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1.
Int J Pediatr Otorhinolaryngol ; 106: 35-40, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29447888

RESUMO

OBJECTIVES: Sickle cell anemia (SCA) and ß -thalassemia major are well-recognized beta-globin gene disorders of red blood cells associated to mortality and morbidity included bone morbidities due to ineffective erythropoiesis and bone marrow expansion, which affect every part of the skeleton. While there are an abundance of described disease manifestations of the head and neck, the manner of paranasal sinuses involvement and its relations to ß-thalassemia and SCA process was not studied yet. Therefore, the aim of this study was to investigate a possible increased risk of rhinosinusitis and the real pathogenetic mechanism of it, comparing these two hematological diseases using msCT, gold standard for paranasal sinuses evaluation. METHODS: A retrospective analysis of 90 patients affected by ß-thalassemia major or SCA (respectively 59 and 31) underwent allogeneic bone marrow transplantation (BMT), and 44 control subjects was performed. Both patient categories and control group have been subjected to hematological and radiological evaluation using 64-multidetector-row CT scanner without contrast injection. RESULTS: Statistical analysis reveals that patients of the two study groups exhibit a significantly increased risk of sinusitis in comparison with the normal controls (RR: 3.55 for ß-thalassemic pediatric subjects; RR: 3.35 for SCA pediatric subjects). A significant difference (p < 0,5) was found between the ß -thalassemic patients on the one side, and SCA and control group on the other side, with regard to the evaluation of the typical anatomic alteration of maxillary sinus: ß-thalassemic children had significant increase in the bone thickness of anterior and lateral sinus walls and significant reduction in volume and density compared to SCA patients and control group, with normal conditions of these parameters. CONCLUSIONS: In these hematological patients, there is an increased incidence of sinonasal infections due their therapy-induced immunosuppression post transplantation. In ß-thalassemic patients, furthermore, the specific anatomical variants play an important confounding factor in radiological interpretation of CT images. Therefore, a cranio-facial CT scan evaluation could be a useful tool in the management of upper airway infections after BMT and should be a routinely exams in order to avoid useless surgical or antibiotic approaches.


Assuntos
Anemia Falciforme/complicações , Transplante de Medula Óssea/efeitos adversos , Rinite/fisiopatologia , Sinusite/fisiopatologia , Talassemia beta/complicações , Adolescente , Anemia Falciforme/cirurgia , Criança , Pré-Escolar , Doença Crônica , Feminino , Humanos , Masculino , Estudos Retrospectivos , Rinite/complicações , Rinite/epidemiologia , Medição de Risco , Sinusite/complicações , Sinusite/epidemiologia , Tomografia Computadorizada por Raios X , Adulto Jovem , Talassemia beta/cirurgia
2.
Bone Marrow Transplant ; 49(11): 1376-81, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25068420

RESUMO

Sickle cell anemia (SCA) remains associated with high risks of morbidity and early death. Allogeneic hematopoietic SCT (HSCT) is the only curative treatment for SCA. We report our experience with transplantation in a group of patients with the non-Black African variant and the Black African variant of SCA. This study included 40 consecutive SCA patients (13 patients with the non-Black African variant and 27 with the Black African variant) who underwent BM transplantation from HLA-identical sibling donors between June 2004 and May 2013, following a myeloablative-conditioning regimen. All patients obtained sustained engraftment. One patient (non-Black African variant) became a stable mixed chimera with 25% donor cells more than 6 years after transplantation. The probabilities of survival, SCA-free survival and TRM at 5 years after transplant were 91%, 91% and 9%, respectively. All surviving patients remained free of any SCA-related events after transplantation. Our results confirm that it is possible to offer a greater than 90% chance of cure to children with SCA. HSCT should be considered the standard of care for who have an HLA-identical donor, before complications result from the sickling of RBC.


Assuntos
Anemia Falciforme/terapia , População Negra , Transplante de Células-Tronco Hematopoéticas , Adolescente , Adulto , Aloenxertos , Anemia Falciforme/etnologia , Anemia Falciforme/mortalidade , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Lactente , Estudos Retrospectivos , Irmãos , Taxa de Sobrevida
3.
Bone Marrow Transplant ; 47(2): 227-30, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21499319

RESUMO

Many patients with thalassemia have been cured with BMT since the first successful transplant in 1981. Allogeneic stem cell gene therapy is the only treatment option for patients with sickle cell anemia (SCA). A total of 11 patients with a median age of 12 years (range, 2-16), affected by SCA, received hematopoietic SCT from HLA-identical, related donors following a myeloablative-conditioning regimen. Indications for transplantation were vaso-occlusive crisis, acute chest syndrome, avascular bone necrosis, chronic RBC transfusions, or hemorrhagic stroke. All patients had sustained engraftment. One patient became a stable mixed chimera with 25% of donor cells at 4 years after transplantation. One patient died at 1 year after transplantation. The probability of survival, SCA-free survival and TRM at 5 years after transplant were 90, 90 and 10%, respectively. All 10 surviving patients remained free of any SCA-related events after transplantation. In conclusion, these data confirm SCT from a suitable HLA-matched, related donor should become the primary option for curing children with SCA. There is an excellent survival rate and a return to normal life, free of SCA-related events.


Assuntos
Anemia Falciforme/terapia , Terapia Genética/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Adolescente , Anemia Falciforme/genética , Anemia Falciforme/cirurgia , Criança , Pré-Escolar , Feminino , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Masculino , Estudos Prospectivos , Taxa de Sobrevida , Quimeras de Transplante , Transplante Homólogo
4.
Bone Marrow Transplant ; 47(1): 107-14, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21317935

RESUMO

We evaluated the incidence of GVHD, risk factors and the impact of graft composition on acute GVHD (aGVHD) in 92 children who underwent BMT for thalassemia following busulfan/cyclophosphamide (BUCY)-based conditioning regimens and GVHD prophylaxis with CSA/short-MTX and methylprednisolone. The incidence of grade 2-4 and 3-4 aGVHD was 35% (95% confidence interval (CI) 25-44) and 9% (95% CI 4-16), respectively. We found that CD3(+) and CD34(+) cell doses above the median were associated with high incidence of grade 2-4 aGVHD (49 vs 20%, P=0.005 and 46 vs 23%, P=0.021, respectively). In multivariate analysis, high CD3(+) (hazard ratio (HR) 4.6; 95% CI 1.4-14.7; P=0.010) and CD34(+) (HR 4.3; 95% CI 1.4-12.7; P=0.011) cell doses were associated with grade 2-4 aGVHD. We further examined the effect of CD3(+) and CD34(+) cell doses on aGVHD using quartile cutoff points and found a minimum threshold for CD3(+) (38 × 10(6)/kg) and CD34(+) (4 × 10(6)/kg) cells above which the incidence of grade 2-4 aGVHD is significantly increased. This study shows for the first time a positive correlation between the number of CD3(+) and CD34(+) cells and aGVHD in children receiving sibling BMT, and indicates that using tailored and more intensive post transplant immunosuppression may permit to better control aGVHD.


Assuntos
Antígenos CD34 , Transplante de Medula Óssea , Complexo CD3 , Doença Enxerto-Hospedeiro/epidemiologia , Doença Enxerto-Hospedeiro/prevenção & controle , Talassemia/terapia , Condicionamento Pré-Transplante , Doença Aguda , Adolescente , Anti-Inflamatórios/administração & dosagem , Bussulfano/administração & dosagem , Criança , Pré-Escolar , Ciclofosfamida/administração & dosagem , Feminino , Humanos , Terapia de Imunossupressão/métodos , Imunossupressores/administração & dosagem , Incidência , Lactente , Masculino , Metotrexato/administração & dosagem , Metilprednisolona/administração & dosagem , Agonistas Mieloablativos/administração & dosagem , Irmãos , Transplante Homólogo
6.
Bone Marrow Transplant ; 42(6): 397-404, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18574445

RESUMO

There is a substantial incidence of graft failure in patients with thalassemia after myeloablative conditioning regimens especially in class 3 patients in whom its incidence could be as high as 8-38.5%. Most patients with graft failure have recurrence of thalassemic marrow. Historically, results of second transplants for thalassemia were poor because of a high rejection rate and/or increased TRM. Sixteen patients with thalassemia recurrence following rejection of the first graft and with a median age of 9 years (range, 4-20) were given second transplants using BM (n=7) or PBSC (n=9) after preparation with a new treatment protocol. All but two patients received stem cells from the same donor. The median interval between two transplants was 28 months (range, 8-204). The sustained engraftment rate was high (94%) with only one patient having primary graft failure. The probability of overall survival, event-free survival, TRM and graft failure were 79, 79, 16 and 6%, respectively. There were three transplant-related deaths. Thirteen patients are alive with Lansky/Karnofsky score of 100. This intensified treatment protocol was well tolerated with no significant increase in toxicity. The excellent results obtained with this new preparative regimen allow us to recommend it for second transplantation for patients with thalassemia recurrence.


Assuntos
Rejeição de Enxerto , Sobrevivência de Enxerto , Talassemia/terapia , Condicionamento Pré-Transplante , Adolescente , Adulto , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Estudos Prospectivos , Recidiva , Irmãos , Taxa de Sobrevida , Talassemia/mortalidade , Fatores de Tempo
8.
Heart ; 90(1): 82-6, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14676252

RESUMO

OBJECTIVE: To investigate the possible link between the G20210A prothrombin gene variant and different forms of ischaemic heart disease. DESIGN: Phenotype-specific meta-analysis of 19 studies published within March 2002, globally including 4944 patients and 7090 controls. Sample size, inclusion criteria, geographical location, clinical presentation, age, cardiovascular risk factors, and angiographic extent of disease were extracted from each study. Analyses were done according to Mantel-Haenszel. RESULTS: Overall, the odds ratio (OR) for unspecified ischaemic heart disease associated with the 20210A allele was 1.21 (95% confidence interval (CI) 0.99 to 1.59, n = 12 034). Similar findings were seen for acute coronary syndromes (unstable angina and myocardial infarction) and for myocardial infarction without age limits (OR 1.24, 95% CI 0.98 to 1.63, n = 10 240; and OR 1.19, 95% CI 0.93 to 1.58, n = 9765). The effects were similar in male and female subjects. In the 1931 subjects < 55 years of age, the OR for myocardial infarction increased to 1.77 (95% CI 1.16 to 3.42) and in the 1359 subjects < 45 years to 2.30 (95% CI 1.27 to 4.59). No significant association was found between the 20210A allele and the presence of angiographically documented coronary disease (OR 1.08, 95% CI 0.70 to 1.64, n = 3444). However, patients with 0/1 vessel disease at angiography showed a greater prevalence of the A allele than those with multivessel disease (relative risk 2.0, 95% CI 1.2 to 3.1, n = 2376). CONCLUSIONS: G20210A prothrombin gene polymorphism may represent a modest but significant risk factor for myocardial infarction at young ages and favour the expression of ischaemic heart disease among individuals who have a limited extent of coronary atherosclerosis at angiography.


Assuntos
Isquemia Miocárdica/genética , Polimorfismo Genético/genética , Protrombina/genética , Adulto , Fatores Etários , Idoso , Estudos de Casos e Controles , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Estudos Prospectivos , Fatores de Risco , Fatores Sexuais
9.
Eur Heart J ; 23(1): 26-30, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11741359

RESUMO

AIMS: To investigate the prevalence of the G20210A prothrombin and G1691A factor V gene variants in patients with acute coronary syndrome stratified according to risk factor profile and to extent of coronary disease, in comparison with matched healthy controls. METHODS AND RESULTS: The 20210 prothrombin and the 1691 factor V loci were genotyped in 247 patients < or =65 years of age (190 myocardial infarction and 57 unstable angina as first presentation of disease) and in 247 healthy age- and sex-matched controls. The prevalence of the 1691A factor V allele was similar in cases and controls. The frequency of heterozygotes for the 20210A prothrombin allele was 6.5% among patients and 2.8% among controls (OR 2.4, 95% CI 1.0-5.9), increasing to 8.7% in patients with a family history of myocardial infarction (OR 3.3, 95% CI 1.2-9.1), to 9.9% in patients (n=81) with < or =1 vessel disease (OR 3.8, 95% CI 1.3-10.8), and to 13.0% in patients who were normocholesterolaemic, non-diabetic, normotensive and non-smokers (OR 5.1, 95% CI 1.2-21.4). CONCLUSIONS: These findings suggest that the 20210A prothrombin allele represents an inherited risk factor for acute coronary syndrome among patients who have limited extent of coronary disease at angiography or who lack major metabolic and acquired risk factors.


Assuntos
Doença das Coronárias/genética , Protrombina/genética , Doença Aguda , Idoso , Alelos , Angiografia Coronária , Doença das Coronárias/diagnóstico por imagem , Fator V/análise , Feminino , Variação Genética , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/genética , Prevalência , Fatores de Risco , Síndrome
10.
Br J Haematol ; 114(1): 150-4, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11472360

RESUMO

Membrane glycoprotein (GP) Ia/IIa mediates platelet adhesion to collagen. The linked C807T/G873A polymorphisms in the GP Ia gene are correlated with a variable expression of the platelet surface receptor, the 807 TT/873 AA genotype being associated with a higher receptor density. Our study aimed to evaluate the possible role of the GP Ia C807T/G873A polymorphism as a risk factor for acute coronary syndrome in the Italian population. We investigated 157 patients with acute coronary syndrome (117 with myocardial infarction and 40 with severe unstable angina) as the first manifestation of coronary disease occurring before 65 years of age, compared with 312 healthy controls. All individuals were of Italian ancestry and were genotyped for the GP Ia C807T/G873A polymorphism. Complete linkage between the 807 and 873 sites was found in all samples. The 807 TT genotype was present in 12.7% of cases and in 4.8% of controls; the odds ratio for acute coronary syndrome was 2.9 (95% CI 1.4--5.8) for the 807 TT genotype compared with C-allele carriers and 0.6 (95% CI 0.4--0.9) for the 807 CC genotype compared with T-allele carriers. For the TT genotype, compared with CC homozygotes, the increase in risk was 3.4-fold in patients with at least one risk factor (smoking, hypercholesterolaemia, diabetes, systemic hypertension) and 4.1-fold in patients with angiographically diagnosed two- or three-vessel disease. We conclude that the GP Ia 807 TT (873 AA) genotype is associated with an increased risk of acute coronary syndrome in the Italian population; conversely, the GP Ia 807 CC (873 GG) genotype seems to represent a protective factor.


Assuntos
Doença das Coronárias/genética , Integrinas/genética , Polimorfismo Genético , Doença Aguda , Adulto , Idoso , Angina Instável/genética , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/genética , Razão de Chances , Receptores de Colágeno , Fatores de Risco
11.
Br J Haematol ; 113(3): 630-5, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11380448

RESUMO

The G20210A mutation in the prothrombin gene is associated with an increased risk of a first venous thromboembolic episode; few data are available about the long-term risk for recurrent venous thromboembolism and it is not known whether or not carriers of the mutation should be recommended lifelong anticoagulant treatment after the first thrombosis. We investigated 624 patients, referred for previous objectively documented deep venous thrombosis of the legs or pulmonary embolism, to determine the risk of recurrent thromboembolism in heterozygous carriers of the G20210A mutation in the prothrombin gene after the first episode of venous thromboembolism. After exclusion of other inherited (anti-thrombin, protein C, protein S deficiency and factor V Leiden) or acquired (anti-phospholipid antibody syndrome) causes of thrombophilia, 52 heterozygous carriers of the prothrombin mutation were compared with 283 patients with normal genotype. The relative risk for recurrent venous thromboembolism was calculated between groups using a Cox's proportional hazard model. The patients with the prothrombin mutation had a risk for spontaneous recurrent venous thromboembolism similar to that of patients with normal genotype (hazard ratio 1.3; 95% CI, 0.7-2.3). The circumstances of the first event (spontaneous or secondary) did not produce any substantial variation in the risk for recurrence. In conclusion, the carriers of the prothrombin mutation should be treated with oral anticoagulants after a first deep venous thrombosis for a similar length of time as patients with a normal genotype.


Assuntos
Protrombina/genética , Embolia Pulmonar/genética , Trombose Venosa/genética , Adolescente , Adulto , Idoso , Anticoagulantes/administração & dosagem , Estudos de Casos e Controles , Esquema de Medicação , Feminino , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Modelos de Riscos Proporcionais , Embolia Pulmonar/tratamento farmacológico , Recidiva , Risco , Trombose Venosa/tratamento farmacológico
14.
Blood Coagul Fibrinolysis ; 11(5): 499-503, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10937811

RESUMO

A hypercoagulable state has been hypothesized as a contributing factor in the pathogenesis of inflammatory bowel disease (IBD); moreover, such patients have an increased risk of thrombotic complications. The aim of the present paper was to study the prevalence of the two most important causes of inherited thrombophilia: factor V Leiden and the G20210A prothrombin-gene mutation in patients with Crohn's disease (CD) and ulcerative colitis (UC). Fifty-two patients affected by IBD (33 UC and 19 CD, 16 female and 36 male; mean age, 42 years) and 156 healthy controls (48 female and 108 male; mean age, 37 years) were studied. Seven out of 52 patients (13%) had previous thrombotic events. High molecular weight DNA was analysed for the presence of factor V Leiden and the G20210A prothrombin-gene mutation. One out of 52 IBD patients (1.9%) and three out of 156 control subjects (1.9%) were heterozygous for factor V Leiden. One IBD patient (1.9%) and four healthy controls (2.6%) were heterozygous for the prothrombin-gene mutation. The prevalence of the two mutations was similar in patients and controls. In the subgroup of IBD patients with previous thrombotic events, only one patient was heterozygous for the prothrombin-gene mutation. Factor V Leiden and the G20210A prothrombin-gene mutation do not seem to play a major role in the pathogenesis of IBD or be associated with an increased incidence of thrombotic complications, but with limited data.


Assuntos
Fator V/genética , Doenças Inflamatórias Intestinais/genética , Mutação , Protrombina/genética , Adulto , Idoso , Colite Ulcerativa/genética , Doença de Crohn/genética , DNA/análise , Fator V/análise , Feminino , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Trombose/genética
15.
Panminerva Med ; 41(3): 261-3, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10568127

RESUMO

We report a rare case of a patient with acute myeloid leukemia following refractory anemia with excess of blasts transformed (RAEB-T) who presented a clinical picture suggestive of thrombophlebitis. The ultrasonographic procedure and the response to corticosteroid treatment suggest that this condition was compatible with an atypical Sweet's syndrome.


Assuntos
Anemia Refratária com Excesso de Blastos/diagnóstico , Leucemia Mieloide/diagnóstico , Neutropenia/diagnóstico , Síndrome de Sweet/diagnóstico , Tromboflebite/diagnóstico , Doença Aguda , Anemia Refratária com Excesso de Blastos/complicações , Diagnóstico Diferencial , Humanos , Leucemia Mieloide/etiologia , Masculino , Pessoa de Meia-Idade , Ultrassonografia
16.
N Engl J Med ; 341(11): 801-6, 1999 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-10477778

RESUMO

BACKGROUND: Point mutations in the factor V gene (factor V Leiden) and the prothrombin gene (the substitution of A for G at position 20210) are the most common causes of inherited thrombophilia. Whether or not factor V Leiden increases the risk of recurrent deep venous thrombosis is controversial, and there is no information on the risk of recurrence among carriers of both mutations. METHODS: We studied a retrospective cohort of 624 patients who were referred for a first episode of deep venous thrombosis. After excluding 212 patients with other inherited or acquired causes of thrombophilia, we compared 112 patients who were heterozygous carriers of factor V Leiden with 17 patients who were heterozygous for both factor V Leiden and the prothrombin mutation and 283 patients who had neither mutation. The relative risk of recurrent deep venous thrombosis was calculated with use of a proportional-hazards model. RESULTS: Patients who were heterozygous for factor V Leiden alone had a risk of recurrent deep venous thrombosis that was similar to that among patients who had neither mutation (relative risk, 1.1; 95 percent confidence interval, 0.7 to 1.6; P=0.76). In contrast, patients who were heterozygous for both factor V Leiden and the prothrombin mutation had a higher risk of recurrent thrombosis than did carriers of factor V Leiden alone (relative risk, 2.6; 95 percent confidence interval, 1.3 to 5.1; P=0.002). When the analysis was restricted to patients with spontaneous recurrences (i.e., ones that occurred in the absence of transient risk factors for venous thrombosis), the risk among carriers of both mutations, as compared with carriers of factor V Leiden alone, remained high (relative risk, 3.7; 95 percent confidence interval, 1.7 to 7.7; P<0.001), particularly if the first event had also been spontaneous (relative risk, 5.4; 95 percent confidence interval, 2.0 to 14.1; P<0.001). In contrast, the risk of recurrence in the presence of transient risk factors was similar among carriers of both mutations and carriers of factor V Leiden alone. CONCLUSIONS: The risk of recurrent deep venous thrombosis is similar among carriers of factor V Leiden and patients without this mutation. Carriers of both factor V Leiden and the G20210A prothrombin mutation have an increased risk of recurrent deep venous thrombosis after a first episode and are candidates for lifelong anticoagulation.


Assuntos
Fator V/genética , Mutação Puntual , Protrombina/genética , Trombose Venosa/genética , Adolescente , Adulto , Idoso , Criança , Estudos de Coortes , Intervalo Livre de Doença , Feminino , Heterozigoto , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Risco , Fatores de Risco , Trombose Venosa/epidemiologia
17.
Br J Haematol ; 106(2): 564-8, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10460623

RESUMO

Mild hyperhomocysteinaemia is an established risk factor for deep vein thrombosis (DVT); few data concerning its potential interaction with thrombophilic genotypes are available at the present time. We investigated 121 thrombosis-free individuals and 111 patients with at least one objectively confirmed episode of DVT. A thrombophilic condition (deficiency in antithrombin, protein C and S, factor V Leiden, prothrombin G20210A) was detected in 25.2% of the patients; mutant factor V or prothrombin genotypes were present in 6.6% of the controls. Hyperhomocysteinaemia was found in 14.4% of patients and 3. 3% of the controls, with a 3.7-fold increase in risk for DVT (95% CI 1.1-12.3). Adoption of different cut-off levels for definition of hyperhomocysteinaemia did not substantially change the magnitude of the risk. Carriership of both hyperhomocysteinaemia and factor V Leiden or prothrombin G20210A was detected in 2.7% of patients for each combination and in none of the controls. An approximate estimate of 30-fold increased risk in carriers of both hyperhomocysteinaemia and factor V Leiden and 50-fold increased risk in carriers of both hyperhomocysteinaemia and prothrombin G20210A was calculated, suggesting a synergistic interaction between hyperhomocysteinaemia and such thrombophilic genotypes. Yet statistical analysis is highly unstable due to the small number of individuals with combined defects. Further investigations on large series of patients are needed.


Assuntos
Fator V/genética , Hiper-Homocisteinemia/genética , Protrombina/genética , Tromboembolia/genética , Trombose Venosa/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Genótipo , Heterozigoto , Humanos , Hiper-Homocisteinemia/epidemiologia , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Mutação/genética , Prevalência
20.
Semin Thromb Hemost ; 24(4): 367-79, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9763354

RESUMO

Inherited resistance to activated protein C (APC) has been recently recognized as a novel cause underlying venous thrombophilia. In most cases APC resistance is due to a single point mutation in the factor V gene leading to a replacement of Arg506 with Gln (factor V Leiden). Factor V Leiden allele is present in about 5% of the Caucasian individuals (Europeans, Jews, Israeli Arabs, and Indians) and is virtually absent in Africans, Asians, and races with Asian ancestry such as Amerindians, Eskimos, and Polynesians; this suggests a single origin of the mutation, which has been proven by haplotype analysis. A low prevalence of the mutation (1%) was noticed in African-Americans for recent racial admixture. Factor V Leiden presents not a major role as risk factor for arterial thrombosis, while it is present in 18% of Caucasian patients with venous thrombosis. This high incidence prevalence mirrors the incidence in the corresponding general populations and can be even higher in some areas according to the ethnic background. Conversely, factor V Leiden is usually not found in non-Caucasian thrombotic patients; this could give reason of the lower incidence of venous thrombotic disease in Africa and Asia in comparison with Europe. Therefore, screening for factor V Leiden is suggested for all Caucasian individuals with previous venous thrombosis; inclusion criteria for the screening should not be stringent because clinical manifestations associated with the mutant genotype can be also mild or secondary to circumstantial risk factors or manifesting at advanced age. Factor V Leiden can act also as concurrent risk factor in individuals with deficiency of natural inhibitors or mild hyperhomocysteinemia. So far, screening for the mutation in individuals with no history of thrombosis is recommended only for relatives of proband patients identified as carriers; the available data do not justify indiscriminate screening before risk situations such as oral contraceptives intake, pregnancy, or high-risk surgery.


Assuntos
Fator V/genética , Mutação Puntual , Triagem de Portadores Genéticos , Humanos , Programas de Rastreamento/métodos , Fatores de Risco , Tromboembolia/genética , Trombofilia/genética , População Branca/genética
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