Successful major and minor surgery using factor VIII inhibitor bypassing activity in patients with haemophilia A and inhibitors.

Surgeries are being increasingly performed in patients with haemophilia A and high-titre inhibitors. Optimal bypassing agent regimens need further delineation. Data pertaining to surgeries from 1989 to 2004 at a single centre were retrospectively analysed. Patients received a standardized factor eight inhibitor bypassing activity (FEIBA) dose for both major and minor elective or emergency surgeries. The standard FEIBA dose was 70 U kg(-1) per infusion. FEIBA was infused at 9 and 1 h before and 8 h after operation. Infusions were routinely repeated every 8 h afterward. Haemostatic efficacy was assessed on the basis of blood loss, occurrence of haematoma and transfusion requirements. Seven adult patients underwent a total of 12 operations: 10 major and two minor. Ten procedures were elective. The median cumulative numbers of infusions and days of therapy were 46 and 17, respectively. Cumulative total FEIBA consumption was a median of 3185 U kg(-1). Observed blood losses, haematoma incidence and transfusion requirements were comparable to those expected for noncoagulopathic patients undergoing similar procedures. The only large haematoma occurred after a hip prosthesis operation and resolved under continuing FEIBA treatment. There were no cases of disseminated intravascular coagulation or other thromboembolic complications. FEIBA provides an effective and safe first-line peri- and postoperative haemostatic therapy for patients with haemophilia A and inhibitors, allowing both major and minor operations to be successfully performed.

Multicenter retrospective study on the utilization of FEIBA in France in patients with factor VIII and factor IX inhibitors. French FEIBA Study Group. Factor Eight Bypassing Activity.

Factor VIII or factor IX replacement is frequently impossible in inhibitor-developing hemophiliacs, because of the level of the inhibitor titer. Activated prothrombin complex concentrates are one of the available options to treat the bleeding episodes in such patients. However, the efficacy of these products and the associated thrombogenic risk, particularly in prolonged administration such as employed during surgeries, are important concerns for hemophilia care providers. We performed a multicenter retrospective study to evaluate the use of FEIBA (Factor Eight Bypassing Activity) in France, and data is presented on 433 bleeding episodes, including surgical procedures, concerning 60 patients from 15 hemophilia centers. The efficacy was judged as good or excellent in 352 episodes (81.3%), poor in 73 episodes (16.9%) and non-existent in 8 episodes (1.8%). Minor and major surgical procedures were successfully performed using FEIBA as a second-line therapy after human or porcine factor VIII, and in some occasions FEIBA was utilized as the only substitution product. The tolerance was assessed as good in 428 episodes (98.8%), but in 5 cases adverse effects were reported. Only 3 patients out of 52 regularly evaluated (5.8%) were HIV-seropositive, and for two of them the seroconversion occurred prior to the first use of FEIBA. In contrast, 80.4% of the patients were HCV-seropositive. An anamnestic response after the administration of FEIBA was noted in 31.5% of cases. This study points out the main features of the use of FEIBA in France, and particularly the low HIV seroprevalence in the patients treated. The good efficacy and the excellent tolerance still confer to this product a place to consider in the therapeutic options for the treatment of inhibitor-developing hemophiliacs or in acquired hemophilia.

Decision aides in immunohematology: detection of anti-erythrocyte antibodies. / Aide à la décision en immunohématologie: recherche des anticorps anti-érythrocytaires (RAI).

Detection and identification of irregular red-cell antibody in the serum or plasma of a patient is of prime importance for the prevention of hemolytic transfusion reactions and the biological supervision of the hemolytic disease of the foetus or the newborn. Practice in these tests is replete with complex biological problems. Using problem solving strategies, we discuss the recognition and resolution of the most frequent difficulties encountered in red cell antibody identification.

[Problem-solving in immunohematology: interpretation of ABO typing and its difficulties]. / Aide à la décision en immunohématologie: interprétation du groupage sanguin ABO et de ses difficultés.

Practice in immunohematology is replete with complex problems that require practitioners' problem-solving performance. In immunohematology, the acquisition of the reasoning process and necessary skills for making clinical decisions is based on teaching problem-solving strategies which potentially reduce errors and improve patient outcome. We discuss the recognition and resolution of the common causes of discrepancies in ABO typing results using problem-solving strategies.

Fourier transform infrared spectroscopic characterization of grafting of 3-aminopropyl silanol onto aluminum/alumina substrate.

In order to remedy the limitations of state-of-the-art methods for red blood cells grouping and antibody screening we have tried to develop a new type of immunosensors based upon a metallic substrate. The first two steps of the manufacturing of such a sensor consist in the anodization and in the silanization of the metal surface. Fourier transform infrared spectroscopy (FTIR) has been used to investigate aluminum samples treated with the above process. FTIR analysis allows the accurate determination of the grafted species, and thus to perform the optimization of the experimental parameters.

[Bilateral prosthesis of the knee in a hemophilia A patient with an inhibitor]. / Prothèse bilatérale de genou chez un hémophile A avec inhibiteur.

A forty-one year old severe haemophiliac A (factor VIII less than 1%) complicated by an antifactor VIII inhibitor was operated on for a bilateral arthroplasty of the knees. Substitutive treatment was started by giving anti-haemophilic A cryoprecipitate at a dose of 40 IU . kg-1. The anamnestic response occurred at day 6. Consumption of the inhibitor begun with the injection of 50,000 IU of concentrated factor VIII. This method proved to be insufficient for mastering the haemorrhagic syndrome, because the antibody titre quickly reached 10 IU Oxford. Treatment was continued with Autoplex (100 IU . kg-1), during three weeks, without any clinical or biological complications. It is suggested that Autoplex be used as the substitutive treatment in cases of major surgery in severe haemophilia complicated by a factor VIII inhibitor.

An enzyme-linked immunosorbent assay for the quantitation of IgG anti-D and IgG subclasses in the sera of alloimmunized patients.

BACKGROUND: IgG subclass composition of maternal alloantibodies to the D antigen seems to play a role in the severity of hemolytic disease of the newborn. The subclassing of IgG anti-D is usually performed by hemagglutination techniques, but the results are not quantitative and sometimes are difficult to interpret. Thus, there is a need for quantitative methods. STUDY DESIGN AND METHODS: The aim of this study was to develop an enzyme-linked immunosorbent assay (ELISA) for the quantitation of specific IgG anti-D and IgG subclasses in the sera of alloimmunized patients. Group O R1R2 red cells were sensitized with anti-D. Red cell membranes were solubilized with nonionic detergent. IgG and IgG subclasses were measured by a sensitive and reproducible immunocapture ELISA. A serum calibrated for its IgG subclass content was used as a reference, and the anti-D preparation 68/419 was used as an internal control. Optimal conditions for the detection of IgG anti-D and IgG subclasses by ELISA were studied. The absolute concentration and the proportions of IgG subclasses were determined in the sera of 14 pregnant women. RESULTS: A close parallelism was observed between dilutions of the IgG reference serum and the IgG anti-D solubilized from sensitized RBCs. The sum of IgG anti-D subclass concentrations, determined by the ELISA, correlated well with other quantitative methods. CONCLUSION: The method described is sensitive and can be used routinely for the quantitative determination of specific IgG anti-D and IgG subclasses in sera.