Thrombophilic risk factors and peripheral arterial disease severity.

Few data are available on thrombophilic risk factors and progression of atherosclerotic peripheral arterial disease (PAD). Thrombophilic alterations can be an aggravating factor when arterial stenoses are present. In a cross-sectional study, we evaluated the presence of the thrombophilic factors fibrinogen, homocysteine, factor (F)VIII, lupus anticoagulant (LAC), FII G20210A, and FV R506Q mutations in 181 patients with PAD at Fontaine's stage II (claudication), in 110 patients with critical limb ischaemia (CLI), and in 210 controls. Fibrinogen was higher in patients with CLI vs. those with claudication and controls (427.9 +/- 10.5 vs. 373.1 +/- 5.2 vs. 348.9 +/- 7.0 p=0.001, respectively). Homocysteine and FVIII were higher in patients with PAD than in controls, but were similar in patients with CLI and claudication. The prevalence of LAC increased in patients with CLI vs. those with claudication and controls (21.4% vs. 7.8% vs. 5.2% p<0.001, respectively). The prevalence of FII 20210A allele was higher in patients with CLI vs. those with claudication and controls. Using a logistic model, FII G20210A mutation (odds ratio [OR] 19.8, confidence interval [CI] 4.5-87.1, p=0.001), LAC (OR 2.7, CI1.1-6.5, p=0.032), and fibrinogen (OR 1.01, CI 1.00-1.01, p=0.001) were associated with CLI, whereas homocysteine, FVIII, and FV R506Q mutation were not. CLI risk increased according to the number of thrombophilic alterations. In conclusion, altered levels of some important thrombophilic risk factors are independently associated with PAD severity. These data suggest that the presence of two or more thrombophilic risk factors raise the likelihood of PAD being more severe, justifying the need for larger longitudinal studies.

Emerging technologies and quality assurance in hemostasis: a review of findings from the Royal College of Pathologists of Australasia Quality Assurance Program.

Regular multilaboratory surveys of laboratories by the Royal College of Pathologists of Australasia Quality Assurance Program (QAP) have been conducted to assess proficiency in tests of hemostasis for the last 40 years. This article focuses primarily on specialized assays of hemostasis, for which surveys have been conducted for some 10 years. For von Willebrand disease (vWD) evaluations, a total of 47 plasma samples have been dispatched to survey participants, including representative samples from normal individuals plus all of the major vWD subtypes (i.e., types 1, 2A, 2B, 2M, 2N, and 3). These surveys have focused partly on the issue of diagnostic interpretive error rates associated with different assays and test panels. In this context, considerable improvement is seen when laboratories incorporate the vWF:collagen-binding assay into the test panel. Thrombophilia-associated tests assessed by the program and discussed in this review include activated protein c resistance, lupus anticoagulant, and deficiencies of protein C, protein S, and antithrombin. Other tests briefly reviewed here include factor assays and inhibitors, D-dimer, and heparin/anti-Xa assays. Anticardiolipin antibody and anti-beta(2)-glycoprotein I antibody (aB(2)GPI) testing, assessed by the Immunology QAP, is also reviewed briefly, as are genetic tests associated with thrombophilic markers such as factor V Leiden and the prothrombin gene.

Standardization, regulation, quality assurance and emerging technologies in hemostasis: issues, controversies, benefits, and limitations.

There are many benefits to the overall process of standardization for tests of hemostasis and thrombosis. Nevertheless, it should also be recognized there are several specific problems and limitations to this process, as highlighted in this review. Some of the issues are formidable, but it is hoped that they are not insurmountable. Sometimes, clinical pressures drive diagnostic test processes before they are formally proven to be of clinical value. Such clinical pressures drive diagnostic changes in the hemostasis laboratory, including the incorporation of new and emerging technologies, which in turn drives the need for evolving and effective external quality assurance. Incorporated into the diagnostic or test-performance process are a large number of organizations involved in driving standardization, with the ultimate intention of improving diagnostics, but this process will also have unintended potential for adverse outcomes. Although this review notes many of the benefits to the process, it focuses primarily on those negative factors that are often less obvious but still require attention and process review.

Elevated activated partial thromboplastin time during administration of first-generation adenoviral vectors for gene therapy for prostate cancer: identification of lupus anticoagulants.

OBJECTIVES: To evaluate the cause and significance of elevated activated partial thromboplastin time (aPTT) in a group of patients who received a first-generation adenoviral vector (Ad-OC-TK) delivering a toxic gene to prostate cancer cells as part of a Phase I clinical trial at the University of Virginia. METHODS: Eleven subjects were injected intratumorally to metastatic lesions of prostate cancer in the prostatic fossa, retroperitoneal lymph nodes, or bone (iliac, ischium, or vertebrae). After the initial laboratory evaluation, patients with elevated aPTT underwent a series of additional tests, including mixing studies, coagulation factor, prekallikrein, and high-molecular-weight kininogen, and lupus anticoagulant studies (modified Russell viper venom time) with phospholipid correction, and a Staclot LA assay. RESULTS: Of the 11 subjects who were enrolled in the trial, 6 had elevated aPTT values. Of the 6 patients, 3 had aPTT elevation of more than 10 seconds above normal. Two of the subjects with higher values demonstrated an inhibitory pattern with the factor VIII and XI assays, and the lupus anticoagulant studies were positive. No clinical sequelae to the elevated aPTT values were observed. CONCLUSIONS: This is, to our knowledge, the first formal report of a first-generation adenoviral vector causing a slight transient elevation of the aPTT through the induction of an antiphospholipid antibody. No clinical sequelae related to elevated aPTT values were observed. The adenoviral protocol was safe; similar protocols should be aware of this phenomenon.

Anti-phospholipid antibodies following vaccination with recombinant hepatitis B vaccine.

This study was undertaken to evaluate the possible role of hepatitis B recombinant vaccine inducing the synthesis of IgG and IgM anti-cardiolipin antibodies (aCL), antibodies against beta(2)GPI (anti-beta(2)GPI), lupus anti-coagulant (LA), anti-nuclear antibodies and antibodies against extractable nuclear antigens (anti-ENA). The study population consisted of 85 healthy students (63 female, 22 male; mean age 20.8 years), vaccinated with three doses of recombinant DNA hepatitis B vaccine. One month after vaccination with the first dose of hepatitis B vaccine a minority of vaccinated individuals showed changes in IgG or IgM aCL or anti-beta(2)GPI or LA activity (P < 0.001). Among subjects in whom changes of IgG anti-beta(2)GPI were observed, a significantly higher number of increased (8/85) than decreased (2/85) values were found (P < 0.01). Analyses of paired data showed that differences in aCL or anti-beta(2)GPI levels before vaccination or 1 month later did not reach statistical significance. In two people aCL transitorily reached medium positivity after the first dose of hepatitis B vaccine with a drop 5 months later. Similar evident anti-beta(2)GPI fluctuation was also observed in one person. Another participant was initially low positive for IgG anti-beta2GPI and the levels were increasing after vaccination. Two participants became positive for anti-nuclear antibodies during 6 months' follow-up. There were no sex-dependent differences in tested antibodies observed and no associations between levels of aPL and levels of anti-HBV antibodies. We conclude that HBV can induce aPL, although rarely. In genetically susceptible individuals or together with some other triggers such combination might confer the risk of developing a continuous autoimmune response in an individual.

Cardiovascular and thrombophilic risk factors for idiopathic sudden sensorineural hearing loss.

BACKGROUND: In recent years there has been a significant increase in the diagnosis of sudden sensorineural hearing loss (SSHL) in western, countries with an incidence of 20 of 100,000 people affected every year. No clear causes for this disease have been found thus far, but cochlear ischemia has been hypothesized in patients in whom an infectious episode or acoustic neurinoma have been excluded. OBJECTIVES: The aim of this case-control study was to investigate a number of acquired and inherited thrombophilic risk factors [antithrombin, protein C and S; factor V (FV) Leiden, FII polymorphism; lupus anticoagulant (LA); anticardiolipin (aCL) antibodies; fasting homocysteine (Hcy); lipoprotein(a) (Lp(a)); plasminogen activator inhibitor-1 (PAI-1)] in addition to cardiovascular risk factors in patients with idiopathic SSHL (ISSHL). PATIENTS AND METHODS: We investigated 155 patients (67 male/88 female; age: 55 (range 19-79 years) with a diagnosis of ISSHL within 30 days from the onset of symptoms, and 155 controls (67 male/88 female; age 54 (range 19-78 years). Fasting Hcy levels were significantly higher in patients than in controls [11.6 (6.7-60) micromol/L vs. 8.7 (5.0-24) micromol/L] as well as PAI-1 levels [19 (2-95) mg/dL vs. 14.5 (4.0-87) mg/dL]. Lupus anticoagulant was present in 13 of 155 (8.4%) patients; 20 patients (12.9%) had positivity of aCL (four IgM and 16 IgG). In no patient was a deficiency of physiological clotting inhibitors antithrombin, protein C and protein S found. No significant differences between patients and controls were observed for Lp(a) plasma levels [111 (1-1146) mg/L vs. 103 (11-695) mg/L] and for the presence of FV Leiden (4.5% vs. 4.5%) and FII variant G20210A (3.8% vs. 3.2%). RESULTS AND CONCLUSIONS: Independent risk factors for ISSHL at the multivariate analysis (adjusted for age, sex and the traditional cardiovascular risk factors) were the positivity of aCL: OR 5.6 (95% CI 2.0-15.3); cholesterol levels within the second and third tertiles (with respect to the first tertile): T2 = OR 4.8 (95% CI 1.9-12.6)/T3 = OR 19 (95% CI 7-50.1); PAI-1 and Hcy levels within the third tertile (with respect to the first tertile): OR 20 (95% CI 7.8-78) and OR 4.0 (95% CI 2.0-8.1), respectively. These preliminary data suggest that hypercholesterolemia, hyperhomocysteinemia, elevated PAI-1 levels and anticardiolipin antibodies are associated with ISSHL, so indirectly supporting the hypothesis of a vascular occlusion in the pathogenesis of the disease.

Antiphospholipid antibodies and antiphospholipid syndrome in patients presenting with immune thrombocytopenic purpura: a prospective cohort study.

The pathogenetic role and the clinical importance of the presence of antiphospholipid antibodies (APAs) in patients with immune thrombocytopenic purpura (ITP) are not clear. In this study, the prevalence and clinical significance of APAs were investigated in patients with ITP. Eighty-two newly diagnosed ITP patients were prospectively studied. They were evaluated for the presence of lupus anticoagulant (LA) and immunoglobulin G/M anticardiolipin antibodies (ACAs). Thirty-one patients (37.8%) were APA positive at diagnosis. No statistically significant differences were found between the APA-positive and APA-negative groups regarding gender, initial platelet counts, or response to methylprednisolone therapy. After 5 years of follow-up, cumulative thrombosis-free survival of APA-positive (n = 31) and APA-negative (n = 51) ITP patients was 39% and 97.7%, respectively. A significant difference was found between these groups by log-rank test (P =.0004). In addition, LA was an important risk marker for the development of thrombosis in ITP patients. After a median follow-up of 38 months, 14 ITP patients (45%) who had APA positivity developed clinical features (thrombosis or fetal losses) of antiphospholipid syndrome (APS). There were no differences between the APA-positive patients with and without APS regarding the initial platelet counts, response to the therapy, or ACA positivity. The positivity rate for LA was significantly higher in those patients with ITP who developed APS (chi(2): P =.0036; relative risk 7.15; 95% confidence interval, 1.7-47). In conclusion, this study indicates that a significant proportion of patients initially presenting with ITP and APA positivity developed APS. In patients with ITP, the persistent presence of APAs is an important risk factor for the development of APS.

Isolation and characterization of apoptotic nucleosomes, free and complexed with lupus autoantibody generated during hybridoma B-cell apoptosis.

Increasing evidence suggests that immune complexes made of anti-nuclear antibodies bound to nucleosomes released from dead cells play an important role in the pathogenesis of lupus nephritis. However, the nature and composition of apoptotic nucleosomes still remain elusive. Since large amounts of nucleosomes are released from cells undergoing apoptosis in hybridoma cell cultures, we used hybridomas secreting anti-DNA and anti-nucleosome antibodies grown in protein-free medium to generate nucleosome/anti-DNA and /anti-nucleosome immune complexes, as well as an irrelevant antibody hybridoma to generate free, non-complexed apoptotic nucleosomes. Hybridoma supernatants were fractionated by size-exclusion gel chromatography and eluted fractions with a ratio of A260/A280 >1.2 were pooled and analysed for DNA and histone profiles by gel electrophoresis and immunoblotting. When run on a 'native' gel, 'intact' apoptotic nucleosomes, free or within anti-nucleosome immune complexes, showed a strikingly reduced size compared with 'standard' nucleosomes prepared in vitro by endonuclease digestion of cell nuclei. Nucleosomal DNA (extracted from either free or complexed apoptotic nucleosomes) appeared as a major band of 160-180 bp, and had the size of 'standard' mononucleosome DNA, suggesting degradation of the histone moiety of apoptotic nucleosomes. Histone immunoblotting revealed degradation of histones H3 and H4, which was dramatically enhanced when apoptotic nucleosomes were complexed with an anti-nucleosome antibody. Our results provide direct evidence for abnormal histone composition of apoptotic nucleosomes and suggest that the fine specificity of the complexing antibody has an influence on complexed nucleosome composition.

Immunological and molecular analysis of three monoclonal lupus anticoagulant antibodies from a patient with systemic lupus erythematosus.

Antiphospholipid antibodies (APA), including lupus anticoagulants (LAC; as detected by in vitro blood clotting tests) and anti-cardiolipin antibodies (ACA; as assayed by solid-phase immunoassay), are strongly associated with recurrent thrombosis, thrombocytopenia, and recurrent fetal loss in some patients with systemic lupus erythematosus (SLE). The combined presence of APA and these clinical manifestations is termed antiphospholipid syndrome (APS). LAC and ACA comprise heterogeneous and somewhat overlapping autoantibody subsets. To date, it is unclear what degree of heterogeneity is present in an individual patient and between patients. To begin to address these issues, we generated three monoclonal LAC antibodies from a patient with SLE and APS. These antibodies were studied for their binding specificities and variable (V) region nucleotide sequences. All three LAC were unreactive with DNA, cardiolipin or other phospholipids. Sequence analysis of these antibodies revealed extensive overlap in their Ig V genes with anti-DNA antibodies and other autoantibodies characteristic of lupus. These data provide the first V gene sequence information on a group of SLE-derived LAC without ACA activity, representative of a similar subset of LAC found in patients with APS.

HLA-DR7 in association with chlorpromazine-induced lupus anticoagulant (LA).

The presence of anti-phospholipid antibodies (aPL) has been associated with the major histocompatibility complex (MHC) genes. These autoantibodies occur in individuals with infections such as that produced by the human immunodeficiency virus 1 (HIV-1) or with syphilis, but they can also occur in drug-induced lupus-like syndromes. In the present study, we analysed the presence of aPL (detected as lupus anti-coagulant) and its relationship with the MHC markers in 93 Caucasian psychiatric patients chronically treated with chlorpromazine. Forty-one out of 93 patients were positive for LA, and the HLA-DR7 antigen was significantly increased in LA-positive patients as compared to normal controls or LA-negative patients (PC = 0.024, RR = 2.12 and P = 0.05, RR = 1.57, respectively). Likewise, we noted a significantly increased frequency of HLA-B44 in LA-positive patients as compared to normal controls (PC = 0.024, RR = 2.12), but not when compared to aPL-negative patients. No significant differences were found among any other class I, II or III MHC antigens. Haplotype analysis showed that DR7 was mostly part of the HLA-B44-DR7-FC31 and B7-DR7-SC31 haplotypes. These results suggest that the HLA-DR7 antigen might be playing a role in the production of aPL in chlorpromazine-treated patients.

The immunogenetics of the antiphospholipid syndrome, anticardiolipin antibodies, and lupus anticoagulant.

Whether a genetic predisposition to develop the antiphospholipid syndrome (APS) and to produce anticardiolipin antibodies (aCL) and lupus anticoagulant (LAC) exists has been addressed by family studies and by population studies on primary APS and on aCL in diseases other than primary APS. Various studies suggest a familial occurrence of aCL and LAC, with or without clinical evidence of APS. This familial tendency could be genetically determined, because APS, aCL, and LAC occur in families carrying haplotypes which contain HLA-DR4, -DR7, and -DRw53. Population studies on primary APS also indicate that HLA genes have a role in conferring susceptibility to develop primary APS. Again, DR4, DR7, and DRw53 are the relevant loci. Population studies on aCL in diseases other than primary APS indicate that aCL are associated with DR4, DR7, and DRw53, at least when they are found in patients with systemic lupus erythematosus. Because HLA-DR4, -DR7, and -DRw53 are in linkage disequilibrium, the genetic association of aCL could be with DRw53 and, depending on the regional frequency of DR4 or DR7, it could be linked with either DR4 or DR7. HLA-DR4 seems to be more important in Anglo-Saxons, whereas DR7 emerges in populations of Latin origin. In this report we review our studies and the pertinent literature in this field.

Production of anticardiolipin antibodies by cultured human lymphocytes.

Antibodies against negatively charged phospholipids, such as those to cardiolipin, can often be detected in the serum of patients with autoimmune related conditions, chronic infections and in patients treated with phenothiazines. In the present study, peripheral blood lymphocytes from nine healthy controls and eight patients with phenothiazine-induced IgM anticardiolipin antibodies (ACA) and the lupus anticoagulant were placed in vitro. Culture supernatants were assayed for ACA by measurement of optical densities using an ELISA. A significant difference (p less than 0.05) was demonstrated between the mean concentration of culture supernatant ACA from the patients as compared to healthy controls. The concentration of ACA in culture supernatants strongly correlated (r = 0.85) with that from the serum. There was a weak correlation between serum and culture supernatant ACA concentration and the lupus anticoagulant activity as measured by prolongation of the partial thromboplastin time. This technique uses readily accessible peripheral blood lymphocytes and should permit dissection of cytokine and cellular immune pathways regulating APA production.