Bakgrund - Hemofili A och B är X-kromosombundna blödarsjukdomar, som beror på genetiska avvikelser i de gener som kodar för koagulationsfaktor VIII respektive IX. I dagsläget förlitar sig hemofilipatienter på kontinuerliga intravenösa injektioner med faktorkoncentrat, för att förhindra att potentiellt livshotande blödningar uppstår. Genterapi med rekombinanta adeno-associerade virus (AAV) skulle kunna erbjuda ett kurativt behandlingsalternativ, genom införandet av friska arvsanlag i hepatocyter. Syfte - Syftet med den här litteraturstudien var att undersöka huruvida genterapi medierad av AAV-vektorer är en effektiv och säker behandling mot hemofili A och B ur ett långsiktigt perspektiv. Metod - Studien är genomförd som en systematisk litteraturstudie och är baserad på sex originalartiklar framsökta via databasen PubMed, med sökorden "hemophilia AND gene therapy". Specificerade sökkriterier användes för att underlätta relevansbedömning och valet av artiklar. Resultat - En ökad endogen koagulationsfaktorproduktion kunde påvisas hos majoriteten av studiedeltagarna efter genterapibehandlingarna. Sammantaget observerades också en väsentlig blödningsreducering och en minskad faktorkoncentratanvändning. Störst förbättring noterades i de kohorter som erhållit högre genterapidoser eller den muterade faktor IX Padua-genen. Ingen immunrespons mot transgenprodukten detekterades i någon studie. Däremot sågs ett humoralt immunsvar mot AAV-kapsiden hos samtliga studiedeltagare. En mycket stor variation i T-cellssvar mot AAV-kapsiden kunde noteras. Förhöjda nivåer av alaninaminotransferas (ALAT) var den vanligast förekommande incidenten, men samtliga fall kunde framgångsrikt behandlas med glukokortikoidpreparat. Slutsats - Genterapibehandling med rekombinanta AAV-vektorer mot hemofili A och B förefaller effektiv och säker. Förhöjda ALAT-nivåer återstår dock som en behandlingsproblematik. Längre uppföljningar av fler genterapibehandlade hemofilipatienter krävs, för att kunna dra några definitiva slutsatser, väga risker mot nytta, samt optimera och individanpassa doser. / Background - Hemophilia A and B are X-linked bleeding disorders, resulting from defects in the genes encoding coagulation factors VIII and IX respectively. The current treatment for hemophiliacs entails frequent intravenous injections of coagulation factor concentrates, to prevent potentially life-threatening hemorrhages. Gene therapy utilizing recombinant adeno-associated viruses (AAV) could offer a potentially curative treatment option through the introduction of healthy genes into hepatocytes. Aim - The aim of this literature study was to investigate the long-term efficacy and safety of AAV vector-mediated gene therapy for the treatment of hemophilia A and B. Methods - The study is conducted as a systematic literature study and is based on six original articles retrieved from the search engine PubMed, using the key words "hemophilia AND gene therapy". Specific search criteria were used to facilitate the relevance assessment and selection of articles. Results - An increased endogenous coagulation factor synthesis was noted in the majority of the study participants after the gene therapy. Overall, a significant reduction in bleeding episodes and the use of factor concentrates were observed. The greatest improvements were noted in the cohorts that received the higher gene therapy doses or the mutated factor IX Padua gene. None of the study participants had an immunologic response to the transgene product. A humoral immune response against the AAV capsid was seen in all participants though. Large differences in AAV capsid-specific T-cell activation were observed. The most common adverse event was an elevation in the alanine aminotransferase (ALT) level. However, these events could be controlled with glucocorticoids. Conclusions - AAV vector-mediated gene therapy for the treatment of hemophilia A and B had a positive efficacy and safety profile. Although increased ALT levels remain a concern. Monitoring of larger numbers of study participants for longer follow-up periods is necessary for any definite conclusions to be drawn, to weigh risks against benefits and to optimize individual dosing.

Les anticorps sont les molécules effectrices de l’immunité adaptatrice humorale. Ils se lient spécifiquement et neutralisent une large panoplie d’antigènes. Au-delà de leurs fonctions classiques, les anticorps possèdent les propriétés moins explorées que sont l’activité catalytique, qui permet aux anticorps de se comporter comme des enzymes, et la polyréactivité, qui représente la capacité d’une molécule d’anticorps à se lier à plusieurs antigènes structurellement différents. Les anticorps catalytiques sont retrouvés dans plusieurs pathologies chez l’homme, telle que l’hémophilie acquise, une maladie caractérisée par la survenue d’autoanticorps anti-facteur VIII. Dans ce travail, nous décrivons des IgG hydrolysant et activant le facteur IX de la coagulation chez les patients avec hémophilie acquise. Par ailleurs, nous avons effectué une étude longitudinale de deux ans des IgG catalytiques chez les patients subissant une transplantation rénale. Les anticorps polyréactifs représentent une proportion importante du répertoire des immunoglobulines circulantes. De plus, les sites inflammatoires sont abondants en molécules, telles que l’hème libre, capables de rendre polyréactives certaines IgG monoréactives. Nous avons étudié l’influence de la nature des régions constantes de la chaîne lourde des anticorps sur leur susceptibilité à devenir polyréactifs. Ce travail apporte un nouvel éclairage sur l’importance physiopathologique des anticorps catalytiques et polyréactifs. / Antibodies are effector molecules of the humoral arm of the adaptive immune system that bind specifically and neutralize diverse array of antigens. Beyond the classical function of antibodies exist the relatively less explored properties, of “catalytic activity” that enable antibodies to act as enzymes and “polyreactivity” that confers the ability to bind to several structurally unrelated antigens. Catalytic antibodies have been associated with several autoimmune, inflammatory and infectious diseases. Acquired hemophilia is an autoimmune disease, reported with the presence of catalytic antibodies against coagulation factor FVIII. In the present work, we have investigated the presence of factor IX (FIX) hydrolyzing IgG in patients with acquired hemophilia. We investigated the molecular mechanism and the physiological relevance of FIX activation upon hydrolysis by patients’ IgG. In addition, a longitudinal follow-up for 2 years was done in patients undergone renal transplant to investigate the evolution of catalytic antibodies in the course of disease. Polyreactive antibodies constitute a major portion of the natural antibody repertoire. Additionally, sites of inflammation are abundant in protein destabilizing agents like free heme that can induce polyreactivity in monoreactive antibodies. We have investigated the effect of the antibody constant domain on heme-induced polyreactivity. The present work has allowed us a better understanding of the physiopathological relevance of catalytic and polyreactive antibodies.

Neste trabalho foram estudados diversos métodos cromatográficos para a purificação de fatores recombinantes de coagulação VII (FVIIr) e VIII (FVIIIr) derivados de linhagens celulares humanas SK-Hep. O FVIIIr é utilizado para o tratamento da Hemofilia A, enquanto o FVIIr é utilizado para o tratamento da Hemofilia B e também a Hemofilia A. Produzir estes fatores em linhagens celulares humanas faz com os padrões de glicosilação, sulfatação e enovelamento destas proteínas sejam extremamente parecidos com os fatores endógenos produzidos no organismo humano. A purificação do FVIIIr através de técnicas de cromatografia multimodais usando a resina CaptoMMC, afinidade usando a resina FVIIISelect e troca iônica (SP-Sepharose) permitiu obter um produto bastante homogêneo e com perfil de banda (por SDS-PAGE) bem definido que demonstrou a presença esperada das cadeias leve e pesada (o Westen-Blott indicou que os anticorpos comerciais reconheceram a cadeia pesada da molécula estudada). As técnicas permitiram uma alta reprodutibilidade do processo onde sequencias de purificação indicaram o mesmo comportamento de perfis cromatográficos e o processo eliminou 99.5% ± 0,5% de proteínas inespecíficas, recuperando até 64% de FVIIIr. O FVIIr foi purificado com apenas uma única técnica cromatográfica usando a resina FVIISelect que isolou a proteína de interesse eliminando cerca de 99% de impurezas, recuperando praticamente todo o produto. O eluido da cromatografia de afinidade foi dialisado em membranas de 5 kDa o que resultou no processo de auto ativação da molécula de FVIIr, resultando em um aumento de sinal de até 5x em relação a quantidade inicial. O gel de SDS-PAGE e o Westen-Blott comprovaram o processo de auto-ativação no qual uma migração de banda de 50 kDa para 30kDa foi observada e os anticorpos comerciais contra FVII foram capazes de detecta-la. O método de purificação também foi bastante reproduzível e o perfil de banda muito semelhante se comparado ao produto comercial existente no mercado. Sendo assim, foi possível obter plataformas de purificação para as proteínas FVIIr e FVIIIr. / In this work, several chromatographic methods were studied for the purification of recombinant clotting factors VII (FVIIr) and VIII (FVIIIr) derived from human SK-Hep cell lines. The FVIIIr is used for the treatment of Hemophilia A, while the FVIIr is used for the treatment of Hemophilia B and Hemophilia A. Producing these factors in human cell lines results in glycosylation, sulphation and folding patterns similar to the endogenous factors produced in the human organism. Purification of FVIIIr by multimodal chromatography techniques using CaptoMMC resin, affinity using FVIIISelect resin and ion exchange (SP-Sepharose) yielded a fairly homogeneous and well-defined band profile (by SDS-PAGE) which demonstrated the expected presence of the light and heavy chains, Westen-Blott indicated that commercial antibodies recognized the heavy chain of the studied molecule. The techniques allowed a high reproducibility of the process where purification sequences indicated the same behavior of chromatographic profiles and the process eliminated 99.5% ± 0.5% nonspecific proteins and recovering up to 64% FVIIIr. FVIIr was purified with only a single chromatographic technique using the FVIISelect resin which isolated the protein by removing about 99% impurities and recovering virtually the entire product. The affinity chromatography eluate was dialyzed on 5 kDa membranes which resulted in the autoactivation process of the FVIIr molecule resulting in a signal increase of up to 5 fold over the initial amount. The SDS-PAGE gel and Westen-Blott demonstrated the auto-activation process where a migration of 50 kDa to 30 kDa band was observed and the commercial antibodies against FVII were able to detect the band. The purification method was also quite reproducible and the band profile very similar compared to the commercial products. Thus, it was possible to obtain purification platforms for the FVIIr and FVIIIr proteins.

Neste trabalho foram estudados diversos métodos cromatográficos para a purificação de fatores recombinantes de coagulação VII (FVIIr) e VIII (FVIIIr) derivados de linhagens celulares humanas SK-Hep. O FVIIIr é utilizado para o tratamento da Hemofilia A, enquanto o FVIIr é utilizado para o tratamento da Hemofilia B e também a Hemofilia A. Produzir estes fatores em linhagens celulares humanas faz com os padrões de glicosilação, sulfatação e enovelamento destas proteínas sejam extremamente parecidos com os fatores endógenos produzidos no organismo humano. A purificação do FVIIIr através de técnicas de cromatografia multimodais usando a resina CaptoMMC, afinidade usando a resina FVIIISelect e troca iônica (SP-Sepharose) permitiu obter um produto bastante homogêneo e com perfil de banda (por SDS-PAGE) bem definido que demonstrou a presença esperada das cadeias leve e pesada (o Westen-Blott indicou que os anticorpos comerciais reconheceram a cadeia pesada da molécula estudada). As técnicas permitiram uma alta reprodutibilidade do processo onde sequencias de purificação indicaram o mesmo comportamento de perfis cromatográficos e o processo eliminou 99.5% ± 0,5% de proteínas inespecíficas, recuperando até 64% de FVIIIr. O FVIIr foi purificado com apenas uma única técnica cromatográfica usando a resina FVIISelect que isolou a proteína de interesse eliminando cerca de 99% de impurezas, recuperando praticamente todo o produto. O eluido da cromatografia de afinidade foi dialisado em membranas de 5 kDa o que resultou no processo de auto ativação da molécula de FVIIr, resultando em um aumento de sinal de até 5x em relação a quantidade inicial. O gel de SDS-PAGE e o Westen-Blott comprovaram o processo de auto-ativação no qual uma migração de banda de 50 kDa para 30kDa foi observada e os anticorpos comerciais contra FVII foram capazes de detecta-la. O método de purificação também foi bastante reproduzível e o perfil de banda muito semelhante se comparado ao produto comercial existente no mercado. Sendo assim, foi possível obter plataformas de purificação para as proteínas FVIIr e FVIIIr. / In this work, several chromatographic methods were studied for the purification of recombinant clotting factors VII (FVIIr) and VIII (FVIIIr) derived from human SK-Hep cell lines. The FVIIIr is used for the treatment of Hemophilia A, while the FVIIr is used for the treatment of Hemophilia B and Hemophilia A. Producing these factors in human cell lines results in glycosylation, sulphation and folding patterns similar to the endogenous factors produced in the human organism. Purification of FVIIIr by multimodal chromatography techniques using CaptoMMC resin, affinity using FVIIISelect resin and ion exchange (SP-Sepharose) yielded a fairly homogeneous and well-defined band profile (by SDS-PAGE) which demonstrated the expected presence of the light and heavy chains, Westen-Blott indicated that commercial antibodies recognized the heavy chain of the studied molecule. The techniques allowed a high reproducibility of the process where purification sequences indicated the same behavior of chromatographic profiles and the process eliminated 99.5% ± 0.5% nonspecific proteins and recovering up to 64% FVIIIr. FVIIr was purified with only a single chromatographic technique using the FVIISelect resin which isolated the protein by removing about 99% impurities and recovering virtually the entire product. The affinity chromatography eluate was dialyzed on 5 kDa membranes which resulted in the autoactivation process of the FVIIr molecule resulting in a signal increase of up to 5 fold over the initial amount. The SDS-PAGE gel and Westen-Blott demonstrated the auto-activation process where a migration of 50 kDa to 30 kDa band was observed and the commercial antibodies against FVII were able to detect the band. The purification method was also quite reproducible and the band profile very similar compared to the commercial products. Thus, it was possible to obtain purification platforms for the FVIIr and FVIIIr proteins.

Ce projet de thèse vise à modéliser puis à apporter la preuve de concept d’une thérapie cellulaire et génique autologue de maladies héréditaires du foie par la transplantation d’hépatocytes différenciés à partir des cellules souches pluripotentes induites (iPSC) spécifiques du patient, une fois celles-ci corrigées du défaut génétique. L’hémophilie B (HB) est une maladie héréditaire causée par une mutation du gène F9, codant le facteur IX (FIX) de la coagulation synthétisé dans le foie par les hépatocytes. Des fibroblastes d’un patient porteur de la « mutation royale » ont été reprogrammés en iPSC puis différenciés en hépatocytes. L’étude de l’ARNm du F9 par séquençage haut débit a confirmé la présence d’un site d’épissage anormal codant une protéine tronquée. D’autres iPSC ont été obtenues à partir des cellules d’un second patient HB exprimant un FIX inactif. Après insertion ciblée d’une cassette thérapeutique codant le FIX dans un site génomique sûr à l’aide d’endonucléases artificielles (CRISPR/Cas9), nous avons différencié les iPSC corrigées et non corrigées en hépatocytes (respectivement corr-HB-Heps et HB-Heps) et confirmé une expression plus importante de l’ARNm du F9 et de la protéine FIX dans les corr-HB-Heps. En revanche, nous n’avons pas détecté d’activité du FIX transgénique sans doute à cause d’une différenciation incomplète des hépatocytes. Nous avons alors développé un protocole de différenciation en sphéroïdes permettant une différenciation plus efficace confirmée aux niveaux ARN et protéine FIX. L’analyse de l’activité du FIX produit nous permettra de valider la correction in vitro avant de la valider in vivo en transplantant les corr-HB-Heps dans un modèle de souris F9KO. Finalement, la dernière partie de ce travail a consisté à développer un protocole de différenciation d’iPSC de singe en hépatocytes en vue d’une transplantation autologue dans le foie de l’animal donneur pour valider la faisabilité et la sécurité de cette approche chez le gros animal. / This PhD project aims to model and to bring a proof of concept for autologous cell/gene therapy of inherited liver diseases by transplanting hepatocytes differentiated from patient-specific induced pluripotent stem cells (iPSCs), after correction of the genetic defect. Hemophilia B (HB) is an inherited disease caused by a mutation in the F9 gene encoding clotting factor IX (FIX), synthesized in the liver by hepatocytes. Fibroblasts of a patient with the "royal mutation" were reprogrammed in iPSCs then differentiated into hepatocytes. The study of the F9 mRNA by high-throughput sequencing confirmed the presence of an abnormal splice site leading to a truncated protein explaining hemophilia. Other iPSCs were obtained and characterized from the cells of a second HB patient expressing an inactive FIX. By targeting in these iPSCs the insertion of a therapeutic cassette encoding FIX into a safe harbor site using artificial endonucleases (CRISPR/Cas9), we differentiated the corrected and non-corrected iPSC into hepatocytes. Quantitative analyzes confirmed a higher expression of F9 mRNA and FIX protein in the corrected clones. In contrast, we did not detect transgenic FIX activity due to a lack of post-translational modifications necessary for FIX activity. We then developed a protocol of differentiation in spheroids quantitatively more efficient to produce FIX. Detection of FIX activity will validate our in vitro approach before validation in vivo by transplanting the corrected hepatocytes in a F9KO mouse model. Finally, the last part of this work consisted in the development of a differentiation protocol of nonhuman primate iPSCs into hepatocytes for autologous transplantation into the liver of the donor animal in order to validate the feasibility and the safety of such an approach in the large animal

<p>Mesenchymal stem cells have shown potential for success in gene therapy due to their ability to differentiate and their immunomodulatory properties <em>in vivo</em>. Although they have many inherent characteristics that are suitable for use within gene therapy, genetic modification of these cells is more difficult. Since MSCs are available in limited quantities and cannot be expanded indefinitely, the modification technique must ensure efficient expression of the transgene, a high cell survival rate and an intact ability to differentiate to various cell lineages. We optimized electroporation conditions for the genetic engineering of bone marrow-derived and umbilical cord blood-derived mesenchymal stem cells. MSCs engineered using electroporation conditions produced more transgene expression than cells engineered with cationic lipids in bone marrow-derived mesenchymal stem cells, but produced similar amounts in umbilical cord blood-derived mesenchymal stem cells. Optimal electroporation conditions also expressed more transgene than polymer based transfection reagent in umbilical cord blood-derived mesenchymal stem cells. Cell survival after optimal electroporation conditions was 67% in umbilical cord blood-derived mesenchymal stem cells. Most importantly, cells maintained their ability to differentiate into osteogenic, chondrogenic and adipogenic cell lineages. Electroporating umbilical cord blood-derived mesenchymal stem cells with a Factor IX containing plasmid lead to the FIX protein being expressed for over 12 days <em>in vitro</em>. This optimized electroporation protocol has created a fast, easy, economic and efficient method for genetically modifying mesenchymal stem cells without altering their ability to differentiate.</p> / Master of Applied Science (MASc)

As hemartroses, a despeito dos avanços terapêuticos ocorridos na hemofilia, continuam sendo os eventos clínicos mais freqüentes. As hemartroses de repetição, sobretudo nos tornozelos, podem estar associadas à instabilidade articular. Sabe-se que a instabilidade articular pode contribuir para aumentar a frequência dessas complicações e prescrevem-se órteses que limitam muito os pacientes. Diante desse quadro buscamos um instrumento para qualificar os desvios nos tornozelos instáveis durante a marcha, dinamicamente e em tempo real. Essa avaliação permitiu a prescrição de palmilhas de fácil confecção, de calçados com contrafortes posteriores e, nos casos muito instáveis, a associação de órteses funcionais, dinâmicas, para tornozelos. A intervenção realizada nos pacientes constou do exame pela podobarometria dinâmica computadorizada, antes e depois da prescrição das órteses. O uso das órteses prescritas conforme as observações podobarométricas permitiu liberdade na marcha, assegurando estabilidade articular. O número de hemartroses nos tornozelos e o consumo de fatores da coagulação em cada hemorragia, nos 43 hemofílicos avaliados, foi verificado nos prontuários médicos dos pacientes, em suas instituições de origem, nos seis meses pré-intervenção e nos seis meses pós-intervenção. Nos 43 hemofílicos avaliados, a média de ocorrência de hemartroses, que era de 4,81, foi reduzida para 2,53 hemartroses por paciente, após a intervenção. A média do consumo de fatores da coagulação reduziu de 9647,7 IU para 4407,0 IU, com p<0,001 . Com base na análise dos resultados concluímos que a podobarometria dinâmica computadorizada é um meio diagnóstico útil na prescrição de estabilizadores para os tornozelos dos hemofílicos, contribuindo significantemente para a redução da incidência de hemartroses. / The haemarthrosis, despite the improvement of therapeutic resources occurred in haemophilia, have been the most frequent haemophiliac\'s clinical event. The repetitive haemarthrosis, speccialy those occurred in ankle joints, could be associated to ankle instabilities. It is known that the joint instability can contribute to increase the frequency of those complications and are prescribed orthosis which severely limit the patients. Face to these facts, we have searched for an instrument able to qualify the deviations in the unstable ankles during the gait, dynamically and in real time. Such evaluation would allow the prescription of insoles, of shoes with posterior counters and, in very unstable cases, the association of dynamic supports. The intervention performed in the patients was constituted of the computerised dynamic pedobarography examination, before and after the prescription of the orthosis. The use of the prescribed orthosis according to the pedobarographic observations allowed joint stability with gait liberty. The number of haemarthrosis in the ankles and the consumption of coagulation factors in each bleeding of the 43 haemophilic evaluated was verified in the patients\' medical records, in their original institutions, in the six months that preceded evaluation and therapeutic intervention in haemophilic patients and during the six months after it. In the 43 evaluated haemophilic patients, the average occurrence of haemarthrosis went from 4,81 episodes before intervention to 2,53 episodes after the intervention. The average coagulation factors consumption went from 9.647,7 IU to 4.407,0 IU. The p value is smaller than 0,001. Based on the analysis of the results, we are able to conclude that the computerised dynamic pedobarography is a useful diagnosis method with a significant contribution to the reduction of incidence of ankle haemarthrosis.

As hemartroses, a despeito dos avanços terapêuticos ocorridos na hemofilia, continuam sendo os eventos clínicos mais freqüentes. As hemartroses de repetição, sobretudo nos tornozelos, podem estar associadas à instabilidade articular. Sabe-se que a instabilidade articular pode contribuir para aumentar a frequência dessas complicações e prescrevem-se órteses que limitam muito os pacientes. Diante desse quadro buscamos um instrumento para qualificar os desvios nos tornozelos instáveis durante a marcha, dinamicamente e em tempo real. Essa avaliação permitiu a prescrição de palmilhas de fácil confecção, de calçados com contrafortes posteriores e, nos casos muito instáveis, a associação de órteses funcionais, dinâmicas, para tornozelos. A intervenção realizada nos pacientes constou do exame pela podobarometria dinâmica computadorizada, antes e depois da prescrição das órteses. O uso das órteses prescritas conforme as observações podobarométricas permitiu liberdade na marcha, assegurando estabilidade articular. O número de hemartroses nos tornozelos e o consumo de fatores da coagulação em cada hemorragia, nos 43 hemofílicos avaliados, foi verificado nos prontuários médicos dos pacientes, em suas instituições de origem, nos seis meses pré-intervenção e nos seis meses pós-intervenção. Nos 43 hemofílicos avaliados, a média de ocorrência de hemartroses, que era de 4,81, foi reduzida para 2,53 hemartroses por paciente, após a intervenção. A média do consumo de fatores da coagulação reduziu de 9647,7 IU para 4407,0 IU, com p<0,001 . Com base na análise dos resultados concluímos que a podobarometria dinâmica computadorizada é um meio diagnóstico útil na prescrição de estabilizadores para os tornozelos dos hemofílicos, contribuindo significantemente para a redução da incidência de hemartroses. / The haemarthrosis, despite the improvement of therapeutic resources occurred in haemophilia, have been the most frequent haemophiliac\'s clinical event. The repetitive haemarthrosis, speccialy those occurred in ankle joints, could be associated to ankle instabilities. It is known that the joint instability can contribute to increase the frequency of those complications and are prescribed orthosis which severely limit the patients. Face to these facts, we have searched for an instrument able to qualify the deviations in the unstable ankles during the gait, dynamically and in real time. Such evaluation would allow the prescription of insoles, of shoes with posterior counters and, in very unstable cases, the association of dynamic supports. The intervention performed in the patients was constituted of the computerised dynamic pedobarography examination, before and after the prescription of the orthosis. The use of the prescribed orthosis according to the pedobarographic observations allowed joint stability with gait liberty. The number of haemarthrosis in the ankles and the consumption of coagulation factors in each bleeding of the 43 haemophilic evaluated was verified in the patients\' medical records, in their original institutions, in the six months that preceded evaluation and therapeutic intervention in haemophilic patients and during the six months after it. In the 43 evaluated haemophilic patients, the average occurrence of haemarthrosis went from 4,81 episodes before intervention to 2,53 episodes after the intervention. The average coagulation factors consumption went from 9.647,7 IU to 4.407,0 IU. The p value is smaller than 0,001. Based on the analysis of the results, we are able to conclude that the computerised dynamic pedobarography is a useful diagnosis method with a significant contribution to the reduction of incidence of ankle haemarthrosis.