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Biomedical subjects

F Peyvandi

Publications and source records attributed to F Peyvandi.

At least 19 recordsLinked to original sources
PubMed2006

Variants of OCTN1-2 cation transporter genes are associated with both Crohn's disease and ulcerative colitis.

BACKGROUND: Two variants in the organic cation transporter gene cluster have been recently reported to confer susceptibility to Crohn's disease (CD). AIM: To investigate these variants in CD and ulcerative colitis (UC), and their interaction with CARD15 gene and correlation to clinical subphenotypes. METHODS: Case-control association analysis was performed in 899 patients (444 CD and 455 UC) and 611 controls. The organic cation transporter gene cluster single nucleotide polymorphisms G207G-->C and 1672C-->T, the IGR2198a_1 single nucleotide polymorphism in the IBD5 locus, and the R702W, G908R and L1007finsC variants of CARD15 gene were genotyped by ABI-7700, restriction fragment length polymorphic analysis and multiplex pyrosequencing, respectively. RESULTS: The 1672TT and -207CC genotype frequencies were increased in both CD (OR = 1.5, P = 0.011; OR = 1.6, P = 0.002), and UC (OR = 1.5, P = 0.017; OR = 1.4, P = 0.033), respectively. Compared with controls, the TC haplotype frequency was increased in both CD (36% vs. 44%, P < or = 0.01) and UC (36% vs. 45%, P < or = 0.01). The frequency of the TC haplotype was 43% in CARD15-positive and 44% in CARD15-negative CD, respectively. Similar results were found in UC. In CD a significant association of the TC haplotype was found with presence of perianal fistulae (P = 0.007) and steno-fistulizing behaviour (P = 0.037). In UC, the TC haplotype was more frequent in patients with more extensive disease (P = 0.015), and those on immunosuppressives (P = 0.004). CONCLUSIONS: Organic cation transporter gene cluster variants may confer susceptibility to both CD and UC, and the TC haplotype may influence some clinical features of IBD, but does not interact with CARD15 variants.

Adult↗
PubMed2006

Prospective study on the behaviour of the metalloprotease ADAMTS13 and of von Willebrand factor after bone marrow transplantation.

Thrombotic microangiopathies (TMAs) are rare but serious complications of bone marrow transplantation (BMT). Clinical manifestations are similar to those of thrombotic thrombocytopenic purpura (TTP), but prognosis is generally poorer despite plasma exchange. The enzymatic activity of the plasma metalloprotease ADAMTS13, which cleaves ultralarge thrombogenic multimers of von Willebrand factor (VWF) derived from activated endothelial cells, is very low or undetectable in patients with classic TTP, and protease deficiency is thought to play a mechanistic role in the formation of platelet thrombi in the microcirculation. This is the first prospective study to evaluate the incidence of TMA in 46 consecutively recruited patients undergoing autologous or allogeneic BMT and explore in parallel the behaviour of ADAMTS13, VWF antigen and VWF multimer size. The incidence of post-BMT TMA was 6% (three of 46); all cases occurred after allogeneic BMT. Compared with baseline values plasma ADAMTS13 activity was significantly reduced in patients undergoing BMT, particularly after the conditioning regimen (mean values: 50 +/- 22 vs. 77 +/- 32%; P < 0.0001). In the three patients who developed TMA, ADAMTS13 decreased after conditioning, but was very low in one case only (8%). VWF antigen levels progressively increased after the conditioning regimen (228 +/- 75 vs. 178 +/- 76% at baseline, P = 0.002). The mean proportion of high-molecular weight VWF multimers did not change in the various stages of BMT, even though ultralarge multimers were transiently found in same cases with and without TMA. Hence, the measurements evaluated in this study are not clinically useful to predict the occurrence of post-BMT TMA.

ADAM Proteins↗
PubMed2006

Genetic diagnosis of haemophilia and other inherited bleeding disorders.

Inherited deficiencies of plasma proteins involved in blood coagulation generally lead to lifelong bleeding disorders, whose severity is inversely proportional to the degree of factor deficiency. Haemophilia A and B, inherited as X-linked recessive traits, are the most common hereditary hemorrhagic disorders caused by a deficiency or dysfunction of blood coagulation factor VIII (FVIII) and factor IX (FIX). Together with von Willebrand's disease, a defect of primary haemostasis, these X-linked disorders include 95% to 97% of all the inherited deficiencies of coagulation factors. The remaining defects, generally transmitted as autosomal recessive traits, are rare with prevalence of the presumably homozygous forms in the general population of 1:500,000 for FVII deficiency and 1 in 2 million for prothrombin (FII) and factor XIII (FXIII) deficiency. Molecular characterization, carrier detection and prenatal diagnosis remain the key steps for the prevention of the birth of children affected by coagulation disorders in developing countries, where patients with these deficiencies rarely live beyond childhood and where management is still largely inadequate. These characterizations are possible by direct or indirect genetic analysis of genes involved in these diseases, and the choice of the strategy depends on the effective available budget and facilities to achieve a large benefit. In countries with more advanced molecular facilities and higher budget resources, the most appropriate choice in general is a direct strategy for mutation detection. However, in countries with limited facilities and low budget resources, carrier detection and prenatal diagnosis are usually performed by linkage analysis with genetic markers. This article reviews the genetic diagnosis of haemophilia, genetics and inhibitor development, genetics of von Willebrand's disease and of rare bleeding disorders.

Blood Coagulation Disorders, Inherited↗
PubMed2006

Rare bleeding disorders.

Deficiencies of coagulation factors other than factor VIII and factor IX (afibrinogenemia, FII, FV, FV+FVIII, FVII, FX, FXI, FXIII) that cause bleeding disorders (RBDs) are inherited as autosomal recessive traits and are rare, with prevalences in the general population varying between 1 in 500,000 and 1 in 2 million for the homozygous forms. As a consequence of the rarity of these deficiencies, the type and severity of bleeding symptoms, the underlying molecular defects, and the actual management of bleeding episodes are not as well established as for hemophilia A and B. The study of the genetic basis of these disorders could represent an important tool for prevention through prenatal diagnosis. Treatment of patients with RBDs during bleeding episodes or surgery is a challenge because of the lack of experience and the paucity of data. For some deficiency factor concentrates are still non available and severe complications can occur. These complications can be minimized by assessment of risks of bleeding and thrombosis, use of haemostatic means other than blood components or no therapy at all. The RBDs pose a problem for guideline writers because there are no suitable clinical trials to supply good evidence for how these people are best treated. The lack of adequate information on clinical manifestations, treatment and genetic basis of RBDs could be improved by the collection of data in an International Database (http://www.rbdd.org), linkable to others previously published. This could be a useful tool to fill the gap between clinical data and clinical practice. This article reviews the genetic basis of RBDs, problems and complications of treatment, problems in the preparation of suitable guidelines for treatment and the future perspectives of the International Registry on RBDs.

Blood Coagulation Disorders, Inherited↗
PubMed2005

Role of the 2 adenine (g.11293_11294insAA) insertion polymorphism in the 3' untranslated region of the factor VII (FVII) gene: molecular characterization of a patient with severe FVII deficiency.

Polymorphic variants in the gene encoding factor VII (F7) affect the plasma levels of this coagulation protein and modify the clinical phenotype of FVII deficiency in some patients. In this study we report the in vitro functional analysis of a novel polymorphic variant located in the 3' untranslated region of F7: g.11293_11294insAA. To determine whether this variant regulates FVII expression, we initially compared an expression vector containing FVII cDNA with g.11293_11294insAA with the FVII wild-type (WT) construct. The kinetics of mRNA production showed that the insertion decreases the steady-state FVII mRNA levels. To assess whether the insertion influences the phenotype of FVII-deficient patients, we evaluated its effect on the expression of FVII in a patient with severe FVII deficiency (undetectable FVII activity and antigen) carrying two additional homozygous missense variations (p.Arg277Cys and p.Arg353Gln). The two substitutions alone reduced the expression of FVII activity and antigen in vitro, but with the insertion polymorphism in our expression vector the patient's phenotype of undetectable plasma FVII was recapitulated. The insertion polymorphism in the 3' untranslated region of F7 is another modifier of FVII expression that might explain the poor genotype-phenotype correlation in some FVII-deficient patients.

3' Untranslated Regions↗
PubMed2005

Glanzmann thrombasthenia and Bernard-Soulier syndrome in south Iran.

Glanzmann thrombasthenia (GT) and Bernard-Soulier syndrome (BSS) are two rare inherited disorders of platelet function. In this study, we report the demographic, clinical and biological characteristics of 23 patients with GT and of seven patients with BSS from southern Iran who had been followed for many years but fully characterized only recently, when platelet aggregation tests and flow cytometric studies became available for the first time in the country. We found a high prevalence of both diseases that can be explained by the high rate of consanguineous marriages in south Iran. Patients affected by GT and BSS suffer mainly from mucocutaneous bleedings causing anemia and transfusion requirements.

Adolescent↗
PubMed2005

A critical role for Gly25 in the B chain of human thrombin.

We have recently identified (Akhavan S et al., Thromb Haemost 2000; 84: 989-97) a patient with a mild bleeding diathesis associated to an homozygous mutation in the thrombin B chain (Gly25Ser, chymotrypsinogen numbering, i.e. position 330 in human prothrombin numbering). Transient transfection of wild-type prothrombin (FII-WT) and mutant prothrombin (designated FII-G25(330)S) cDNA in COS-7 cells showed a mild reduction (50%) in FII-G25(330)S production. Recombinant proteins, stably expressed in Chinese hamster ovary cells, were isolated and activated by Taipan snake or Echis carinatus venoms. We show that the G25(330)S mutation results in a decrease in the rate of prothrombin proteolytic activation. The mutation also significantly decreases (i) the catalytic activity of thrombin with a 9-fold reduction in catalytic efficiency of the mutant toward S-2238; (ii) the interaction with benzamidine; (iii) the rate of inhibition by TLCK and antithrombin; and (iv) the rate of hydrolysis of macromolecular substrates (fibrinogen, protein C). In contrast, exosite I does not appear to be affected by the molecular defect. These results, together with molecular modeling and dynamics, indicate that Gly25(330) is important for proper expression and probably proper folding of prothrombin, and also plays a critical role in both the alignment of the catalytic triad and the flexibility of one of the activation segments of prothrombin.

Animals↗
PubMed2005

Tissue plasminogen activator antigen is strongly associated with myocardial infarction in young women.

Women who develop acute myocardial infarction (AMI) at a young age have fewer classical risk factors and less coronary stenosis than older women. In this rare population, it is plausible that a heightened hemostatic system may play an important mechanistic role in thrombus formation and in the development of AMI. We chose to investigate whether or not there is an association between premature AMI and the plasma concentrations of five hemostatic measurements that had been previously established as risk factors for AMI, and of the inflammation marker C-reactive protein (CRP). Women who had survived AMI at the age of 45 years or less (n = 141) were drawn from those admitted to 125 Italian coronary care units over a 3-year period. In them, and in an equal number of controls, plasma levels of immunoreactive tissue plasminogen activator (tPA), plasminogen activation inhibitor 1 (PAI-1), von Willebrand factor (VWF), fibrinogen, D-dimer and CRP were measured. Higher levels of VWF, fibrinogen, CRP and tPA were associated with AMI. After adjustment for both classical and hemostatic risk factors, only tPA maintained an independent association with AMI: the odds ratios (taken as an index of relative risk) for tPA values in the middle and higher tertiles were 2.86 (CI 1.63-5.02) and 8.18 (CI 2.66-25.20), respectively. In conclusion, there is a strong association between non-fatal AMI and increased plasma levels of tPA antigen. This finding is thought to be the expression of a reduced rather than enhanced fibrinolytic activity.

Adult↗
PubMed2004

Presentation and pattern of symptoms in 382 patients with Glanzmann thrombasthenia in Iran.

Glanzmann thrombasthenia (GT) is a rare autosomal recessive disease characterized by prolonged bleeding time with normal platelet count and morphology. It is caused by the quantitative or qualitative deficiency of the platelet glycoprotein IIb-IIIa. In 382 Iranian patients with GT diagnosed at a single center during the period 1969-2001, consanguinity between parents was 86.6%, in accord with the high frequency of intrafamilial marriages in Iran. Almost all patients had had abnormal mucocutaneous bleeding (epistaxis and gum bleeding); at follow-up, 4/5 of the patients had been transfused at least once to control hemorrhagic episodes. As expected, almost all the patients had a normal platelet count while the leukocyte count was increased in 19.3%. Among women, an unexpected low rate of pregnancies was observed.

Adult↗
PubMed2004

Comparison of attitudes towards prenatal diagnosis and termination of pregnancy for haemophilia in Iran and Italy.

Prenatal diagnosis (PND) is an important issue in the comprehensive care of haemophiliacs. As a consequence of technological progress made in the field of PND, the early detection of an affected fetus provides the expectant couple with a chance to terminate pregnancy. This study was undertaken to assess the attitudes of two different haemophilic populations in Iran and Italy towards PND and termination of pregnancy. This study series included 59 Iranians (38 haemophilia A patients and 21 mothers) and 50 Italians (27 haemophilia A patients, 16 mothers and seven fathers). All the 109 participants received a questionnaire including demographic characteristics and evaluating the psychological effects stemming from PND and termination of pregnancy. Approximately 84.7% of the Iranians and 35.4% of the Italians were not familiar with the possibilities afforded by PND for haemophilia (P < 0.001). Termination of pregnancy appeared to be accepted by 58.2% of the Iranian and 16.7% of the Italian participants (P < 0.001). The greater rate of acceptability of abortion in Iranians may be due to differences in the quality of patient care in the two countries.

Abortion, Induced↗
PubMed2003

Severe factor V deficiency: exon skipping in the factor V gene causing a partial deletion of the C1 domain.

BACKGROUND: Severe factor V (FV) deficiency is a rare coagulation disorder, characterized by very low or unmeasurable plasma levels of functional and immunoreactive FV. Among rare inherited coagulopathies, FV deficiency is the least characterized from a molecular point of view (only 12 mutations have been reported). OBJECTIVES: The aim of this work was to investigate, at the molecular level, the pathogenetic mechanisms responsible for a case of severe FV deficiency. PATIENTS AND METHODS: A 19-year-old Iranian man showing unmeasurable FV activity and severely reduced FV antigen level in plasma was studied. Mutation screening was performed by sequencing. The effect of the identified mutation was investigated both at the mRNA and at the protein level. RESULTS: Molecular analysis of the factor V (FV) gene identified a novel homozygous A-->T transversion at position + 3 of the donor splice site of intron 19 (IVS19 + 3A-->T). Production of mutant mRNA in HeLa cells demonstrated that this mutation causes the entire exon 19 to be skipped from the FV mRNA. The mutant processed transcript codes for a deleted FV, lacking the first 24 amino acids of the C1 domain. Expression of the mutant FV protein in COS-1 cells showed that the deleted protein was synthesized but not secreted; moreover, the intracellular amount of deleted FV was reduced compared to wild type, suggesting intracellular degradation of mutant FV. CONCLUSIONS: This work reports the molecular characterization of the first mutation causing a partial deletion in the FV molecule, resulting in a severe impairment of protein secretion.

Adult↗
PubMed2002

Rare coagulation deficiencies.

UNLABELLED: Deficiencies of coagulation factors (other than factor VIII and factor IX) that cause a bleeding disorder are inherited as autosomal recessive traits and are generally rare, with prevalences in the general population varying between 1 : 500 000 and 1 : 2 000 000. In the last few years, the number of patients with recessively transmitted coagulation deficiencies has increased in European countries with a high rate of immigration of Islamic populations, because in these populations, consanguineous marriages are frequent. Owing to the relative rarity of these deficiencies, the type and severity of bleeding symptoms, the underlying molecular defects and the actual management of bleeding episodes are not as well established as for haemophilia A and B. This article reviews these disorders in terms of their clinical manifestations and characterization of the molecular defects involved. The general principles of management are also discussed. KEYWORDS: afibrinogenaemia, autosomal recessive disorders, factor VIII, factor XI, factor XIII.

Blood Coagulation Factors↗