[The subpopulation of CD34+ cells and their importance in the healing of grafts in family-related allogenic transplants of peripheral stem cells]. / Subpopulace CD34+ bunek a jejich vyznam pro prihojeni stepu u príbuzenských alogenních transplantací periferních kmenových bunek.

CURRENT STATUS: The determination of concentration of CD34+ cells is the standard method for evaluation of the quality of a bone marrow graft and of peripheral stem cells. Although the relationship between the dose of CD34+ cells and the speed of graft healing in autologous transplants is a proven fact, it may not always be the case in allogenic transplants. PATIENTS AND METHOD: The correlation between the dose of CD34+ cell subpopulations and the speed of healing was monitored in patients indicated for allogenic transplantation of haematopoietic stem cells. The patients were divided according to the type of preparatory regimen they underwent for the purpose of analysis; one group contained those under a myeloablative regimen; a second group contained those under a non-myeloablative regimen. The data was subject to analysis of variance in regression models and non-parametric tests. RESULTS: From among the monitored subpopulations, CD34+36+ cells had the greatest effect on the healing process and were the most significant predictor of the speed of healing in patients under a myeloablative regimen. Nevertheless, a dose ofCD34+ cells continued to be the best healing predictor in patients under a non-myeloablative regimen. Also subpopulations of CD34+38+ and CD34+61+ cells had a significant effect on the speed of healing in both groups. CONCLUSION: Haematopoietic stem cells and progenitor cells defined by co-expression of specific antigens are likely to play a role, through different mechanisms of action, in the process of healing in patients in different pre-transplant regimens. While the dose of CD34+ cells is still the one which correlates best with the speed of healing in patients who underwent transplantation after non-myeloablative regimen, the dose of CD34+36+ cells appears to be a better predictor for the speed of healing after myeloablative regimens.

[Density expression of the CD20 antigen on population of tumor cells in patients with chronic B-lymphocyte lymphoproliferative diseases]. / Denzita exprese antigenu CD20 na populaci nádorových bunek u pacientu s chronickými lymfoproliferacemi B-lymfocytární rady.

BACKGROUND: Rituximab is being used successfully in the treatment of patients with chronic B-cell lymphoproliferative diseases. The success of treatment by rituximab is influenced, among other factors, by the antigen density on tumor cells. Therefore, the authors analyzed and compared the densities of the CD20 antigen in patients with chronic lymphoproliferative diseases. METHODS AND RESULTS: Previously untreated patients with B-chronic lymphocytic leukemia (B-CLL), mantle-cell lymphoma (MCL), and small-cell lymphocytic lymphoma (SCLL) were evaluated by flow cytometry. The control group consisted of blood donors. The CD20 density was measured on tumor cell populations in patients and on the B-lymphocytes of the control group. The density was expressed in MESE In the patients with B-CLL and SCLL, the CD20 density was low (25,300 vs. 36,100 MESF) and it was significantly lower than in donors (172,800 MESF; p<0.001). The difference between B-CLL and SCLL patients was not statistically significant. The density in MCL patients (196,300 MESF) was comparable to that of donors. CONCLUSIONS: We did not prove statistical different density of CD20 antigen in patients with SCLL when compared with B-CLL patients. High density in MCL patients may be helpful in differential diagnosis against B-CLL and

[Analysis of phenotypes and kinetics of CD34+ cells and lymphocytes in donors of hematopoietic stem cells for allogenic transplantation]. / Analýza fenotypu a kinetiky subpopulací CD34+ bunek a lymfocytu dárcu periferních hematopoetických kmenových bunek pro alogenní transplantace.

BACKGROUND: Amount of CD34+ cells is a critical parameter for quality assessment and successful engraftment of peripheral blood hematopoietic stem cells (PBSC) during the transplantation of haemopoisis. CD34+ cells are routinely analysed by immunophenotyping in PBSC and in peripheral blood during mobilization. Other leukocyte subpopulations are not usually assessed. METHODS AND RESULTS: The authors present results of immunophenotyping of subpopulations of CD34+ cells and leucocytes in samples from donors of PBSC for allogeneic transplantations, who were stimulated with the growth factor G-CSF at dose 16 micrograms/kg/day. The amount of CD34+ cells was not significantly different between days 4 and 5; however, there was a significant drop at day 6. CD34+90+ and CD34+61+ subpopulations reached their maximum at the day 4; partially differentiated CD34+ cells with co-expression of CD33, CD19, and CD7 reached maximum at the day 6. CD4+ Th-lymphocytes were concentrated in the grafts during leukapheresis, CD4/CD8 ratio in the grafts was increased to average 3.06. CONCLUSIONS: The knowledge of kinetics of CD34+ subpopulations, together with stem cell selection and ex vivo manipulation, may have an impact on the speed of engraftment or GvHD prevention in transplanted patients.