Jerome Teitel

Plasma Urokinase Antigen and Plasminogen Activator Inhibitor-1 Antigen Levels Predict Angiographic Coronary Restenosis

BACKGROUND The fibrinolytic system is intimately involved in several processes that contribute to restenosis, including clot dissolution, cell migration, and tissue remodeling. However, the role of the individual activators (urokinase [uPA] and tissue plasminogen [tPA] activators) and inhibitors (plasminogen activator inhibitor [PAI-1]) of the fibrinolytic system in maintaining patency after coronary artery angioplasty and stenting is unclear. METHODS AND RESULTS We prospectively studied 159 patients with stable angina who underwent successful elective angioplasty (n=110) or stenting (n=49) of de novo native coronary artery lesions. Plasma samples were drawn at baseline (before angioplasty) and serially after angioplasty (immediately afterward and 6 hours, 24 hours, 3 days, 7 days, 1 month, 3 months, and 6 months afterward). Antigen and activity assays were performed for uPA, tPA, and PAI-1. Follow-up quantitative coronary angiography was performed in 92% of eligible patients. The overall angiographic restenosis rate (diameter stenosis >50%) was 31% (37% in PTCA patients, 17% in stented patients). At all time periods, including baseline, uPA antigen levels were significantly higher and PAI-1 antigen levels were significantly lower in patients with restenosis. Restenosis rates for patients in the upper tertile of baseline uPA antigen levels were 2-fold higher than for those in the lower 2 tertiles (46% versus 24% and 22%, respectively; P<0.004). In a stepwise regression multivariate analysis, obstruction diameter after the procedure and uPA antigen were significant predictors of follow-up diameter stenosis. CONCLUSIONS Plasma uPA antigen levels and PAI-1 antigen levels identify patients at increased risk for restenosis after percutaneous coronary revascularization.

Hemophilia B Gene Therapy with a High-Specific-Activity Factor IX Variant

Background The prevention of bleeding with adequately sustained levels of clotting factor, after a single therapeutic intervention and without the need for further medical intervention, represents an important goal in the treatment of hemophilia. Methods We infused a single‐stranded adeno‐associated viral (AAV) vector consisting of a bioengineered capsid, liver‐specific promoter and factor IX Padua (factor IX–R338L) transgene at a dose of 5×1011 vector genomes per kilogram of body weight in 10 men with hemophilia B who had factor IX coagulant activity of 2% or less of the normal value. Laboratory values, bleeding frequency, and consumption of factor IX concentrate were prospectively evaluated after vector infusion and were compared with baseline values. Results No serious adverse events occurred during or after vector infusion. Vector‐derived factor IX coagulant activity was sustained in all the participants, with a mean (±SD) steady‐state factor IX coagulant activity of 33.7±18.5% (range, 14 to 81). On cumulative follow‐up of 492 weeks among all the participants (range of follow‐up in individual participants, 28 to 78 weeks), the annualized bleeding rate was significantly reduced (mean rate, 11.1 events per year [range, 0 to 48] before vector administration vs. 0.4 events per year [range, 0 to 4] after administration; P=0.02), as was factor use (mean dose, 2908 IU per kilogram [range, 0 to 8090] before vector administration vs. 49.3 IU per kilogram [range, 0 to 376] after administration; P=0.004). A total of 8 of 10 participants did not use factor, and 9 of 10 did not have bleeds after vector administration. An asymptomatic increase in liver‐enzyme levels developed in 2 participants and resolved with short‐term prednisone treatment. One participant, who had substantial, advanced arthropathy at baseline, administered factor for bleeding but overall used 91% less factor than before vector infusion. Conclusions We found sustained therapeutic expression of factor IX coagulant activity after gene transfer in 10 participants with hemophilia who received the same vector dose. Transgene‐derived factor IX coagulant activity enabled the termination of baseline prophylaxis and the near elimination of bleeding and factor use. (Funded by Spark Therapeutics and Pfizer; ClinicalTrials.gov number, NCT02484092.)

Successful treatment using recombinant factor VIIa for severe bleeding post cardiopulmonary bypass

PurposeTo describe a case of persistent and excessive bleeding following an aortic valve and ascending aorta replacement that was successfully managed with recombinant factor VIIa (rFVIIa). The postulated mechanisms for rFVIIa are discussed.Clinical featuresA 75-yr-old female with no preoperative coagulopathy underwent a tissue aortic valve replacement and supracoronary ascending aorta replacement for severe aortic stenosis and an ascending aortic aneurysm. Following surgery, she bled in excess of 200 mL·hr−1 despite a nearly normal platelet count and nearly normal coagulation parameters. The patient was surgically re-explored twice in seven hours, and despite the presence of near normalin vitro coagulation parameters, the patient continued to bleed. Multiple units of fresh frozen plasma, platelets and cryoprecipitate were administered empirically. We then administered a single 6-mg (107 μg·kg−1)iv dose of rFVIIa. Following the administration of rFVIIa, blood loss decreased to a total of 440 mL over the next 12 hr.ConclusionsThis case describes the use of rFVIIa for intractable bleeding postcardiovascular surgery in the presence of nearly normal laboratory markers of coagulation. Further controlled laboratory and clinical studies are required to define the role of rFVIIa in patients undergoing cardiovascular surgery.RésuméObjectifDécrire un cas de saignement persistant et abondant, après le remplacement d’une valvule aortique et de l’aorte ascendante, traité avec succès par le facteur VIIa recombinant (rFVIIa). Les mécanismes proposés pour le rFVIIa sont discutés.Éléments cliniquesUne femme de 75 ans, sans coagulopathie préopératoire, a subi le remplacement tissulaire d’une valve aortique et le remplacement de l’aorte ascendante supracoronaire à cause d’une sténose aortique sévère et d’un anévrysme de l’aorte ascendante. Après l’opération, elle a perdu beaucoup de sang, plus de 200 mL·hr−1 malgré une numération plaquettaire normale et des paramètres de coagulation près de la normale. La patiente a été réopérée, deux fois en sept heures et, malgré des paramètres de coagulation in vitro pratiquement normaux, a continué à saigner. De nombreuses unités de plasma frais congelé, de plaquettes et de cryoprécipités ont été administrées empiriquement. Nous avons donné ensuite une seule dose iv de 6 mg (107 μg·kg−1) de rFVIIa. Après quoi l’hémorragie a diminué à 440 mL pendant les 12 h suivantes.ConclusionCe cas illustre l’usage du rFVIIa pour traiter des saignements réfractaires après une opération cardiovasculaire en présence de marqueurs de coagulation pratiquement normaux. D’autres études cliniques contrôlées et d’autres études de laboratoire contrôlées sont nécessaires à la définition du rôle du rFVIIa chez des patients en chirurgie cardiovasculaire.

From theory to practice: Applying current clinical knowledge and treatment strategies to the care of hemophilia A patients with inhibitors

Two bypassing agents are currently available to circumvent the need for factor FVIII in hemophilia A patients with inhibitors: the activated prothrombin complex FEIBA VH and recombinant activated factor VII (NovoSeven. Both products are highly effective in controlling bleeding in the presence of inhibitory alloantibodies, yet their hemostatic efficacy can be unpredictable. As the results of the FEIBA NovoSeven( Comparative (FENOC) study illustrate, patients may respond better to one bypassing agent than the other. Furthermore, guidelines from an expert panel reflect that responsiveness to bypassing therapy may change from one bleed to the next in the same patient and even from hour to hour during the course of a single bleeding event. These findings underscore the need to have both bypassing products available to treat bleeding episodes in inhibitor patients, to frequently evaluate the efficacy of hemostasis during the course of a bleeding event, and to switch products early if the response to treatment is unsatisfactory.

Comparison of accessory cell functions of endothelial cells and monocytes: IL-2 production by T cells and PFC generation

It has been previously shown that endothelial cells (EC) can modulate T-cell responsiveness by mimicking monocyte (AC) function in several different in vitro systems. We now report that EC and AC differ quantitatively in their ability to provide help for IL-2 generation and T-cell induced B-cell differentiation into immunoglobulin secreting cells (ISC). Equal numbers of EC were deficient when compared to AC for promoting ISC generation, but exceeded AC for IL-2 production. Adding optimal numbers of EC drive non-adherent cell cultures to produce more than twice as much IL-2 as adding any number of AC. Furthermore, small numbers of EC were capable of modulating ongoing immune responses when added to cultures containing AC. IL-2 production by PBM was doubled by the addition of enough EC to comprise only 3% of the total culture. EC do not just mimic monocytes in immune responses, but modulate these responses in unique ways.

Clinical and immunologic effects of Staphylococcal protein A immunoadsorption therapy for inhibitor to factor VIII

Abstract A 74-year mild hemophiliac with an inhibitor to factor VIII underwent five 2-L plasma immunoadsorption procedures with a Staphylococcal protein A (Prosorba) column over 7 days. Initially, the inhibitor level increased from 56 to 154 BU/mL. Serum immunoglobulins, immune complexes, C3 and C4 fell progressively with each procedure: C3a was increased. Before therapy, the patient had increased cytotoxic T and activated T cells which decreased to the normal range with treatment. The proportion of T inducer cell and CD4:CD3 ratios increased progressively with each treatment. Natural killer cell activity remained unchanged. Unstimulated patient lymphocytes showed high proliferative activity, but after therapy there was markedly reduced response to mitogens. Both patient and normal lymphocytes showed marked increase in thymidine incorporation when incubated with adsorbed plasma (from column outlet), compared to incubation with unadsorbed plasma (column inlet). The patients serum showed a progressive rise in this “mitogenicity” effect, maximal after the third procedure, then declining to pre-treatment levels after the fifth procedure. After the third immunoadsorption, inhibitor level was 70 BU/mL and he was given prednisone and cyclophosphamide; after the fifth procedure it was 32 BU/mL and 6 months later was undetectable. Although subsequent decrease in the inhibitor may have been due to the plasma immunoadsorption, it is important to note that this treatment may be paradoxically associated with a rise in antibody levels. In addition to antibody changes, Staph. protein A perfusion affected cellular immunity.

Endothelial Cells Modulate Both T-Cell-Dependent and T-Cell-Independent Plaque-Forming Cell Generation in vitro

The effects of live endothelial cells (EC), paraformaldehyde fixed EC, and EC supernatant were measured on pokeweed mitogen (PWM)-induced T-cell-dependent plaque-forming cell (PFC) generation by peripheral blood mononuclear cell (PBM). At low doses (less than or equal to 2 x 10(4) cells/culture) live EC helped PFC generation. At higher doses (greater than or equal to 10 x 10(4) cells/culture) the effect of live EC was always marked suppression (less than 10% of baseline PFC). In contrast both fixed EC and EC supernatant provided help exclusively over a wide dose range. The EC-helper effect enhanced the sensitivity of PBM to suboptimal PWM doses and also accelerated the rate of PFC generation during culture. EC influences on PFC could not be modified by gamma-interferon induction of surface DR which is known to modify EC accessory cell ability. There was also only minimal helper activity of live EC and fixed EC on the PFC generation by Epstein-Barr virus-induced cultures of purified B cells (which had been depleted of both T cells and monocytes). In contrast, suppression (greater than 97%) of PFC in isolated B-cell cultures was found even when EC constituted less than 1% of cultured cells. These results imply EC have the potential of providing multiple regulatory signals which modulate in vitro antibody production. EC-derived mechanisms are independent of their accessory cell function and require interaction with non-B cells for help, but suppression may occur directly at the B-cell level.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of Algorithms for the Treatment of Problem Bleeding Episodes in Patients With Hemophilia Having Inhibitors.

The correlation between real-world clinical decisions and adherence to published treatment algorithms for problem bleeding episodes in patients with severe hemophilia and inhibitors and the resultant impact on clinical outcomes were assessed. Nine cases documenting treatment for problem bleeding episodes in patients with severe hemophilia and inhibitors were retrospectively reviewed. Adherence to treatment algorithms was rated on a scale of 1 to 5, 1 being no adherence and 5 being very high adherence. Adherence ratings >3 were assigned to 7 cases in which high adherence was associated with ≤4 days to achieve hemostatic control; hospitalization for ≤7 days was noted in 6 of these cases. In cases rated ≤3 (n = 2), time to hemostatic control ranged from 5 to 8 days and hospitalization duration ranged from 10 to 16 days. These findings suggest that adherence to treatment algorithms may be beneficial in treating problem bleeding events in patients with hemophilia and inhibitors.

Retrospective review of Acquired Haemophilia A from the largest Canadian Haemophilia treatment centre

1 . Franchini M , Coppola A , Tagliaferri A , Lippi G . FEIBA versus NovoSeven in hemophilia patients with inhibitors . Semin Thromb Hemost . 2013 ; 39 ( 7 ): 772 778 . 2 . Takedani H , Shima M , Horikoshi Y , et al. Tenyear experience of recombinant activated factor VII use in surgical patients with congenital haemophilia with inhibitors or acquired haemophilia in Japan . Haemophilia . 2015 ; 21 ( 3 ): 374 379 . 3 . Hoffman M , Dargaud Y . Mechanisms and monitoring of bypassing agent therapy . J Thromb Haemost . 2012 ; 10 ( 8 ): 1478 1485 . 4 . Brown SA , Barnes C , Curtin J , et al. How we use recombinant activated Factor VII in patients with haemophilia A or B complicated by inhibitors. Working group of hematology experts from Australia and New Zealand, Melbourne, April 2011 . Intern Med J . 2012 ; 42 ( 11 ): 1243 1250 . 5 . Villar A , Aronis S , Morfini M , et al. Pharmacokinetics of activated recombinant coagulation factor VII (NovoSeven) in children vs. adults with haemophilia A . Haemophilia . 2004 ; 10 ( 4 ): 352 359 . 6 . Quintana-Molina M , Martínez-Bahamonde F , González-García E , et al. Surgery in haemophilic patients with inhibitor: 20 years of experienc e . Haemophilia . 2004 ; 10 ( Suppl 2 ): 30 40 . 7 . Neunert CE , Miller KL , Journeycake JM , Buchanan GR . Implantable central venous access device procedures in haemophilia patients without an inhibitor: systematic review of the literature and institutional experience . Haemophilia . 2008 ; 14 ( 2 ): 260 270 . 8 . Fonseca A , Nagel K , Decker K , et al. Central venous access device insertion and perioperative management of patients with severe haemophilia A: a local experience . Blood Coagul Fibrinolysis . 2016 ; 27 ( 2 ): 156 159 . 9 . Ljung R , van den Berg M , Petrini P , et al. PortACath usage in children with haemophilia: experience of 53 cases . Acta Paediatr . 1998 ; 87 ( 10 ): 1051 1054 . 10 . Bollard CM , Teague LR , Berry EW , Ockelford PA . The use of central venous catheters (portacaths) in children with haemophilia . Haemophilia . 2000 ; 6 ( 2 ): 66 70 .

The authors respond to “Is referral necessary for abnormal bleeding?”

We thank Dr. Giles[1][1] for her interest and commentary on our article.[2][2] For clarification, Drs. Sholzberg, Teitel and Hicks are hematologists, and Dr. Sholzberg is the medical director of the coagulation laboratory at St. Michael’s Hospital. In addition, Drs. Sholzberg and Teitel co-direct