PB2372 THE CORRELATION AND PREDICTIVE VALUE OF IMMATURE PLATELET FRACTION TO PLASMA PLATELET RECOVERY IN PATIENTS RECEIVING AUTOLOGOUS STEM CELLS TRANSPLANTATION
Authors: S. L. Chong, S. Tan, G. Chong, K. Law, K. Chang
Journal: HemaSphere (2019)

Background: Engraftment is a critical milestone of the hematopoietic stem cell transplantation process. The immature platelet fraction (IPF) are considered early indicators of bone marrow recovery. Aims: The objective of this study was to assess this parameter as predictors of autologous stem cell transplantation. Methods: The cross-sectional study was conducted at Ampang Hospital from June 2016 to January 2019, and included 30 autologous transplant patients with various hematologic malignancies. The results of post-transplant IPF and PLT were traced from the hematology laboratory, and validated by a hematologist before analysis. The role of IPF towards post-transplant PLT recovery was investigated by using parameters such as transient increase in IPF (%), time to transient increase in IPF (days), and 7 days mean IPF (%), towards PLT engraftment (days), lowest PLT, time to lowest PLT (days), PLT recovery (%), and PLT recovery time (days) from transplant day and lowest PLT. The degree of correlation was determined based on the Cohen's convention (1988). Patients with incomplete results (more than 50% missing data) were excluded from the analysis. Results: The median age of the cohort was 37 years, ranging from 18 to 67 years. The conditioning regimens used for autologous transplant included BEAM (69.6%), high dose melphalan (21.7%) and Bu/TT/Cy (8.7%). The mean of PLT engraftment was 11.4, ranging from 10.7 – 12.0 days after autologous transplantation. The cohort presented a mean value of 5.43% for transient increase in IPF, 4.7 days for time to transient increase in IPF, and 3.67% for 7 days IPF. The mean values in relation to PLT recovery were 14.40 × 109/L for lowest PLT, 5.3 days for time to lowest PLT, 225% for PLT recovery, and 6.9 days for PLT recovery time from transplant day and 1.7 days for PLT recovery time from lowest PLT. Statistically significant and positive correlations were found in the transient increase in IPF towards the PLT recovery time from the lowest PLT achieved in transplant patients (r = 0.6141, p = 0.0114); in the transient increase in IPF towards the PLT recovery time from transplant day (r = 0.6028, p = 0.0135); in post-transplant 7 days mean IPF towards the PLT recovery time from the lowest PLT achieved in transplant patients (r = 0.7450, p = 0.0014). A negative correlation was found in the time to the transient increase in IPF towards the PLT recovery time from the lowest PLT (r = –0.5245,p = 0.0370). The degree of the above correlations were considered strong (|r| > 0.5). Summary/Conclusion: The generation and release of IPF, as part of hematopoietic activity seemed to be predictive and correlated with the PLT recovery time. A transient increase in the IPF preceded the PLT recovery by approximately 2 days and may be used to predict PLT recovery in patients receiving autologous transplantation. The longest time to have a transient increase in the IPF, the shortest time required for PLT to bounced back from its lowest level.