Implementation of SintromacWeb(R), a new internet-based tool for oral anticoagulation therapy telecontrol: Study on system consistency and patient satisfaction.

Most computer- or internet-assisted systems for oral anticoagulation therapy (OAT) telemanagement have limitations when it comes to implementation within a healthcare center. It was the objective of this study to evaluate convenience and patient satisfaction with the use of SintromacWeb, a new OAT telecontrol system, compared with the conventional control. SintromacWeb consists of a point-of-care device for patient international normalized ratio (INR) self-testing and software that allows internet mediated interaction with physicians. Patients initiated the use of SintromacWeb and were followed up during a three-month period. A score-based questionnaire was completed in three controlled visits, and data were subsequently analysed. A total of 102 patients were enrolled. At first visit, 55.7% of the patients had their INR within normal range, and 64.9% at the final visit. Internal consistency of the questionnaire was good (Cronbach's a: 0.79). Scores in the questionnaire were independent of patient's age, education level, working status and INR value. The most valued features of SintromacWeb were: fewer visits to the hospital, simplicity and convenience of the system, and time administration for control tasks (86.7%, 82.7% and 77.6% of very satisfied patients, respectively). Also, patients showed indifference or were dissatisfied with the conventional system. At the final visit, 99% of patients declared that they were satisfied with their OAT control. Moreover, all patients continued using SintromacWeb after completion of the study. In conclusion, SintromacWeb telecontrol is a new model for management of anticoagulated patients. It was highly accepted and can be used by all patients regardless of their sociodemographic characteristics.

Novel missense mutation c.2685G>C (p.Q895H) in VWF gene associated with very low levels of VWF mRNA.

Homozygous patients for null alleles in VWF gene show a severe von Willebrand phenotype, whereas compound heterozygous patients only show the phenotype of the expressed allele. Five members of the same family were studied. The two patients showed borderline VWF levels, a mild factor VIII (FVIII) deficiency and a decrease of the binding of VWF to exogenous FVIII. The genetic analyses of the VWF gene confirmed that the patients were compound heterozygous for c.2561G>A (R854Q) and c.2685G>C (p.Q895H) mutations. The latter, is located in the 3' extreme of exon 20, and it has not been previously described. Studies of the cDNA from platelet mRNA were performed to investigate the expression of p.H895 allele. The loss of heterozygosity at the cDNA level suggests a lack of expression of the p.H895 allele. The overall studies can explain the type 2N phenotype of the two patients, since the allele carrying the new missense mutation p.Q895H has shown a low expression of VWF gene.

Severe and moderate hemophilia A: identification of 38 new genetic alterations.

Hemophilia A is an X-linked recessive disorder caused by a lack or decrease of factor VIII activity. Its socio-economic impact is high given its high bleeding expression and treatment cost. Our aim was to establish the mutation of each patient to improve family management. A total of 116 unrelated families with severe and moderate hemophilia A were involved. Non-carriers of intron 22 and intron 1 rearrangements were included in F8 gene screening. Intron 1 and 22 inversion frequencies were 3% and 52.5% respectively. Putative mutations were identified in all the families; 38 were new. The cumulative inhibitor incidence was 22%. Approximately half the families carry non-recurrent mutations, which were unique in around one third. Harmful effects for mutations predicting null alleles are expected. Missense mutation consequences are not easily predictable, despite the help of some bio-informatics tools.

Von Willebrand's disease: a novel mutation, P1824H and the incidence of R1205H defect among families with dominant quantitative von Willebrand factor deficiency.

To date, few mutations associated with a dominant quantitative deficiency of von Willebrand factor (VWF) and a high penetrance have been reported. This phenotype was confirmed in seven unrelated families of several patients diagnosed with von Willebrand's disease out of 70 who requested genetic studies of the VWF gene. The mutations linked to this type were identified: R1205H in five families; T1156M in one family; and the new P1824H alteration in one other family. The R1205H mutation linked to the different haplotypes might well be frequent among this variant. The P1824H in the A3 domain is associated with very low VWF levels and with a moderate-to-severe bleeding tendency, unlike the other mutations reported in this domain.

Importancia de la proteasa escindidora del factor von Willebrand en la fisiopatología, diagnóstico y tratamiento de la púrpura trombótica trombocitopénica / Relevance of von Willebrand factor cleanin protease in the pathophysiology, diagnosis and treatment of thrombotic thromboytopenic purpura

La púrpura trombótica trombocitopénica (PTT) es una forma diseminada de microangiopatía trombótica caracterizada por la aparición de trombocitopenia grave, anemia hemolítica microangiopática, alteraciones renales, neurológicas y fiebre. El desencadenante inicial en la patogénesis de la PTT es la lesión de la célula endoletial que junto con la presencia de formas multiméricas de factor von Willebrand (FvW) anormalmente grandes posibilita la adhesión-agregación plaquetar y la oclusión de las arteriolas terminales. Recientemente se ha aislado en el plasma de individuos sanos una proteasa con capacidad de degradar el FvW. En los pacientes con PTT esta protesa estaría ausente bien por una deficiencia congénita o bien por la presencia de inhibidores contra esta enzima. Los casos de PTT familiar con una deficiencia congénita de proteasa probablemente respondan al tratamiento con recambios plasmáticos y transfusión de plasma fresco. En los casos de PTT no familiar con déficit de proteasa debido a la presencia de un autoanticuerpo este tratamiento puede ser insuficiente y precisar la asociación de tratamiento inmunosupresor. En pacientes con síndrome hemolítico urémico (SHU) los niveles de esta proteasa serían normales. El aislamiento de esta proteasa escindidora del FvW ha permitido mejorar el conocimiento de la fisiopatología de la PTT, establecer su carácter congénito o adquirido con la posibilidad de individualizar tratamientos y establecer el diagnóstico diferencial entre la PTT y el SHU. Se precisan métodos de laboratorio sencillos y rápidos para determinar la proteasa escindidora del FvW y confirmar el impacto definitivo que este hallazgo puede tener sobre el tratamiento y por tanto el pronóstico de esta entidad (AU)