Cartilage restoration in haemophilia: advanced therapies

Preliminary study on non-viral transfection of F9 (factor IX) gene by nucleofection in human adipose-derived mesenchymal stem cells

Background. Hemophilia is a rare recessive X-linked disease characterized by a deficiency of coagulation factor VIII or factor IX. Its current treatment is merely palliative. Advanced therapies are likely to become the treatment of choice for the disease as they could provide a curative treatment.

Methods. The present study looks into the use of a safe non-viral transfection method based on nucleofection to express and secrete human clotting factor IX (hFIX) where human adipose tissue derived mesenchymal stem cells were used as target cells in vitro studies and NOD. Cg-Prkdcscid Il2rgtm1Wjl/SzJ mice were used to analyze factor IX expression in vivo studies. Previously, acute liver injury was induced by an injected intraperitoneal dose of 500 mg/kg body weight of acetaminophen.

Results. Nucleofection showed a percentage of positive cells ranging between 30.7% and 41.9% and a cell viability rate of 29.8%, and cells were shown to secrete amounts of hFIX between 36.8 and 71.9 ng/mL. hFIX levels in the blood of NSG mice injected with ASCs transfected with this vector, were 2.7 ng/mL 48 h after injection. Expression and secretion of hFIX were achieved both in vitro cell culture media and in vivo in the plasma of mice treated with the transfected ASCs. Such cells are capable of eventually migrating to a previously damaged target tissue (the liver) where they secrete hFIX, releasing it to the bloodstream over a period of at least five days from administration.

Conclusions. The results obtained in the present study may form a preliminary basis for the establishment of a future ex vivo non-viral gene/cellular safe therapy protocol that may eventually contribute to advancing the treatment of hemophilia.

Declining trends in invasive orthopedic interventions for people with hemophilia enrolled in the Universal Data Collection program (2000-2010)

INTRODUCTION

Recurrent joint hemarthroses due to hemophilia (Factor VIII and Factor IX deficiency) often lead to invasive orthopedic interventions to decrease frequency of bleeding and/or to alleviate pain associated with end-stage hemophilic arthropathy.

AIM

Identify trends in invasive orthopedic interventions among people with hemophilia who were enrolled in the Universal Data Collection (UDC) program during the period 2000-2010.

METHODS

Data were collected from 130 hemophilia treatment centers in the United States annually during the period 2000-2010, in collaboration with the Centers for Disease Control and Prevention (CDC). The number of visits in which an invasive orthopedic intervention was reported was expressed as a proportion of the total visits in each year of the program. Invasive orthopedic interventions consisted of arthroplasty, arthrodesis, and synovectomy. Joints included in this study were the shoulder, elbow, hip, knee, and ankle.

RESULTS

A 5.6% decrease in all invasive orthopedic interventions in all joints of people with hemophilia enrolled in the UDC program over the 11-year study period was observed.

CONCLUSIONS

These data reflect a declining trend in invasive orthopedic interventions in people with hemophilia. Further research is needed to understand the characteristics that may influence invasive orthopedic interventions.

Osteochondral repair in hemophilic ankle arthropathy: from current options to future perspectives

Young hemophilic patients are frequently affected by ankle arthropathy. At the end stage of the disease, the current treatments are arthrodesis and arthroplasty, which have significant drawbacks. Validated procedures capable of slowing down or even arresting the progression towards the end stage are currently lacking. This review aims to discuss the rationale for and feasibility of applying, in mild hemophilic ankle arthropathy, the main techniques currently used to treat osteochondral defects, focusing in particular on ankle distraction, chondrocyte implantation, mesenchymal stem cell transplantation, allograft transplantation and the use of growth factors. To date, ankle distraction is the only procedure that has been successfully used in hemophilic ankle arthropathy. The use of mesenchymal stem cells have recently been evaluated as feasible for osteochondral repair in hemophilic patients. There may be a rationale for the use of growth factors if they are combined with the previous techniques, which could be useful to arrest the progression of the degeneration or delay end-stage procedures.

Treatment of Hemophilic Ankle Arthropathy with One-Step Arthroscopic Bone Marrow-Derived Cells Transplantation

OBJECTIVE

Ankle arthropathy is a frequent and invalidating manifestation of hemophilia. Arthrodesis is the gold standard surgical procedure in end-stage disease, with many drawbacks in young patients. Recent literature has shown increase interest in regenerative procedures in hemophilic arthropathy, which may be desirable to delay or even avoid arthrodesis. The aim of this article is to present five cases of osteochondral lesions in ankle hemophilic arthropathy treated with a regenerative procedure: bone marrow-derived cells transplantation (BMDCT).

DESIGN

We report five hemophilic patients (four cases with hemophilia type A; one case with hemophilia type B) who have undergone BMDCT treatment, synovectomy, and arthroscopic debridement, with the use of autologous platelet-rich fibrin, to treat osteochondral lesions in hemophilic ankle arthropathy. The patients, included within this retrospective study, were clinically and radiologically evaluated with serial follow-ups, using the American Orthopaedic Foot and Ankle Society (AOFAS) scores, radiographs, and magnetic resonance imaging (MRI).

RESULTS

The mean preoperative AOFAS score was 35. After a mean follow-up of 2 years, the mean postoperative AOFAS score was 81, which included three patients returning back to sporting activities. The MRI Mocart score demonstrated signs of regeneration of chondral and bony tissue. No progression of joint degeneration was shown radiographically.

CONCLUSION

BMDCT is a promising regenerative treatment for osteochondral lesions in mild ankle hemophilic arthropathy, which may be useful to delay or even avoid ankle arthrodesis. Nevertheless, longer follow-ups and a larger case series are required.

Biological therapies for inherited diseases: social and bioethical considerations. Hemophilia as an example

INTRODUCTION

In hemophilia, advanced therapies are warranted from a conceptual and methodological standpoint. Current advanced therapy strategies are centered on the use of adeno-associated viral vectors, although problems related to immunogenicity and hepatotoxicity still remain.

AREAS COVERED

Future clinical trials will have to scrupulously observe international bioethical standards in terms of patient selection, particularly children. Patient recruitment rates are likely to remain low due to the stringent exclusion criteria usually imposed on the trial population regarding their hepatic and immunological markers and the presence of viral coinfection; and to the existence of an optimal palliative treatment.

EXPERT OPINION

Accordingly, the results obtained are likely to be of low statistical significance, which could hinder their application to clinical practice. Another important issue is the degree to which society embraces these new emerging therapies. The unfamiliarity of society with these new methods, together with the many unresolved questions about them that remain, may threaten their acceptance not only by society at large but also by health-care professionals, which would limit their translational application to clinical practice.

Advanced therapies for the treatment of hemophilia: future perspectives

Monogenic diseases are ideal candidates for treatment by the emerging advanced therapies, which are capable of correcting alterations in protein expression that result from genetic mutation. In hemophilia A and B such alterations affect the activity of coagulation factors VIII and IX, respectively, and are responsible for the development of the disease. Advanced therapies may involve the replacement of a deficient gene by a healthy gene so that it generates a certain functional, structural or transport protein (gene therapy); the incorporation of a full array of healthy genes and proteins through perfusion or transplantation of healthy cells (cell therapy); or tissue transplantation and formation of healthy organs (tissue engineering). For their part, induced pluripotent stem cells have recently been shown to also play a significant role in the fields of cell therapy and tissue engineering. Hemophilia is optimally suited for advanced therapies owing to the fact that, as a monogenic condition, it does not require very high expression levels of a coagulation factor to reach moderate disease status. As a result, significant progress has been possible with respect to these kinds of strategies, especially in the fields of gene therapy (by using viral and non-viral vectors) and cell therapy (by means of several types of target cells). Thus, although still considered a rare disorder, hemophilia is now recognized as a condition amenable to gene therapy, which can be administered in the form of lentiviral and adeno-associated vectors applied to adult stem cells, autologous fibroblasts, platelets and hematopoietic stem cells; by means of non-viral vectors; or through the repair of mutations by chimeric oligonucleotides. In hemophilia, cell therapy approaches have been based mainly on transplantation of healthy cells (adult stem cells or induced pluripotent cell-derived progenitor cells) in order to restore alterations in coagulation factor expression.