Gabriella Gamba

Natural history and risk factors for thrombosis in 360 patients with antiphospholipid antibodies: A four-year prospective study from the italian registry

PURPOSE To assess the natural history and risk factors for thrombosis in a large cohort of unselected patients with antiphospholipid antibodies. PATIENTS AND METHODS Three hundred sixty consecutive patients (118 males, 242 females, median age 39 years [range 2 to 78]) fulfilling the currently accepted criteria for diagnosis of lupus anticoagulant (LAC) (n = 326) and/or raised immunoglobulin G anticardiolipin antibodies (IgG ACA) (n = 185) were collected from 16 Italian institutions and prospectively observed for a median of 3.9 years (range 0.5 to 5). Main endpoints were the occurrence of arterial or venous thrombosis, the outcome of pregnancies, and any severe complications leading to hospitalization or death. RESULTS Thirty-four patients developed a thrombotic complication, with a total incidence of 2.5% patient-years. Multivariate logistic regression analysis identified two independent risk factors for thrombotic events: a previous thrombosis (RR 4.9; 95% CI, 1.76 to 13.7; P < 0.005) and IgG ACA titer above 40 units (RR 3.66; 95% CI, 1.24 to 10.8; P < 0.01). A total of 28 pregnancies were observed in 25 women and 11 (39%) were abortive. Adverse pregnancy outcomes were significantly more frequent in women with a history of miscarriage or vascular occlusion (9/16, 56%) than in asymptomatic women (2/12, 17%) (P = 0.035). Four patients developed non-Hodgkins lymphoma during the follow-up. Eighteen patients died. Vascular events and hematological malignancies represented the most frequent causes of death (n = 5 for each). CONCLUSIONS The present study shows that: (a) previous thrombosis and ACA titer > 40 U are independent predictors of thrombosis; (b) history of miscarriage or vascular disease is significantly associated with adverse pregnancy outcome; (c) hematological malignancies can develop during follow-up in patients with antiphospholipid antibodies.

Safety and efficacy of thalidomide in patients with myelofibrosis with myeloid metaplasia

We administered the anti‐angiogenic drug thalidomide to 21 patients (12 men) with myelofibrosis with myeloid metaplasia (MMM), who were not responsive to standard treatment. Patients received thalidomide at an escalating dose from 100 to 400 mg/d. Administration of the drug was discontinued before the planned 6 months of treatment in 19 patients (90·5%), mainly because of somnolence and/or fatigue, neurological symptoms or neutropenia. Of the 13 evaluable patients (who received more than 30 d of therapy), anaemia improved in three out of seven (43%) who were treated because of anaemia; thrombocytopenia improved in two out of three (66·6%) who were treated because of thrombocytopenia; splenomegaly was reduced in four (30·8%). Undesired increases in white blood cell and platelet counts were observed in three (23·1%) and five (38·5%) patients respectively. A severity score, indexed on haematological and clinical parameters, improved in two patients (15·4%), but worsened in five (38·5%). In conclusion, standard‐dose thalidomide in MMM patients is burdened with a high rate of side‐effects, which prevent prolonged treatment. Because the drug is effective in improving anaemia and thrombocytopenia and in reducing splenomegaly, low‐dose therapy warrants evaluation. The unexpected observation of leucocytosis and thrombocytosis suggests biological studies and better criteria for selection of patients for treatment.

Thrombin Activity and Early Outcome in Unstable Angina Pectoris

BACKGROUND The blood coagulation system is frequently activated in the acute phase of unstable angina, but it is unknown whether the augmented function of the hemostatic mechanism may serve as a marker of increased risk for an early unfavorable outcome. METHODS AND RESULTS Plasma concentrations and 24-hour urinary excretion of fibrinopeptide A were prospectively determined in 150 patients with unstable angina. All patients underwent 24-hour Holter monitoring, during which time urine was collected; at the end of this period, a blood sample was taken and coronary arteriography was performed. The patients were followed up for the occurrence of cardiac events (death and myocardial infarction) until they underwent coronary revascularization or until they were discharged from the hospital. Fibrinopeptide A plasma levels and 24-hour urinary excretion were found to be abnormally elevated in 50% and 45% of the study population, respectively. During hospitalization, 11 patients developed myocardial infarction and 2 patients died. Kaplan-Meier analysis demonstrated a significantly higher probability of developing cardiac events in patients with abnormal rather than normal plasma levels of fibrinopeptide A (P<.01), whereas no difference in outcome was observed between patients with normal and those with abnormal 24-hour urinary excretion. Cox regression analysis showed that the only variables independently related to an early unfavorable outcome were the presence of persistent ischemia during 24-hour Holter monitoring (P<.0001), the presence of intracoronary thrombosis at angiography (P=.016), and abnormal fibrinopeptide A plasma levels (P=.038). CONCLUSIONS Patients with unstable angina pectoris and abnormal fibrinopeptide A plasma levels are at increased risk for an early unfavorable outcome.

Study of three patients with monoclonal gammopathies and ‘lupus‐like’ anticoagulants

In three patients with monoclonal gammopathies: a case of multiple myeloma, a case of monoclonal gammopathy of uncertain significance (MGUS) and a case of monoclonal gammopathy associated with lymphocytic lymphoma, we found the presence of a circulating lupus‐like anticoagulant. Coagulative studies showed that the paraproteins: an IgG3k, an IgG1k and an IgMλ, were responsible for the anticoagulant activity by interacting with the thromboplastin phospholipids. Using isoelectrofocusing we demonstrated that the three monoclonal immunoglobulins had a strong basic charge which may have contributed to determining their interaction with the acidic thromboplastin phospholipids. The binding of various phospholipids to the monoclonal proteins was assessed by the fluorescence quenching method which showed heterogeneous specificity. In order to establish whether the electrical charge is also relevant in cases with polyclonal lupus anticoagulant, the polyclonal immunoglobulins were fractionated according to their charge. The strongest inhibitor activity was found in the most basic immunoglobulins. Monoclonal lupus‐like anticoagulants represent useful tools for investigating the heterogeneous world of polyclonal lupus‐like anticoagulants.

Plasma fibronectin, von Willebrand factor antigen, and blood rheology. Association with diabetic microvascular disease

SummaryPlasma fibronectin might play a role in the pathogeneis and progression of diabetic microvascular disease. To test this hypothesis we measured plasma fibronectin, von Willebrand factor antigen, fibrinogen, erythrocyte filtrability, whole-blood viscosity, proteinuria and albuminuria in 25 control subjects and 29 diabetic patients with and without microvascular complications. Plasma fibronectin was significantly higher in the diabetic patients, especially in those with retinopathy and nephropathy. A significant correlation between fibronectin and von Willebrand factor antigen was found in both patients with and without microangiopathy (p<0.001). In diabetic patients with and without microvascular complications, several significant correlations were found between increased fibronectin levels and reduced erythrocyte filtrability (p<0.001) and between the increase of fibronectin and whole-blood viscosity (p<0.001). Furthermore, a significant correlation was found between plasma fibronectin levels, proteinuria (p<0.001) and albuminuria (p<0.001). The relationship between plasma fibronectin and changes of blood rheology may be important for the occurrence and progression of diabetic microangiopathy.

Bleeding Tendency of Unknown Origin and Protein Z Levels

known origin showed low levels of protein Z, suggesting that a protein Z assay must be included in

Platelet function after in vivo and in vitro treatment with thrombolytic agents

Whereas in vitro studies showed that plasmin may induce both inhibition and activation of platelets, in vivo and ex vivo investigations suggested that thrombolytic agents are responsible for platelet stimulation. To gain further information on this topic, ex vivo platelet function was studied in 24 subjects with acute myocardial infarction treated with streptokinase or recombinant tissue-type plasminogen activator (rt-PA). Ten patients with acute myocardial infarction who did not receive thrombolytic treatment were also investigated. The data shows that at the end of thrombolytic infusion, the maximal extent of platelet aggregation and adenosine triphosphate release was reduced in treated patients compared with that in untreated ones. In subjects treated with streptokinase, the defect in platelet aggregation derived from both cellular and plasmatic defects. Plasmatic beta-thromboglobulin concentration was significantly reduced after streptokinase, but unchanged after rt-PA. Three days after thrombolytic treatment, platelet aggregation of patients receiving streptokinase or rt-PA was not significantly different from that of untreated subjects. A similar defect in platelet function was obtained in vitro, incubating normal platelet-rich plasma with pharmacologic concentrations of streptokinase. Again, platelet function defect derived from both cellular and plasmatic damages. It cannot be excluded that platelet activation occurs in patients with acute myocardial infarction during the very early phases of thrombolytic treatment. However, it is suggested that a transient defect in platelet function follows both streptokinase and rt-PA infusion.

Abnormalities in thrombin-antithrombin pathway in AL amyloidosis.

Various pathogenic factors have been proposed to explain the abnormal hemostasis observed in AL amyloidosis. Since imbalance between clotting factors and inhibitors could play a pathogenic role in both hemorrhagic and thrombotic manifestations, we investigated the thrombin-antithrombin pathway in 35 patients with AL amyloidosis. Ten patients suffered from bleeding while 3 patients experienced deep venous thrombosis. Thrombin time was prolonged in 29 subjects, the mean values of antithrombin III activity (ATIII Act) were significantly lower than those of antithrombin III antigen (ATIII Ag) with loss of relationship between these two different techniques of ATIII detection, normally observed in healthy controls. In 19 patients increased levels of thrombin-antithrombin (TAT) complexes were present. Crossed immunoelectrophoresis of ATIII, performed in presence of heparin, evidenced ATIII forms with reduced binding capacity to heparin and TAT complexes of various electrophoretic mobilities. In conclusion, the impairment of the thrombin-antithrombin pathway, in association with the low ATIII biological activity, might play a pathogenic role in the hypercoagulable state reported in AL amyloidosis, despite the higher frequency of bleeding manifestations.

Efficacy and safety during formulation switch of a pasteurized VWF/FVIII concentrate: results from an Italian prospective observational study in patients with von Willebrand disease

Von Willebrand disease (VWD) is an inherited bleeding disorder caused by the quantitative or qualitative deficiency of von Willebrand factor (VWF). Replacement therapy with plasma‐derived VWF/factor VIII (FVIII) concentrates is required in patients unresponsive to desmopressin. To assess the efficacy, safety and ease of use of a new, volume‐reduced (VR) formulation of VWF/FVIII concentrate Haemate® P in patients requiring treatment for bleeding or prophylaxis for recurrent bleeding or for invasive procedures. Pharmacoeconomic variables were also recorded. Data were analysed using descriptive statistics. This was a multicentre, prospective, observational study. Consecutively enrolled patients received Haemate® P VR according to their needs, and were followed for 24 months. Of the 121 patients enrolled, 25.6% had type 3 VWD and more than 40% had severe disease. All patients were followed for 2 years, for a total of 521 visits. On‐demand treatment was given to 61.9% of patients, secondary long‐term prophylaxis to 25.6% and prophylaxis for surgery, dental or invasive procedures to 45.5%. The response to treatment was rated as good to excellent in >93–99% of interventions. The new formulation was well tolerated by all patients with no report of drug‐related adverse events. The switch to volume‐reduced Haemate® P was easy to perform and infusion duration was decreased twofold compared with the previous formulation. Volume‐reduced Haemate® P was at least as effective and well‐tolerated as the previous formulation.

Activation of platelet prostaglandin biosynthesis pathway during neoplastic cell-induced platelet aggregation

In a previous study we found a correlation between metastatic potential and platelet aggregating activity in sublines of a benzopyrene-induced murine fibrosarcoma ( mFS6 ); the purpose of the present work was to elucidate the role of thromboxane biosynthesis by platelets and/or by neoplastic cells in the activation of platelets in this system. The cells of the more malignant subline induced higher aggregation and TxB2 production than those of the non metastasizing one. The supernatants of aggregating cell suspensions contained very few TxB2; furthermore, preincubation of platelets with ASA or Apyrase resulted in inhibition of aggregation and TxB2 production, while preincubation of the cells was ineffective; these results suggest the platelet origin of the measured TxB2 and indicate that platelet-derived ADP plays an important role in their activation, while the production of ADP by the cells does not seem to be relevant in this model. The involvement of platelet prostaglandin biosynthesis pathway in neoplastic cell induced platelet activation could play an important role in the development of platelet-dependent tumour metastasis.