Peripheral Blood Progenitor Cell Transplantation Estimated by Three-Colour (CD34, HLA-DR, CD33) Flow Cytometry

Abstract

The relationships between transfused cell number of CD34+ cell subpopulations divided by HLA-DR and CD33 antibodies and hematopoietic recovery patterns after peripheral blood progenitor cell transplantation (PBPCT) subsequent to myeloablative chemoradiotherapy were investigated in 14 children with cancer. Both logarithm of transfused CD34+ cell number/10⁶/kg and logarithm of transfused cell number/10⁶/kg of the CD34+HLA-DR+CD33+ sub-population, which is supposed to be myeloid-committed cells, were correlated with myeloid recovery after PBSCT, though they were not correlated with erythroid or platelets recovery. On the other hand, logarithm of transfused cell number/10⁶/kg of CD34+HLA-DR-CD33- subpopulation, which is supposed to be immature progenitor cells, was not correlated with myeloid recovery but correlated with erythroid recovery and platelet recovery. These results suggested that rapid myelopoiesis after PBPCT occurs following transfusion of sufficient numbers of myeloid-committed cells and complete hematopoietic reconstitution occurs after transfusion of sufficient numbers of immature hematopoietic progenitor cells.

Role of the CD34+38− cells in posttransplant hematopoietic recovery

“…However, many investigators did not find any linear correlation between the number of infused CD34' cells and neutrophil engraftment, and had instead attempted to define CD34' cell threshold values above those where prompt engraftment occurs with increasing confidence. Threshold CD34' cell values varying from 2 to 5 X 106/kg have been suggested to be necessary to achieve rapid neutrophil and platelet recovery from BC infusion [5,10,[13][14][15]. In fact, our present study found a linear correlation between the time to recovery of PB cell counts postautograft and the absolute number of CD34' cells in the graft.…”

“…Most investigators now insist on the powerful predictive role of the graft content in CD34' cells in optimally predicting the rapidity of the further engraftment kinetics [4,5,10,131. However, many investigators did not find any linear correlation between the number of infused CD34' cells and neutrophil engraftment, and had instead attempted to define CD34' cell threshold values above those where prompt engraftment occurs with increasing confidence.…”

A European reference protocol for quality assessment and clinical validation of autologous haematopoietic blood progenitor and stem cell grafts

“…The resulting Milan/Mulhouse manual is still a valuable procedure reference in laboratory practice. 9,10 The subsequent years have resulted in several publications about the standardisation of flow cytometry analysis [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] as well as reports on the clinical implication of the enumeration of CD34 ϩ cells. 24,[26][27][28][29][30][31][32][33][34][35][36][37] The CD34 antigen is stage-specific and identifies cells in the early stages of haemopoietic differentiation.…”

“…In the first phase, the CD34 technique was established in the laboratory and analysed for specificity, sensitivity, reproducibility and accuracy. [5][6][7][8][9][10][16][17][18][19][20][21][22][23][24][25][26] The subsequent second phase, documented a likely clinical influence by single centres analysing retrospective material/data. [27][28][29][30][31][32][33][34]36,37 The third phase prepared convincing single centre prospective evaluation [51][52][53][54][55][56][57][58] evolving into the most important phase four, a multicentre prospective evaluation based upon important clinical end-points (Table 2).…”

“…Ideally, phases II-III document the usefulness, convincing one or more centres to participate in a phase IV validation trial, which however in this A European Reference Protocol on CD34 ϩ cell enumeration (Table 3) Recently, several reports have presented protocols on flow cytometry enumeration and several companies have announced standard kits for absolute enumeration of CD34 ϩ cells. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] These protocols seem different at several levels depending on the designer and none has been proved superior to the others, if it fulfills 'the state-of-the-art' recommendation. The major conclusion from the work done over the last decade is that training diminishes the interlaboratory variations with only minor differences between first-and second-line strategies.…”