[The cord blood bank at the Instituto Mexicano del Seguro Social]

BACKGROUND

Hematopoietic stem cells have been used for over 50 years in the treatment of diverse diseases. Umbilical cord blood (UCB) has proved to be a viable source of hematopoietic stem cells for transplantation purposes. The aim was to report the contribution of the umbilical cord blood bank over the past 9 years, in the treatment of various diseases.

METHODS

Since 2005 the number of units of blood from the umbilical cord and their use for transplantation in diverse disease were analyzed. A selection of volunteer pregnant women in labor was performed. Umbilical cord blood was obtained from them, which underwent processing, cryopreservation and validation, as well as compatibility test before using for transplantation.

RESULTS

Ten thousand and ninety nine candidates to donation were assessed, from whom 2481 unit of UCB were collected. Of these, 893 unit were processed and cryopreserved for transplantation. In 65% of cases there was histocompatibility between the cord cell and the receptors. Transplantation was done in 87 patients, 67% had hematologic neoplasias, who have received 140 units of UCB in 102 transplants. This Bank of UCB ranks second in the world in productivity according to the rate of utility of units in transplantation (3.3%).

CONCLUSIONS

Our bank of UCB has been able to develop a cell line (hematopoietic stem cells) with international quality standards and has been beneficial for patients served by our institution with need of a transplant mainly in hemato-oncologic patients.

Establishing a cord blood banking and transplantation program in Mexico: a single institution experience

BACKGROUND

Over the past decade, umbilical cord blood (UCB) banking and transplantation have increased significantly worldwide. The experience in developing countries, however, is still limited. In January 2005 the Mexican Institute of Social Security (IMSS) initiated its UCB banking and transplantation program. This study reports on the experience generated at this institution during the first 2 years of activities.

STUDY DESIGN AND METHODS

A public UCB bank was established at La Raza Medical Center, IMSS, in Mexico City. Good manufacturing practices and standard operating procedures were used to address donor selection, as well as UCB collection, processing, and cryopreservation. Based mainly on human leukocyte antigen (HLA) and total nucleated cell (TNC) content, specific UCB units were thawed, processed, and released for transplantation.

RESULTS

Based on stringent selection criteria, 360 UCB units were collected from January 2005 to December 2006. A total of 201 (56%) units (minimum volume, 50 mL without anticoagulant) were processed and stored. Median values for specific parameters were as follows: volume, 89.9 mL; viability, 94.8%; TNCs, 0.91 x 10(9); CD34+ cells, 3.13 x 10(6); and colony-forming cells, 1.20 x 10(6). During this period, 10 units had been released for transplantation to seven patients (six children and one adult). Engraftment was observed in five patients; four of them were still in remission (114-293 days after transplant). In spite of showing sustained engraftment, one patient died on Day +88. Two patients showed no engraftment and died 29 to 30 days after transplant.

CONCLUSION

The results obtained during this initial period are encouraging and indicate that the UCB banking and transplantation program at IMSS will help to improve already existing hematopoietic cell transplant programs in Mexico. The experience generated at IMSS may be helpful to other institutions, particularly those in developing countries.

Kinetics of hematopoiesis in bone marrow cultures from patients with chronic myeloid leukemia: effect of recombinant cytokines in dexter-type long-term cultures

Chronic myeloid leukemia (CML) is a hematological neoplasia that results from the transformation of a hematopoietic stem cell. It is characterized by the expansion of the myeloid lineage, which results in the accumulation of mature and immature granulocytes in peripheral blood and bone marrow. However, when CML marrow cells are cultured in Dexter-type long-term cultures (LTMC) hematopoiesis is defective and can be sustained for only a few weeks. One possible explanation for the deficient growth of hematopoietic cells in CML LTMC is that some factors that act as key regulators of hematopoiesis are absent in this experimental system. Thus, we tested this hypothesis by adding recombinant cytokines to these cultures. As a first approach, we added recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF), rhGranulocyte-CSF (rhG-CSF) and rhErythropoietin (rhEPO); each factor was added individually once a week. Addition of rhGM-CSF and rhG-CSF resulted in a significant increase in the levels of nucleated cells and myeloid progenitors; the highest effects were seen in the presence of rhGM-CSF. Interestingly, such a cytokine also induced a significant decrease in the levels of erythroid progenitors. Recombinant hEPO had no significant effects on nucleated cells or myeloid progenitors, however, it induced a significant, although transient, increase in the levels of erythroid cells. The above results indicate that the hematopoietic regulators used here (rhGM-CSF, rhG-CSF and rhEPO) are capable of stimulating the growth of hematopoietic cells in LTMC from CML patients. Thus, this study demonstrates that it is, indeed, possible to manipulate CML LTMC by the addition of recombinant cytokines; this observation may be of particular relevance, since this in vitro experimental system has already been used as a method for purging of leukemic cells in autologous transplant settings. By using specific recombinant hematopoietic modulators it might be possible to make LTMC a more efficient system for such a clinical purpose.

Kinetics of hematopoiesis in Dexter-type long-term cultures established from human umbilical cord blood cells

In the present study, we have established Dexter-type long-term cultures (D-LTC) from human umbilical cord blood (UCB) and followed the kinetics of different hematopoietic progenitor cells (HPCs)--including multipotent (colony forming unit [CFU]-Mixture), erythroid (CFU-erythroid, BFU-E), and myeloid (CFU-granulocyte, CFU-macrophage, CFU-granulocyte/marcophage) progenitors as well as of morphologically recognizable erythroid, myeloid and lymphoid cells--during a nine-week culture period. D-LTC were also established from adult bone marrow (BM) as controls. On day 0, both UCB and BM showed similar total numbers of HPCs (about 310/10(5) cells), however, UCB showed a higher proportion of primitive HPCs (i.e., CFU-Mixture, CFU-granulocyte/macrophage and BFU-E). A poor adherent cell layer, consisting almost exclusively of macrophages, was developed in UCB D-LTC and this correlated with a continuous decline in HPC numbers throughout the culture period. In contrast, adherent cell numbers in BM D-LTC, including fibroblasts and macrophages, were two- to fourfold higher than in UCB cultures, and the numbers of HPCs were also significantly higher, reaching plateau levels between weeks 6 and 9. In both types of cultures, erythroid and multipotent progenitors declined relatively fast, reaching undetectable levels after five weeks of culture. Myeloid progenitors, on the other hand, were sustained longer (always at higher levels in BM cultures) and were still detected by week 9. Among myeloid progenitors, a shift towards the predominance of macrophage HPCs was observed, both in UCB and BM D-LTC, and this correlated with an increase in the proportion of mature monocytes and macrophages. Taken together, our results indicate that myeloid progenitor cell growth is deficient in UCB D-LTC and suggest that this is due to the impaired development of an adherent cell layer, unable to provide the factors and conditions required for their growth. Interestingly, throughout the culture period the total numbers of multipotent and erythroid progenitors were similar both in UCB and BM cultures regardless of the number and types of adherent cells present; this suggests that the stroma developed in D-LTC is not sufficient for the proliferation of these progenitor cells.