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N Ciavarella

Publications and source records attributed to N Ciavarella.

At least 55 records · Page 3Linked to original sources
PubMed1984

Efficacy of porcine factor VIII in the management of haemophiliacs with inhibitors.

We report our experience with polyelectrolyte-fractionated highly purified porcine factor VIII concentrate (Hyate:C). Porcine factor VIII concentrate was used to treat 14 haemorrhagic episodes including seven severe haemarthroses, three severe haematomata, two episodes of oral bleeding, one traumatic and the other after multiple dental extractions and two life-threatening intestinal haemorrhages. Altogether 60 infusions of Hyate:C were given to five haemophiliacs with inhibitors. At the time of the first infusion with porcine factor VIII the anti-human inhibitor level ranged from 60 to 2.5 modified Bethesda units/ml (MBU 4 h incubation). The porcine cross-reactivity of these inhibitors was 25.6% and 5.4% of the human inhibitor level in two patients and scarcely measurable in the other three patients. We injected an amount of porcine factor VIII concentrate corresponding to the calculated porcine neutralizing units plus the units required for haemostasis. The clinical efficacy was excellent and no adverse effects were encountered, apart from two episodes of mild pyrogenic reactions well controlled by hydrocortisone. The anamnestic antibody response against human factor VIII was of slight degree in all cases, while the porcine cross-reactivity showed no significant variation. Our results emphasize the role of porcine factor VIII in the treatment of haemophiliacs with inhibitors.

Animals↗
PubMed1984

Evaluation of the effectiveness of DDAVP in surgery and in bleeding episodes in haemophilia and von Willebrand's disease. A study on 43 patients.

1-deamino-8-D-arginine-vasopressin (DDAVP), was used in a wide spectrum of clinical situations employing two different dosages (0.3 and 0.4 microgram/kg b.w.) for the management of 43 patients with factor VIII deficiencies--mild and moderate haemophilia A and von Willebrand's disease (vWD). In most instances, the drug was given in association with antifibrinolytics. Twenty-five dental extractions were carried out with two different protocols: one based upon a single infusion and the other based upon three infusions. Bleeding occurred in three patients regardless of the protocol used. The vasopressin analogue promptly stopped bleeding in 12 'spontaneous' open bleeds (haematuria, epistaxis, menometrorrhagia, gum bleeding) and it appears to be also effective in closed bleeds. DDAVP was used to minimize blood loss during surgical interventions and to avoid haemorrhage in the postoperative period. Nine surgical procedures were carried out in six vWD patients and three haemophiliacs. Bleeding occurred late in the postoperative period on one occasion only. No difference was demonstrated between the two doses of the drug either in terms of clinical benefit or rise of factor VIII coagulant activity. The efficacy of DDAVP and the absence of side-effects make this vasopressin analogue worthy of consideration as a reliable alternative to factor VIII concentrates in a wide variety of clinical situations.

Antigens↗
PubMed1981

Factor VII deficiency: immunological characterization of genetic variants and detection of carriers.

Twenty-one patients with congenital factor VII deficiency belonging to 16 different kindreds were investigated. The existence of three immunochemical variants on the ground of factor VII activity (VII:C) and factor VII-related antigen (VII:Ag) levels (VII-, VII+ and VIIR) was established. There was no correlation between the presence of factor VII:Ag and either the clinical picture or the specific function as studied with the Km calculations. Genetically the model of inheritance is the same whatever the immunological variant, but the identification of carriers is simplified when the presence of factor VII-related antigen is assayed throughout a kindred.

Antigens↗
PubMed1981

Precipitating antibodies to factor VIII/von Willebrand factor in von Willebrand's disease: effects on replacement therapy.

Precipitating antibodies to factor VII/von Willebrand factor can develop in patients with severe homozygous-like von Willebrand's disease following multiple transfusions with blood derivatives. This study of 4 patients treated with cryoprecipitate for 13 different bleeding episodes demonstrates that the occurrence of such antibodies interferes with the management of the disease. The control of mucosal bleeding was poor, whereas more favorable responses were obtained in soft-tissue hemorrhages. These findings probably relate to failure of replacement therapy to shorten the prolonged bleeding time. Immediately after treatment, measurement of plasma factor VIII/von Willebrand factor-related antigen and ristocetin cofactor showed either no increase, or very low values, depending on the pre-infusion antibody titer. Levels of the factor VIII/von Willebrand factor-related procoagulant activity in the circulation were also lower than predicted and usually there was no evidence of the delayed and sustained rise typically observed in uncomplicated von Willebrand's disease. An anamnestic rise in antibody titer appeared 6-15 days after treatment and showed no obvious relationship with the amount of cryoprecipitate infused. Replacement therapy invariably caused severe side effects during, or immediately after, concentrate infusion. The results of in vitro studies support the view that these reactions were due to the appearance of circulating immune complexes.

Antibodies↗
PubMed1980

Heightened interaction between platelets and factor VIII/von Willebrand factor in a new subtype of von Willebrand's disease.

The form of von Willebrand's disease characterized by a qualitative abnormality of Factor VIII/von Willebrand factor (FVIII/vWF) in plasma has been designated as Type II. We have now identified 20 persons from five families whose qualitatively abnormal FVIII/vWF shows heightened responsiveness to ristocetin. We have classified this form of the disease as Type IIB and reclassified as Type IIA the form previously described as Type II, in which the interaction of the abnormal FVIII/vWF with platelets is decreased or absent in the presence of ristocetin. The enhanced reactivity of FVIII/vWF in Type IIB was evident in studies of ristocetin-induced platelet agglutination and of binding of FVIII/vWF to platelets in the presence of ristocetin. In both Type IIA and IIB, crossed immunoelectrophoresis of plasma FVIII/vWF demonstrated similar absence of the larger, less anodic forms. These findings suggest that ristocetin-mediated interactions between platelets and FVIII/vWF do not accurately reflect the "bleeding-time" (von Willebrand factor) defect in this newly described subtype of von Willebrand's disease.

Bleeding Time↗
PubMed1979

Familial incidence of precipitating antibodies in von Willebrand's disease: a study of four cases.

Precipitating antibodies directed toward human F.VIII/WF were found in the plasma of four out of 17 multitransfused patients with severe, homozygous-like VWD. The familial incidence was illustrated by the development of these antibodies in three patients from the same kindred. Such antibodies, titrated with newly developed quantitative assays of anti-VIIIR:Ag and anti-VIIIR:RCo, were directed toward only these components of F.VIII/WF. VIII:C was neutralized in a time-independent manner in plasma and was not inactivated when separated from F.VIII/WF by solid-phase PE absorption. Plasma, serum, or immunoglobulin reacted in precipitation systems (immunodiffusion, EID, CIE) with human VIIIR:Ag, with some degree of cross-reactivity toward VIIIR:Ag from other mammalian plasmas. When used in IRMA, these antibodies demonstrated the same abnormalities as heterologous antisera in variant VWD: decreased binding affinity or nonparallelism of the dose-response curves. They are polyclonal IgG with both kappa and lambda light chains. It is suggested that in some patients with severe homozygous-like VWD, the synthesis of the component of F.VIII/WF carrying VIIIR:Ag and VIIIR:RCo is suppressed whereas VIII:C production is not completely abolished.

Antibody Formation↗