Successful umbilical cord blood stem cell transplantation for chronic granulomatous disease

Progress in treating chronic granulomatous disease

Chronic granulomatous disease is a primary immunodeficiency due to a defect in one of six subunits that make up the nicotinamide adenine dinucleotide phosphate oxidase complex. The most commonly defective protein, gp91^phox , is inherited in an X-linked fashion; other defects have autosomal recessive inheritance. Bacterial and fungal infections are common presentations, although inflammatory complications are increasingly recognized as a significant cause of morbidity and are challenging to treat. Haematopoietic stem cell transplantation offers cure from the disease with improved quality of life; overall survival in the current era is around 85%, with most achieving long-term cure free of medication. More recently, gene therapy is emerging as an alternative approach. Results using gammaretroviral vectors were disappointing with genotoxicity and loss of efficacy, but preliminary results using lentiviral vectors are extremely encouraging.

Allogeneic Hematopoietic Cell Transplantation for Chronic Granulomatous Disease: Controversies and State of the Art

Chronic granulomatous disease (CGD) is a congenital disorder characterized by recurrent life-threatening bacterial and fungal infections and development of severe inflammation secondary to a congenital defect in 1 of the 5 phagocyte oxidase (phox) subunits of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. Hematopoietic cell transplant (HCT) is a curative treatment for patients with CGD that provides donor neutrophils with functional NADPH and superoxide anion production. Many characteristics of CGD, including preexisting infection and inflammation and the potential for cure with mixed-donor chimerism, influence the transplant approach and patient outcome. Because of the dangers of short-term death, graft-versus-host disease, and late effects from chemotherapy, HCT historically has been reserved for patients with high-risk disease and a matched donor. However, as advances in CGD and HCT treatments have evolved, recommendations on transplant eligibility also must be amended, but the development of modern guidelines has proven difficult. In this review, we provide an overview of HCT in patients with CGD, including the debate over HCT indications in them, the unique aspects of CGD that can complicate HCT, and a summary of transplant outcomes.

A Cohort of 169 Chronic Granulomatous Disease Patients Exposed to BCG Vaccination: a Retrospective Study from a Single Center in Shanghai, China (2004-2017)

PURPOSE

Clinical diagnosis and treatment for chronic granulomatous disease (CGD) have advanced greatly in recent years. However, CGD patients in China have unique clinical features and infection spectrums, which are challenging to their caretakers. Here, we summarized the clinical characteristics, genetic features, treatment, and prognosis of CGD in a single center in Shanghai.

METHODS

One hundred sixty-nine CGD patients were recruited between January 2004 and May 2017 based on clinical diagnosis. Electronic medical charts were reviewed to collect clinical data.

RESULTS

Among the 169 patients recruited, CYBB mutations were identified in 150 cases, whereas CYBA mutations were identified in 7 cases, NCF1 in 5, and NCF2 in 7. The medium age at onset was 1 month (interquartile range 1-3). The medium age at diagnosis was 8 months (interquartile range 3-19). The most common infection sites were the lung (95.9%), lymph node (58.5%), skin (45.4%), intestinal (43.1%), and perianal (38.5%). Bacillus Calmette-Guérin (BCG) infections were common (59.2%). In addition, other non-infectious complications were also common, including anemia (55.4%) and impaired liver functions (34.6%). Thirty-one patients received stem cell transplantation. By the end of this study, 83/131 patients survived.

CONCLUSIONS

Similar to other non-consanguineous populations, X-linked CGD accounted for the majority of the cases in China. However, BCG infections were a clinical challenge unique to China. In addition, severe infections were the major cause of death and the overall mortality was still high in China.

Successful Unrelated Cord Blood Stem Cell Transplantation in an X-linked Chronic Granulomatous Disease Patient with Disseminated BCG-induced Infection

A 19-month-old boy with chronic granulomatous disease (CGD) received umbilical cord blood transplantation (UCBT) from an unrelated donor after experiencing a life-threatening disseminated Bacillus Calmette-Guérin infection. After busulfan and cyclophosphamide conditioning, we performed a 5/6-matched UCBT. Engraftment and mixed chimerism was 100% in peripheral blood, and 100% of his neutrophils had normal oxidative burst activity on day 17. The patient is now 3 years old, free from infection, and growing well. To our knowledge, this is the second case of CGD treated with UCBT in Taiwan. His successful outcome illustrates that UCBT in a patient with CGD should be considered early if a human leukocyte antigen-matched donor is not available or the patient has just recovered from a severe infection.

Concise review: umbilical cord blood transplantation: past, present, and future

Allogeneic hematopoietic stem cell transplantation is an important treatment option for fit patients with poor-risk hematological malignancies; nevertheless, the lack of available fully matched donors limits the extent of its use. Umbilical cord blood has emerged as an effective alternate source of hematopoietic stem cell support. Transplantation with cord blood allows for faster availability of frozen sample and avoids invasive procedures for donors. In addition, this procedure has demonstrated reduced relapse rates and similar overall survival when compared with unrelated allogeneic hematopoietic stem cell transplantation. The limited dose of CD34-positive stem cells available with single-unit cord transplantation has been addressed by the development of double-unit cord transplantation. In combination with improved conditioning regimens, double-unit cord transplantation has allowed for the treatment of larger children, as well as adult patients with hematological malignancies. Current excitement in the field revolves around the development of safer techniques to improve homing, engraftment, and immune reconstitution after cord blood transplantation. Here the authors review the past, present, and future of cord transplantation.

Non-Aspergillus fungal infections in chronic granulomatous disease

Chronic granulomatous disease (CGD) is a congenital immunodeficiency, characterised by significant infections due to an inability of phagocyte to kill catalase-positive organisms including certain fungi such as Aspergillus spp. Nevertheless, other more rare fungi can cause significant diseases. This report is a systematic review of all published cases of non-Aspergillus fungal infections in CGD patients. Analysis of 68 cases of non-Aspergillus fungal infections in 65 CGD patients (10 females) published in the English literature. The median age of CGD patients was 15.2 years (range 0.1-69), 60% of whom had the X-linked recessive defect. The most prevalent non-Aspergillus fungal infections were associated with Rhizopus spp. and Trichosporon spp. found in nine cases each (13.2%). The most commonly affected organs were the lungs in 69.9%. In 63.2% of cases first line antifungal treatment was monotherapy, with amphotericin B formulations being the most frequently used antifungal agents in 45.6% of cases. The overall mortality rate was 26.2%. Clinicians should take into account the occurrence of non-Aspergillus infections in this patient group, as well as the possibility of a changing epidemiology in fungal pathogens. Better awareness and knowledge of these pathogens can optimise antifungal treatment and improve outcome in CGD patients.

Myeloablative transplantation using either cord blood or bone marrow leads to immune recovery, high long-term donor chimerism and excellent survival in chronic granulomatous disease

The curative potential of hematopoietic stem cell transplantation in patients with chronic granulomatous disease depends on availability of a suitable donor, successful donor engraftment, and maintenance of long-term donor chimerism. Twelve consecutive children (median age, 59.5 months; range, 8-140 months) with severe chronic granulomatous disease (serious bacterial/fungal infections pretransplantation; median, 3; range, 2-9) received myeloablative hematopoietic stem cell transplantation using sibling bone marrow ([SibBM]; n = 5), unrelated cord blood (UCB; n = 6), and sibling cord blood (n = 1) at our center between 1997 and 2010. SibBM and sibling cord blood were HLA matched at 6/6, whereas UCB were 5/6 (n = 5) or 6/6 (n = 1). Recipients of SibBM were conditioned with busulfan and cyclophosphamide ± anti-thymocyte globulin (ATG), whereas 6 of 7 cord blood recipients received fludarabine/busulfan/cyclophosphamide/ATG. Seven patients received granulocyte-colony stimulating factor-mobilized granulocyte transfusions from directed donors. The first 2 UCB recipients had primary graft failure but successfully underwent retransplantation with UCB. Highest acute graft-versus-host disease was grade III (n = 1). Extensive chronic graft-vs-host disease developed in 3 patients. All patients are alive with median follow-up of 70.5 months (range, 12-167 months) with high donor chimerism (>98%, n = 10; 94%, n = 1; and 92%, n = 1). Myeloablative hematopoietic stem cell transplantation led to correction of neutrophil dysfunction, durable donor chimerism, excellent survival, good quality of life, and low incidence of graft-vs-host disease regardless of graft source.

Chronic granulomatous disease: a review of the infectious and inflammatory complications

Chronic Granulomatous Disease is the most commonly encountered immunodeficiency involving the phagocyte, and is characterized by repeated infections with bacterial and fungal pathogens, as well as the formation of granulomas in tissue. The disease is the result of a disorder of the NADPH oxidase system, culminating in an inability of the phagocyte to generate superoxide, leading to the defective killing of pathogenic organisms. This can lead to infections with Staphylococcus aureus, Psedomonas species, Nocardia species, and fungi (such as Aspergillus species and Candida albicans). Involvement of vital or large organs can contribute to morbidity and/or mortality in the affected patients. Major advances have occurred in the diagnosis and treatment of this disease, with the potential for gene therapy or stem cell transplantation looming on the horizon.

Chronic granulomatous disease: overview and hematopoietic stem cell transplantation

Chronic granulomatous disease (CGD) still causes significant morbidity and mortality. The difficulty in considering high-risk yet curative treatments, such as allogeneic bone marrow transplantation, lies in the unpredictable courses of both CGD and bone marrow transplantation in different patients. Some patients with CGD can have frequent infections, granulomatous or autoimmune disorders necessitating immunosuppressive therapy, or both but also experience long periods of relative good health. However, the risk of death is clearly higher in patients with CGD of all types, and the complications of CGD short of death can still cause significant morbidity. Therefore, with recent developments and improvements, bone marrow transplantation, previously considered an experimental or high-risk procedure, has emerged as an important option for patients with CGD. We will discuss the complications of CGD that result in significant morbidity and mortality, particularly the most common infections and autoimmune/inflammatory complications, as well as their typical management. We will then discuss the status of bone marrow transplantation.

Hematopoietic stem cell transplantation for chronic granulomatous disease

Chronic granulomatous disease (CGD) is a primary immunodeficiency disease that is caused by the lack of 1 of 5 subunits of the superoxide-producing nicotinamide adenine dinucleotide phosphate oxidase of neutrophils, macrophages, and eosinophils. Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative treatment for CGD and can be offered to selected patients. Improved outcome with supportive care and high clinical variability in the disease course, however, make selection of eligible patients for HSCT difficult. This article addresses recent progress in HSCT for CGD, delineates present limitations, and points to future developments.

Hematopoietic stem cell transplantation from matched unrelated donors in chronic granulomatous disease

We report on 12 patients with chronic granulomatous disease transplanted with hematopoietic stem cells from matched unrelated (n = 9) or matched sibling donors (n = 3). The most common infectious complication was pulmonary aspergillosis, which nine patients had previously developed. Only 5 of 12 individuals had normal lung function prior to transplantation. At a mean follow-up of 53 months 9 of the 12 patients are alive including 7 of 9 following matched unrelated donor (MUD) transplantation. One patient died from ARDS, another from systemic BK virus infection, the third from complications of chronic graft-versus-host disease. Seven of nine surviving patients have normal lung function now. HSCT from a MUD is an option worth considering when no matched family donor is available. Restricted lung function prior to HSCT does not appear to be a limiting factor for such treatment.

Successful unrelated cord blood transplantation for chronic granulomatous disease: a case report and review of the literature

CGD is a rare inherited immunodeficiency disorder that is caused by disability of oxidative killing. We presented a two-yr-old boy with CGD who was suffering from multiple systemic abscesses. He received the first BMT from his HLA-haploidentical mother after conditioning with Flu, melphalan, and ATG. Although the maximum of 42% donor chimerism was achieved, it disappeared 73 days after the BMT. Then, we performed 5/6-matched unrelated cord blood re-transplantation after conditioning with Flu, Bu, and TBI (2 Gy). Engraftment and complete donor chimerism were achieved on days 18 and 19, respectively. The patient is now free from infection and maintains complete donor chimerism without GVHD 36 months after the cord blood re-transplantation. We postulate that the unrelated CBT has a potential to be an alternative strategy and might be beneficial for patients with CGD who do not have an HLA-identical donor.

Unrelated donor and HLA-identical sibling haematopoietic stem cell transplantation cure chronic granulomatous disease with good long-term outcome and growth

Chronic granulomatous disease (CGD) causes recurrent infection and inflammatory disease. Despite antimicrobial prophylaxis, patients experience frequent hospitalisations and 50% mortality by 30 years. Haematopoietic stem cell transplantation (HSCT) can cure CGD with resolution of infection and colitis. This study reports the survival and long-term outcome in 20 conditioned patients treated between 1998 and 2007, using 10 matched sibling (MSD) and 10 unrelated donors (URD). Age at HSCT, graft-versus-host disease (GvHD), growth, and outcome were analysed. Fourteen had > or = 1 invasive infection, 10 had colitis and seven had growth failure before HSCT. Median age at transplantation was 75 months (range 15 months-21 years). Eighteen (90%) were alive 4-117 months (median 61) after HSCT with normal neutrophil function. Two died from disseminated fungal infection. Two experienced significant chronic GvHD, with continuing sequelae in 1. Colitis resolved within 8 weeks of HSCT. Mean weight and height for age Z scores on recovery from HSCT rose significantly (P < 0.001). HSCT with MSD or URD gave excellent engraftment and survival, remission of colitis and catch-up growth, with low incidence of significant GvHD. Transplant-associated complications were restricted to those with pre-existing infection or inflammation, supporting the argument for early HSCT for more CGD patients with a well matched donor.

First successful bone marrow transplantation for X-linked chronic granulomatous disease by using preimplantation female gender typing and HLA matching

Allogeneic hematopoietic stem cell transplantation from an human leukocyte antigen (HLA)-identical donor is currently the only proven curative treatment for chronic granulomatous disease. Hematopoietic stem cell transplantation with alternative donors is associated with higher morbidity and mortality. Therefore, we performed in vitro fertilization and preimplantation HLA matching combined with female sexing for hematopoietic stem cell transplantation in chronic granulomatous disease. Ethical and psychological issues were considered carefully. We used in vitro fertilization with X-enriched spermatozoa followed by preimplantation genetic diagnosis to identify female HLA-genoidentical embryos in a family in need of a suitable donor for their boy affected with severe X-linked chronic granulomatous disease. Two preimplantation genetic diagnosis cycles were performed in the family. In the second cycle, 2 HLA-genoidentical female embryos were transferred and a singleton pregnancy was obtained, resulting in the birth of an unaffected girl at term. Because of insufficient cell numbers in the cord-blood source, conventional hematopoietic stem cell transplantation had to be performed at 12 months of age of the donor and 5 years of age of the recipient and resulted in complete stable donor chimerism and immunologic reconstitution up to 25 months post-hematopoietic stem cell transplantation. Hematopoietic stem cell transplantation after in vitro fertilization and combined female sexing and HLA matching offers a new and relatively rapid therapeutic option for patients with X-linked primary immunodeficiency such as chronic granulomatous disease who need hematopoietic stem cell transplantation but lack an HLA-genoidentical donor.

Comparison of gene expression of mitogenic kinin path in adherent and non-adherent CD 34-stem cells using oligonucleotide microarrays

One of the more interesting cells present in the umbilical cord blood - as far as their potential clinical use is concerned - are stem cells not presenting the CD34 antigen. These are the pluripotential cells with their biological properties similar to mesenchymal stem cells, with the ability to differentiate into such tissue types as bone, cartilage, nervous (to some extent), glia and muscle. The authors compared the activity of genes coding the proteins in mitogenic signal paths activated by kinin receptors using oligonucleotide microarrays in adherent and non-adherent CD 34- cells derived from umbilical cord blood. In the linear regression model with a 95% prognosis area for differentiating genes outside this area, the following genes were selected: c-jun (present in 3 isoforms) and c-fos. The fos and jun genes create the AP-1 transcriptive factor which regulates the expression of genes taking part in numerous cellular processes, including the cell cycle and mitosis. The obtained results shed some light on the molecular processes behind the MSC proliferation and are a starting point for further studies on the mesenchymal stem cell biology.

Correction of chronic granulomatous disease after second unrelated-donor umbilical cord blood transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is curative for chronic granulomatous disease (CGD), but many patients lack a suitably matched related donor. We report successful outcomes after mismatched, unrelated-donor umbilical cord blood transplantation (uUCBT) in two boys with X-linked CGD. Both patients experienced autologous recovery after first transplants, required second transplants to achieve durable donor engraftment, and are alive 27 and 15 months post-transplant. Both had invasive fungal disease and received granulocyte transfusions. In conclusion, uUCBT is effective in children with CGD, but immunosuppression in the conditioning regimen may need to be increased to decrease the risk of graft rejection.

Treatment of McLeod phenotype chronic granulomatous disease with reduced-intensity conditioning and unrelated-donor umbilical cord blood transplantation

Patients with chronic granulomatous disease (CGD) complicated by antimycotics-refractory invasive aspergillosis have an extremely poor prognosis if they cannot undergo allogeneic hematopoietic stem cell transplantation from a suitable related donor while in good clinical condition. We successfully treated a 20-year-old man with very rare McLeod phenotype CGD with reduced-intensity conditioning and unrelated-donor umbilical cord blood transplantation. We postulate that reduced-intensity conditioning-allogeneic hematopoietic stem cell transplantation is a promising therapeutic strategy for patients with CGD even if only unrelated-donor umbilical cord blood is available.

Gastrointestinal manifestations of chronic granulomatous disease

OBJECTIVE

Chronic granulomatous disease is a rare clinical entity characterized by recurrent infective and inflammatory complications. Patients are usually assigned to specialist centres, but nonspecialist clinicians may be required to treat these patients in the emergency setting. This review serves as a management guide to those clinicians who are faced with patients presenting with gastrointestinal manifestations of chronic granulomatous disease.

METHODS

This review is based on a literature search (Medline and NLM PubMed) with manual cross-referencing of all articles related to gastrointestinal chronic granulomatous disease.

RESULTS

Gastrointestinal tract involvement is present in most affected patients. Clinical presentation can mimic common surgical complications such as colitis, perianal sepsis, gastric outlet obstruction and liver abscess. A history of recurrent infections during childhood is common. Management involves haematological, microbiological, endoscopic and radiological investigations. Treatment modalities include early aggressive empirical antimicrobial therapy for sepsis, immunomodulation for inflammatory complications and surgical drainage of abscesses.

CONCLUSION

Early involvement of a centre with immunological expertise combined with aggressive management of complications significantly improves morbidity and mortality from this rare condition.

Distribution, infections, treatments and molecular analysis in a large cohort of patients with primary immunodeficiency diseases (PIDs) in Taiwan

One hundred and twenty-four patients (from 120 families) diagnosed as primary immunodeficiency diseases were enrolled from five tertiary medical centers. The distribution by an update eight categories showed 45 patients (13 females/32 males; 36.3%) with "predominant antibody deficiencies," 27 patients (6/21; 21.8%) with "T- and B-cell immunodeficiency," 25 patients (9/16; 20.2%) with "congenital defects of phagocyte," 25 patients (4/21; 20.2%) with "other well-defined immunodeficiency syndromes," one boy (0.8%) with "disease in immune deregulation" (Chediak-Higashi syndrome) and another with "complement 3 deficiency." None had "defects in innate immunity" or "auto inflammatory disorders." Pseudomonas and Salmonella spp. were the two most identified microorganisms in septicemia (39.7%; 27/68 episodes). Twenty-three patients (18.5%) had mortality. Stem cell transplantation succeeded in 7 of 12 patients. In addition to nine patients with DiGerge syndrome recognized by FISH, direct sequencing identified 12 unique mutations from 20 families, reflecting distinct Taiwan geography, although a selection bias may exist.

Topical issues in unrelated donor haematopoietic stem cell transplants: a report from a workshop convened by the Anthony Nolan Trust in London - 2005

Over more than three decades, The Anthony Nolan Trust (ANT) has provided an unrelated donor (UD) for over 4000 children and adults lacking a suitable family member donor, and has remained at the forefront of developments in haematopoietic stem cell transplantation (HSCT) and bone marrow register management. These three decades have seen major changes in clinical practice of UD-HSCT, including new indications, increased use of alternative haematopoietic cell sources, significant improvement of the outcome as a result of better support care, less-toxic conditioning regimens, and better donor selection, and expansion to older patients with higher comorbidities. In order to foster our goal of improving UD-HSCT availability and outcome in a progressively more complex clinical scenario, a new initiative from ANT was launched in 2005 to convene an experts workshop to address the topical issues in this field. Four consecutive panels addressed factors influencing donor selection and transplant outcome, the use of cord blood, regulatory and accreditation issues, and future developments in this field. This report summarizes the discussions held in this workshop, which will likely develop into a periodic event where transplant clinicians, scientists and registry members will meet to share their experience and vision in the field of UD-HSCT.

Human umbilical cord blood-derived stromal cell, a new resource of feeder layer to expand human umbilical cord blood CD34+ cells in vitro

Allogeneic transplantation with human umbilical cord blood (hUCB) in adult recipients is mainly limited by a low CD34+ cell dose. To break the limit, hUCB as a novel source of hUCB-derived stromal cells was incorporated in an attempt to expand CD34+ cells from hUCB in vitro. Cord blood CD34 cells were separated by MACS system. HUCB-derived stromal cells were cultured by the Dexter system and characterized by morphologic, immunophenotypical, and functional analysis. We studied the effects of hUCB-derived stromal cells, cytokines, and hUCB-derived stromal cells combined with cytokines on expansion of hUCB CD34 cells. The CD34+ cells were assessed for the degree of expansion and the number of colony-forming units in semisolid culture. Our research found that hUCB-derived stromal cells were mainly composed of three kinds of cell components, with CD106, CD29, CD44, CD45, CD50, CD68, CD31, Fn, Lm, and collagen IV positive, but CD34 negative immunophenotype. Functionally, it was discovered by cell cycle and growth curve analyses that the capability of colony and parietal layer formation of hUCB-derived stromal cells was poorer than that of BM stromal cells, and the doubling time of hUCB-derived stromal cells was longer than that of BM stromal cells. It was indicated by ELISA and RT-PCR that hUCB-derived stromal cells express higher level of TPO and less GM-CSF and SCF than BM stromal cell. Adherent layer of hUCB-derived stromal cells alone or combining with cytokines, increased CD34+ cell expansion. In vitro formation of CFUs by expanded CCD34 cells was significantly higher than that of unexpanded CD34+ cells (P < 0.05). When cocultured with hUCB-derived stromal cells in the presence of cytokines, cell growth was significantly enhanced: CD34 cells by 8.02 +/- 0.96-fold, CFU-GM by 217.60 +/- 6.72-fold, CFU-E by 1940.80 +/- 52.78-fold, and CFU-Mg by 142.60 +/- 4.39-fold. HUCB-derived stromal cells have significant superiority on the expansion of CFU-Mg (P < 0.05). The results indicate that human umbilical cord blood-derived stromal cells may be a suitable feeder layer for expansion of hematopoietic progenitors from hUCB in vitro.

Single centre experience of umbilical cord stem cell transplantation for primary immunodeficiency

Primary immunodeficiencies (PID) are an important cause of childhood mortality. Haematopoietic stem cell transplantation (HSCT) is the best treatment for many PID. Umbilical cord stem cells are an alternative source of HSC. There is little data regarding outcome of umbilical cord stem cell transplantation (UCSCT) for PID. Our single centre experience is reported. A retrospective study of 14 of 148 patients transplanted for PID, who have received 15 UCSCT was performed, with specific regard to graft-versus-host disease (GvHD) and immune reconstitution. Eight patients with severe combined immunodeficiency (SCID), and six with other combined immunodeficiencies were treated. Of the patients, 12 received unrelated cords, and two had sibling transplants. Median age at transplant was 3.5 months, median nucleated cell dose was 0.8 x 10(8)/kg. All engrafted. Median time to neutrophil engraftment was 22 days, median time to platelet engraftment was 51 days. One developed significant grade III GvHD post transplantation. In total, 11 patients had full donor T and six full donor B-cell chimerism, six of nine patients >1 year post-BMT had normal IgG levels and specific antibody responses to tetanus and Hib vaccines; two are being assessed. Two patients died of multi-organ failure related to pre-existing infection and inflammatory complications respectively. UCSCT should be considered for patients requiring stem cell therapy for PID.

In vitro differentiation of human umbilical cord blood-derived mesenchymal stem cells into hepatocyte-like cells

In addition to long-term self-renewal capability, human mesenchymal stem cells (MSCs) possess versatile differentiation potential ranging from mesenchyme-related multipotency to neuroectodermal and endodermal competency. Of particular concern is hepatogenic potential that can be used for liver-directed stem cell therapy and transplantation. In this study, we have investigated whether human umbilical cord blood (UCB)-derived MSCs are also able to differentiate into hepatocyte-like cells. MSCs isolated from UCB were cultured under the pro-hepatogenic condition similar to that for bone marrow (BM)-derived MSCs. Expression of a variety of hepatic lineage markers was analyzed by flow cytometry, RT-PCR, Western blot, and immunofluorescence. The functionality of differentiated cells was assessed by their ability to incorporate DiI-acetylated low-density lipoprotein (DiI-Ac-LDL). As the cells were morphologically transformed into hepatocyte-like cells, they expressed Thy-1, c-Kit, and Flt-3 at the cell surface, as well as albumin, alpha-fetoprotein, and cytokeratin-18 and 19 in the interior. Moreover, about a half of the cells were found to acquire the capability to transport DiI-Ac-LDL. Based on these observations, and taking into account immense advantages of UCB over other stem cell sources, we conclude that UCB-derived MSCs retain hepatogenic potential suitable for cell therapy and transplantation against intractable liver diseases.

Skeletal myogenic differentiation of mesenchymal stem cells isolated from human umbilical cord blood

Human umbilical cord blood (UCB) has been regarded as an alternative source for cell transplantation and cell therapy because of its hematopoietic and nonhematopoietic (mesenchymal) potential. Although there has been debate about whether mesenchymal stem cells (MSCs) are invariably present in UCB, several reports showed that MSC-like cells could be consistently derived from human UCB and, moreover, could differentiate into various cells of a mesodermal origin. However, it remains unclear whether these UCB-derived MSCs are also capable of differentiating into skeletal muscle cells. In this study, we isolated MSCs from human UCB and induced them to differentiate into skeletal muscle cells. During cell culture expansion, UCB-derived mononuclear cells gave rise to adherent layers of fibroblast-like cells expressing MSC-related antigens such as SH2, SH3, alpha-smooth muscle actin, CD13, CD29, and CD49e. More important, when these UCB-derived MSCs were incubated in promyogenic conditions for up to 6 weeks, they expressed myogenic markers in accordance with myogenic differentiation pattern. Both flow cytometric and reverse transcriptase-polymerase reaction analyses showed that two early myogenic markers, MyoD and myogenin, were expressed after 3 days of incubation but not after 2 weeks. At week 6, more than half of UCB-derived MSCs expressed myosin heavy chain, a late myogenic marker. Our results demonstrate that UCB-derived MSCs possess a potential of skeletal myogenic differentiation and also imply that these cells could be a suitable source for skeletal muscle repair and a useful tool of muscle-related tissue engineering.