Mirjana Kovac

The use of D-dimer with new cutoff can be useful in diagnosis of venous thromboembolism in pregnancy

OBJECTIVE D-dimer testing has an important role in the exclusion of acute venous thromboembolism (VTE) in the nonpregnant population. Establishing D-dimers role in the diagnosis of VTE in pregnancy is hampered because of the substantial increase of D-dimer throughout gestational age. STUDY DESIGN In a prospective study we followed 89 healthy pregnant women to establish the reference range of D-dimer for each trimester. D-dimer testing was also performed in 12 women with clinical suspicion of VTE and their results were compared with the established new reference range of D-dimer, and with the recorded ultrasound findings. RESULTS In the first trimester, 84% women from reference group had normal D-dimer, in the second 33%, and by the third trimester only 1%, which suggests that D-dimer has no practical diagnostic use in ruling out VTE if the threshold of 230 ng/mL for abnormal is used. All pregnant women with thrombosis who had positive ultrasound findings also had statistically significant elevation of the D-dimer level, considering the established reference range of the corresponding trimester. We found 100% sensitivity of D-dimer test. A women developed thrombosis in the first trimester had 6.7-7.6 time higher level of D-dimer than the mean value in the reference group, and in the third trimester thrombotic women had 2.0-3.8 time higher level of D-dimer, p<0.0001. CONCLUSION D-dimer test with the new threshold for: the first of 286, the second of 457 and the third trimester of 644 ng/mL can be useful in diagnosis of pregnancy related VTE.

A novel prothrombin mutation in two families with prominent thrombophilia--the first cases of antithrombin resistance in a Caucasian population.

V. DJORDJEV IC ,* M. KOVAC,†‡ P . MIL J IC ,†§ M. MURATA, ¶ A. TAKAGI , ¶ I . PRUNER ,* D . FRANCUSK I , * T . KOJ IMA ¶ and D . RADOJKOVIC* *Institute of Molecular Genetics and Genetic Engineering, University of Belgrade; †Faculty of Medicine, University of Belgrade; ‡Hemostasis Department, Blood Transfusion Institute of Serbia; §Clinic of Hematology, University Clinical Center, Belgrade, Serbia; and ¶Department of Pathophysiological Laboratory Sciences, Nagoya University Graduate School of Medicine, Higashi-ku, Nagoya, Japan

The c.-1639G>A polymorphism of the VKORC1 gene in Serbian population: retrospective study of the variability in response to oral anticoagulant therapy.

A single nucleotide polymorphism c.-1639G>A in the promoter region of vitamin K-epoxide reductase (VKORC1) gene has been found to account for most of the variability in response to oral vitamin K antagonist (VKA). Our aim was to study the effect of c.-1639G>A polymorphism on the acenocoumarol dosage requirements in a group of patients under stable anticoagulation, and to estimate the variability in response to VKA. We conducted a retrospective cohort analysis of 200 stable anticoagulation patients followed from the initiation of VKA. Out of 43 low-dose patients, 40 (93%) carried the A allele. The A allele was less frequent in the group of 30 patients requiring high VKA dose; among these patients 13 (43.3%) carried the A allele in the heterozygous form and none of them carried AA genotype. Patients with GG genotype required 2.6 times higher dose than patients carriers of AA genotype (P < 0.0001). Carriers of AA genotype were more likely to be overanticoagulated during follow-up after initiation of VKA when compared with carriers of the GA and GG genotypes (P < 0.0001). Patients with GG genotype spent more time below therapeutic range compared with patients carriers of AA (P = 0.0328) and GA genotype (P < 0.0001). VKORC1 c.-1639G>A polymorphism significantly influenced VKA dose and represented a good predictor of individuals predisposed to unstable anticoagulation. Pharmacogenetic testing could predict a high risk of overdose among 28.5% of our patients, carriers of AA genotype, before the initiation of anticoagulation.

Factor V Leiden, FII G20210A, MTHFR C677T mutations as risk factors for venous thrombosis during pregnancy and puerperium

BACKGROUND Venous thrombosis is the most common cause of obstetric morbidity and mortality during pregnancy and puerperium. The incidence of pregnancy-associated venous thrombosis varies from 1 in 1000 to 1 in 2000 deliveries. Factor V G1691A (FV Leiden), FII G20210A and MTHFR C677T mutations are the most common genetic risk factors for thromboembolism. The aim of this study was to establish the presence of these risk factors in a group of women with an episode of deep venous thrombosis during pregnancy or puerperium. METHODS The study was carried in a group of 45 women with the first episode of deep venous thrombosis during pregnancy or puerperium. The patients with antiphospholipid antibodies, antithrombin III, protein C or protein S deficiency, and autoimmune and malignant diseases were excluded from the study. FV Leiden, FII G20210A, and MTHFR C677T mutations were detected by polymerase chain reaction, followed by digestion with specific restriction enzymes. RESULTS Twenty heterozygous carriers of the FV Leiden mutation and one homozygous carrier were detected, which represents the frequencies of 44.4% and 2.2%, respectively. For the FII G20210A mutation, six heterozygous carriers were identified, giving the frequency of 13.3%. The MTHFR C677T mutation was observed in 31 patients (22 heterozygous and 9 homozygous carriers) which represents the frequencies of 48.9% and 20%, respectively. CONCLUSION Our study suggested that the obligatory testing for FV Leiden and FII G20210A mutations was strongly recommended in women with history of venous thrombosis during pregnancy and puerperium. We found a slight effect of MTHFR 677T allele, but it should be considered in association with other risk factors.

Type and location of venous thromboembolism in carriers of Factor V Leiden or prothrombin G20210A mutation versus patients with no mutation.

Factor V Leiden (FVLeiden) and prothrombin G20210A are the most common genetic causes of thrombophilia and established risk factors for different clinical manifestations of venous thromboembolism (VTE). This study investigated whether the clinical manifestation of VTE, the extension of deep vein thrombosis (DVT) and the presence of transient risk factors at the time of the first VTE, differed among patients with mutations (97 with FVLeiden; 33 with prothrombin G20210A) and in 109 patients without thrombophilia. Isolated pulmonary embolism (PE) was less prevalent in patients with FVLeiden (6%) and no thrombophilia (6%) than in those with prothrombin G20210A (15%). No difference was found in the incidence of distal DVT. Regarding the extension of proximal DVT, the lowest incidence for isolated popliteal vein and the highest for iliofemoral vein were observed in patients with prothrombin G20210A. No difference was observed between groups of patients with or without thrombophilia by unprovoked VTE. The pregnancy/puerperium was the most prevalent risk factor in carriers of prothrombin G20210A. Among FVLeiden carriers, the most prevalent risk factor was surgery, and in patients without thrombophilia, it was trauma (P < .05). Thrombosis of the upper limb was more frequent in a group without thrombophilia than in patients with mutations (P < .01). Transverse sinus venous thrombosis was present only in patients with prothrombin G20210A. Carriers of prothrombin G20210A have an increased risk of developing isolated PE and more severe clinical manifestations than those with FVLeiden or without thrombophilia.

Thrombophilia in Women with Pregnancy-Associated Complications: Fetal Loss and Pregnancy-Related Venous Thromboembolism

Backgound/Aims: Existing data regarding the prevalence of thrombophilia in women with pregnancy complications are conflicting. Methods: To investigate the relationship between pregnancy-associated complications and the presence of thrombophilia, we studied the records of 453 women with pregnancy-associated complications. In 55 women, intrauterine fetal death (fetus mortus in utero, FMU) after 20 weeks of gestation was recorded, in 231 two or more consecutive recurrent fetal losses (RFL) were recorded, while 167 had a venous thromboembolism (VTE) during one of their pregnancies. The control group consisted of 128 healthy women, with no previous history of thrombotic events or miscarriages. Results: In the FMU group we found 54.5% of women had thrombophilia, in the RFL group 38%, and in the VTE group 52.7%. The most frequent thrombophilia in the VTE group was the FV Leiden (OR 17.9, 95% CI 4.2–75.9). The most frequent thrombophilia in the FMU group was the FII G20210A (OR 7.09, 95% CI 1.8–27.9). Statistical difference between RFL and the control group was observed only for FV Leiden (OR 6.8, 95% CI 1.6–29.7). Conclusion: Thrombophilia was found to be considerably more common in women with pregnancy-associated complications in comparison with the women with normal pregnancies, most frequently in patients with VTE or FMU.

Inherited Thrombophilia is Associated With Pregnancy Losses That Occur After 12th Gestational Week in Serbian Population

Recurrent fetal loss (RFL) is a significant clinical problem, occurring in 1% to 5% of reproductive females. Inherited or acquired thrombophilia has been diagnosed in 50% to 65% of women with history of unexplained fetal loss. The objective of our study was to determine the prevalence of thrombophilia in women with unexplained RFL in Serbian population and to find out whether the presence of thrombophilia is associated with pregnancy losses that occur later than 12th gestational week. We have examined 147 women with unexplained RFL or intrauterine fetal death and 128 healthy women with at least 1 uncomplicated pregnancy. The antithrombin (AT), protein C (PC), protein S (PS), activated protein C (APC) resistance, factor V (FV) G1691A, factor II (FII) G20210A, and MTHFR C677T were determined. At least 1 inherited thrombophilic defect was found in 54 (36.7%) of 147 women with repeated fetal losses and in 11 (8.59%) of 128 controls (P < .001, OR 6.17, 95% CI 3.06-12.48). The most common thrombophilic abnormalities were homozygosity for MTHFR 677TT, FV Leiden, and FII G20210A. Deficiency of natural anticoagulants occurred in 10 patients, with protein S deficiency being the most frequent one. Thrombophilia was found in 46 of 94 women with RFL that occurred later than the 12th gestational week and in only 8 of 53 with RPL earlier than 12th week (P = .001). Our study has shown the association between the hereditary thrombophilia and RFL that occurred after the 12th gestational week in Serbian population.

Factor V Leiden mutation and high FVIII are associated with an increased risk of VTE in women with breast cancer during adjuvant tamoxifen — Results from a prospective, single center, case control study

BACKGROUND Estimates of the risk ratio of tamoxifen-associated venous thromboembolism (VTE) in breast cancer patients range from 2.4 to 7.1. The occurrence of thrombosis in patients with breast cancer complicates the clinical condition and causes a change of treatment. Our study was conducted in order to investigate the influence of patient-related risk factors for thrombosis development in breast cancer patients whose treatment included adjuvant tamoxifen. METHODS The prospective, single center, case control study included 150 breast cancer women, 50 whom developed venous thrombosis during adjuvant tamoxifen and 100 whom did not have thrombosis, as a control group. Patient-related risk factors such as: age, body mass index, previous VTE, varicose veins, concomitant diseases, the presence of prothrombotic mutations (FV Leiden, FII G20210A) and FVIII activity were evaluated in both groups. RESULTS In respect of prothrombotic mutations, the FV Leiden mutation was present in a higher number of women from the VTE group (10/50 vs 7/100; P=0.020). Additionally, FVIII activity was significantly higher in the VTE group; median (IQR), of 1.79 (0.69) vs 1.45 (0.55); P<0.001 and more women in this group (24/50 vs 34/100) had increased FVIII activity; P=0.020. In those women with FVIII>1.5IU/ml, who were carriers of prothrombotic mutations, an OR of 3.76 (CI 95% 1.276-11.096; P=0.016) was obtained for VTE. CONCLUSION The results of our study showed that the factor V Leiden mutation and high FVIII are associated with an increased risk of VTE in women with breast cancer during adjuvant tamoxifen.

Thrombin generation, D-dimer and protein S in uncomplicated pregnancy.

Abstract Background: Gestational age-specific reference values are essential for the accurate interpretation of haemostatic tests during pregnancy. Methods: Our 1-year prospective study included 40 healthy pregnant women with a median age of 30 (range 22–40) years; the subjects were followed in order to establish the gestational age dependent values for endogenous thrombin potential (ETP), D-dimer and protein S (activity and free). Results: During the first trimester 50% of studied women had ETP >100% (reference values out of pregnancy); in the second trimester an ETP over 100% was observed in all women; ETP values remained unchanged during the third trimester. In the first trimester, the median D-dimer concentration of 0.30 mg/L, in the second 0.91 mg/L and in the third of 1.45 mg/L were observed. During the first trimester 14/40 subjects had protein S activity below reference range (<59%, out of pregnancy); the median value of 61.35; interquartile range (IQR) 20.38; in the second 21/37; the median value of 53.1 (IQR 15.65); in the third trimester 28/37 had low level of protein S activity with the median value of 49.0 (IQR 18.8). Free protein S showed a slight decrease from the first trimester; it remained almost stable during the rest of pregnancy, with the equal number of pregnant women with reduced free protein S. Conclusions: Related to the gestational age, a significant increase of ETP and D-dimer, from the second trimester was observed; the decrease of protein S was observed already from the early pregnancy, with more pronounced variability of protein S activity.

Does anticoagulant therapy improve pregnancy outcome equally, regardless of specific thrombophilia type?

The study was conducted to evaluate the effect of anticoagulant therapy in women with thrombophilia and to detect the possible differences among carriers of mutations (factor V [FV] Leiden and FIIG20210) and those with natural anticoagulant deficiency. The 4-year prospective investigation included 85 pregnant women, with a history of recurrent fetal loss (RFL). They were treated with prophylactic doses of low-molecular-weight heparin (nadroparin) starting from 6 to 8 weeks of gestation. Pregnancy outcomes were evaluated based on the thrombophilia type. Carriers of thrombophilic mutations had a live birth rate of 93%, compared to 41.6% for women with natural anticoagulant deficiencies. Significant differences between the groups were also observed for intrauterine fetal death, intrauterine growth restriction, and postpartum thrombosis. The optimal therapy for women with natural anticoagulant deficiency and RFL remains unclear and future prospective study with a large number of patients is required to determine the best treatment for these severe thrombophilic conditions.