Donor characteristics and hematopoietic stem cell transplantation outcome: experience of a single center in Southern Brazil

ABSTRACT Background: Hematopoietic stem cell transplantation is a curative treatment for many patients with hematological disorders. Donor-recipient genetic disparity, especially involving the human leukocyte antigen system is a critical factor for transplant outcome. Objective: To evaluate retrospectively donor characteristics and correlations with the occurrence of acute and chronic graft-versus-host disease, disease-free survival and overall survival in a Brazilian population submitted to allogeneic hematopoietic stem cell transplantation between 1994 and 2012 in a single center. Results: Three hundred and forty-seven consecutive transplantations were included. Related transplants (81.2%) were significantly more common than unrelated transplants (18.7%); donor and recipient median ages were 34 (range: 1-61) and 33 (range: 3-65) years respectively with donor HLAs being matched for 333 (95.9%) patients. Donor gender, cytomegalovirus status and ABO incompatibility did not influence the five-year overall survival. In univariate analyses, overall survival was negatively influenced by the presence of acute graft-versus-host disease (33% vs. 47%, respectively; p-value = 0.04), unrelated transplant (41.5% vs. 50.9%, respectively; p-value = 0.045) and donors aged over 40 years (41% vs. 52%, respectively; p-value = 0.03). Older donors were associated with a higher rate of acute (52% vs. 65.8%; p-value = 0.03) and chronic graft-versus-host disease (60% vs. 43%, respectively; p-value = 0.015). In multivariate analyses, acute graft-versus-host disease [relative risk (RR): 1.8; 95% confidence interval (CI): 1.1-29; p-value = 0.008] and older donors (RR: 1.6; 95% CI 1.11-2.24; p-value = 0.013) were associated with higher transplant-related mortality. Conclusions: In transplant patients, to have a donor older than 40 years of age seems to significantly increase the incidence of acute and chronic graft-versus-host disease and transplant-related mortality with no impact on disease-free survival and overall survival. In spite of the rather small cohort of patients, these findings are similar to what is described in the literature suggesting that a younger donor should be chosen whenever possible.

Células-tronco mesenquimais: caracterização, cultivo, propriedades imunológicas e aplicações clínicas / Mesenchymal stem cells: characterization, cultivation, immunological properties and clinical applications

As células-tronco mesenquimais (CTM) são consideradas células multipotentes não hematopoéticas com propriedades de autorrenovação e capacidade de diferenciação em tecidos mesenquimais e, possivelmente, em não mesenquimais. Vários estudos recentes têm reforçado o caráter multipotente destas células pela capacidade de diferenciarem-se em células derivadas da mesoderma embrionário: osteócitos, condroblastos e adipócitos. Devido ao fácil isolamento e cultivo, potencial de diferenciação e produção de fatores de crescimento e citocinas, as CTMs têm se tornado as candidatas ideais para os protocolos da medicina regenerativa. Este artigo revisa as principais características dessa célula, forma de obtenção e cultivo, propriedades imunológicas e aplicações clínicas.

Mesenchymal stem cells (MSC) are nonhematopoietic multipotent cells with selfrenewal properties and the ability to differentiate into mesenchymal tissues and possibly nonmesenchymal cells. Several lines of evidence in the past few years have confirmed the ability of these cells to differentiate into cells derived from embryonic mesoderm, such as osteocytes, adipocytes and chondroblasts. Because they are easy to isolate and culture and due to their differentiation potential and production of growth factors and cytokines, MSC have become ideal candidates for regenerative medicine protocols. This study reviews the main characteristics of MSC, how to isolate and culture them, and their immunological properties and clinical applications.