Total nucleated cells as a sole predictor of distinct targets of hematopoietic potential (CD34+ cells) in cord blood units: the results of a large series analysis in autologous cord blood units

Background Rapid identification of eligible cord blood units (CBUs) for banking is an important issue in hematopoietic stem cell procurement. Distinct contents of CD34+ cells in CBU can contribute to identify grafts that may be banked also for unrelated transplants or limited to family-directed or autologous use. Study Design and Methods Considering thresholds of CD34+ cell content of 3 × 106, 2 × 106, and 1 × 106 CD34+ cells, we analyzed a consecutive series of 1309 CBUs. CBUs were collected for autologous banking without any volume-based preselection criteria. Predictors of distinct content of CD34+ cells have been assessed by receiver operating characteristic (ROC) curve analysis. Results Median total nucleated cell (TNC) and CD34+ cell counts of the series were 6.97 × 108 (range, 0.36 × 108-34.9 × 108) and 1.47 × 106 (0-20.56 × 106). Volumes ranged from 21 to 163 mL, with a median of 73.8 mL. For the CD34+ target of 1 × 106, the best predictor was TNC count with a threshold of 6.63 × 108; volume results were less predictive with a value of 68.1 mL. For CD34+ targets of 2 × 106 and 3 × 106, ROC curves confirmed a stronger predictive power of TNC, above the collected volume, with thresholds of 7.55 × 108 and 8.98 × 108. ROC analysis by combining all predictors (TNC, volume, TNC2, volume2, age of mothers, types of delivery, birthweight) gave worse results than TNC count alone. Conclusions This analysis, carried out on a large, unrestricted CBU series, shows that TNC alone is the best predictor of distinct targets of hematopoietic potential with the chance to predict CBU potentially useful for unrelated recipients or limited for family-directed or autologous use.