Clinical and Molecular Profile Of Hereditary Antithrombin (AT) Deficiency: A Single Institution Cohort

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2369-2369
Author(s):  
Ashish V Chintakuntlawar ◽  
Jennifer Guenther ◽  
Rajiv K Pruthi ◽  
John A. Heit ◽  
Mrinal M. Patnaik
Keyword(s):  
Conflicts Of Interest ◽  
Thrombotic Event ◽  
Factor V Leiden ◽  
Bleeding Complications ◽  
Molecular Profile ◽  
Cerebrovascular Event ◽  
Factor V Leiden Mutation ◽  
At Deficiency

Abstract Introduction Hereditary antithrombin (AT) deficiency is an autosomal dominant thrombophilia. It is classified into type 1 (quantitative) or type 2 (qualitative) deficiency based on the AT antigen and activity levels (Haemophilia 2008:14; 1229). The goal of this study was to correlate clinical phenotype with AT molecular defects. Methods After IRB approval, patients with a diagnosis of hereditary AT deficiency established at the Mayo Clinic, Rochester, were identified from the clinical database (1997-2012). AT activity was assayed by a chromogenic Factor Xa assay and AT antigen level was assayed by latex immunoassay. Peripheral blood leukocyte genomic DNA was extracted using standard methods. PCR-amplification and ABI BigDye Terminator cycle sequencing kit was performed for all SERPINC1 exons, intronic splicing regions and the 3’UTR. SERPINC1 sequence was analyzed using Mutation Surveyor software (SoftGenetics). Clinical data were obtained from patient interview and medical record review. An event was defined as an episode of venous thromboembolism (VTE), including deep vein thrombosis and/or pulmonary embolism; arterial thrombosis, including cerebrovascular event and/or myocardial infarction, and an obstetric event, including miscarriages and/or spontaneous abortions. Statistical analysis was performed with SAS 9.1.3 (SAS Institute Inc. Cary, NC). Results Of 30 patients with hereditary AT deficiency; sequence data was available on 22. Twenty-nine (97%) patients were white, and 19 (63%) were females. Six patients (20%) were smokers and 9 (30%) had a body mass index of >30. Based on the AT activity and antigen levels, 18 (81%) had type 1 AT deficiency, while the remainder had type 2. Eleven patients were heterozygous for six novel (all type 1) mutations. One patient was also a homozygous carrier for the Factor V Leiden mutation. The median age at first thrombotic event was 24.4 years (range, 16.2-70.7), and the median age at diagnosis of AT deficiency was 40.7 years (range, 17.8-76). Both, the median ages at first thrombotic event and at diagnosis were comparable in type 1 versus type 2 AT deficiency patients (P=0.52 and 0.97 respectively). Thirteen patients (43%) had unprovoked thrombotic events. Majority had VTE (n=21, 70%), which included one patient each with splanchnic venous thrombosis, and cerebral venous sinus thrombosis. At last follow up, twenty-one patients (70%) were on chronic anticoagulation [17 (81%) were on warfarin, 2 (9.5%) on enoxaparin and 2 (9.5%) were on rivaroxaban]. Median number of events was 1 (range 0-7). Four patients (19%) had bleeding complications from anticoagulation. Only one death was noted in the cohort and cause of death could not be determined. Conclusions Type 1 hereditary AT deficiency is the most clinically prevalent subtype in practice. Of the patients who developed thrombosis; clinical characteristics did not differ between type 1 and type 2 AT deficiency. We report 6 novel mutations in patients with hereditary AT deficiency. Disclosures: No relevant conflicts of interest to declare.

Clinical & Molecular Analysis of Patients with Type 2 (Qualitative) Hereditary Antithrombin (AT) Deficiency

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4201-4201
Author(s):  
Mrinal M. Patnaik ◽  
Jennifer Guenther ◽  
Rajiv Pruthi ◽  
John Heit
Keyword(s):  
Molecular Analysis ◽  
Conflicts Of Interest ◽  
Novel Mutation ◽  
Adult Life ◽  
Obstetric Complications ◽  
Molecular Testing ◽  
At Deficiency ◽  
The Mean

Abstract Abstract 4201 Background: Hereditary AT deficiency is classified as type 1 (quantitative) or type 2 (qualitative). Type 2 deficiency can be further subdivided into type 2a (reactive center loop [RCL]), type 2b (heparin binding domain), and type 2c (pleiotropic) based on functional and molecular AT analysis. Patients with heterozygous type 2b AT deficiency are thought to be at a lower risk for venous thromboembolism (VTE). Objectives: 1) To estimate the frequency of type 2 hereditary AT deficiency. 2) To utilize molecular analysis to accurately sub type patients with type 2 defects. 3) To correlate thrombotic and obstetric complications with AT deficiency sub types. Methods: Apparently unrelated Mayo Clinic AT-deficient patients (n=20) were categorized as type 1 or 2 based on plasma AT activity and antigen, or by molecular analysis for previously reported type 2a-c mutations. Demographic and clinical characteristics were abstracted from patient medical records. The SERPINC1 putative promoter region, all exons (n=7) and splice junctions, and the 3′UTR were PCR amplified from leukocyte genomic DNA, and sequenced with nested forward and reverse primers. For patients without identifiable mutations, multiplex ligand-dependent probe amplification (MLPA) was performed. Results: Out of 20 probands tested 7 (35%) had type 2 AT deficiency. The mean patient age at diagnosis was 36 years (range 18–65) and 5 (69%) were women. There were 2 patients with type 2a, 4 with type 2b (including 1 with a homozygous defect), and 1 with type 2c AT deficiency. The mean plasma AT (range) activity/antigen for these patients were 50% (37-67%)/93% (78-103%) [AT activity & antigen normal range=80-130%]. 6 patients had a previously described mutation, whereas 1 had a novel mutation [S380R] affecting the RCL (Table1). All patients with type 2a and type 2c AT deficiency had unprovoked VTE occurring at a young age. All 3 patients with heterozygous type 2b AT deficiency had no VTE or obstetric complications. One patient with a homozygous type 2b defect (AT Vienna) presented with an unprovoked DVT at age 15. One family with AT Toyama (type 2b AT deficiency) had 5 asymptomatic adult family members with the mutation. Background: Molecular testing is important for an accurate subtyping of patients with type 2 AT deficiency. Type 2 defects have a diverse clinical spectrum. Patients with heterozygous type 2b AT deficiency have a low rate of VTE and obstetric complications. Homozygous type 2b AT deficiency can be compatible with adult life. Disclosures: No relevant conflicts of interest to declare.

The Potential Role of Molecular Analysis in Hereditary Antithrombin (AT) Deficiency Diagnosis and Management.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2976-2976
Author(s):  
Mrinal M Patnaik ◽  
Jennifer Guenther ◽  
Rajiv Pruthi ◽  
John A. Heit
Keyword(s):  
Molecular Analysis ◽  
Conflicts Of Interest ◽  
Clinical Manifestations ◽  
Young Age ◽  
Diagnosis And Management ◽  
At Deficiency ◽  
The Mean

Abstract Abstract 2976 Poster Board II-955 Background: AT deficiency is classified as type 1 (quantitative), or type 2 (qualitative), based on plasma AT activity and antigen levels. However, such levels can sometimes be only mildly and equivocally reduced. Type 2 deficiency can be subdivided into type 2a (reactive center loop [RCL]), type 2b (heparin binding domain), and type 2c (pleiotropic), usually by molecular analysis, but the role of AT molecular analysis in patient diagnosis and management is uncertain. Objectives: 1) to estimate the frequency of mutation detection in possible hereditary AT deficiency, and 2) to correlate clinical manifestations with AT deficiency type as determined by plasma AT, and by AT genotype. Methods: Mayo Clinic patients (n=16) were categorized as type 1 or 2 by plasma AT, or by molecular analysis for previously reported type 2a-c mutations. Patient characteristics were abstracted from medical records. The SERPINC1 putative promoter region, all exons (n=7) and splice junctions, and the 3'UTR were PCR amplified from leukocyte genomic DNA, and sequenced with both forward and reverse primers. Results: The mean patient age at diagnosis was 32 years (range 18-65); 11 (69%) were women. 12 (75%) patients were type 1 by plasma AT, while 4 were type 2 by molecular analysis (Table). The mean plasma AT (range) activity/antigen for types I and 2 patients were 52% (39-71%)/53% (39-68%) and 58% (43-67%)/85% (60-103%), respectively [normal range=80-130%]. 13 (82%) patients had VTE (8 [61%] idiopathic; 10 [77%] recurrent); 5 (32%) had stroke/TIA, 4 at a young age. Thrombosis “penetrance” appeared greater among type 1 families. Only 2 pregnancy losses occurred in 14 pregnancies among 6 type 1 women, and no losses occurred in 5 pregnancies among 2 type 2b women. Among the 14 (88%) patients with mutations identified, all were heterozygous and 8 patients had 6 novel mutations; 2 patients had no mutation detected. Plasma AT activity/antigen did not always correlate with genotype; 1 patient each with type 2b and 2c by molecular analysis had concordant decreases in plasma AT activity and antigen (i.e., a type 1 plasma phenotype), while amino acid changes (T85K and F239L) predicting reduced plasma AT activity only had a type 1 plasma phenotype. One type 2b (Q118P) patient had extensive recurrent VTE. Conclusion: 88% of patients had a detrimental mutation, suggesting that molecular analysis can be helpful for diagnosis. While our findings should be interpreted with caution, type 1 patients may have a higher prevalence of stroke/TIA at a young age and a higher family thrombosis penetrance compared to type 2. Plasma AT activity and antigen frequently did not correlate with genotype. However, whether molecular analysis is useful for clinical management remains uncertain. Finally, 50% of patients had a novel mutation, suggesting that reported mutations causing AT deficiency have not reached gene saturation. Disclosures: No relevant conflicts of interest to declare.

Genetic Basis of Inherited Thrombophilia in Korea: A Single-Institution Experience.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4135-4135
Author(s):  
Hee-Jin Kim ◽  
Duk-Kyung Kim ◽  
Sung-Hwan Bang ◽  
Jong-Won Kim ◽  
Sun-Hee Kim
Keyword(s):  
Genetic Basis ◽  
Medical Center ◽  
Direct Sequencing ◽  
Genetic Diagnosis ◽  
Factor V Leiden ◽  
Splice Mutation ◽  
Single Institution ◽  
Factor V Leiden Mutation ◽  
Inherited Thrombophilia ◽  
At Deficiency

Abstract Background: Inherited thrombophilia (HT) is a condition that genetically imposes a risk to develop thrombosis. It has been known that the genetic basis of IT is different between Caucasians and Asians; factor V Leiden mutation (R506Q) and the prothrombin gene mutation G20210A are major causes of HT among Caucasians, while they are extremely rare among Asians. Thus the deficiency of anticoagulant factors such as protein C (PC), protein S (PS), and antithrombin (AT) are believed to play a major role in Asians. Genetic study is important to confirm the diagnosis, since there are many acquired conditions including anticoagulant therapy that may mimic inherited form of deficiency. In this study, consecutive patients with a clinical and laboratory suspicion of IT were recruited for genetic diagnosis at a single institution, Samsung Medical Center, Seoul, Korea. Materials and Methods: From December 2004 to July 2005, a total of 15 patients had presumptive diagnosis of IT; seven were suspected to have PC deficiency (activity, 43~ 51%), four PS deficiency (free Ag; 12~38%), and four AT deficiency (activity, 63~67%). All exons and their flanking sequences of the PROC gene, PROS1, or SERPINC1 were directly sequenced and analyzed. Results: All seven patients with PC deficiency were shown to have a mutation in PROC. Of note, four of them had a common missense mutation, and the haplotype analysis using polymorphic markers showed that it is a mutation hot focus rather than a founder effect. Two other mutations were novel. Two of four patients with PS deficiency had a mutation in PROS1, each of which was novel. Three of four AT deficiency had a mutation in SERPINC1; one with a novel splice mutation and two shared a common splice mutation, which has not been reported, either. Overall, nine mutation carriers were detected through family study. Conclusion: This study revealed the genetic basis, mutation spectrum, and the mutation detection rate of IT in consecutive Korean patients. Since diverse (known or novel) mutations underlie genetic deficiency of anticoagulants in Koreans, genetic studies employing direct sequencing for the whole gene are necessary to confirm the diagnosis, and for further family studies.

Effects of Anti-FVIII Inhibitors On Factor VIIa/Tissue Factor-Catalyzed Activation and Inactivation of Factor VIII.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3169-3169
Author(s):  
Koji Yada ◽  
Keiji Nogami ◽  
Kenichi Ogiwara ◽  
Katsumi Nishiya ◽  
Masahiro Takeyama ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Conflicts Of Interest ◽  
Factor Viia ◽  
Fviii Inhibitor ◽  
Fviii Activity ◽  
Normal Individuals ◽  
The Difference ◽  
Functional Inactivation

Abstract Abstract 3169 Poster Board III-110 Factor (F)VIIa with tissue factor (TF) is a primary trigger of blood coagulation. We have recently demonstrated that FVIIa/TF rapidly activated FVIII by proteolysis of the heavy chain (HCh), and served physiologically as a potent activator for up-regulation of FVIII activity in very early-timed phase (ASH #1036, 2008). FVIII inhibitors develop as alloantibodies in multi-transfused patients with hemophilia A and also arise as autoantibodies in normal individuals. FVIII inactivation by inhibitors is associated with impairment of FVIII(a) cofactor function through the binding to functional crucial epitopes in FVIII. Anti-C2 inhibitors prevent FVIII binding to phospholipid, von Willebrand factor, and FXa. Anti-A2 inhibitors prevent FVIII binding to FIXa and thrombin. However, effects of these inhibitors on FVIIa action for FVIII have remained to be studied. In this study, we prepared 13 of anti-FVIII inhibitor IgGs (2 of anti-A2, 7 of anti-C2 with type 1 behavior, and 4 of anti-C2 with type 2). We first examined FVIIa/TF-catalyzed FVIII activation in the presence of anti-FVIII inhibitors in one-stage clotting assay. The levels of FVIII activity (10 nM) elevated rapidly by ∼2.0-fold within 30 sec after adding of FVIIa/TF (1 nM), and subsequently decreased to the initial level within 20 min. The presence of anti-FVIII inhibitors did not significantly affect FVIIa/TF-catalyzed FVIII activation (by 1.7∼2.2-fold) compared to normal IgG. This action was independent of the difference of inhibitor epitopes. In addition, FVIIa-catalyzed FVIIIa inactivation with anti-A2 or anti-C2 with type 2 inhibitors was little affected, similar to that with normal IgG. However, of note, all of anti-C2 with type 1 significantly inhibited FVIIa-catalyzed inactivation of FVIIIa. Inactivation rates of FVIIa with anti-C2 with type 1 (k ∼0.15) was ∼40% less than that with control IgG (k ∼0.24), supporting that the presence of anti-C2 with type 1 might persist the activity of FVIIIa generated by FVIIa. To clarify this inhibitory mechanism of anti-C2 with type 1, we performed FVIIa-catalyzed FVIII cleavage in Western blotting. FVIIa/TF (1 nM) proteolyzed the HCh of FVIII (10 nM) rapidly by cleavages at Arg372 (and Arg740), whilst cleavage at Arg336 in the A1 domain was appeared at ∼2.5 min, supporting that cleavages at Arg372 and Arg336 by FVIIa contribute to the up- and down-regulation of FVIII(a) activity, respectively. All inhibitors, independent of recognizing epitopes, did not affect FVIIa-catalyzed cleavage at Arg372. However, the presence of anti-C2 type 1 delayed the cleavage at Arg336 in timed- and dose-dependent manners, whilst either anti-A2 or anti-C2 type 2 did not affect, consistent with the functional inactivation results. FVIIa binds to the A2, A3, and C2 domains in FVIII. Based on our findings, FVIIa-interactive sites on FVIII unlikely overlapped with anti-A2 and -C2 inhibitor epitopes, and inhibition of Arg336 cleavage may be due to conformational change caused by antibody binding. Furthermore, FVIIa indeed activates FVIII even in the presence of anti-FVIII inhibitors, different from thrombin, FXa, etc, and it would be important to predict the effect of FVIIa for FVIII to determine the characteristics of anti-FVIII inhibitors. Disclosures No relevant conflicts of interest to declare.

Frequency and Determinants of Thrombotic and Bleeding Complications in Ph Negative Myeloproliferative Neoplasms (MPN): The Role of Adamts-13 and VWF Activities in an Italian Cohort 0f 88 Well Characterized Patients

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3369-3369
Author(s):  
Augusto B. Federici ◽  
Maria C Carraro ◽  
Antonella Lattuada ◽  
Chiara Vanelli ◽  
Veronica Sciumbata ◽  
...  
Keyword(s):  
Risk Factors ◽  
Multivariate Analysis ◽  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasms ◽  
Thrombotic Event ◽  
Previous History ◽  
Bleeding Complications ◽  
Post Surgery ◽  
Bleeding Episodes

Abstract Abstract 3369 Background: Patients with Ph-negative Myeloproliferative Neoplasms (MPN) such as Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF) can be exposed during the course of these MPN to thrombotic and bleeding complications, with increased morbidity and mortality. Age, previous history of thrombosis, increased White Blood Cell (WBC) and Jak2 allele burden have been proposed as risk factors for Venous (VTE) and Arterial (ATE) thromboses while bleeding has been previously associated with abnormalities of the von Willebrand factor (VWF). Aims: To investigate any significant role of ADAMTS-13 and VWF activities in the thrombotic and bleeding complications observed in a small but well characterized cohort of MPN patients. Patients and Methods: 88 consecutive patients were diagnosed at the Hematology and Transfusion Medicine Division, L.SACCO University Hospital of Milan, according to WHO criteria. Patients signed an informed consent to participate in this clinical study with a protocol approved by local IRB and they showed MPN type (%), mean age (range), gender M/F and Jak2 positivity (%) as follows: PV[n=42 (48%), 68 (36–86), 18/24; 85.7%]; ET [n=34 (38%), 66 (30–93), 10/24, 61.7%]; PMF [n=12 (14%), 67 (37–88), 7/5, 58%]. Thrombotic and bleeding episodes were recorded and managed from the time of diagnosis and associated with the use of aspirin (ASA) and of other MPN therapies. Among additional lab parameters, plasmatic ADAMTS-13 and VWF activities were also measured at enrolment as endothelial/platelet marker. These activities were assayed with Technozym ADAMTS-13 activity (Technoclone GmbH, Austria), Innovance VWF-GPIb activity (Siemens AG, Germany) and HemosIL-VWF antigen (Instrumentation Laboratory, USA). Multimeric analyses were also tested using very sensitive intermediate SDS-agarose gel electrophoresis. Statistical analyses were performed by SPSS-17.2. Results: 59/88 (67%) patients did not show any thrombotic or bleeding complications during the 6-year follow-up. In these cases mean (range) values of VWF:GPIb and VWF:Ag were 104 (29–202) and 133 (52–288) U/dL while ADAMTS-13 was 102 (63–143). 20/88 (23%) cases showed at least one thrombotic event (13ATE/7VTE): AMI (6), STROKE (6), TIA (2), PE (1), DVT (7). Patients with thromboses showed relatively higher values VWF:GPIb and lower ADAMTS-13 and this was confirmed in multivariate analysis especially for ET [VWF:GPIb=135 (61–237) U/dL, p=0.004 and ADAMTS-13=89(62–134), p=0.009]. Major bleeding episodes mainly mucosal (5 gastrointestinal, 3 post-surgery, 1 severe menorrhagia) requiring blood transfusions or hysterectomy were observed in 9/88 (10%) patients. At the multivariate analysis, major bleedings were significantly associated with lower VWF:GPIb [68 (25–111) U/dL, p=0.022), lower VWF:Ag [93 (35–146) U/dL, p=0.016] and to the ASA intake (p=0.006). Most of these bleeders showed also a relative loss of the highest molecular weight multimers. Conclusions: Based on these observations, we confirm that thrombotic events in MPN may certainly have multiple risk factors: however, lower ADAMTS-13 and higher VWF activities might play a role as additional risk factors especially in ET. Conversely, lower levels of VWF with loss of the largest multimers are important risk factors for bleeding in MPN especially in patients treated with ASA. Disclosures: No relevant conflicts of interest to declare.

Management Of Pregnancy In Patients With Antithrombin Deficiency

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 216-216
Author(s):  
Mario von Depka ◽  
Stefanie Döpke ◽  
Anja Henkel-Klene ◽  
Cornelia Wermes ◽  
Mahnaz Ekhlasi-Hundrieser ◽  
...  
Keyword(s):  
High Risk ◽  
Pregnancy Loss ◽  
Conflicts Of Interest ◽  
Fetal Loss ◽  
Bleeding Complications ◽  
Thromboembolic Events ◽  
Increased Risk ◽  
History Of ◽  
At Deficiency ◽  
The Mean

Abstract Introduction During pregnancy women have a four- to five-fold increased risk of thromboembolism (TE) compared to women who are not pregnant. Among the most important risk factors for TE in pregnancy is the presence of thrombophilia. Multiple reports have described an association between antithrombin (AT) deficiency and an increased rate of thromboembolic events especially during pregnancy. As the placental development depends on well-balanced pro- and anticoagulant mechanisms, thrombophilia, e.g. AT deficiency may be associated with poor pregnancy outcome. Despite anticoagulation with low molecular weight heparin (LMH) during pregnancy and the postpartum period alone, women with AT deficiency are still at a high risk to develop TE, especially perinatal and during puerperium because of withheld anticoagulation to prevent bleeding complications. Therefore, several guidelines recommend the administration of antithrombin concentrates during high risk situations as pregnancy. Here, we present the results of our study on the usage of AT concentrates in pregnant women with AT deficiency who either suffered from fetal loss or thromboembolism prior inclusion. Methods In total, 22 pregnancies in 19 patients (age: 31.9±4.7; 22-41) with AT deficiency were included in this open-label, single-center study. Ten patients (53%) had a history of fetal loss, 9/19 (47%) patients hat a history of thromboembolism. During all pregnancies AT concentrate (AT-C) was administered, in 18/22 (81.8%) pregnancies LMH was given in addition. Prior pregnancy losses (21/30, 70%) occurred in all trimester (t1: n=11, t2: n=5, and in t3: n=5). Historical live birth rate (LBR) was 30%. Blood samples were collected in all trimesters and postpartum to analyze AT activity and antigen, endogenous thrombin potential (ETP), thrombin-antithrombin-complex (TAT), Fragment 1+2 (F1+2) and c-reactive protein test (CRP). A total of 114 uneventful pregnancies of 113 healthy women served as controls. Furthermore, the mean doses of AT concentrates/kg BW and the mean total number of infusions were calculated. Results In total, 21 pregnancies (95.5%) were successful. Mean total requirement of AT concentrate per pregnancy was 79.454 IU (range: 3.000-272.000 IU) during 27.8 treatment days per pregnancy (range: 1-88). Our data show an increase of F1+2 in the course of pregnancy. Mean levels of F1+2 at t1, t2 and t3 (t1= 255.9 ± 107.6, t2= 360.9 ± 117.4, t3= 545.3 ± 220.3 pmol/L) were significantly higher than in controls (t1= 82.2 ± 43, t2= 140 ± 100.2, t3= 183.5 ± 103.1, p<.001). Mean level of TAT was higher (3.1 ± 1.4 ng/mL) than in controls (1.7 ± 1.6 ng/mL, p=.001) in t1, whereas mean TAT in t2 and t3 was lower than in controls (3.8 ± 1.3 vs. 4.8 ± 1.9, p=.03; 5.0 ± 1.4 vs. 6.1 ± 3.0 ng/mL, n.s., resp.). No thromboembolic events occurred. In patients receiving AT-C, LBR increased from 30% to 95.5% (p<0.001) with a relative risk of 49.0 to develop pregnancy loss without anticoagulant treatment (5.7 – 421.8; 95% CI). Conclusion In patients with AT deficiency receiving AT concentrate and LMH we could demonstrate a significant increase of LBR from 30% to 95.5%. Furthermore, no thromboembolic events occurred, though almost half of the patients had a history of thromboembolism. There was no clear evidence of increased hypercoagulability. We conclude that combined AT concentrate and LMH are safe and efficacious for mother and child in preventing thromboembolism and pregnancy loss. Further studies to evaluate the exact mode of anticoagulation and benefit of combining AT concentrate and LMH are warranted. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Calreticulin mutations Are Present in Polyclonal As Well As Clonal ET

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4590-4590
Author(s):  
Xylina Gregg ◽  
Sabina Swierczek ◽  
Soo Jin Kim ◽  
Josef T. Prchal
Keyword(s):  
T Cells ◽  
X Chromosome ◽  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasms ◽  
Hematopoietic Stem ◽  
Clonal Hematopoiesis ◽  
Calr Mutations ◽  
Calr Mutation

Abstract First and second authors contributed equally During female embryogenesis, most of the genes in either the maternal or paternal X-chromosome are randomly inactivated in each cell, a process that remains remarkably constant in their progeny. X-chromosome inactivation has been used to define clonality in myeloproliferative neoplasms (MPNs) such polycythemia vera (PV), primary myelofibrosis (PMF) and essential thrombocythemia (ET). One such method to determine clonality uses a quantitative, transcriptional clonality assay based on conservative exonic polymorphisms in five X-chromosome genes (MPP1, FHL1, IDS, BTK, and G6PD). Females who are heterozygous for any of these polymorphisms are considered “informative” and can be studied for clonality by interrogating their platelets’ and granulocytes’ RNA allelic usage ratio. JAK2 mutations occur in >95% of PV and 50-60% of ET and PMF; cMPL mutations are found in another 5-10% of ET and MF. Somatic calreticulin (CALR) mutations have been identified in a majority of patients with ET and MF who lack JAK2 and cMPL mutations. CALR mutations are reported to be associated with a more favorable prognosis and are believed to be acquired early in the disease course. More than 30 CALR mutations have been described, but type 1 (52-bp deletion; c.1092_1143del) and type 2 (5-bp insertion; c.1154_1155insTTGTC) mutations are the most frequent. We analyzed 61 females informative for a transcriptional clonality assay and 44 males with unexplained thrombocytosis or marrow fibrosis and no detectable JAK2 or cMPL mutations for CALR mutations in their granulocytes. With the exception of an absence of a clonal marker, these patients met WHO criteria for ET or PMF. A CALR mutation (20 type 1 and 17 type 2) was present in 37 of these 105 patients (22 females and 15 males). One of the CALR mutated females had a paternal grandmother with JAK2V617F –positive PV, confirming a previous report that, in familial clustering of MPNs, affected individuals may carry different disease-defining somatic mutations. In those CALR positive patients who had available T cells, no detectable CALR mutations were found in their T cells. In one of these subjects, CD34+ cells were available and had a similar mutation level as in the granulocytes. Of the 22 females with a CALR mutation, 19 had clonal hematopoiesis, but 3 had polyclonal hematopoiesis; all 3 had previously unexplained thrombocytosis. None of these patients had any prior treatment for thrombocytosis. Clonal hematopoiesis was present in 26 of the 39 females without a CALR mutation. All female patients with myelofibrosis had clonal hematopoiesis, regardless of CALR mutation status. In contrast to the polyclonal hematopoiesis seen in some CALR positive ET patients, 166 informative PV and JAK2V617F-positive ET or PMF females all had clonal hematopoiesis. We report that CALR mutations are associated with polyclonal hematopoiesis in some ET patients. This finding differs from JAK2V617F-positive ET and PMF and PV females, where clonal hematopoiesis was always seen. This indicates that CALR mutated clones have a weaker suppressive effect on residual normal hematopoietic stem cells than JAK2 mutated clones and may contribute to the possibly more benign course of CALR mutated ET. The CALR mutation was not detected in T cells, which also differs from JAK2V617F mutated MPNs, where a small level of the JAK2 mutation is often detected in T cells. Similar to other reports, we found a lower prevalence of the CALR mutation in JAK2 or cMPL non-mutated ET and PMF than initially described. Disclosures No relevant conflicts of interest to declare.

scholarly journals Heritable Thrombophilia in Venous Thromboembolism in Northern Pakistan: A Cross-Sectional Study

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Maria Khan ◽  
Chaudhry Altaf ◽  
Hamid Saeed Malik ◽  
Muhammad Abdul Naeem ◽  
Aamna Latif
Keyword(s):  
Venous Thromboembolism ◽  
Protein C ◽  
Gene Mutations ◽  
Factor V Leiden ◽  
Factor V ◽  
Protein C Deficiency ◽  
Factor V Leiden Mutation ◽  
Inherited Thrombophilia ◽  
At Deficiency ◽  
Prothrombin Gene

Background. Venous thromboembolism (VTE) is referred to as formation of clots in a deep vein or lodging of thrombus towards the lungs which could be fatal yet preventable. The risk of developing VTE can be increased by various factors. Where there are innumerable acquired causes, the possibility of inherited thrombophilia cannot be ignored. In view of this, we have evaluated all patients with venous thromboembolism for inherited thrombophilia. Objective. To evaluate the frequencies of antithrombin (AT) deficiency, protein C and S deficiencies, Factor V Leiden, and prothrombin gene mutations in patients harboring venous thromboembolism. Materials and Methods. A study comprising of 880 patients who were presented with manifestations of venous thromboembolism was conducted from July 2016 to June 2017. A blood sample collected from patients was screened for thrombophilia defects encompassing AT, protein C and S deficiencies, Factor V Leiden, and prothrombin gene mutations. All acquired causes of thrombosis were excluded. Results. Of 880 patients who underwent screening for thrombophilia, 182 patients demonstrated VTE history. Their age ranged from 1 to 58 years. Males constituted a predominant group. About 45 (24.7%) patients had evidence of heritable thrombophilia. Of these, 20 (10.9%) had AT deficiency, 9 (4.9%) had Factor V Leiden mutation, 6 (3.2%) had protein C deficiency, whereas protein S deficiency and prothrombin gene mutation both were found in 5 (2.7%) patients. Conclusion. Our study illustrated the highest frequency of antithrombin deficiency among other investigated thrombophilia defects.

scholarly journals Calr Mutational Status in Egyptian Patients with Myeloproliferative Neoplams

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5388-5388
Author(s):  
Eman A. Soliman ◽  
Samah I. El-Ghlban ◽  
Abdelaleem H. Abdelaleem ◽  
Sherin Abdel-Aziz ◽  
Sameh Shamaa ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasm ◽  
Response To Therapy ◽  
Hcv Infection ◽  
Number Of Patients ◽  
Significant Difference ◽  
Egyptian Patients ◽  
Calr Mutations

It has been known that the insertion/deletion mutation of CALR gene is the second deriver mutation in myeloproliferative neoplasm (MPN) of essential thrompocythemia (ET) and primary myelofibrosis (PMF). As the molecular workup has been incorporated for the prospective screening and diagnosis of MPN in our Oncology Center. An Egyptian 87 cohort of patients with non-mutated JAK2 (58 ET and 29 MF) were investigated using polymerase chain reaction (PCR) as a pilot study. We found that 37 out of 87 patients (42%) were carrying CALR mutations (30 out of ET (52%) and 7 out of MF (24%)). Sanger sequencing was used to determine the type of CALR mutations in all positive patients and we found that 13 out of 37 (35%) had type 1/type 1-like and 36 out of 37 (97%) with type 2/type 2-like. This CALR mutation profile in Egyptian patients appear different from the western status as type2/type 2-like is the highest in our patients (97%) versus 35-45% and type1/type 1-like was 35% versus 55-65% compared to western results. Meanwhile, the clinical course and phenotype of our cohort of patients is not similar to that in western as there is no significant difference of overall survival between type1/type1-like and type2/type2-like. This finding might be due to the different environmental and genetic backgrounds of Egyptian population. A part of it might be related to the HCV infection as 12 out of 37 (32%) had HCV infection. Further study is in progress on a large number of patients to correlate that with the clinicopathological status, response to therapy and the mechanistic pathway of oncogenic transformation. Disclosures No relevant conflicts of interest to declare.

Protein-Z-Mangel bei ungeklärter Neigung zu Thrombosen, Blutungen oder Aborten

2012 ◽  
Vol 32 (S 01) ◽  
pp. S95-S97
Author(s):  
H. Radtke ◽  
A. Jainz ◽  
F.-P. Schmidt ◽  
H. Kiesewetter
Keyword(s):  
Factor V Leiden ◽  
Disease Type ◽  
Von Willebrand Disease ◽  
Bleeding Complications ◽  
Factor V ◽  
Protein Z ◽  
Factor V Leiden Mutation ◽  
Vein Occlusion ◽  
Retinal Branch Vein Occlusion ◽  
Von Willebrand

SummaryA protein Z deficiency is presumably related with a threefold risk of venous and arterial thrombosis. Mucosal bleedings and post-operative haematomas can occur more frequently. This is seen in an increased in vivo bleeding time without other plasmatic coagulation disorders or thrombopathies. Pregnancy complications, especially abortions before the 15th week of gestation, are described as well. Patients, methods: Since May 2011 the plasmatic concentration of protein Z has been tested in 684 patients of the Hämostaseologicum. Results: In 74 patients a protein Z deficiency has been found. In other 45 patients protein Z was reduced because of the intake of phenprocoumon or coumadin. Of the 74 patients with diminished protein Z concentration 39 were marginally decreased (protein Z 1000–1500 μg/l). Of the 35 patients with a protein Z concentration <1000 μg/l 12 had had a thrombosis before (6 strokes, 3 DVT or PE, 1 arterial thrombosis, 1 retinal branch vein occlusion, 1 acute hearing loss). 7 had arterial hypertension, 2 suffered from diabetes mellitus. Of the patients who had a thrombosis 6 had a heterozygous factor V Leiden mutation. 10 had a microcirculation disorder (Raynaud’s phenomenon), 4 had had bleeding complications before, 3 had a von Willebrand disease type I, 6 patients had had abortions and 4 were healthy. Of the 39 patients with protein Z concentrations between 1000 and 1500 μg/l 18 had experienced a thrombosis before (9 DVT or PE, 3 myocardial infarctions, 1 CHD, 3 strokes, 1 retinal branch vein occlusion, 1 PAOD I, 1 tinnitus). 5 additionally had arterial hypertension. 13 suffered from Raynaud’s phenomenon, of which 7 had a hypotension. Of the patients with thromboses 3 had a heterozygous factor V Leiden mutation and one a protein C deficiency. 7 patients had had an abortion before. Bleeding complications were seen in 4 patients, of which 3 suffered from von Willebrand disease type 1.

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