Typology and applications

Types of STEM cells

Hematopoietic stem cells are the first and only category of stem cells, which to date has demonstrated its clinical therapeutic part. The practice of over 40 years, as well as the thousands of patients treated annually by hematopoietic stem cell transplantation confirm the importance of this therapeutic resource especially in the field of hematology, but also of some genetic diseases or malignancies.
Hematopoietic stem cells are the cells that form the basis for initiating hematopoiesis, i.e. the mix of mechanisms that ensure the continuous and regular replacement of blood cells (red blood cells, white cells and platelets).
In physiological conditions, after birth hematopoiesis takes place only in the hematogenic bone marrow present in flat bones (sternum, pelvic bones)

Sources of hematopoietic stem cell grafts:


Currently there are 3 main accepted sources of hematopoietic stem cell grafts: bone marrow, peripheral blood and cord blood.
The bone marrow was the first identified source of hematopoietic stem cells. Given that 2/3 of the patients with indication of making a bone marrow stem cell transplantation, failed to identify an immunologically compatible donor in their family, or in public records, or to obtain the graft in due time, another source of hematopoietic stem cells was looked for.

Cord blood was identified, although it had been classically considered to be a “biological waste”.
Mesenchymal stem cells is another category of stem cells, identified and isolated in the bone marrow, in cord blood, adipose tissue (fat), creating a cell diversion: fibroblasts, fat cells, cartilage cells, bone, etc.. This category of stem cells is much lower in number as compared to hematopoietic stem cells.

Stem cell therapeutic indications for use:
Standard indications for the use of hematopoietic stem cell grafts contain more than 70 diseases, most of these being haematological malignancies (eg Acute or chronic leukemia, Hodgkin or non-Hodgkin's lymphoma) or non malignant haematological diseases, but characterized by the severity of symptoms and evolution. (eg Cooley major anemia;Congenital Fanconi anemia).
Immune deficits (ex.SCID - severe combined immunodeficiency) and hereditary metabolic diseases (e.g. Gaucher disease, Krabbe disease). In these cases the indication of making transplantation has curative intent for healing can be added to these.
But there is also the possible indication of making the transplantation for adjuvant ends, complementary to the standard treatment for cancer. This is also the case of malignant solid tumors (e.g. Neuroblastoma, retinoblastoma). In these situations the existence of a stem cell graft allows the initiation of a more aggressive chemoradiotherapy treatement (in higher doses) in order to reduce the incidence of tumor recurrence or metastasis.

Over the past 10 years, in medicine there has been a significant increase in the activity of stem cell research. Its purpose is to deepen knowledge on the cellular properties unique to stem cells to extend the possibilities of their therapeutic application in other medical fields, apart from the haematological field.

These studies also include the other types of stem cells (e.g. Mesenchymal stem cells) apart from the hematopoietic stem cells, assessing the peculiarities and similarities between them, to identify the best therapeutic solutions. All this research activity has allowed the foreshadowing of a new field in medicine, that is tissue and organic regenerative medicine, considered by some researchers as the medicine of the future.