ABSTRACT
ABSTRACT Introduction and hypothesis: Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells for allogeneic hematopoietic stem cell transplantation in the absence of a compatible donor. The UCB transplantation has a lower incidence of chronic graft versus host disease (GvHD), but is associated with slower engraftment and slower immune reconstitution, compared to other sources. Dendritic cells (DCs) and Natural Killer cells (NKs) play a central role in the development of GvHD and the graft versus leukemia (GvL) effect, as well as in the control of infectious complications. Method: We quantified by multiparametric flow cytometry monocytes, lymphocytes, NK cells, and DCs, including their subsets, in UCB samples from 54 healthy newborns and peripheral blood (PB) from 25 healthy adult volunteers. Results: In the UCB samples, there were higher counts of NK cells 56bright16- (median 0.024 × 109/L), compared to the PB samples (0.012 × 109/L, p < 0.0001), NK 56dim16bright (median 0.446 × 109/L vs. 0.259 × 109/L for PB samples, p = 0.001) and plasmacytoid dendritic cells (pDCs, median 0.008 × 109/L for UCB samples vs. 0.006 × 109/L for PB samples, p = 0.03). Moreover, non-classic monocyte counts were lower in UCB than in PB (median 0.024 × 109/L vs. 0.051 × 109/L, respectively, p < 0.0001). Conclusion: In conclusion, there were higher counts of NK cells and pDCs and lower counts of non-classic monocytes in UCB than in PB from healthy individuals. These findings might explain the lower incidence and severity of chronic GvHD, although maintaining the GvL effect, in UCB transplant recipients, compared to other stem cell sources.
Subject(s)
Fetal BloodSubject(s)
Humans , Female , Aged , Leukemia, Plasma Cell , Waldenstrom Macroglobulinemia , Flow CytometryABSTRACT
ABSTRACT Chronic lymphocytic leukemia is characterized by clonal proliferation and progressive accumulation of B-cell lymphocytes that typically express CD19+, CD5+ and CD23+. The lymphocytes usually infiltrate the bone marrow, peripheral blood, lymph nodes, and spleen. The diagnosis is established by immunophenotyping circulating B-lymphocytes, and prognosis is defined by two staging systems (Rai and Binet) established by physical examination and blood counts, as well as by several biological and genetic markers. In this update, we present the recommendations from the Brazilian Group of Chronic Lymphocytic Leukemia for the diagnosis and treatment of chronic lymphocytic leukemia. The following recommendations are based on an extensive literature review with the aim of contributing to more uniform patient care in Brazil and possibly in other countries with a similar social-economic profile.