Browsing by Author "Morais, S."
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- Advances in the genotyping of thrombosis genetic risk factors: clinical and laboratory implications.Publication . Cabeda, J.; Pereira, M.; Oliveira, J.; Estevinho, A.; Pereira, I.; Morais, S.; Justiça, B.; Campos, M.Since FV-Leiden polymorphism was first described in 1994, a growing number of polymorphic loci have been identified in association with increased genetic risk for thrombophilia. Often however, these risk factors have been studied in isolation of the remaining known phenotype linked polymorphisms. This fact has, at least in part, been justified by the laborious techniques traditionally used in the genotyping studies, as well as its relatively high costs. Another major problem concerning these studies has been the non-negligible incidence of dubious genotypes, resulting from the manual, labour intensive techniques applied, and their sometimes difficult to read output's. These difficulties have also hampered the widespread use of genotyping data in the clinical assessment of the genetic risk levels both in patients and their relatives, leaving some clinicians less than convinced about its clinical usefulness. Recently however, the introduction of new genetic techniques in the clinical genetics laboratory has started to change this picture. Most notably, the advent of Real-time-PCR has brought the possibility of genotyping patients and controls at a large scale, with increased specificity, automation and speed. Moreover, the use of these techniques in the clinical genetics setting has not only increased the quality of the results, but most importantly has also increased our capability of answering questions at a deeper level. Among the new questions that can now be answered without increased costs and uncertainty is the study of the association of genetic risk factors in thrombophilia. Our results show that indeed even common polymorphic loci may increase our ability to further discriminate the genetic thrombosis risk of individual patients and relatives. It must however be noted that the innovation level in the clinical genetics lab is just starting to grow. In fact we haven't even started to experience the advantages brought about by the genome program, and its massive identification of SNP's. The technology to test these is also presently being refined, and is expected to go from research to the clinical lab in the near future. Only then, can we expect to define with high certainty the combined genetic risks for such complex pathologies as the thrombophilias.
- Circulating endothelial cells in patients with venous thromboembolism and myeloproliferative neoplasmsPublication . Torres, C.; Fonseca, A.; Leander, M.; Matos, R.; Morais, S.; Campos, M.; Lima, M.Background Circulating endothelial cells (CEC) may be a biomarker of vascular injury and pro-thrombotic tendency, while circulating endothelial progenitor cells (CEP) may be an indicator for angiogenesis and vascular remodelling. However, there is not a universally accepted standardized protocol to identify and quantify these cells and its clinical relevancy remains to be established. Objectives To quantify CEC and CEP in patients with venous thromboembolism (VTE) and with myeloproliferative neoplasms (MPN), to characterize the CEC for the expression of activation (CD54, CD62E) and procoagulant (CD142) markers and to investigate whether they correlate with other clinical and laboratory data. Patients and Methods Sixteen patients with VTE, 17 patients with MPN and 20 healthy individuals were studied. The CEC and CEP were quantified and characterized in the blood using flow cytometry, and the demographic, clinical and laboratory data were obtained from hospital records. Results We found the CEC counts were higher in both patient groups as compared to controls, whereas increased numbers of CEP were found only in patients with MPN. In addition, all disease groups had higher numbers of CD62E+ CEC as compared to controls, whereas only patients with VTE had increased numbers of CD142+ and CD54+ CEC. Moreover, the numbers of total and CD62+ CEC correlated positively with the white blood cells (WBC) counts in both groups of patients, while the numbers of CEP correlated positively with the WBC counts only in patients with MPN. In addition, in patients with VTE a positive correlation was found between the numbers of CD54+ CEC and the antithrombin levels, as well as between the CD142+ CEC counts and the number of thrombotic events. Conclusions Our study suggests that CEC counts may reveal endothelial injury in patients with VTE and MPN and that CEC may express different activation-related phenotypes depending on the disease status.
- Effects of highly conserved major histocompatibility complex (MHC) extended haplotypes on iron and low CD8+ T lymphocyte phenotypes in HFE C282Y homozygous hemochromatosis patients from three geographically distant areasPublication . Costa, M.; Cruz, E.; Barton, J.; Thorstensen, K.; Morais, S.; da Silva, B.; Pinto, J.; Vieira, C.; Vieira, J.; Acton, R.; Porto, G.Hereditary Hemochromatosis (HH) is a recessively inherited disorder of iron overload occurring commonly in subjects homozygous for the C282Y mutation in HFE gene localized on chromosome 6p21.3 in linkage disequilibrium with the human leukocyte antigen (HLA)-A locus. Although its genetic homogeneity, the phenotypic expression is variable suggesting the presence of modifying factors. One such genetic factor, a SNP microhaplotype named A-A-T, was recently found to be associated with a more severe phenotype and also with low CD8(+)T-lymphocyte numbers. The present study aimed to test whether the predictive value of the A-A-T microhaplotype remained in other population settings. In this study of 304 HH patients from 3 geographically distant populations (Porto, Portugal 65; Alabama, USA 57; Nord-Trøndelag, Norway 182), the extended haplotypes involving A-A-T were studied in 608 chromosomes and the CD8(+) T-lymphocyte numbers were determined in all subjects. Patients from Porto had a more severe phenotype than those from other settings. Patients with A-A-T seemed on average to have greater iron stores (p = 0.021), but significant differences were not confirmed in the 3 separate populations. Low CD8(+) T-lymphocytes were associated with HLA-A*03-A-A-T in Porto and Alabama patients but not in the greater series from Nord-Trøndelag. Although A-A-T may signal a more severe iron phenotype, this study was unable to prove such an association in all population settings, precluding its use as a universal predictive marker of iron overload in HH. Interestingly, the association between A-A-T and CD8(+) T-lymphocytes, which was confirmed in Porto and Alabama patients, was not observed in Nord-Trøndelag patients, showing that common HLA haplotypes like A*01-B*08 or A*03-B*07 segregating with HFE/C282Y in the three populations may carry different messages. These findings further strengthen the relevance of HH as a good disease model to search for novel candidate loci associated with the genetic transmission of CD8(+) T-lymphocyte numbers.
- Efficacy and Safety of Direct-Acting Oral Anticoagulants Use in Acute Portal Vein Thrombosis Unrelated to CirrhosisPublication . Nery, F.; Valadares, D.; Morais, S.; Teixeira-Gomes, M.; De Gottardi, A.In acute portal vein thrombosis (APVT) unrelated to cirrhosis, anticoagulant therapy is classically started with low molecular weight heparin or vitamin K antagonists. New direct-acting oral anticoagulants (DOACs) are used in the treatment of venous thrombosis outside the splanchnic vascular bed, but not in the latter. We report a young female with APVT occurring in a non-cirrhotic liver linked to heterozygosity of factor V-Leiden and prothrombin G20210A gene mutations. Rivaroxaban was started, with total recanalization of the left and partial recanalization of the right portal vein branches, without complications. New DOACs do not need daily subcutaneous injections nor routinely blood coagulation control tests, making its use attractive, eventually increasing patient's compliance. If proved to be safe and effective in the future studies, its use may be extended to PVT treatment. This case shows that rivaroxaban was safe, not only prevented the extension of thrombosis in the portal tract, but also resolved PVT, at least partially.
- Neonatal Hemophilia: A Rare PresentationPublication . Ferreira, N.; Proença, E.; Godinho, C.; Oliveira, D.; Guedes, A.; Morais, S.; Carvalho, C.Hemophilia A is a X-linked hereditary condition that lead to decreased factor VIII activity, occurs mainly in males. Decreased factor VIII activity leads to increased risk of bleeding events. During neonatal period, diagnosis is made after post-partum bleeding complication or unexpected bleeding after medical procedures. Subgaleal hemorrhage during neonatal period is a rare, severe extracranial bleeding with high mortality and usually related to traumatic labor or coagulation disorders. Subgaleal hemorrhage complications result from massive bleeding. We present a neonate with unremarkable family history and uneventful pregnancy with a vaginal delivery with no instrumentation, presenting with severe subgaleal bleeding at 52 hours of life. Aggressive support measures were implemented and bleeding managed. The unexpected bleeding lead to a coagulation study and the diagnosis of severe hemophilia A. There were no known sequelae. This case shows a rare hemophilia presentation reflecting the importance of coagulation studies when faced with unexplained severe bleeding.
- Síndrome de Hanhart – caso clínicoPublication . Rios, H.; Carnide, C.; Morais, S.; Branco, M.; Mesquita, J.; Galhano, E.; Ramos, L.RESUMO Introdução: Em 1950 Hanhart descreveu três casos de aglossia e deformidades dos membros. A associação de malformações oromandibulares e dos membros é rara, verificando-se grande variabilidade fenotípica entre os casos descritos. Caso Clínico: Gravidez com diagnóstico pré-natal ecográfico (24 semanas) de agenesia do pé direito, ausência do primeiro dedo do pé esquerdo e presença apenas da primeira falange do primeiro e quinto dedos da mão esquerda. Às 38 semanas de gestação nasce um recém-nascido, sexo masculino, com hipotonia generalizada e dificuldade respiratória com necessidade de manobras de reanimação. Ao exame físico destacava-se a presença de microretrognatia, microstomia e várias malformações ósseas a nível das mãos e pés. Desde as primeiras horas de vida que apresentou quadro de apneias com dessaturações recorrentes vindo a falecer na decorrência de um desses episódios. Discussão: A associação de microstomia, microretrognatia, hipoglossia, malformações dos membros e atingimento dos pares cranianos, permite-nos estabelecer o diagnóstico clínico de Síndrome de Hanhart. O seu diagnóstico nem sempre é fácil, dada a grande variabilidade fenotípica.
- SOBRECARGA DE FERRO: HEMOCROMATOSEPublication . Morais, S.
- The spectrum of mutations and molecular pathogenesis of hemophilia A in 181 Portuguese patientsPublication . David, D.; Ventura, C.; Moreira, I.; Diniz, M.; Antunes, M.; Tavares, A.; Araújo, F.; Morais, S.; Campos, M.; Lavinha, J.; Kemball-Cook, G.Disease-causing alterations within the F8 gene were identified in 177 hemophilia A families of Portuguese origin. The spectrum of non-inversion F8 mutations in 101 families included 67 different alterations, namely: 36 missense, 8 nonsense and 4 splice site mutations, as well as 19 insertions/deletions. Thirty-four of these mutations are novel. Molecular modeling allowed prediction of the conformational changes introduced by selected amino acid substitutions and their correlation with the patients' phenotypes. The relatively frequent, population-specific, missense mutations together with de novo alterations can lead to significant differences in the spectrum of F8 mutations among different populations