, antithrombin III deficiency in 4%, protein C deficiency in 6%, and protein S deficiency in 11% in this cohort. Lupus anticoagulant was detected in 8% and anticardiolipin antibodies in 6%. Our results confirm the usefulness of thrombophilia work-up in patients with venous thrombosis before the age of 45 years in our region. The diagnosis of inherited thrombophilia is important for further management of these patients.     

Anticardiolipin antibodies in acute myeloid leukemia: Prevalence and clinical significance

This prospective study was designed to explore the prevalence and the clinical and prognostic significance of anticardiolipin (ACL) antibodies in patients with acute myeloid leukemia (AML). The study includes 37 consecutive AML patients >15 years old without previous history of thromboembolism, recurrent fetal loss, or autoimmune disease and with no evidence of infection at the time of enrollment. ACL antibodies were found in 25 patients (68%). None of the patients had high positive titers; 8 had moderately positive while 17 had low positive ACL antibody titers. ACL antibody positivity did not predict response to chemotherapy and was not correlated with age, gender, FAB class, platelet and white blood cell counts at presentation, and the risk of thromboembolism. ACL antibody titers did correlate, however, with AML activity in the majority of patients (93%) during 4–19 months of follow up. These results demonstrate a high prevalence of ACL antibodies in AML patients and suggest that serum ACL antibodies may be a useful adjunct in predicting relapse and documenting disease activity and therapy response. Am. J. Hematol. 57:139–143, 1998. © 1998 Wiley-Liss, Inc.     

Prevalence of antiphospholipid antibodies is not different in Chilean diabetic patients and normal individuals

Diabetes mellitus (DM) is complicated by vascular and neurological events. Antiphospholipid (aPL) antibodies have already been associated with many clinical conditions, including venous and arterial thrombosis, as well as recurrent fetal loss. However, a significant association between aPL antibodies and DM has not been widely reported yet. In the present study, we investigated the prevalence of aPL antibodies in diabetic patients. This study included 100 Chilean diabetic patients (67 of them with some complications and 33 without complications; 28 with Type 1 and 72 with Type 2 DM) and 100 healthy blood donor controls. Each sample was analyzed for IgG, IgM and IgA anticardiolipin (aCL), anti-beta(2) glycoprotein I (anti-beta(2)GPI), antiprothrombin (aPT) antibodies, and lupus anticoagulant (LA). Fourteen out of 100 (14%) diabetic patients presented some type of aPL antibodies. Four patients were positive for aCL antibodies, two for anti-beta(2)GPI antibodies, and nine for aPT antibodies. All patients were LA negative. The incidence of different isotypes was similar in each of the aPL antibodies studied, and their activities were low. No significant correlation was observed between aPL antibodies and vascular complications.     

Clinical analysis of 125 patients with the lupus anticoagulant

:A retrospective analysis of 125 consecutive lupus anticoagulant (LA) positive patients and 125 age, sex matched lupus anticoagulant negative controls is reported with the aims of defining further the clinical spectrum of disease, determining at-risk subgroups and management strategies. There was no significant difference in the incidence or pattern of complications in those with systemic lupus erythematosus (SLE) and related disorders, and those without SLE. Venous thromboembolism, immune thrombocytopenia, foetal loss, depression and hypertension were statistically more common in the LA group than in the control group. In contrast to previous reports, children aged ten years or less with the LA developed significantly more complications than controls. Patients with the LA secondary to drugs also developed complications, a finding which is also at variance with previous reports. There was a significant difference in the outcome of arterial disease (p < 0.04) and venous thromboembolism ( p < 0.001) when long term anticoagulation was part of the treatment regimen. (Aust NZ J Med 1993; 23: 151–156.)     

Prospective study of fluctuations of lupus anticoagulant activity and anticardiolipin antibody titre in patients with systemic lupus erythematosus.

Fluctuations of lupus anticoagulant activity and anticardiolipin antibody titres were studied in 53 patients with systemic lupus erythematosus (SLE). The median study time was 26 months with a median number of 12 samples. Lupus anticoagulant was measured by the kaolin clotting time (KCT) and dilute Russell viper venom time (dRVVT) assays; anticardiolipin antibodies were assayed by an enzyme linked immunosorbent assay (ELISA). Normal and increased KCTs or dRVVTs were seen during follow up in 13 and 12 patients, respectively. IgG anticardiolipin antibodies changed from negative to positive or positive to negative in 26 patients and IgM anticardiolipin antibodies in 16 patients. Disease activity and treatment with prednisone could account for these fluctuations in the kaolin clotting time (KCT) in 7 of 13 patients and in the dRVVT in 2 of 12 patients. Whole group analysis showed that the KCT, dRVVT, and IgM anticardiolipin antibodies were not associated with disease activity, in contrast with IgG anticardiolipin antibodies. During treatment with prednisone normal KCT and dRVVT results were obtained more easily than normal anticardiolipin antibody levels. It is recommended that lupus patients should not be classified as antiphospholipid antibody positive or negative on the basis of only one sample.     

LUPUS ANTICOAGULANT AS A PROGNOSTIC MARKER IN SYSTEMIC LUPUS ERYTHEMATOSUS

To evaluate the prognostic significance of lupus anticoagulant(LA), 37 SLE patients with LA and 37 age- and sex-matched SLEpatients without LA were followed up for a median of 22 years,of which 16 years (median) after the initial LA-testing. Deepvenous thrombosis was observed in 20 (54%) patients with LA.Of these patients, 90% had the first episode within 8 yearsafter the onset of SLE symptoms, as compared to only one ofthe six LA-negative patients with deep venous thrombosis (P0.0001). Cerebral artery occlusions were more common in patientswith LA (P 0.016), but typically appeared as a late phenomenon.Nephritis or neuropsychiatric manifestations, previously associatedwith a poor outcome in SLE, did not correlate with the presenceof LA. However, higher mortality was associated with both LA(P 0.021) and a history of deep venous thrombosis (P 0.004),as well as with nephritis (P 0.038). The most common cause ofdeath in both LA positives and negatives was vascular occlusion. In conclusion, it appears that the first episode of deep venousthrombosis in patients with LA is typically seen early in thecourse of disease, and that LA and a history of deep venousthrombosis are both associated with increased mortality. KEY WORDS: Antiphospholipid antibodies, Lupus anticoagulant, Lupus erythematosus, Survival, Thrombocytopenia, Thrombosis     

Lack of association between the C677T mutation in the 5,10-methylenetetrahydrofolate reductase gene and venous thromboembolism in Northwestern Greece.

BACKGROUND: Hyperhomocysteinemia has been associated with venous thrombosis. Under known and unknown conditions the C677T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene is accompanied by elevated levels of homocysteine. However, the relationship of this mutation with venous thromboembolism (VTE) remains controversial. The purpose of this study was to evaluate the association of the MTHFR mutation with VTE. METHODS: The presence of the C677T mutation in the MTHFR gene was investigated in a population of 176 consecutive patients with a history of venous thromboembolism and in a control group of 300 healthy subjects, using DNA analysis. RESULTS: The prevalence of homozygosity in the patient group was 13.6% and in healthy subjects 10%. The odds ratio for venous thromboembolism in the presence of the homozygous genotype (677TT) was 1.4 (95% confidence interval (C.I.), 0.8 to 2.5), which was not statistically significant. CONCLUSIONS: Homozygosity for the T677 allele of the MTHFR gene, although slightly more prevalent in patients compared to controls, has not been found in association with venous thromboembolism.     

Association of antiphospholipid antibodies with retinal vascular disease in systemic lupus erythematosus.

OBJECTIVES: To study the prevalence and characteristics of retinal vascular disease in patients with systemic lupus erythematosus (SLE) and to analyze their relationship with antiphospholipid antibodies (aPL) and other serological markers. PATIENTS AND METHODS: Eighty-two consecutive patients (77 women and 5 men; mean age, 36 years) were studied. All patients fulfilled the 1982 revised criteria of the American College of Rheumatology for the classification of SLE. Ophthalmologic examination included assessment of best corrected visual acuity, tonometry, slit-lamp biomicroscopy, and fundus examination. Serologic studies included determination of anticardiolipin antibodies (aCL) (ELISA), lupus anticoagulant (LA) (coagulation tests), antinuclear antibodies (indirect immunofluorescence), anti-DNA (Farr's test), and anti-ENA antibodies (counterimmunoelectrophoresis). RESULTS: Retinal vascular disease was detected in 13 (15%) of 82 SLE patients. The retinal lesions consisted of retinal vascular occlusions in six patients (five arterial and one venous), cotton-wool spots in three, optic disc edema in three, retinal hemorrhages in three, and ischemic optic neuropathy in one. Antiphospholipid antibodies were detected in 10 (77%) of these 13 patients: nine had aCL and two had the LA. When compared with patients without retinal vascular disease, patients with retinopathy had a higher prevalence of aPL (77% v. 29%, P = .005). CONCLUSIONS: Retinal vascular disease is frequent in patients with SLE. The presence of aPL is associated with a higher prevalence of retinal abnormalities in SLE patients.     

The activated seven lupus anticoagulant assay detects clinically significant antibodies.

Lupus anticoagulants are a heterogeneous group of autoantibodies detected by their effects on phospholipid-dependent coagulation assays. Persistent lupus anticoagulants are associated with thrombotic disease, but not all are clinically significant. Antibody heterogeneity and reagent and test variability dictate that at least 2 tests, of different types, should be used to screen lupus anticoagulants. The objective of this study was to investigate whether the activated seven lupus anticoagulant assay detects clinically significant antibodies. Eighty-two patients with antiphospholipid syndrome (APS) and 32 with systemic lupus erythematosus + positive for activated seven lupus anticoagulant and who were without thrombosis, who were positive by activated seven lupus anticoagulant assay, were investigated for lupus anticoagulants by dilute Russell's viper venom time, dilute activated partial thromboplastin time, and Taipan snake venom time, and for anticardiolipin antibodies. Fifty-seven of the APS patients were positive for lupus anticoagulants in multiple assays, 25 in activated seven lupus anticoagulant alone. Fourteen of the latter group were previously positive in other antiphospholipid antibodies assays, and 11 had only been positive for lupus anticoagulants by activated seven lupus anticoagulant. Twenty-eight had elevated anticardiolipin antibodies, 6 of whom were from the group that was positive in activated seven lupus anticoagulant only. Eight of the systemic lupus erythematosus + lupus anticoagulants (without thrombosis) patients were positive for lupus anticoagulant by activated seven lupus anticoagulant alone and had only been positive in activated seven lupus anticoagulant previously, and none had elevated anticardiolipin antibodies. The remaining 24 patients were lupus-anticoagulant positive in multiple assays, and 9 had elevated anticardiolipin antibodies. Dilute Russell's viper venom time and Dilute activated partial thromboplastin time are widely used to detect lupus anticoagulants and are considered to detect clinically significant antibodies. Activated seven lupus anticoagulant detected antibodies in APS patients who were positive by these assays and also lupus anticoagulants undetectable by the dilute Russell's viper venom time/dilute activated partial thromboplastin time reagents used, demonstrating its utility as a first-line or second-line assay.