Risk of Bleeding and Inhibitor Development After Circumcision in Minimally Treated Severe Hemophilia A Patients: A One Year Prospective Study,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4653-4653
Author(s):  
Mohsen Saleh Elalfy ◽  
Nancy Samir Elbarbary ◽  
Mohamed Soliman Eldebeiky

Abstract Abstract 4653 Background Circumcision is a cultural practice for males in the Middle-East during first weeks of life. All parents of hemophilics are eager to do circumcision to their sibs, however, it may carry a risk for development of factor VIII inhibitors as well as risk of excessive bleeding. Objective To evaluate post-circumcision bleeding and assess incidence and time of inhibitor development over 12 months follow-up period of minimally treated severe hemophilia A patients. Patients and methods This prospective analysis has been conducted on eighteen minimally treated patients with severe hemophilia A (age range 8–36 months) with a median age of 18 months, who underwent circumcision during 2009 and twenty four age matched non circumcised patients minimally treated severe hemophilia A. Both groups were followed up for12 months from study entry and all were treated on demand therapy with a single plasma-derived factor VIII product. Hemophilic patients who underwent circumcision were inhibitor negative except two with low- titer inhibitor(3.3 and 4.4 BU/ml) respectively. One hour before the operation, intravenous tranexamic acid (25 mg/ kg) and first dose of factor concentrate (25 unit / Kg) were given to the patients. After reaching a trough plasma factor level more than 90%, patients underwent circumcision using general anesthesia and same surgical technique for all. Bolus injections of factor VIII concentrate were repeated in a dose of (25 units / Kg ) twenty four hours after operation. However, the two patients with inhibitors were given factor VIII concentrate in a dose of (50 units /Kg) with an extra dose at forty-eight hours. Another dose of factor concentrate (25 units/ Kg) was given just before removal of gauze dressing at 5th −7th day post operative. Follow up for inhibitor development was assessed every 8 exposure days (EDs) for 12 months or 100 EDs whichever comes first. Results: Of the eighteen patients enrolled, only one of the 2 patients with low- titer inhibitor had postoperative bleeding at day 5 and 7 respectively. First attack responded to a single dose of factor administration (50 units/Kg), whereas haemostasis was achieved in the second episode after a single dose of Recombinant Factor VIIa (90 microgram/kg) and applying absorbable haemostatic agent (gelatin sponge) and binding. None of the other patients had any bleeding or infection at site of surgery. High -titer inhibitors developed in three patients (16.6 % ) during the follow-up; after 8, 16 and 40 EDs respectively in contrast to four patients (16.6 %) developed high titer inhibitor in the non circumcised group; after a median of 16 exposure days (range 8– 60 EDs). Conclusion: Our study has shown that bleeding following circumcision was absent except in low- titer inhibitor patient necessitating administration of Recombinant Factor VIIa. Moreover, circumcision was not a risk for development of inhibitor where the incidence of high- titer inhibitors during12 months follow up was low in this cohort of minimally treated patients and comparable to non circumcised group. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4004-4004
Author(s):  
Louis M. Aledort ◽  
Gilbert C. White ◽  
Georges E. Rivard

After contamination of factor concentrates with blood-borne viruses, U.S. FDA requirements for new product licensure was based on the safety and efficacy of new biologicals as determined in previously untreated patients (PUPs). While PUPs provided an excellent model for assessing contamination of new products HIV, hepatitis, and other blood-borne viruses, they were not a good model for risk of inhibitor development, since inhibitor development in one form or another was unpredictable and occurred in up to 30-35% of PUPs. More recently, the Factor VIII & IX Subcommittee of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis has recommended that inhibitor induction potential of new factor replacement products is best studied in previously treated patients (PTPs). At the conclusion of the five-year study of 73 PUPs on Recombinate (Baxter) [Bray GL, Gomperts ED, Courter SG et al. A multicenter study of recombinant factor VIII (recombinate): safety, efficacy, and inhibitor risk in previously untreated patients. Blood1994; 83: 2428–35.], the Data Safety and Monitoring Board (DSMB) independently initiated a five-year follow-up to determine how many new inhibitors occurred, and how many transient inhibitors recurred during this time. Data collection was a simple form to determine presence or absence of inhibitor yearly; if an inhibitor was reported to develop, did the subject remain on Recombinate or use other recombinant factor concentrate, and the inhibitor titer. Sixty-five of the original PUPs had data reported. For all 5 years, there were 21, for 4 years, 20, for 3 years, 5, for 2 years, 9, for 1 year, 10. For the 65 who have provided adequate data: Two subjects had a recurrence of their transient inhibitor with titers ranging from 0.78 to 1.3. They both stayed on Recombinate. They lost these inhibitors over the ensuing two years. Three subjects developed a new inhibitor. Their titers ranged from 0.9 to 4 Bethesda units. All stayed on Recombinate. None of these inhibitors were of high titer (>5.0 BU). These patients are PTPs, and on continued recombinant factor replacement, few new inhibitors occur, and those that did were low-titered, and some that disappear recur. Thus, five-year follow-up does not tell the whole story and continues to raise the issue of how many inhibitors are acceptable to regulatory agencies for licensure of a new product.


Blood ◽  
2007 ◽  
Vol 109 (11) ◽  
pp. 4693-4697 ◽  
Author(s):  
Samantha C. Gouw ◽  
Johanna G. van der Bom ◽  
Günter Auerswald ◽  
Carmen Escuriola Ettinghausen ◽  
Ulf Tedgård ◽  
...  

Abstract It has been suggested that plasma-derived factor VIII products induce fewer inhibitors than recombinant factor VIII products. We investigated the relationship of factor VIII product type and switching between factor VIII products with the risk to develop inhibitors. This multicenter retrospective cohort study included 316 patients with severe hemophilia A born between 1990 and 2000. The outcome was clinically relevant inhibitor development, defined as the occurrence of at least 2 positive inhibitor titers with decreased recovery. The risk of inhibitor development was not clearly lower in plasma-derived compared with recombinant factor VIII products (relative risk [RR], 0.8; 95% confidence interval [CI], 0.5-1.3). Among high-titer inhibitors, the possible reduction in risk was even less pronounced (RR, 0.9; CI, 0.5-1.5). Plasma-derived products with considerable quantities of von Willebrand factor (VWF) carried the same risk for inhibitor development as recombinant factor VIII products (RR, 1.0; CI, 0.6-1.6). Switching between factor VIII products did not increase the risk for inhibitors (RR, 1.1; CI, 0.6-1.8). In conclusion, our findings support neither the notion that plasma-derived factor VIII products with considerable concentrations of VWF confer a lower risk to develop inhibitory antibodies than recombinant factor VIII products, nor that switching between factor VIII product brands increases inhibitor risks in previously untreated patients with severe hemophilia A.


1998 ◽  
Vol 80 (11) ◽  
pp. 779-783 ◽  
Author(s):  
Y. Laurian ◽  
E. P. Satre ◽  
A. Borel Derlon ◽  
H. Chambost ◽  
P. Moreau ◽  
...  

SummaryFifty French previously untreated patients with severe hemophilia A (factor VIII <1%), treated with only one brand of recombinant factor VIII (rFVIII), were evaluated for inhibitor development, assessment of risk factors and outcome of immune tolerance regimen. The median period on study was 32 months (range 9-74) since the first injection of rFVIII. Fourteen patients (28%) developed an inhibitor, four of whom (8%) with a high titer (≥10 BU). All inhibitor patients but one continued to receive rFVIII either for on-demand treatment or for immune tolerance regimen (ITR). Among these patients, inhibitor was transient in 2 (4%), became undetectable in 6 and was still present in 6. The prevalence of inhibitor was 12%. Presence of intron 22 inversion was found to be a risk factor for inhibitor development. Immune tolerance was difficult to achieve in our series despite a follow-up period of 16 to 30 months: immune tolerance was complete in only one out of the 3 patients undergoing low dose ITR and in one out of the 5 patients with high dose ITR.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3482-3482
Author(s):  
Joan Cox Gill ◽  
Michelle A Stapleton ◽  
Nancy Kern ◽  
Karen Stephany ◽  
Megan Gavin

Abstract Abstract 3482 Poster Board III-419 About 25% of patients with severe hemophilia A develop neutralizing antibodies to factor VIII (FVIII), termed inhibitors, within a median of eleven exposure days to factor VIII containing therapeutic replacement products. Effective monitoring of inhibitor development in young hemophilic children is hampered by their frequently difficult venous access and their limitations on blood sample size, often making it a challenge to obtain samples suitable to carry out standard PTT based Bethesda assays. We evaluated the performance of the Factor VIII Antibody Screen (GTI Diagnostics, Waukesha, WI), an ELISA-based assay to detect FVIII antibodies in a cohort of hemophilia A patients as they were first exposed to FVIII replacement therapy for treatment of hemorrhages. FVIII antibodies were detected in the assay by incubation of duplicate patient samples and controls in microtiter wells coated with recombinant FVIII. After washing, bound FVIII antibody was detected with alkaline phosphatase conjugated goat anti-human IgG, and a colorimetric endpoint (optical density [OD] read at 405or 410 nm by spectrophotometry) determined in an ELISA plate-reader after incubation with p-nitrophenyl phosphate. Samples were considered positive if the average of the sample ODs was higher than the positive controls or negative if the average of the sample ODs was lower than the negative controls. Thirty consecutively identified patients with severe hemophilia A, who were enrolled in a longitudinal inhibitor study, and had samples of serum or plasma banked from the time of their first exposures to FVIII-containing therapeutic products were included. Patients were followed a median of 15.5 years (range 2 – 23 years). Nineteen (63%) of the patients never developed clinical or laboratory evidence of inhibitor development during follow-up. Eleven of the thirty (37%) developed an inhibitor during follow-up; one of these occurred in a 5 year-old after more than 650 exposure days to factor VIII concentrate. There were no differences in the time-to-first-exposure or pattern of hemorrhages in the two groups with the exception that all post-circumcision hemorrhages (N=6) occurred in the non-inhibitor group. In the non-inhibitor group, banked samples were selected corresponding to 0, 5, 10 and >50 factor VIII exposure-days; none of these samples had a positive result in the FVIII antibody screen ELISA. In the 11 inhibitor patients, banked samples were selected that corresponded with the earliest available sample, a sample obtained prior to the first positive Bethesda assay, the first Bethesda positive sample, a sample obtained at the initiation of immune tolerance induction (ITI), the peak Bethesda titer sample, the first negative Bethesda titer sample during ITI, and the most recent sample. All eleven of those who developed an inhibitor underwent successful immune-tolerance therapy with high dose (100 units/kg/day) factor VIII infusions. All Bethesda positive samples were positive by the FVIII antibody screen ELISA with one exception, a sample from one of the inhibitor patients just prior to development of a recurrent inhibitor. There were 5 Bethesda assay negative/FVIII antibody screen ELISA positive samples in the inhibitor patients; each of these samples had been obtained during ITI at 24-48 hours post factor VIII concentrate infusions, and were concordant with lower than expected factor VIII recoveries. We conclude that the ELISA-based FVIII antibody screen is sensitive and specific for the detection of factor VIII antibodies in patients with hemophilia A who develop inhibitors. Because it can be carried out with small serum as well as plasma samples, it provides a convenient method to obtain results in small patients with poor venous access, although quantification of the antibody titer in positive samples would require additional sample to carry out a PTT-based Bethesda assay. Unlike the Bethesda assay, this ELISA-based assay was able to detect antibodies in transfused patients undergoing ITI without the need for a prolonged washout period. Prospective studies to determine the utility and cost-effectiveness of this method are warranted. Disclosures: Gill: GTI Diagnositcs: Consultancy. Stapleton:GTI Diagnostics: Employment. Kern:GTI Diagnostics: Employment.


1993 ◽  
Vol 4 (2) ◽  
pp. 108-115
Author(s):  
Kenji NISHIO ◽  
Akira YOSHIOKA ◽  
Ken TAKAGAWA ◽  
Shigeki MIYATA ◽  
Yong Dong PARK ◽  
...  

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1303-1303 ◽  
Author(s):  
Karin Kurnik ◽  
Susan Halimeh ◽  
Daniela Manner ◽  
Susanne Holzhauer ◽  
Carmen Escuriola Ettingshausen ◽  
...  

Abstract Abstract 1303 Poster Board I-325 Background A number of environmental and genetic factors have been identified to influence inhibitor development in children with severe hemophilia A (HA): among them, individual therapeutic regimens and the use of different factor VIII products have been controversially discussed. Methods In the present multicenter cohort study we evaluated the impact of i) treatment intensity [median individual dose administered during the first 6 to 8 weeks] and ii) type of factor VIII product [plasma-derived (pd); recombinant-derived (r)] on the risk of high-titre inhibitor development in 150 previously untreated patients with severe hemophilia A (HA) consecutively ascertained between 1982 and 2007 from five German catchment areas. Patients were followed over a period of 200 exposure days from HA onset. Study endpoint was inhibitor-free survival time related to treatment with adjustment for treatment period. Plasma levels of factor VIII were determined by one-stage clotting assays. Inhibitor testing was performed at least monthly to 3 monthly when on therapy using the Bethesda method or its modification [Nijmegen]: The lower detection limit was set at 0.6 Bethesda units [BU]. A peak inhibitor titer of > 5 BU was defined as high responder [HR]. A positive inhibitor testing was stated when an inhibitor was measured at least in two independent follow-up visits. The cumulative inhibitor-free survival was calculated using multivariate Cox regression [hazard ratio (HR) and 95% confidence intervals [CIs]]. Results During the follow-up period 30 of 150 children (20.0%) developed a high titre inhibitor. In univariate analysis the median dose increase per IU/kgbw significantly increased the hazard towards HR inhibitor development [HR/CI: 1.08/1.05-1.11]. In addition, 14 of 52 children treated with rFVIII concentrates (27%) versus 16 of 98 children (16.3%) treated with pdFVIII concentrates developed HR during the observation period [HR/CI: 1.9/0.9-3.9]. In multivariate analysis treatment intensity adjusted for FVIII products and treatment period were independently associated with the development of clinical meaningful inhibitors [HR/95%CI: 1.08/1.1-1.1]. Conclusion Data presented here support the hypothesis that clinical meaningful inhibitor development is of multifactorial origin and that treatment intensity plays a major role. Disclosures Off Label Use: Enoxaparin (LMWH) is used off-label in children to prevent symptomatic thromboembolism.


Blood ◽  
2002 ◽  
Vol 99 (1) ◽  
pp. 175-179 ◽  
Author(s):  
Ton Lisman ◽  
Laurent O. Mosnier ◽  
Thierry Lambert ◽  
Evelien P. Mauser-Bunschoten ◽  
Joost C. M. Meijers ◽  
...  

Recombinant factor VIIa (rFVIIa) is a novel prohemostatic drug for patients with hemophilia who have developed inhibitory antibodies. The postulation has been made that hemophilia is not only a disorder of coagulation, but that hyperfibrinolysis due to a defective activation of thrombin activatable fibrinolysis inhibitor (TAFI) might also play a role. In this in vitro study, the potential of rFVIIa to down-regulate fibrinolysis via activation of TAFI was investigated. rFVIIa was able to prolong clot lysis time in plasmas from 17 patients with severe hemophilia A. The prolongation of clot lysis time by rFVIIa was completely abolished by addition of an inhibitor of activated TAFI. The concentration of rFVIIa required for half maximal prolongation of clot lysis time (Clys½-VIIa) varied widely between patients (median, 73.0 U/mL; range, 10.8-250 U/mL). The concentration of rFVIIa required for half maximal reduction of clotting time (Cclot½-VIIa) was approximately 10-fold lower than the Clys½-VIIa value (median, 8.4 U/mL; range, 1.7-22.5 U/mL). Inhibition of TFPI with a polyclonal antibody significantly decreased Clys½-VIIa values (median, 2.6 U/mL; range, 0-86.9 U/mL), whereas Cclot½-VIIa values did not change (median, 7.2 U/mL; range, 2.2-22.5 U/mL). On addition of 100 ng/mL recombinant full-length TFPI, a nonsignificant increase of Clys½-VIIa values was observed (median, 119.2 U/mL; range, 12.3-375.0 U/mL), whereas Cclot½-VIIa values did not change (median, 8.8 U/mL; range, 2.6-34.6 U/mL). In conclusion, this study shows that rFVIIa both accelerates clot formation and inhibits fibrinolysis by activation of TAFI in factor VIII-deficient plasma. However, a large variability in antifibrinolytic potential of rFVIIa exists between patients.


Blood ◽  
2012 ◽  
Vol 119 (12) ◽  
pp. 2922-2934 ◽  
Author(s):  
Samantha C. Gouw ◽  
H. Marijke van den Berg ◽  
Johannes Oldenburg ◽  
Jan Astermark ◽  
Philip G. de Groot ◽  
...  

Abstract This systematic review was designed to provide more precise effect estimates of inhibitor development for the various types of F8 gene mutations in patients with severe hemophilia A. The primary outcome was inhibitor development and the secondary outcome was high-titer-inhibitor development. A systematic literature search was performed to include cohort studies published in peer-reviewed journals with data on inhibitor incidences in the various F8 gene mutation types and a mutation detection rate of at least 80%. Pooled odds ratios (ORs) of inhibitor development for different types of F8 gene mutations were calculated with intron 22 inversion as the reference. Data were included from 30 studies on 5383 patients, including 1029 inhibitor patients. The inhibitor risk in large deletions and nonsense mutations was higher than in intron 22 inversions (pooled OR = 3.6, 95% confidence interval [95% CI], 2.3-5.7 and OR = 1.4, 95% CI, 1.1-1.8, respectively), the risk in intron 1 inversions and splice-site mutations was equal (pooled OR = 0.9; 95% CI, 0.6-1.5 and OR = 1.0; 95% CI, 0.6-1.5), and the risk in small deletions/insertions and missense mutations was lower (pooled OR = 0.5; 95% CI, 0.4-0.6 and OR = 0.3; 95% CI, 0.2-0.4, respectively). The relative risks for developing high titer inhibitors were similar.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3488-3488 ◽  
Author(s):  
Shannon Carpenter ◽  
J. Michael Soucie ◽  
Sophia Sterner ◽  
Rodney J Presley

Abstract Abstract 3488 Poster Board III-425 Neutralizing inhibitor formation occurs in up to 20-30% of patients with severe factor VIII deficiency, leading to significantly increased morbidity in affected individuals. It has been well-established that patients of African descent have a higher prevalence of inhibitor development. [Oldenburg, J et al. Semin Hematol, 2004] The Hispanic population also has been assumed to have an increase in inhibitor development when compared with Caucasians. The study presented here is the first to definitively demonstrate an increased prevalence of inhibitors in the Hispanic population. We compared inhibitor prevalence among various racial and ethnic groups in a cross-sectional analysis of 6198 males with severe hemophilia A that participated in the Universal Data Collection project sponsored by the Centers for Disease Control and Prevention. We used logistic regression analysis to control for potential confounding variables including age, insurance type (as a proxy for access to care and socio-economic status), age at first bleed, age at diagnosis and use of prophylaxis. The included table shows those variables that were determined to be independently predictive of inhibitors. We assigned Mexican derivation to participants who labeled themselves as Hispanic and who were born either in Mexico, in states bordering Mexico or in states with large Mexican populations as established by Census data. The prevalence of high titer inhibitors in the Mexican-Hispanic population was 26.3% compared to 16.4% for Caucasian patients [OR 1.5, 95% CI 1.1, 1.9], and 26.8% for African-Americans. The underlying cause of increased inhibitor prevalence in these populations is still unknown, though a recent study in African-Americans demonstrated wild-type factors unique from commercially available product. [Viel KR, et al. Inhibitor of Factor VIII in Black Patients with Hemophilia. N Engl J Med, 2009] Further investigation of this phenomenon in the Mexican-Hispanic population, as well as the potential impact of differing immune responses, is warranted. Multivariate analysis of ethnicity and other variables found to be independently predictive of a prevalent inhibitor Characteristic Odds Ratio 95% CI Race/Ethnicity African-American 1.5 1.2 - 1.9 Mexican Hispanic 1.5 1.1 - 1.9 Hispanic 1.2 0.9 - 1.7 Other 1.2 0.9 - 1.6 White Ref Age* (years) <2 4.2 3.0 - 5.9 2-5 6.4 5.1 - 8.0 6-10 2.8 2.2 - 3.5 11-18 1.7 1.4 – 2.1 >18 Ref Insurance type Medicare 1.8 1.4 - 2.3 Medicaid 1.3 1.1 - 1.5 State program 1.1 0.6 - 1.9 TRICARE 1.0 0.4 - 2.1 Other 0.8 0.6 - 1.2 Uninsured 1.6 1.0 - 2.4 Commercial Ref Prophylaxis Yes 0.6 0.5 - 0.7 No Ref * Age with inhibitor or last UDC visit if no inhibitor The authors wish to acknowledge the contributions of the Hemophilia Treatment Center Network Investigators in the completion of this study. Disclosures: No relevant conflicts of interest to declare.


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