Correlation between flow cytometrically detectable CD41⁺PI⁺ cells and immmunohistochemically detectable CD41⁺ cells. Umbilical cord blood MNCs was cultured for 8 days in culture containing 10 ng/mL rhTPO and either control or ITP plasma. Results were presented as the percentage of the controls. A significant correlation (r = 0.75; P < .0001; n = 62) was found by Pearson analysis.