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Biomedical subjects

G E Bergman

Publications and source records attributed to G E Bergman.

At least 19 recordsLinked to original sources

Safety and efficacy of monoclonal antibody purified factor IX concentrate in previously untreated patients with hemophilia B.

The safety and efficacy of a monoclonal antibody purified factor IX concentrate were evaluated in two continuing trials of 32 previously untreated patients with mild, moderate, or severe hemophilia B. Patients were evaluated every 2 weeks for 24 weeks and every 3 months thereafter for at least 1 year. No patients became positive for human immunodeficiency virus antibody or hepatitis C virus antibody during the trial. Two patients developed a false-positive hepatitis B core antibody, one transiently, but neither had elevated levels of alanine aminotransferase (ALT). None of the 25 patients evaluable for non-A, non-B, non-C hepatitis by strict International Society of Thrombosis and Hemostasis criteria developed elevated levels of ALT indicative of posttransfusion infection. Anaphylaxis occurred in one subject who also developed an inhibitor to factor IX (19.3 Bethesda units). Five of the eight adverse events reported (63%) were mild in severity, and the relationship of three of these to therapy was considered remote. Hemostasis with monoclonal antibody purified factor IX concentrate was excellent in all patients.

Adolescent↗

Safety of high doses of a monoclonal antibody-purified factor IX concentrate. The Mononine Study Group.

This report summarizes safety and efficacy information among patients treated with high doses (> 75 U/kg) of a monoclonal antibody-purified factor IX concentrate [coagulation factor IX (human) monoclonal antibody purified)] in two clinical trials. One hundred infusions of this factor IX concentrate at doses > 75 U/kg were administered to 35 patients, six of whom had experienced thrombotic complications during previous treatment with prothrombin complex concentrate. Hemostasis in all patients was rated as "excellent," and there were no thrombotic complications.

Adult↗

Concomitant treatment with factor IX concentrates and antifibrinolytics in hemophilia B.

Concomitant use of the monoclonal antibody-purified factor IX concentrate (Mononine, Armour Pharmaceutical Company, Collegeville, Pa.) and two antifibrinolytic agents, epsilon-aminocaproic acid (EACA; Amicar, Immunex, Seattle, Wash.) or tranexamic acid (AMCA; Cyklokapron, Kabi Pharmacia, Piscataway, N.J.) was examined for safety and efficacy in patients with hemophilia B. In a retrospective review of 19 patients treated with monoclonal antibody-purified factor IX and EACA on 35 occasions, bleeding was successfully controlled and no instances of clinical thrombotic complications were reported; one instance of urticaria resolved without additional treatment. The use of EACA or AMCA in combination with monoclonal antibody-purified factor IX was also examined prospectively in a study of 9 patients. Bleeding was effectively controlled and no thrombotic events were detected clinically with either antifibrinolytic agent. No significant changes in hematocrit or hemoglobin were detected, and there was no evidence of thrombosis as evaluated clinically and by sensitive molecular markers. It was concluded from both the retrospective and prospective data that monoclonal antibody-purified factor IX concentrate in combination with an antifibrinolytic agent does not activate the coagulation cascade and is a safe and effective treatment for prevention and control of oral bleeding in hemophilia B patients.

Aminocaproates↗

Variability of in vivo recovery of factor IX after infusion of monoclonal antibody purified factor IX concentrates in patients with hemophilia B. The Mononine Study Group.

Monoclonal antibody purified factor IX concentrate, Mononine (Armour Pharmaceutical Company, Kankakee, Illinois, USA), is a recently developed replacement factor concentrate for the treatment of patients with hemophilia B. The pharmacokinetic properties of monoclonal antibody purified factor IX concentrate (MAb Factor IX concentrate) have been evaluated in only small samples of patients, and little is known about those factors that might influenced in vivo recovery of factor IX after infusion is a larger patient population. In vivo recovery of factor IX was therefore evaluated for 80 different indications in 72 patients who received MAb Factor IX concentrate for the management of spontaneous or trauma-induced bleeding, or as prophylaxis with surgery. The average recovery after infusions for presurgical pharmacokinetic analysis (mean +/- standard deviation) was 1.28 +/- 0.56 U/dl rise per U/kg infused (range 0.41-2.80), and the average recovery after all infusions for treatment was 1.23 +/- 0.49 U/dl rise per U/kg infused (range - 0.35-2.92). Recovery values for multiple MAb Factor IX doses in a given patient were also variable; the average recovery was 1.22 +/- 0.53 U/dl rise per U/kg given, and standard deviations ranged from 0.03 to 1.26. Patient age, weight, and MAb Factor IX concentrate dose minimally but significantly influenced factor IX recovery. There was no significant effect of either race, history of previous thrombotic complications during treatment with other replacement factor concentrates, or bleeding state on recovery. All of the patients treated with this preparation experienced excellent hemostasis, and no thrombotic complications were observed.

Adolescent↗

Three-year randomised study of high-purity or intermediate-purity factor VIII concentrates in symptom-free HIV-seropositive haemophiliacs: effects on immune status.

The availability of monoclonal-antibody-purified factor VIII (FVIII) concentrates allows us to test the hypothesis, based on in vitro observations, that their use in HIV seropositive haemophiliacs would result in a difference in the rate of deterioration of immune function. We designed a multicentre, prospective, randomised, controlled study of symptom-free HIV-infected patients with haemophilia A who were assigned to receive either an intermediate-purity or monoclonal-antibody-purified product. All had CD4 lymphocyte counts of 100-600/microL, were negative for hepatitis B surface antigen, had not received any antiretroviral or immunomodulating drugs before study entry, and had previously received replacement therapy with intermediate purity FVIII concentrates. Use of antiretroviral therapy was permitted. 60 patients were recruited and 30 were assigned to each group. 35 completed the 3 year study, 20 in the monoclonal arm and 15 in the intermediate-purity arm. Among those completing the study, there were no differences between the two groups in the occurrence of AIDS-defining diagnoses (1 in each group). There were, however, striking and significant differences in terms of changes in absolute CD4 counts. The group receiving monoclonal-antibody-purified concentrates had essentially stable counts while a significant drop was observed in the group receiving intermediate-purity FVIII. These differences were independent of the use of antiretroviral therapy. These observations support the use of high-purity concentrates in the treatment of symptom-free HIV-positive patients with haemophilia A, and they should be taken into account along with cost, by doctors making therapeutic decisions.

Adolescent↗

Purified factor IX using monoclonal immunoaffinity technique: clinical trials in hemophilia B and comparison to prothrombin complex concentrates.

Replacement therapy for hemophilia B (factor IX deficiency) using prothrombin complex concentrate (PCC) has been associated with serious complications of thromboembolic events and transmission of viral infections. Monoclonal antibody-purified factor IX (Mononine) provides a highly purified factor IX concentrate, while eliminating other vitamin K-dependent factors (II, VII, and X). Mononine was evaluated for in vivo recovery, half-life, and for its safety and efficacy in 10 patients with hemophilia B. The in vivo recovery of factor IX with Mononine was a 0.67 +/- 0.14 U/dL (mean +/- SD) increase per 1U/kg of infused factor IX, and the biologic half-life (t1/2), determined using the terminal phase of elimination, was 22.6 +/- 8.1 hours. Comparison of in vivo recovery of other vitamin K-dependent factors following a single infusion of either Mononine or PCC showed that, whereas Mononine infusion caused no changes in other vitamin K-dependent factors or in prothrombin activation fragment (F1+2), PCC infusion was associated with significant increases of factors II (2.7 U/dL per 1 U/dL of IX increase) and X (2.2 U/dL for 1 U/dL for 1 U/dL of IX). Patients who used Mononine as their sole therapeutic material during the 12-month period showed an excellent response in hemostasis for their bleeding episodes. Their experience with long-term use of Mononine was at least equivalent to their previous experience with PCC in the frequency and amount of factor usage. No patients developed antibody against mouse IgG or an increase in IX inhibitor during the 12-month period. These results indicate that monoclonal antibody-purified factor IX concentrate provides hemostatically effective factor IX replacement while avoiding extraneous thrombogenic substances.

Antibodies, Monoclonal↗

Clinical experience of a new monoclonal antibody purified factor IX: half-life, recovery, and safety in patients with hemophilia B.

Highly purified factor IX, produced by a monoclonal antibody immunoaffinity technique, contains a high concentration of factor IX with negligible amounts of other vitamin K-dependent coagulation factors. When infused in patients with hemophilia B, monoclonal factor IX concentrate yielded a mean half-life of 34.6 +/- 13.1 (+/- SD) hours and in vivo recovery of 0.67 +/- 0.14 U/dL rise per each U/kg of factor IX infused. Unlike prothrombin complex concentrate (PCC) infusion, monoclonal IX infusion was not associated with rises in factors II, VII, and X, but achieved in vivo recovery and half-life at least comparable to PCC. Long-term use of monoclonal IX as a home-care product provided excellent response in the control of bleeding episodes and was equivalent to previous patient experience with PCC. The results indicate that monoclonal IX concentrate raises factor IX levels effectively, while avoiding extraneous thrombogenic components.

Adult↗

Blister cells in children with sickle hemoglobinopathies.

The presence of blister cells in the peripheral blood of patients with sickle hemoglobinopathies was investigated to assess whether their presence was predictive of the patients' clinical state and would be diagnostically useful. Peripheral blood smears (PBS) were examined from 23 children with sickle hemoglobinopathies, 20 children with iron deficiency, and 29 healthy control children. The number of blister cells per 1,000 red blood cells was then correlated with the child's health state: well, minor illness, and illness requiring hospitalization. The presence or number of blister cells was found to be unreliable to predict the state of health or the cause of a pulmonary insult in children with sickle hemoglobinopathies.

Adolescent↗

Combined iron deficiency and lead poisoning in children. Effect on FEP levels.

Concern for the concomitant occurrence of iron deficiency and elevated blood lead in children is raised by animal studies documenting increased gastrointestinal lead absorption in the presence of iron deficiency. An elevation in free erythrocyte protoporphyrin (FEP) above 35 mg/dl is seen with both iron deficiency and lead toxicity. To determine whether the degree of elevation in FEP is useful in predicting which children with elevated blood lead levels have concomitant iron deficiency, 109 children suspected of having an elevated lead burden were studied. A complete blood count, reticulocyte count, FEP, lead, and ferritin were measured on each child. The effect of the independent variables, lead and iron status, both alone and in combination, on the dependent variable, FEP, was analyzed through a linear regression model. Lead status alone accounted for 42 percent of the explained variance in FEP, and the lead-iron interaction increased the explained variance by only an additional 1 percent. Screening for iron deficiency in children with elevated blood lead should continue to be based on dietary and socioeconomic risk factors and not on degree of elevation in FEP.

Analysis of Variance↗

Pediatric resident objectives for hematology/oncology.

Pediatric residents are exposed to a massive amount of scientific information and data from each pediatric subspecialty discipline. The residents may or may not know what is important and what is relevant from a general pediatrician's point of view. Educational objectives have been written by three pediatric hematologists/oncologists to guide the resident specifically as to the minimal expectations of knowledge and performance in this discipline. Other pediatric residency programs may wish to use the objectives as a starting point or an outline for their own objectives.

Education, Medical↗