Venous thrombotic events (VTE), including both deep venous thrombosis and pulmonary emboli, are now recognized as an important complication of Wegener's granulomatosis (WG), but the mechanism(s) of this occurrence is unclear. The frequency of anticardiolipin antibodies (aCL), anti-beta2-glycoprotein antibodies (anti-beta2-GP), and several genetic hypercoagulable factors were examined in a large cohort of patients with WG.
One hundred eighty patients with active WG had serum and DNA samples collected upon entry into a clinical trial. Of the 180 patients, 29 patients had VTE -- 13 before trial entry, 16 during trial. aCL (IgG, IgM, and IgA) and anti-beta2-GP (IgG and IgM) were evaluated in 176 patients. Factor V Leiden (FVL), the prothrombin gene mutation (G20210A, PGM), and methylenetetrahydrofolate reductase (MTHFR) gene mutation were tested in the 29 patients with thrombotic events, and 36 patients without.
aCL occurred with increased frequencies in patients with WG when compared to the general population (1%-5%): 12% had aCL and 3% had anti-beta2-GP. There was no difference in the prevalences of aCL or anti-beta2-GP based on clotting status. The prevalence of the genetic hypercoagulable factors examined in patients with WG was comparable to the reported rates in the general population.
Although the incidence of clinically significant VTE is increased in patients with WG, this increased risk is not explained by increased prevalences of aCL, anti-beta2-GP, FVL, or mutations in PGM or MTHFR. These observations suggest a need to search for new genetic or acquired prothrombotic abnormalities to account for the increased thrombotic event rate in patients with active WG.
[Show abstract][Hide abstract] ABSTRACT: Patients with inflammatory vascular disease caused by anti-neutrophil cytoplasmic autoantibodies (ANCA) can harbor antibodies not only to the autoantigen proteinase 3 (PR3) but also to complementary PR3 (cPR3(105-201)), a recombinant protein translated from the antisense strand of PR3 cDNA. The purpose of this study was to identify potential endogenous targets of anti-cPR3(105-201) antibodies. Patients' plasmapheresis material was tested for the presence of antigens reactive with affinity-purified rabbit and chicken anti-cPR3(105-201) polyclonal antibodies. Antigen-containing fractions were tested with patients' anti-cPR3(105-201) affinity-purified IgG, and putative protein targets were sequenced by mass spectrometry. Unexpectedly, plasminogen was identified as a target of anti-cPR3(105-201). Reactivity of affinity-purified antibodies from two patients was lost when plasminogen was converted to plasmin, indicating restricted specificity. Antiplasminogen antibodies from five patients bound plasminogen at a surface-exposed loop structure within the protease domain. This loop contains an amino acid motif that is also found in a portion of recombinant cPR3(105-201); site-directed mutagenesis of this sequence decreased antibody reactivity by 30%. Functionally, antiplasminogen antibodies delayed the conversion of plasminogen to plasmin and increased the dissolution time of fibrin clots. Serologically, antiplasminogen antibody levels were higher in PR3-ANCA patients (n = 72) than healthy control subjects (n = 63), myeloperoxidase-ANCA patients (n = 34), and patients with idiopathic thrombosis (n = 57; P = 0.001). Of the patients with PR3-ANCA, nine had documented deep venous thrombosis events, five of whom were positive for antiplasminogen antibodies. In summary, capitalizing on interactions with complementary proteins, specifically complementary PR3, this study identified plasminogen as a previously undescribed autoantigen in PR3-ANCA vasculitis.
Journal of the American Society of Nephrology 09/2008; 19(12):2421-9. DOI:10.1681/ASN.2008030270 · 9.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To describe a case series of seven women with SLE and other systemic autoimmune rheumatic diseases (SARDs) who required cyclophosphamide therapy and underwent fertility preservation treatments.
Of the seven patients reported here, five women had SLE with nephritis, the sixth had immune thrombocytopenia purpura (ITP) and the seventh had microscopic polyangiitis (MPA) with renal involvement. All women were nulliparous and younger than 35 yrs.
Patients with SLE underwent in vitro maturation (IVM) of immature oocytes aspirated during a natural menstrual cycle followed by vitrification of the matured oocytes if a male partner was not available, or vitrification of embryos if one was available. The patient with ITP and the patient with MPA underwent gonadotropin ovarian stimulation followed by oocyte or embryo vitrification. All women completed fertility preservation treatment successfully and mature oocytes or embryos (36 and 13, respectively) were vitrified. No complications were associated with this treatment and cytotoxic therapy was initiated as scheduled in all cases.
Oocyte or embryo cryopreservation should be considered for fertility preservation in young women with SARDs who face imminent gonadotoxic treatment. In patients, where gonadotropin ovarian stimulation is deemed unsafe, IVM of immature oocytes, aspirated during a natural menstrual cycle, followed by vitrification or fertilization of the mature oocytes, seems to be safe and feasible. For patients in whom hormonal ovarian stimulation is not contraindicated, this method may be considered depending on the urgency to start cytotoxic therapy.
[Show abstract][Hide abstract] ABSTRACT: To give an overview of recent clinical findings of thromboembolic disease in vasculitis and provide insight into possible explanations of the association between thrombosis and inflammation.
A high incidence of venous thrombotic events has recently been described in four distinct cohorts of patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), especially during periods of active disease. No factors other than the vasculitis itself have been identified that explain this high occurrence of thrombosis. Several studies have shown an increased rate of thrombosis in Behçet's disease, with a different clinical presentation from that observed in AAV. Recent laboratory findings provide exciting insights into a bidirectional feedback loop between coagulation and inflammation that may be applicable to vasculitis.
Thrombosis is an important clinical manifestation of some types of vasculitis. Better understanding of the association of thrombosis with inflammation in vasculitis might lead to development of clinically useful biomarkers and new approaches to therapy. Additionally, study of the specific factors involved in thrombosis in systemic vasculitis could help explain the role of inflammation in more common settings of venous thrombotic events.
Current opinion in rheumatology 02/2009; 21(1):41-6. DOI:10.1097/BOR.0b013e32831de4e7 · 4.89 Impact Factor
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