Haemophilia in Spain.

To determine the prevalence of haemophilia A and B and their complications in Spain, and to characterize the health care network providing support to haemophiliac patients. The study examines clinical and genetic characteristics, treatment options, and complications observed during the course of the disease. Cross-sectional multi-centre study. The study population were patients with HA and HB in active follow-up at any Spanish hospital by December 2006. We studied 2400 haemophiliacs, 2081 (86.7%) HA and 319 (13.3%) HB patients. Illness was severe in 32.3% of patients, moderate in 16.4%, and mild in 51.3%. Genetic screening was carried out in 32.6% of the patients. Treatment administered in 2006 consisted of coagulation factor concentrates in 60% of patients. Until December 2006, 45.8% of severely ill patients were taking prophylaxis. The mean number of bleeding episodes in 2006 was four for patients not receiving primary prophylaxis and 1.3 for those taking primary prophylaxis. Thirty percent of patients had established haemophiliac arthropathy in at least one joint; 16.8% of patients were HIV-infected and 34.8% HCV-infected. Inhibitors were detected in 10% of severe HA patients and in 6.5% of severe HB patients. Immune tolerance induction therapy was started in 34 patients. This is the first comprehensive study on the epidemiology of haemophilia in Spain. It will enable us to draw comparisons with neighbouring countries, to assess the quality of care provided to haemophiliacs in Spain, and to provide evidence-based guidance for the even provision and improvement of such care.

One-stage and chromogenic FVIII:C assay discrepancy in mild haemophilia A and the relationship with the mutation and bleeding phenotype.

The discrepancy of the levels of factor VIII activity (FVIII:C) by different assays in some mild and moderate haemophilic A patients has been long known. Specific mutations affecting FVIII:C discrepancies have been described. No consensus exit as to which method most accurately represents the FVIII cofactor function in vivo and which has a better correlation with the haemorrhagic clinical expression. We studied 163 mild A haemophiliacs, and detected discrepancies in 20% of the patients, most of whom presented higher levels of FVIII:C with the one-stage assay. In nine families, the FVIII mutation was found, while three showed mutations not previously described (Leu1978Phe and Ser1791Pro associated with higher levels of FVIII:C by one-stage method; Arg1639His in a patient with low level of FVIII:C by the one-stage, but normal, chromogenic assay). Assessing the level of FVIII:C by different methods could help to learn the possible haemorrhagic expressions of patients.

Clinical and echographical control protocol of haemarthrosis in haemophilia patients with inhibitors: evaluation of the efficacy of recombinant factor VIIa in the evolution process (EFFISEVEN protocol).

The intention of the 'clinical and echographical protocol of evaluation the efficacy of recombinant activated factor VII in the haemarthrosis' (EFFISEVEN protocol) was to provide an extensive study of the evolution of haemarthrosis, and second, of its repercussions on the degenerative process of joints. The clinical evaluation of haemarthroses and their evolution is based on a well-established methodology, although very few studies have sought to determine the correlation between pain, mobility and the objective data regarding the haemorrhage. We believe that it is necessary to unify criteria and that the EFFISEVEN protocol may contribute data that improve standards which, in turn, will influence the degenerative process of joints, and consequently affect the quality of life of haemophilia patients with inhibitors. Echographical control of haemarthrosis is an objective method that allows control over how the haemorrhage evolves and also helps in the identification of rebleeding. Therefore, its use adds a new dimension to patient management strategies. Techniques used to monitor recombinant activated factor VII (rFVIIa) treatment require further study, although preliminary results guarantee their efficacy.

Inhibitor development in one patient and laboratory discrepancies in several families with both mild haemophilia and Arg531Cys mutation.

Certain mutations in mild haemophilia A have been associated with a greater risk of inhibitor development, especially when associated with intense treatment. We present a patient with both mild haemophilia A and Arg531Cys mutation, which developed lowtitre inhibitors and was not seen to be related to the intense substitute treatment. The inhibitor has a greater effect on the exogenous factor VIII, permiting an adequate response to treatment with desmopressin. A discrepancy exists in the factor VIII activity in this our patient and in the haemophiliacs of another two families with the same mutation when determination is performed with one-stage or chromogenic method.

Inhibitors in haemophilia A: current management and open issues.

The incidence of inhibitors in haemophilia A is 21-33%. The development of inhibitors to factor VIII (FVIII) is one of the most serious complications in haemophilia therapy and is an important challenge in haemophilia care. The main short-term objective of the treatment of haemophilic patients with inhibitors is to control bleeding episodes, and the long-term one is to eradicate the inhibitor by means of immune tolerance induction (ITI). The choice of treatment for bleeding in inhibitor patients is dictated by the current inhibitor titre, the severity of the bleed and the previous anamnesic response to FVIII. In low responder inhibitor patients the best treatment is large doses of concentrates of FVIII to attain haemostatic levels of the factor infused. The same approach can also be considered in high responders who have a temporarily low inhibitor level and major haemorrhage. High responders patients with high inhibitors titre or with minor haemorrhage must be treated with bypassing agents, such as FEIBA (factor VIII inhibitor bypassing activity) or recombinant activated FVII (rVIIa); there is no agreement which of both agents should be chosen in the different clinical situations. Only in patients waiting to start ITI treatment the rFVIIa use is clearly recommended, in order to avoide an anamnesic responce. In case of failure with this agents, extracorporeal immunoadsortion may be considered. All haemophiliac children who develop an inhibitor should be considered for ITI. The start of ITI should be deferred until the inhibitor has declined below 10 Bethesda units/mL (BU ml(-1)) where possible. Starting the treatment when inhibitor titre is below 10 BU ml(-1) is the strongest predictor of success. However, there are many other points to clarify: recommended FVIII doses in the ITI; if the results can be affected by concomitant infections during ITI; if there are any differences using plasma derived or recombinant concentrates, even more if the plasma-derived concentrate contains large amounts von willebrand factor or not; age of starting the ITI and the delay in beginning it; if using immunosupresors can help in the treatment of patients with a bad prognosis; and when the treatment must be left in patients without a clear failure.

Modelo agregométrico aplicado al estudio de la estabilidad de los concentrados de plaquetas conservados en solución aditiva PAS-2 / Aggregometric model applied to the study of platelet concentrates stability preserved in additive solution PAS-2

La demanda creciente de concentrados de plaquetas (CP) ha impulsado el desarrollo de investigación dirigidas al estudio de sustancias sintéticas que puedan sustituir al plasma en el proceso de producción de los CP. Nuestro objetivo es establecer una metodología que nos permita llevar a cabo un prorama de calidad en los CP y estudiar la influencia del PAS-2 sobre la función plaquetar a lo largo de su almacenamiento. Este programa de calidad se basa en la medida de la reacción plaquetar sobre plaquetas de los CP resuspendidos en plasma fresco congelado de un donante y la utilización de colágeno, ionóforo de calcio y ADP más epinefrina a unas concentraciones de: 16,6 µg/ml, 20 µM y 3 µM más 20 µM, respectivamente. Los resultados de la agregación plaquetar fueron algo superiores en CP-P que en CP-PAS. Sin embargo, la actividad plaquetar al sexto día de almacenamiento se mantiene en los CP-PAS con colágeno e ionóforo de calcio y desciente discretamente en los CP-P cuando utilizamos colágeno y ADP más epinefrina. Estos resultados sugieren que el PAS-2 es un buen medio sintético para utilizarlo como conservante en los CP. Este estudio in vitro se complementará con otro en desarrollo sobre la valoración del rendimiento in vivo de los CP producidos con medios sintéticos (AU)

Relaciones entre la estructura molecular-función del FVIII y el mecanismo de acción de los inhibidores anti-FVIII en hemofilia A / Relationship between molecular structure and function of factor VIII and mechanism of action of anti-FVIII inhibitors in hemophilia A

No disponible

beta-Amyloid precursor protein (beta APP) in human gut with special reference to the enteric nervous system.

The distribution of the beta-amyloid precursor protein (betaAPP) in the human gastrointestinal tract, from esophagus trough rectum, was studied using immunoblotting, as well as combined immunohistochemical and image analysis (optic microdensitometry) techniques. The study was focused on the enteric nervous system. betaAPP was detected by means of a monoclonal antibody (22C11), which recognizes all betaAPP isoforms as well as betaAPP-like proteins. Immunoblotting revealed two main protein bands, one corresponding to full-length betaAPPs (estimated molecular masses of approximately 97-115 kDa); the other corresponded to a protein with estimated molecular masses of 55 kDa. Specific betaAPP immunoreactivity (IR) was found in the submucous and myenteric plexuses localized in the supporting glial cells rather than in neurons. Differences were encountered neither in the localization nor in the intensity of immunostaining among different segments of the gastrointestinal tract. Moreover, no age-dependent changes were found. betaAPP IR was also regularly observed in blood vessels, primarily labelling endothelial cells. Our results provide evidence for the occurrence of betaAPP in human gastrointestinal tract of healthy people in both neuronal and nonneuronal tissues. Whether or not these findings have functional or clinical relevance remains to be clarified in future studies.

Immunoreactivity for beta/A4 protein, but not for its precursor, in human chromaffin cells.

The present study was designed to establish a) whether chromaffin cells of the human adrenal medulla express immunoreactivity for beta-amyloid precursor protein (beta APP) and/or beta-amyloid protein (beta/A4); and b) whether cells expressing one or both of the above-mentioned proteins display immunoreactivity for the low- (gp75) and/or the high-affinity (gp140-trkA) nerve growth factor receptor. To identify chromaffin cells and their supporting cells, chromogranin A, neurofilament proteins, and S-100 protein were studied in parallel. Beta APP and beta/A4 immunoreactivity (IR) was observed primarily labeling two different cell populations, without colocalization: Beta APP IR was found in the adrenal cortical cells, which were mainly localized in the reticulate layer and in the blood vessel walls, whereas beta/A4 IR was observed in the chromaffin cells. Furthermore, supporting cells were also immunoreactive for beta/A4, and sympathetic ganglionic cells were immunoreactive for both beta APP and beta/A4. Interestingly, clusters of cells expressing beta/A4 IR also displayed gp 75 IR and/or gp140-trkA IR. Finally, all chromaffin cells (identified by chromogranin A IR) were immunolabeled for the 200 kDa neurofilament subunit, but not for a phosphorylated epitope of this protein. These results demonstrate the occurrence of beta/A4 IR, but not of beta APP, in the chromaffin cells of the human adrenal gland. The complementary distribution of amyloid-related proteins, and the possible involvement of neurotrophins in beta/A4 metabolism are discussed.

Expression of beta-amyloid precursor protein (APP) in human dorsal root ganglia.

The present study reports the occurrence and localization of beta-amyloid precursor protein (APP) immunoreactivity (IR) in human lumbar dorsal root ganglia of healthy adult subjects (age range 25-43 years). To ascertain that ganglionic cells displayed APP IR, neurofilament (NFP) and S-100 proteins (S100P) were studied in parallel. Immunoblotting revealed four or five major proteins with apparent molecular masses between 100-125 kDa, which corresponded with the different full-length APP isoforms. Moreover, an additional protein of approximately 55 kDa was detected. Selective APP IR was observed restricted to the satellite glial cell cytoplasms whereas neuron cell bodies resulted unlabeled. Moreover, some intraganglionic nerve fibers also displayed APP IR, apparently labelling Schwann cells. No individual differences among subjects were observed neither in the pattern of APP IR distribution, nor in the intensity of APP IR. Although it remains to be demonstrated whether or not human primary sensory neurons express APP, present results strongly suggest that supporting glial cells may be a primary source of APP or any related peptide, at least in adult healthy people. The functional and clinical relevance of these findings, if any, remain to be clarified.