Unilateral inguinofemoral lymphadenectomy in patients with early-stage vulvar squamous cell carcinoma and a unilateral metastatic sentinel lymph node is safe.

OBJECTIVE: Optimal management of the contralateral groin in patients with early-stage vulvar squamous cell carcinoma (VSCC) and a metastatic unilateral inguinal sentinel lymph node (SN) is unclear. We analyzed patients who participated in GROINSS-V I or II to determine whether treatment of the contralateral groin can safely be omitted in patients with a unilateral metastatic SN. METHODS: We selected the patients with a unilateral metastatic SN from the GROINSS-V I and II databases. We determined the incidence of contralateral additional non-SN metastases in patients with unilateral SN-metastasis who underwent bilateral inguinofemoral lymphadenectomy (IFL). In those who underwent only ipsilateral groin treatment or no further treatment, we determined the incidence of contralateral groin recurrences during follow-up. RESULTS: Of 1912 patients with early-stage VSCC, 366 had a unilateral metastatic SN. Subsequently, 244 had an IFL or no treatment of the contralateral groin. In seven patients (7/244; 2.9% [95% CI: 1.4%-5.8%]) disease was diagnosed in the contralateral groin: five had contralateral non-SN metastasis at IFL and two developed an isolated contralateral groin recurrence after no further treatment. Five of them had a primary tumor ≥30 mm. Bilateral radiotherapy was administered in 122 patients, of whom one (1/122; 0.8% [95% CI: 0.1%-4.5%]) had a contralateral groin recurrence. CONCLUSION: The risk of contralateral lymph node metastases in patients with early-stage VSCC and a unilateral metastatic SN is low. It appears safe to limit groin treatment to unilateral IFL or inguinofemoral radiotherapy in these cases.

2019 IUSTI-Europe guideline for the management of anogenital warts.

This guideline is an update of the 2011 European Guideline for the Management of Anogenital Warts. It is intended to support best practice in the care of patients with anogenital warts by including evidence-based recommendations on diagnosis, treatment, follow-up and advice to patients. It is intended for use by healthcare professionals in sexual healthcare or dermato-venereology clinics in Europe but may be adapted for use in other settings where the management of anogenital warts is undertaken. As a European guideline, recommendations should be adapted according to national circumstances and healthcare systems. Despite the availability of vaccine to prevent HPV types 6 and 11, the cause of >95% anogenital warts, they remain an important and frequent health problem. The previous systematic review of randomized controlled trials for anogenital warts was updated. The changes in the present guideline include the following: Updated background information on the prevalence, natural history and transmission of human papillomavirus (HPV) infection and anogenital warts. Key recommendations for diagnosis and treatment have been graded according to the strength of the recommendation and the quality of supporting evidence. 5-fluorouracil, local interferon and photodynamic therapy have been evaluated and included as potential second-line treatment options. Evidence of the impact of HPV vaccination on the incidence of anogenital warts has been updated.

Patient-centred value framework for haemophilia.

INTRODUCTION: Growing budgetary demands have led to increased scrutiny of healthcare spending for rare diseases, leading to a unified goal within the haemophilia community to define objectively patient-centred value in haemophilia care. AIM: To develop a patient-centred outcomes framework with global applicability for assessing value in haemophilia healthcare. METHODS: An international, multidisciplinary panel of experts convened to identify the range of patient impacts of haemophilia health care and organize these into a three-tiered, patient-centred outcomes framework based on Porter's model for assessing value. RESULTS: In addition to measures common to other chronic diseases (eg survival and quality of life), Tier 1, health status achieved or retained, includes haemophilia-specific outcomes of bleeding frequency, musculoskeletal complications and life-threatening bleeds, as well as measures of function or activity. Tier 2, process of recovery, includes such outcomes as time to initial treatment, time to recovery and time missed at education/work; also included are disutility of care, measured by inhibitor development, pathogen transmission/infections, orthopaedic intervention and difficult venous access. Tier 3, sustainability of health, is measured by bleed avoidance, maintenance of productive lives and good health over time; potential long-term negative consequences include insufficient or inappropriate therapy and age-related complications. The applicability of the outcomes framework for different types of haemophilia healthcare interventions is described. CONCLUSION: Haemophilia health care can affect multiple patient-centred outcomes across diverse patient types and healthcare systems. This framework organizes those outcomes for informing value-based decision making by multiple stakeholders and provides the basis for further refinement and development of a standardized outcomes set.

Estimating the potential cost of a high dose immune tolerance induction (ITI) therapy relative to the cost of a combined therapy of a low dose ITI therapy with bypassing agent prophylaxis.

INTRODUCTION: The International Immune Tolerance Study (I-ITI) demonstrated comparable success rates between low (FVIII 50 IU/kg/TIW) and high dose (FVIII 200 IU/kg/day) regimens. While costlier, the high dose ITI regimen achieved shorter time-to-treatment success with fewer bleeding episodes compared to the low dose ITI regimen. Adding bypassing agent prophylaxis (BAP) to a low dose ITI regimen may reduce bleeding while still being less costly than high dose ITI. AIM AND METHODS: An economic model was developed to compare high dose ITI to low dose ITI with BAP. All model inputs were derived from clinical trials. The I-ITI study indicated a median time to negative inhibitor titre of 4.6 and 9.2 months and average number of bleeds/patient of 4.2 and 9.9 for the high and low dose regimens respectively. Based on the BAP trials, aPCC (85 U/kg/TIW) and rFVIIa (90 µg/kg/day) achieved a 62% and 45% reduction in bleeding frequency respectively. Cost analysis was from a US third party payer perspective and limited to drug costs. One-way, two-way and probabilistic sensitivity analyses were performed. RESULTS: Costs of low dose ITI with aPCC prophylaxis until negative inhibitor titre is achieved was 24.0% less compared to high dose ITI. Low dose ITI with rFVIIa prophylaxis cost 46.5% more compared to high dose ITI. Model results were robust in the majority of the sensitivity analyses. CONCLUSION: A low dose ITI regimen with aPCC prophylaxis may be cost saving compared to a high dose ITI regimen with the potential to reduce morbidity by lowering the risk for breakthrough bleeds.

Complications of haemophilia in babies (first two years of life): a report from the Centers for Disease Control and Prevention Universal Data Collection System.

AIM: To describe the prevalence and complications in babies ≤2 years with haemophilia. METHODS: We used a standardized collection tool to obtain consented data on eligible babies aged ≤2 years with haemophilia enrolled in the Centers for Disease Control and Prevention Universal Data Collection System surveillance project at US Hemophilia Treatment Centers (HTCs). RESULTS: Of 547 babies, 82% had haemophilia A, and 70% were diagnosed within one month of birth. Diagnosis was prompted by known maternal carrier status (40%), positive family history (23%), bleeding (35%) and unknown 2%; 81% bled during the first two years. The most common events were bleeding (circumcision, soft tissue, oral bleeding) and head injury. There were 46 episodes of intracranial haemorrhage (ICH) in 37 babies (7%): 18 spontaneous, 14 delivery related, 11 traumatic, 2 procedure related and 1 unknown cause. Of the 176 central venous access devices (CVADs) in 148 (27%) babies, there were 137 ports, 22 surgically inserted central catheters and 20 peripherally inserted central catheters. Ports had the lowest complication rates. Inhibitors occurred in 109 (20%) babies who experienced higher rates of ICH (14% vs. 5%; P = 0.002), CVAD placement (61% vs. 19%; P < 0.001) and CVAD complications (44% vs. 26%; P < 0.001). The most common replacement therapy was recombinant clotting factor concentrates. CONCLUSION: Bleeding events in haemophilic babies ≤2 years were common; no detectable difference in the rates of ICH by the mode of delivery was noted. Neonatal factor exposure did not affect the inhibitor rates. Minor head trauma, soft tissue and oropharyngeal bleeding were the leading indications for treatment.

Rare coagulation disorders: fibrinogen, factor VII and factor XIII.

Rare coagulation disorders (RCDs) include the inherited deficiencies of fibrinogen, factor (F) II, FV, combined FV and VIII, FVII, FX, combined FVII and X, FXI, FXIII and combined congenital deficiency of vitamin K-dependent factors (VKCFDs). Despite their rarity, a deep comprehension of all these disorders is essential to really understand haemostasis. Indeed, even if they share some common features each RCD has some particularity which makes it unique. In this review, we focus on three disorders: fibrinogen, FVII and FXIII.

Efficacy and safety of prophylactic treatment with plasma-derived factor XIII concentrate (human) in patients with congenital factor XIII deficiency.

UNLABELLED: Congenital factor XIII (FXIII) deficiency is an extremely rare, potentially life-threatening bleeding disorder. Routine prophylactic management is recommended for individuals with clinically relevant FXIII deficiency. This prospective, multicentre, open-label study evaluated the long-term efficacy and safety of prophylactic infusions of FXIII concentrate (human) 40 IU kg(-1) in patients with congenital FXIII deficiency. FXIII concentrate (human) was administered every 4 weeks for 12 months. Dosing was adjusted to maintain trough FXIII activity levels of 5-20%. Logistical and ethical constraints precluded use of a placebo control group. Annualized incidence of spontaneous bleeding was compared with historical rates; safety was assessed as a secondary objective. Forty-one patients were enrolled and completed the study. The annualized rate for spontaneous bleeding episodes requiring FXIII treatment was 0.000 episodes per patient-year (95% CI: 0.000; 0.097). The study met its primary endpoint: the upper limit of the 95% CI was substantially below the historical rate of 2.5 bleeding episodes per patient-year. Five spontaneous bleeding episodes (involving three patients; none requiring FXIII treatment) and eight trauma-related bleeding episodes (two requiring FXIII treatment) occurred. Five patients had surgery during the study, only one of whom required FXIII treatment for post-surgical bleeding. Most patients (≥ 85%) had trough FXIII activity levels ≥ 10%. No patient discontinued treatment due to an adverse event. No adverse events related to thromboembolism or viral transmission were reported. Prophylactic treatment with FXIII concentrate (human) was well tolerated and prevented spontaneous bleeding episodes that were serious enough to require treatment with FXIII-containing product. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov/ct2/show/NCT00885742.

Pharmacokinetics and safety of plasma-derived factor XIII concentrate (human) in patients with congenital factor XIII deficiency.

UNLABELLED: Congenital factor XIII (FXIII) deficiency is a rare condition with substantial risk for life-threatening bleeding. Replacement of deficient FXIII with plasma-derived FXIII concentrate is a treatment option. The current 12-week study evaluated the steady-state pharmacokinetic (PK) and safety profile of prophylactic infusions of FXIII concentrate (human) in patients with congenital FXIII deficiency. Patients received FXIII concentrate (human) 40 IU kg(-1) on Days 0, 28, and 56. FXIII levels were assessed before and after each infusion; steady-state PK parameters were assessed up to 28 days after the infusion on Day 56. Treatment effectiveness in maintaining trough FXIII activity levels ≥ 5% over 28 days and safety parameters were also assessed. Fourteen patients received FXIII concentrate (human) and 13 completed the study. Post-infusion, FXIII activity levels increased to within the range found in patients without congenital FXIII deficiency without reaching supra-therapeutic levels. Non-baseline-adjusted trough FXIII activity levels were maintained at or above 10% at all post-baseline visits in all patients. Steady-state PK parameters were baseline-adjusted; maximum FXIII activity was 87.7% at 1.72 h post-infusion, subsequently declining to a minimum of 5.0%. The half-life was 6.6 days. FXIII concentrate (human) was generally well tolerated. Two patients had possibly treatment-related adverse events. There were no reports of thromboembolism, viral transmission, bleeding events or treatment-related hypersensitivity. These findings support use of FXIII concentrate (human) 40 IU kg(-1) every 28 days as an appropriate regimen for routine, long-term prophylaxis in children and adults with congenital FXIII deficiency. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov/ct2/show/NCT00883090.

Haemophilia Experiences, Results and Opportunities (HERO) study: treatment-related characteristics of the population.

The HERO (Haemophilia Experiences, Results and Opportunities) quantitative surveys collected information on characteristics and perceptions of adult persons with haemophilia (PWH) and parents of children with haemophilia. The aim of this article is to describe the perceptions of PWH and parents on psychosocial aspects related to treatment. Two online surveys (one for PWH, one for parents) were conducted in 10 countries. Among 675 PWH respondents, 77% reported having responsibility for their own care; 72% of 561 parent respondents had the main responsibility for their son. PWH were most commonly treated on demand (45% of 648 adults using factor concentrate), with 32% on regular prophylaxis and 23% treated on demand with short-term prophylaxis (e.g. for sports/physiotherapy). Children were most often treated with prophylaxis (65% of 549 children using factor concentrate), with 26% treated on demand and 8% treated on demand with short-term prophylaxis. Factor was generally used as instructed at home. Some respondents (41% PWH; 30% parents) had difficulties/concerns with factor availability/affordability. PWH reported more bleeds in the last 12 months than parents reporting their son's bleeds (mean 17.8 vs. 8.7). Both PWH and parents generally perceived that overall, their (their son's) haemophilia was well controlled. Results differed by country. The HERO study captured new, patient-based data regarding many facets of life relevant to PWH, including treatment. The information conveyed in this article largely represents new insights regarding perceptions of treatment and provides initial benchmark statistics for further research.

Pharmacokinetic characterization of recombinant factor XIII (FXIII)-A2 across age groups in patients with FXIII A-subunit congenital deficiency.

Three trials investigated the pharmacokinetics (PK) of recombinant factor XIII (rFXIII) A-subunit. To compare the PK characteristics of rFXIII among trials and different age groups of patients. Dosing with rFXIII 35 IU kg(-1) every 4th week. Blood samples for PK assessments were collected regularly throughout the dosing interval from a total of 68 individual patients with FXIII congenital deficiency. The mean PK parameters were similar across the three age groups, and for the three trials, as well as constant over time based on results from patients participating in both mentor 1 and mentor 2 trials. The geometric mean half-life ranged from 11.6 to 15.0 days, and the trough FXIII activity levels ranged from 0.15 to 0.21 IU mL(-1) . The population PK model identified body weight as a statistically significant covariate influencing clearance (CL) and volume of distribution (Vd ), with a similar increase in both parameters with increased body weight. The half-life was not affected by body weight. Gender (females vs. males) and age category (paediatric vs. adult) did not affect CL. The PK profile of rFXIII, after dosing with 35 IU kg(-1) of rFXIII, was independent of age and comparable between trials and FXIII trough activity levels were constant. Despite rather large individual variation in the maximal FXIII activity levels, all individual mean trough activity levels were above 0.1 IU mL(-1) during the entire duration of the trials. The results support that monthly dosing with 35 IU kg(-1) of rFXIII to patients with FXIII A-subunit deficiency, regardless of age, is adequate for prophylaxis.

Haemophilia Experiences, Results and Opportunities (HERO) Study: survey methodology and population demographics.

Psychosocial factors have a significant impact on the quality of life of persons with haemophilia (PWH). The Haemophilia Experiences, Results and Opportunities (HERO) initiative was developed to provide a greater understanding of the psychological components which influence the lives of PWH. This article describes the HERO methodology and the characteristics of respondents. Two online surveys (one for adult PWH ≥18 years and one for parents of children <18 years with haemophilia) were developed by an international advisory board and conducted in 10 countries. The surveys included demographic and treatment characteristics, relationships, sexual intimacy, quality of life, barriers to treatment and sources of information. A total of 675 PWH [age, median (range) 36 (18-86 years)] and 561 parents [39 (23-68 years)] completed the survey. PWH/parents reported haemophilia A (74%/76%), B (13%/16%) or with inhibitors (13%/8%). Spontaneous joint bleeding was reported in 76%/52% of PWH/children with haemophilia A, 67%/47% with haemophilia B and 93%/76% with inhibitors. Median number of bleeds (interquartile range) was 7 (2-20) for PWH and 4 (2-10) for children in the past year. Most PWH and children were treated with factor concentrate. PWH reported arthritis (49%) and HIV/HCV infections (18%/43%) related to haemophilia. Most PWH and parent respondents had received formal education (85%/89%) and were employed full- or part-time (60%/72%). HERO is one of the largest multinational studies focused on psychosocial issues in haemophilia, including historical and treatment information that will allow for multivariate analyses of determinants of health in haemophilia.

Haemophilia Experiences, Results and Opportunities (HERO) Study: influence of haemophilia on interpersonal relationships as reported by adults with haemophilia and parents of children with haemophilia.

Evidence delineating the effects of haemophilia on interpersonal relationships is sparse and largely outdated, failing to reflect the impact of current treatment strategies. HERO (Haemophilia Experiences, Results and Opportunities) was commenced to garner a more comprehensive understanding of psychosocial issues facing persons with haemophilia (PWH). This article describes the findings of the quantitative HERO survey relating to the influence of haemophilia on interpersonal relationships of adult PWH, and parents/caregivers of children with haemophilia. Separate questionnaires were completed by adult PWH and parents of minor children from 10 countries, including satisfaction with support from partners, family, friends and other social contacts; disclosure of haemophilia and carrier status and family dynamics. A total of 675 PWH and 561 parents completed the survey. Over half of PWH (57%) and parents (84%) were married. Most PWH were satisfied with support from partners (94%), family (90%) and friends (85%), with lower percentages reported among those with inhibitors. Most parents were likewise satisfied with support from partners (88%) and family (83%). Whereas PWH were reticent to disclose their diagnosis beyond family and friends, parents were more likely to share their son's diagnosis, and most were satisfied with the support from their son's peers (74%), teachers (83%) and other adults in supervisory roles (85%). PWH and parents surveyed were satisfied overall with the support they received from partners, family, friends and social contacts. Relationships are affected by haemophilia in various ways, and particularly affected in terms of disease burden, age and social life.

Standardization of thromboelastography: a report from the TEG-ROTEM working group.

Laboratory evaluation of bleeding disorders has been performed with the standard clotting assays such as the PT and PTT for several decades. Our improved understanding of the process of blood coagulation has now revealed the important role played by the cellular elements such as platelets, monocytes and red blood cells. The need for a test that can assess clotting in a more 'global' manner, beyond the initiation of clot formation, has led to greater interest in assays such as thrombin generation and thromboelastography. Even though there are several publications using thromboelastography it remains a research tool as the methodology is not standardized. In an attempt to show reproducibility and consistency using thromboelastography, a group of investigators from different countries joined hands to form the TEG-ROTEM Working Group. Two studies were performed using PRP and FVIII deficient plasma and an intrinsic pathway activator. This article summarizes the results of the first international effort at standardization of thromboelastography. Both of the instruments using this technology (TEG(®) and ROTEM(®)) were used. Nine laboratories from countries around the globe participated in this effort. The results showed a significant inter-laboratory variance with CV's greater than 10%. Although these results were not satisfactory, this has been the first effort to standardize this methodology and significant work remains to be done to improve reliability and reproducibility. These studies were performed on PRP and the results may be more reliable when preformed on whole blood samples. We believe that it is important to continue this work so that we may investigate the usefulness and potential applications of thromboelastography in the evaluation of bleeding and thrombosis.

Surveillance of female patients with inherited bleeding disorders in United States Haemophilia Treatment Centres.

Inherited bleeding disorders are especially problematic for affected girls and women due to the monthly occurrence of menstrual periods and the effects on reproductive health. Although heavy menstrual bleeding (HMB) is the most common manifestation, females with inherited bleeding disorders (FBD) experience other bleeding symptoms throughout the lifespan that can lead to increased morbidity and impairment of daily activities. The purpose of this article is to describe the utility of a female-focused surveillance effort [female Universal Data Collection (UDC) project] in the United States Haemophilia Treatment Centres (HTCs) and to describe the baseline frequency and spectrum of diagnoses and outcomes. All FBD aged 2 years and older receiving care at selected HTCs were eligible for enrollment. Demographic data, diagnoses and historical data regarding bleeding symptoms, treatments, gynaecological abnormalities and obstetrical outcomes were analysed. Analyses represent data collected from 2009 to 2010. The most frequent diagnoses were type 1 von Willebrand's disease (VWD) (195/319; 61.1%), VWD type unknown (49/319; 15.4%) and factor VIII deficiency (40/319; 12.5%). HMB was the most common bleeding symptom (198/253; 78.3%); however, 157 (49.2%) participants reported greater than four symptoms. Oral contraceptives were used most frequently to treat HMB (90/165; 54.5%), followed by desmopressin [1-8 deamino-D-arginine vasopressin (DDAVP)] (56/165; 33.9%). Various pregnancy and childbirth complications were reported, including bleeding during miscarriage (33/43; 76.7%) and postpartum haemorrhage (PPH) (41/109; 37.6%). FBD experience multiple bleeding symptoms and obstetrical-gynaecological morbidity. The female UDC is the first prospective, longitudinal surveillance in the US focusing on FBD and has the potential to further identify complications and reduce adverse outcomes in this population.

Further characterization of the thrombasthenia-related idiotype OG. Antiidiotype defines a novel epitope(s) shared by fibrinogen B beta chain, vitronectin, and von Willebrand factor and required for binding to beta 3.

A patient (OG) with Glanzmann thrombasthenia became refractory to platelet transfusion after the production of an immunoglobulin G (IgG) isoantibody (Ab1) specific for the integrin subunit beta 3. To determine the frequency at which the OG idiotype is found in the general population and in immune-mediated disease states, we developed a rabbit polyclonal antibody (Ab2) specific for affinity-purified OG anti-beta 3 Fab. The binding of Ab2 to Ab1 is inhibited by purified alpha IIb beta 3. Ab2 als binds to IgG specific for alpha IIb beta 3 obtained from one nonrelated Glanzmann thrombasthenia patient ES who has developed isoantibodies of similar specificity. On the other hand, Ab2 does not recognize alpha IIb beta 3-specific antibodies produced by two Glanzmann thrombasthenia patients, AF and LUC, who have developed isoantibodies with specificities distinct from that of the OG isoantibody. Moreover, Ab2 does not recognize alpha IIb beta 3-specific antibodies developed by three representative patients with (autoimmune) thrombocytopenic purpura or six representative patients with alloimmune thrombocytopenias, nor does it bind to IgG from any of 13 nonimmunized individuals. We have found that Ab2 also binds to selected protein ligands of alpha IIb beta 3 namely, fibrinogen, vitronectin, and von Willebrand factor, but not to other protein ligands or control proteins, such a fibronectin, type I collagen, and albumin. The epitope(s) recognized by Ab2 on each adhesive protein are either very similar or identical since each protein can inhibit the binding of Ab2 to any of the other proteins. The epitope on fibrinogen recognized by Ab2 resides in the B beta chain, and is likely contained within the first 42 amino acids from the NH2 terminus. Since OG IgG inhibits fibrinogen binding to alpha IIb beta 3, the specificity of the OG idiotype defines a novel binding motif for the integrin alpha IIb beta 3 that is shared by fibrinogen, vitronectin, and von Willebrand factor, but distinct from previously described RGD-containing sites on the fibrinogen, A alpha chain or the fibrinogen gamma chain COOH-terminal decapeptide site. Our findings reported here represent an excellent example of molecular mimicry in which an antigen-selected, IgG inhibitor of alpha IIb beta 3 function shares a novel recognition sequence common to three physiologic protein ligands of that receptor.

Prophylactic therapy with Fibrogammin P is associated with a decreased incidence of bleeding episodes: a retrospective study.

SUMMARY: Congenital factor XIII (FXIII) deficiency is an extremely rare, yet potentially life-threatening, bleeding disorder, with a 30% rate of spontaneous intracranial haemorrhage. Routine prophylactic management is recommended for all individuals with clinically relevant (FXIII) deficiency and for all symptomatic individuals with congenital factor deficiency. Fibrogammin P is a purified, pasteurized concentrate of FXIII that appears to carry negligible risk of viral transmission, unlike other unprocessed products containing FXIII. An ongoing Phase II/III study of Fibrogammin P in patients with congenital FXIII deficiency is being conducted to evaluate the prophylactic efficacy and long-term safety of this product. Using retrospective chart review data from subjects enrolled in the Phase II/III study, the current analysis was designed to compare spontaneous bleed-event rates prior to and after the initiation of Fibrogammin P prophylaxis. Seven subjects were evaluable for comparison, having received no other prophylactic FXIII-containing product during the 24 months prior to study entry. The mean annual number of spontaneous bleeds was 2.5 events per year prior to Fibrogammin P prophylaxis and 0.2 events per year during Fibrogammin P prophylaxis (P = 0.01). Patients reported no severe bleeds during Fibrogammin P therapy. This small sample supports a consistent and clinically meaningful reduction in spontaneous bleeding with prophylactic use of Fibrogammin P.

Comparison of kaolin and tissue factor activated thromboelastography in haemophilia.

A limitation of bypassing agent therapy for haemophilia patients with inhibitors is the absence of a laboratory assay, which predicts the clinical response to treatment. Recent investigations have demonstrated the potential for thromboelastography to assess the effects of bypassing agent therapy in this patient population. While tissue factor activation has been used in several prior studies, a recent multicentre study failed to demonstrate an expected concentration-response effect of rFVIIa and called into question the tissue factor activation methods that have been employed. A comparison of kaolin to two concentrations of tissue factor as the activation method for thromboelastography was investigated in patients with haemophilia. We performed kaolin and tissue factor activated thromboelastography on blood from inhibitor and non-inhibitor patients with and without addition of rFVIIa and rFVIII. The results demonstrate that kaolin leads to a longer R, K and angle than the higher dilution of tissue factor (1:17 000) at baseline (no factor) and after addition of rFVIIa for both the inhibitor and non-inhibitor patients. Kaolin led to a longer R and K in comparison to a low dilution of tissue factor (1:42 000) following the addition of rFVIIa in the inhibitor patients. The longer R and K allows for better discrimination of the effects of rFVIIa thus making kaolin the most sensitive activation method in this setting. Thus kaolin activated thromboelastography should be considered an effective, perhaps the most effective, activator when utilizing thromboelastography to assess the effects of rFVIIa in haemophilia patients with inhibitors.

Engineering a stable and selective peptide blocker of the Kv1.3 channel in T lymphocytes.

Kv1.3 potassium channels maintain the membrane potential of effector memory (T(EM)) T cells that are important mediators of multiple sclerosis, type 1 diabetes mellitus, and rheumatoid arthritis. The polypeptide ShK-170 (ShK-L5), containing an N-terminal phosphotyrosine extension of the Stichodactyla helianthus ShK toxin, is a potent and selective blocker of these channels. However, a stability study of ShK-170 showed minor pH-related hydrolysis and oxidation byproducts that were exacerbated by increasing temperatures. We therefore engineered a series of analogs to minimize the formation of these byproducts. The analog with the greatest stability, ShK-192, contains a nonhydrolyzable phosphotyrosine surrogate, a methionine isostere, and a C-terminal amide. ShK-192 shows the same overall fold as ShK, and there is no evidence of any interaction between the N-terminal adduct and the rest of the peptide. The docking configuration of ShK-192 in Kv1.3 shows the N-terminal para-phosphonophenylalanine group lying at the junction of two channel monomers to form a salt bridge with Lys(411) of the channel. ShK-192 blocks Kv1.3 with an IC(50) of 140 pM and exhibits greater than 100-fold selectivity over closely related channels. After a single subcutaneous injection of 100 microg/kg, approximately 100 to 200 pM concentrations of active peptide is detectable in the blood of Lewis rats 24, 48, and 72 h after the injection. ShK-192 effectively inhibits the proliferation of T(EM) cells and suppresses delayed type hypersensitivity when administered at 10 or 100 microg/kg by subcutaneous injection once daily. ShK-192 has potential as a therapeutic for autoimmune diseases mediated by T(EM) cells.

Glycoprotein Ic-IIa functions as an activation-independent fibronectin receptor on human platelets.

Soluble fibronectin binds specifically to glycoprotein (GP) IIb-IIIa on thrombin-activated platelets, and this binding is not observed with platelets of patients with Glanzmann's thrombasthenia (GT) which lack GPIIb-IIIa. Here we report that GT platelets retain the ability to interact with fibronectin-coated surfaces. Adhesion to fibronectin does not require platelet activation and is inhibited by soluble fibronectin, antibodies specific for fibronectin, peptides containing the sequence Arg-Gly-Asp and polyclonal antibodies specific for band 3 of the chicken embryo fibroblast fibronectin receptor (anti-band 3). Using anti-band 3, we have purified a second fibronectin receptor from human platelets, a heterodimer composed of glycoproteins previously designated GPIc and GPIIa. The GPIc-IIa complex is found on both GT and normal platelets and appears to be identical to the GP138 kD-GP160 kD complex recently immunopurified by Giancotti et al. (1986. Exp. Cell Res. 163:47-62) and by Sonnenberg et al. (1987. J. Biol. Chem. 268:10376-10383). In this report, we provide the first evidence that GPIc-IIa actually mediates adhesion of platelets to fibronectin-coated surfaces. GPIc-IIa thus represents a second functional fibronectin receptor, distinct from GPIIb-IIIa, that is largely responsible for the adhesion of nonactivated platelets to fibronectin-coated surfaces.

Sites of initial bleeding episodes, mode of delivery and age of diagnosis in babies with haemophilia diagnosed before the age of 2 years: a report from The Centers for Disease Control and Prevention's (CDC) Universal Data Collection (UDC) project.

Lack of detailed natural history and outcomes data for neonates and toddlers with haemophilia hampers the provision of optimal management of the disorder. We report an analysis of prospective data collected from 580 neonates and toddlers aged 0-2 years with haemophilia enrolled in the Universal Data Collection (UDC) surveillance project of the Centers for Disease Control and Prevention (CDC). This study focuses on a cohort of babies with haemophilia whose diagnosis was established before the age of two. The mode of delivery, type and severity of haemophilia, onset and timing of haemorrhages, site(s) of bleeding, provision of prophylaxis with coagulation factor replacement therapy, and the role played by the federally funded Haemophilia Treatment Centers (HTC) in the management of these infants with haemophilia were evaluated. Seventy-five per cent of haemophilic infants were diagnosed early, in the first month of life, especially those with a family history or whose mothers were known carriers; infants of maternal carriers were more likely to be delivered by C-section. Involvement of an HTC prior to delivery resulted in avoidance of the use of assisted deliveries with vacuum and forceps. Bleeding from the circumcision site was the most common haemorrhagic complication, followed by intra- and extra-cranial haemorrhages and bleeding from heel stick blood sampling. Eight per cent of the infants were administered factor concentrate within 24 h of birth; more than half were treated to prevent bleeding. This study highlights the significant rate and the sites of initial bleeding unique to very young children with haemophilia and underscores the need for research to identify optimal evidence-based recommendations for their management.