Growth of erythroid cells from thawed unseparated cord blood in vitro without exogenous erythropoietin.

INTRODUCTION: Previous erythroid cell cultures have depended on added serum or erythropoietin. In this paper, the growth of erythroid cells from thawed unseparated cord blood units in vitro without serum or exogenous erythropoietin is reported. METHODS: Thawed volume-reduced cord blood was cultured in conditions designed to support the megakaryocytic lineage, with thrombopoietin and interleukins 3 and 6. Erythroid cells were detected with glycophorin A (GlyA), CD71, and benzidine (flow cytometry and immunocytochemistry). RESULTS: Nucleated and anucleated GlyA-positive, as well as benzidine-positive cells were observed from day 9. In flow cytometry, at days 0 and 9, 5.9% and 14% of all events were GlyA+, and 14% and 53% were CD71+, respectively. At days 0 and 9, 4.5% and 12% of the events were double-positive for GlyA and CD71, respectively. By day 14, the percentages of GlyA+, CD71+ and double-positive events had started to decrease (9.7%, 35%, and 5.3%, respectively). CONCLUSIONS: Erythroid cells were generated from thawed unseparated cord blood units without exogenous erythropoietin. Thawed cord blood possesses the potential for erythroid growth in vitro in a culture medium designed for other cell types.

Association of stress-related perinatal factors and cord blood unit hematopoietic progenitors is dependent on delivery mode.

BACKGROUND: Perinatal characteristics, variably utilized in cord blood (CB) selection for banking, affect CB hematopoietic progenitor cells (HPCs). The association between perinatal stress factors and CB unit HPCs was evaluated. STUDY DESIGN AND METHODS: Umbilical arterial (UA) pH, absolute and relative birth weight (BW) and placental weight (PW), and PW/BW ratio of 167 healthy, full-term infants were compared with CB unit prefreeze total nucleated cells (TNCs), total CD34+ (TCD34+) cells, and total colony-forming unit (CFU-TOT) number. Cesarean section (C-section, n = 104) and vaginal delivery subgroups were also analyzed. RESULTS: UA pH (median, 7.28; range, 7.04-7.40) correlated with CB unit CFU-TOT number (n = 166; r = -0.32, p < 0.0001), TCD34+ cells (r = -0.31, p < 0.0001), and TNCs (r = -0.29, p = 0.0002). Similarly, BW, PW, and PW/BW ratio correlated with HPCs. In multiple linear regression analysis, CFU-TOT number was predicted by collected CB TNCs and UA pH in vaginal deliveries (R(2) = 0.53), in contrast with TNCs, PW, and BW in C-sections (R(2) = 0.37). TCD34+ cells were predicted by adding UA pH (vaginal deliveries, R(2) = 0.75) or PW (C-sections, R(2) = 0.36) to collected CB TNCs. CONCLUSIONS: Stress-related perinatal factors, particularly UA pH, are associated with CB unit HPCs and may improve unit selection. Multiple linear regression models may prove useful for predicting HPCs. Mode of delivery affects model choice; UA pH has a strong effect on HPCs in vaginal deliveries.

Association of cord blood platelet characteristics and hematopoietic progenitor cells.

BACKGROUND: Total nucleated cell (TNC) dose is associated with neutrophil and platelet (PLT) engraftment after cord blood (CB) transplantation and thus is used for selection of CB for banking. The goal of this study was to evaluate the internal relationships of CB PLT characteristics, TNC, and the hematopoietic progenitor cell (HPC) content of CB units. STUDY DESIGN AND METHODS: HPC and TNC counts of 167 CB units processed with an automated cell separation system were compared with CB PLT count and mean PLT volume (MPV). Megakaryocyte progenitors (CFU-MK) were cultured from a subset of units (n = 24). RESULTS: PLT concentration correlated with MPV (r = -0.39), which was also associated with both TNC and total CD34+ cells before and after processing (r = 0.37 and 0.35 and r = 0.41 and 0.42, respectively). In addition, MPV was associated with HPC counts in the CB unit. The p value was less than 0.001 for all associations. PLT count was inversely associated with markers of hematopoietic potential. Median removal of PLTs during processing was 62 percent (range, 40%-84%). All 24 CB units of the subset exhibited CFU-MK growth. In multivariate linear regression analysis, MPV improved prediction of the HPC content of the CB unit compared to prediction with CB volume and nucleated cell concentration only. CONCLUSION: Mean PLT volume correlated with current markers of CB hematopoietic potential and is potentially useful for evaluating CB collections for banking. The question of the clinical significance of PLT characteristics in CB transplantation remains unanswered.