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T Barbui

Publications and source records attributed to T Barbui.

At least 163 records · Page 9Linked to original sources
PubMed1992

Anticoagulant activity of beta 2-glycoprotein I is potentiated by a distinct subgroup of anticardiolipin antibodies.

Plasmas of 16 patients positive for both IgG anticardiolipin (aCL) antibodies and lupus anticoagulant (LA) antibodies were subjected to adsorption with liposomes containing cardiolipin. In 5 of these plasmas both the anticardiolipin and the anticoagulant activities were co-sedimented with the liposomes in a dose-dependent manner, whereas in the remaining cases only the anticardiolipin activity could be removed by the liposomes, leaving the anticoagulant activity (LA) in the supernatant plasma. aCL antibodies purified from the first 5 plasmas were defined as aCL-type A, while the term aCL-type B was used for antibodies in the other 11 plasmas, from which 2 were selected for this study. Prolongation of the dRVVT was produced by affinity-purified aCL-type A antibodies in plasma of human as well as animal (bovine, rat and goat) origin. aCL-type B antibodies were found to be devoid of anticoagulant activity, while the corresponding supernatants containing LA IgG produced prolongation of the dRVVT only in human plasma. These anticoagulant activities of aCL-type A and of LA IgG's were subsequently evaluated in human plasma depleted of beta 2-glycoprotein I (beta 2-GPI), a protein which was previously shown to be essential in the binding of aCL antibodies to anionic phospholipids. Prolongation of the dRVVT by aCL-type A antibodies was abolished using beta 2-GPI deficient plasma, but could be restored upon addition of beta 2-GPI. In contrast, LA IgG caused prolongation of the dRVVT irrespective of the presence or absence of beta 2-GPI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Acute undifferentiated leukemia with CD7+ and CD13+ immunophenotype. Lack of molecular lineage commitment and association with poor prognostic features.

The authors studied six adult patients with acute leukemia with these unusual characteristics: unclassifiable morphology and undifferentiated cytochemistry by French-American-British (FAB) criteria; concurrent expression of CD13 (and CD33) myeloid and early T-cell CD7 immune markers; no evidence of T-cell lineage commitment as determined by T-cell receptor beta (beta), gamma (gamma), and delta (delta) chain gene rearrangement study and cytoplasmic CD3 epsilon expression; and no evidence of myeloid cell lineage commitment, as shown by absent myeloid-specific c-fms proto-oncogene expression and negative myeloperoxidase ultrastructural staining (one case). Clinically, these diagnostic features matched with a poor prognosis, being associated with refractoriness to treatment, relapse and progression of disease, antecedent hematologic abnormality, and other malignancy. These cases may represent a distinct stem cell leukemia syndrome deserving immediate recognition and a nonconventional chemotherapeutic approach.

Acute Disease↗
PubMed1992

Inefficacy of intravenous immunoglobulin in patients with low-risk thrombotic thrombocytopenic purpura/hemolytic-uremic syndrome.

OBJECTIVE: To assess the efficacy of intravenous immunoglobulin (IVIG), in comparison with plasma exchange (PE), in the treatment of patients with thrombotic thrombocytopenic purpura/hemolytic-uremic syndrome (TTP/HUS). DESIGN: Prospective, nonrandomized comparative study. SETTING: Hematology department in a general hospital. PATIENTS: 17 consecutive adult patients, six of them pregnant, with diagnosis of TTP/HUS. Three had a severity score at diagnosis less than or equal to 4 and were treated with IVIG and 14 had a severity score of greater than or equal to 5 and/or were pregnant and received PE. The response was evaluated after 5 days of therapy. RESULTS: Complete remission was obtained in 0/3 cases treated with IVIG and 10/14 (71%) with PE (Fisher's exact test P = 0.05). Three patients died for widespread TTP-HUS, and four had persistent disease. In three of the four resistant patients, complete remission was obtained by further PE but not by further IVIG. The overall remission rate was 76% (13/17). CONCLUSIONS: Our study does not confirm the utility of IVIG in the management of TTP-HUS, as suggested by earlier single case reports.

Adult↗
PubMed1992

Constitutive expression of IL-1 beta, M-CSF and c-fms during the myeloid blastic phase of chronic myelogenous leukaemia.

During the myeloid blast crisis (BC) of chronic myelogenous leukaemia (CML) non-random additional chromosome abnormalities occur in over 80% of patients. However, these cytogenetic changes have been reported to precede the clinical signs of CML-BC by several months to years suggesting that other biological events may participate in the multistep process of acute transformation of CML. The autocrine production of growth factors has been recently shown to occur in several haematological malignancies and particularly in acute myeloblastic leukaemia (AML). In the present report we demonstrate that IL-1 beta gene is expressed in almost all cases of CML in myeloid blast crisis. The secretion of IL-1 from CML blasts in culture supernatants was confirmed in all five of the patients we studied. A high proportion of cases showed constitutive expression of the M-CSF gene and many of the same patients often had a simultaneous co-expression of the proto-oncogene c-fms which encodes for the M-CSF receptor. After exposure of leukaemic cells to phorbol myristate acetate (PMA), release of M-CSF protein was documented in three of five patients studied. No significant interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF) or granulocyte colony-stimulating factor (G-CSF), was detected in these patients demonstrating that a different pattern of growth factors secretion exist in AML and CML, where distinct molecular events are likely involved in the control of leukaemic proliferation.

Adult↗
PubMed1991

Modulation of cell proliferation and cytokine production in acute myeloblastic leukemia by interleukin-1 receptor antagonist and lack of its expression by leukemic cells.

Interleukin-1 (IL-1) is spontaneously produced by acute myeloblastic leukemia (AML) cells. IL-1 also induces synthesis of colony-stimulating factors (CSFs) and sustains leukemic growth. An IL-1-specific inhibitor has been recently purified and cloned; this molecule binds to IL-1 receptors but has no IL-1 activity, fulfilling the characteristics of an IL-1 receptor antagonist (IL-1ra). Because high-affinity binding sites for IL-1ra were shown on AML cells by radioligand binding studies, we studied the effect of IL-1ra on the proliferative activity of blast cells isolated from 16 cases of AML. In each case, spontaneous proliferation was inhibited by addition of the IL-1ra in a dose-dependent manner (1 to 100 ng/mL). Culture supernatants of unstimulated leukemic cells contained IL-1 beta and granulocyte-macrophage CSF (GM-CSF), but when incubated with the IL-1ra, a reduction or disappearance of GM-CSF was observed in 8 of 10 cases, whereas spontaneous IL-1 production was reduced in four of seven cases. By Northern hybridization, IL-1 beta gene transcripts were shown in 20 of 23 AML cases, whereas IL-1ra-specific messenger RNA was present in only two of the patients studied. These data show a role for IL-1 in the spontaneous proliferation and cytokine production of AML cells and suggest that an imbalanced synthesis of IL-1 and of its natural receptor antagonist may contribute to the unrestricted growth of AML cells.

Binding, Competitive↗
PubMed1991

Lupus anticoagulant IgG's (LA) are not directed to phospholipids only, but to a complex of lipid-bound human prothrombin.

Plasmas from 16 patients that were found to be positive both for anticardiolipin antibodies (ACA) and lupus anticoagulants (LA) were incubated with liposomes that contained anionic phospholipids. In 11 of these plasmas, ACA could be cosedimented with the liposomes in a dose-dependent manner, whereas LA activity of the remaining supernatant was unaffected. LA activity of purified total IgG from 6 patients was measured in three different coagulation tests, using normal plasmas from different species. Prolongation of the aPTT, KCT and dRVV clotting times was observed only with normal plasma from human origin, not with bovine, rat or sheep plasma. Highly purified coagulation factors Xa, Va and prothrombin, both of human and bovine origin, were used to establish for two patient IgG's the effect of LA on the rate of thrombin formation in the presence and absence of lipid vesicles composed of 20 mole% phosphatidylserine and 80 mole% phosphatidylcholine. A strong and dose dependent inhibition by LA was observed only when human prothrombin was used as substrate in the prothrombinase complex in the presence of lipids. No inhibition was found when bovine prothrombin was used as substrate. The inhibitory effect observed in the presence of human prothrombin was independent of the source of factors Xa and Va, and was not found in the absence of lipid. Preliminary binding studies suggest that LA only associate with a lipid surface, provided that human prothrombin and calcium ions are present. These data indicate that LA are not directed to phospholipids alone, but presumably recognize an epitope which becomes exposed upon Ca(2+)-mediated binding of human prothrombin to phospholipids.

Adult↗
PubMed1991

High risk of severe bleeding in aged patients with chronic idiopathic thrombocytopenic purpura.

The purpose of this study was to estimate the incidence and to establish which factors were associated with an increased risk of hemorrhagic complications in an historic cohort of 117 consecutive and unselected patients with chronic idiopathic thrombocytopenic purpura (ITP). Sixty-eight patients (58%) underwent medical treatment and/or splenectomy and 33 (48% of treated) achieved a complete stable remission. At equivalent platelet count the incidence of major hemorrhagic complications was significantly higher in aged (greater than 60 years) than in younger (less than 40 years) patients (10.4% v 0.4%/pt-y, relative risk = 28.9, P less than .01). A previous hemorrhagic event was identified as another major risk factor for hemorrhage (relative risk = 27.5, P less than .0005), while hypertension and underlying disorders had no influence. We conclude that age more than 60 years and a previous history of bleeding are major risk factors for severe hemorrhages in adults with ITP.

Adult↗
PubMed1991

In vivo efficacy of intravenous gammaglobulins in patients with lupus anticoagulant is not mediated by an anti-idiotypic mechanism.

The authors have investigated the presence in commercially available intravenous gammaglobulins (IVIg) of anti-idiotypic antibodies directed to Lupus Anticoagulant (LA). In vitro incubation of 4 LA plasmas with increasing concentrations of IVIg (from 0 to 39 mg/ml) resulted in a dose-dependent inhibition of LA activity (the highest inhibitions ranged from 14.0 to 53.4%). Similar results were obtained when patients' plasma was substituted with total IgG (the highest inhibitions ranged from 43.0 to 55.0% and were obtained at IgG:IVIg molar ratios ranging from 1:15 to 1:50). Also the incubation of patients' F(ab')2 with F(ab')2 from IVIg produced a similar dose-dependent inhibition of LA activity. These data are suggestive of an in vitro idiotypic-anti-idiotypic interaction between LA and IVIg. However, when injected in patients with LA, IVIg do not seem to operate by this mechanism of action. In fact, reduction or disappearance of LA was only observed in 2 out of 4 patients; also the quick reappearance of LA activity was not consistent with the time course of anti-idiotypic response. Finally, this effect was reached by half the IVIg concentrations necessary to produce an appreciable inhibitory effect on LA activity in vitro. Thus, it is concluded that, even if IVIg contain anti-idiotypic antibodies reacting with LA, the clinical efficacy of IVIg treatment in patients with these autoantibodies should be attributed to other mechanisms.

Adult↗
PubMed1991

Doxorubicin and m-AMSA induced DNA damage in blast cells from AML patients.

We investigated m-AMSA or doxorubicin (Dx) induced DNA single-strand breaks (DNA-SSB) in myeloid leukemia cells obtained from 8 adult patients suffering from AML. Highly purified AML cells were stimulated to proliferate with the addition of the appropriate growth factor (GCT) and exposed to different concentrations of m-AMSA or Dx for 1 or 4 h, respectively. DNA-SSB were determined by alkaline elution techniques. Either the kinetics or the amounts of DNA-SSB caused by both topoisomerase II inhibitors were variable among different cases. By increasing m-AMSA concentrations there was a concomitant increase in DNA-SSB up to a plateau at the highest concentrations. Dx induced DNA-SSB followed a bell shape curve with a decrease in the number of breaks at the highest concentrations that was evident in most cases. The interindividual variability of Dx-induced DNA-SSB was not correlated with intracellular Dx concentrations as assessed by flow cytometry. No correlation was evident between the amount of DNA breaks induced by m-AMSA and that induced by Dx. These data suggest that AML cells derived from different patients are not necessarily cross-sensitive or cross-resistant to topoisomerase II inhibitors with different chemical structures such as amsacrine or anthracyclines.

Adult↗
PubMed1991

Long-term results of the HEAVD protocol for adult acute lymphoblastic leukaemia.

Between 1979 and 1987, 82 adults (age 14-71 years) with acute lymphoblastic leukaemia (ALL) were treated with a 6-course protocol called HEAVD, the main feature of which was the early postremission administration of escalating doses of doxorubicin (total 405 mg/m2) and cyclophosphamide (total 2.5 g/m2). A complete remission (CR) was attained in 66 patients (80%, 95% confidence intervals, [CI] 71%-89%). Factors affecting favourable CR achievement were age less than 60 years and absence of lymphadenopathy-hepatosplenomegaly at presentation (P less than 0.05). Median duration of CR was 27 months. 26 patients remain in first continuous and unmaintained CR, 18 of whom between 5.9 and 11.1 years, for an estimated 39% prolonged disease-free survival (95% CI 27%-51%). CR duration correlated significantly with absolute blast cell count (15 x 10(9)/l or less compared to more) and age (30 years or under compared to over). Overall, 29 patients are alive with a median follow-up of 6.7 years, the projected long term survival being 35% at 11 years (95% CI 24%-46%). Treatment-related toxicity included 1 lethal case of L-asparaginase-related thromboembolism and 3 toxic deaths among 66 CR patients. Late-onset toxicity was not observed in long-term survivors. The relatively late occurrence of endpoint events (relapse and death) in adult ALL confirms that long-term updating is necessary to determine the curative potential of modern chemotherapy programs for the disease.

Adolescent↗
PubMed1991

A cathepsin-like cysteine proteinase proaggregating activity in thrombotic thrombocytopenic purpura.

The platelet aggregating activity (PAA) of serum and plasma from thrombotic thrombocytopenic purpura (TTP, eight patients) and haemolytic uraemic syndrome (HUS, three patients) was investigated. Sample-induced aggregation of washed platelets and the parallel 3H-serotonin release were studied both in the presence and the absence of purified von Willebrand factor (vWF) or defibrinated cryoprecipitate, according to Kelton et al (1987). All the samples but two were positive in the test, vWF being indispensable for aggregation in all but two of the active cases. Samples from five patients during remission were ineffective under the same conditions, as were 14 controls from healthy donors. An inhibition study using four cysteine proteinase inhibitors (1 mM iodoacetamide, 0.5 mM E-64, 0.1 mM antipain and 0.1 mM leupeptin) and two serine proteinase inhibitors (200 U/ml aprotinin and 0.2 U/ml hirudin) confirmed that TTP/HUS's PAA behaved enzymatically as a cysteine proteinase, as described (Murphy et al, 1987a). These results were confirmed on a protein preparation obtained from pooled plasmas after Al(OH)3 adsorption, ammonium sulphate precipitation, binding to and elution from a p-(chloromercuri)benzoate (PCMB) affinity resin. To further characterize this activity we investigated whether it was a calcium-dependent neutral protease or a lysosomal cathepsin by testing the sensitivity to a series of peptidyl diazomethyl ketones, synthetic inhibitors specifically designed for cysteine proteinases. We confirm here the presence of a circulating platelet aggregating cysteine proteinase in TTP/HUS and provide evidence for the first time that this activity behaves like a lysosomal cathepsin.

Adolescent↗
PubMed1991

Long-term outcome of adults with acute myelogenous leukaemia: results of a prospective, randomized study of chemotherapy with a minimal follow-up of 7 years.

In a prospective study running between 1981 and 1983, a group of 156 adult (under 60 years of age) patients with de-novo acute myelogenous leukaemia were randomly assigned to receive a daunorubicin, cytosine arabinoside and thioguanine combination or a regimen containing lower dosages of these drugs but also containing etoposide and vindesine. Patients who entered complete remission received maintenance therapy for 2 years. The survival and remission duration curves of the two groups were exactly superimposable and for this long-term analysis all patients have been considered together. The follow-up times range between 84 and 104 months. Actual survival at 7 years is 15% (95% confidence intervals 9-20%), with a stable curve thereafter. Actual probability of continuous complete remission at 7 years is 22% (95% C.I. 13-31%) with a stable curve beyond that point. These findings, similar to those of the few other studies of chemotherapy with comparable follow-up times, suggest that only a small fraction of adult patients become long-term survivors, irrespective of the precise type or amount of antineoplastic agents administered.

Adolescent↗