Factor XI deficiency: two novel mutations in asymptomatic Italian patients.

SUMMARY: Factor XI (FXI) deficiency is a rare bleeding disorder, resulting in a wide range of bleeding manifestations, from asymptomatic bleeding to injury-related bleeding. To identify mutations in FXI-deficient patients and to establish a possible relationship between clinical phenotype and genotype, we studied two patients from Southern Italy with FXI deficiency. They were identified by presurgical or routine laboratory screening. None of them showed bleeding. Three different mutations were detected (Glu117Stop, Cys118Arg and Trp497Gly); two of them were novel (Cys118Arg and Trp497Gly). One patient (with severe FXI levels) showed a compound heterozygosity (Glu117Stop with Cys118Arg). Two novel missense mutations were highly conserved among different species. In our patients, bleeding tendency did not appear to be correlated with FXI levels or with a single mutation in heterozygosis. On the other hand, the compound heterozygosis might explain low FXI levels, but it is not associated with bleeding. Our data confirm that a severe FXI deficiency is not necessarily associated with bleeding.

The JAK2 V617F mutation frequently occurs in patients with portal and mesenteric venous thrombosis.

BACKGROUND: Myeloproliferative disorders (MPDs) represent a risk factor for thrombosis in the portal, mesenteric, and hepatic districts. OBJECTIVE: We aimed to assess whether the Janus kinase 2 (JAK2) V617F mutation, an acquired mutation that occurs in MPD patients, is a risk factor for portal and mesenteric venous thrombosis (PMVT) independently of the presence of overt MPDs. PATIENTS AND METHODS: The medical histories of 99 patients presenting with PMVT were obtained. The presence of the JAK2 V617F and VHL 598C > T mutations was determined by polymerase chain reaction followed by restriction enzyme analysis and direct cycle sequence analysis. RESULTS: Over a 10-year period of observation, of the 99 patients presenting with PMVT, the JAK2 V617F mutation was detected in heterozygous state in 17 individuals [17.2%; 95% confidence interval (95% CI) 10.9-25.9]. None of the patients presenting with the JAK2 V617F mutation carried an inherited thrombophilic risk factor. Seven patients with (43.8%; 95% CI 19.8-70.1) and two without (2.4%; 95% CI 0.3-8.4) the JAK2 V617F mutation had a diagnosis of MPD at the occurrence of the venous thrombotic event. After a median follow-up of 41 months (range 3-114 months), three out of the 10 patients carrying the JAK2 V617F mutation were then diagnosed as having idiopathic myelofibrosis (n = 2) or polycythemia vera (n = 1), whereas in seven patients a MPD was not detected. Two of the 83 patients without the JAK2 V617F mutation went on to develop MPDs. CONCLUSIONS: Determination of the JAK2 V617F mutation may contribute to the search for genetic determinants of PMVT and may be useful to recognize patients who should be carefully observed for the subsequent development of overt MPDs.

Clinical Pregnancies and Live Births in women approaching ART: a follow-up analysis of 157 women after thrombophilia screening.

INTRODUCTION: The role of thrombophilia screening and antithrombotic therapy in unselected women undergone Assisted Reproductive Technologies (ART) is largely unknown. Nonetheless, in many Countries infertile women undergo thrombophilia screening and/or antithrombotic therapy. MATERIALS AND METHODS: We carried out a follow-up study. The original sample (n=1107) consisted of infertile women observed in 13 years. A cohort of 157 women with at least 1 cycle before thrombophilia test and 1 after test was investigated. All underwent thrombophilia screening; an antithrombotic treatment was prescribed in 216 out of 801 cycles. Clinical pregnancy and live birth rates were the main clinical objectives. RESULTS: Overall, 15 (9.6%) women carried thrombophilia. The Cox regression showed that LMWH alone or combined with ASA was significantly associated with the outcome "live birth" "live births" (p: 0.015, HR: 2.8, 95%CI: 1.2-6.6 for combined therapy), independently of the carriership of thrombophilia. Women with a lower number of attempts had a higher likelihood of delivering a live-born child using the combined therapy (p<0.001, HR: 0.7, 95%CI: 0.7-0.8), independently of the presence of thrombophilia. CONCLUSIONS: A potential benefit of LMWH in improving number of live births, independently of the presence of thrombophilia, is suggested. Universal thrombophilia screening before ART is not useful to discriminate women with a worse pregnancy prognosis.

Low-molecular -weight heparin in pregnancies after ART -a retrospective study-.

INTRODUCTION: The utility of an antithrombotic prophylaxis in Assisted Reproductive Technologies (ART) is highly debated. It has been hypothesised that specific effects of heparin on the coagulation system during implantation can improve the number of clinical pregnancies and live births. MATERIALS AND METHODS: We studied a cohort of 327 women undergone at least 1 ART cycle before thrombophilia testing. Overall, a number of 751cycles was analysed. Low-Molecular-Weight Heparin (LMWH) and/or low-dose aspirin (ASA) were prescribed in 132 (17.6%) cycles. Furthermore, all the women underwent thrombophilia screening. RESULTS: The univariate analysis showed that LMWH with/without ASA was significantly associated with both the outcomes clinical pregnancy and live birth, while the use of ASA was not associated with live birth. The logistic regression showed that the use of LMWH was significantly associated with both the outcomes, clinical pregnancy (OR: 6.0, 95%CI: 2.8-15.6) and live birth (OR: 10.7, 95%CI: 3.2-36.1). The type of ART procedure significantly influenced the likelihood of achieving clinical pregnancy. CONCLUSIONS: Present findings suggest that LMWH alone or combined with ASA could have a role in fostering the implantation of embryos and improving the number of live births after ART.

Risk of obstetric and thromboembolic complications in family members of women with previous adverse obstetric outcomes carrying common inherited thombophilias.

BACKGROUND: Factor (F)V Leiden and the prothrombin 20210A mutation (PTm) are associated with the occurrence of obstetric complications, including pregnancy-related venous thromboembolism (VTE). It is not known whether family members of women with FV Leiden or PTm and previous obstetric complications have a higher risk of VTE or adverse obstetric outcomes. METHODS: A retrospective family study including 563 relatives of 177 women with previous adverse outcomes carrying FV Leiden or PTm, referred between April 1993 and June 2010. A history of obstetric complications and VTE was obtained. Prevalence of VTE and obstetric complications in relatives with and without inherited thrombophilias was compared. Adjusted odd ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression models that controlled for predictors (age, FV Leiden and PTm). RESULTS: Relatives carrying FV Leiden had a significant and independent risk for obstetric complications (OR: 1.98, 95% CI 1.03-3.83); this risk was not observed in the presence of PTm (OR: 1.03, 95% CI 0.46-2.32). The presence of FV Leiden or PTm in heterozygosis was significantly and independently associated with the occurrence of VTE (OR: 5.2, 95% CI: 1.70-15.91). Severe thrombophilias were strong risk factors for VTE (OR: 23.2, 95% CI: 6.0-89.85). Male gender was a significant and independent risk factor for VTE (OR: 3.49, 95% CI: 1.51-8.05). The risk did not change when relatives of women with a previous pregnancy-related VTE were excluded (OR: 3.49, 95% CI: 1.51-8.05). CONCLUSIONS: Knowledge of thrombophilia status may help to better define the obstetric and thromboembolic risks in asymptomatic family members of women who suffered from obstetric complications.