Demographic and Clinical Donor Characteristics as Predictors of Total Nucleated Cell Concentrations in Harvested Marrow Products.

Abstract

BACKGROUND\nSuccessful allogeneic hematopoietic stem cell transplantation (alloHSCTs) relies significantly on adequate allograft cell composition to achieve sustained engraftment, and a minimum of 2\u202f×\u202f108 total nucleated cells (TNC) per kilogram (kg) of the recipient body weight has been determined as the pre-requisite cell dose for successful engraftment of marrow-derived products. To meet this minimum requirement, marrow harvest volumes are estimated based on anticipated TNC concentrations of 18.3\u202f×\u202f106 per milliliter (mL). However, there is considerable variability in marrow TNC concentrations. Thus, an algorithm that incorporates baseline donor characteristics to predict TNC concentrations could optimize outcomes for both donors and recipients.\n\n\nMETHODS\nDonor baseline characteristics and corresponding unstimulated marrow products harvested between 2004 and 2017 at a single large volume donor center were collected. Multivariable analysis was used to identify significant predictors of TNC concentration. Two models (ordinary least squares (OLS) and least absolute shrinkage and selection operator (LASSO) regression) were compared for their fitness to the data, and their utility in predicting TNCs.\n\n\nRESULTS\nDonors with higher BMIs, younger age, male sex, White race/ethnicity, smaller harvest volumes, lower pre-harvest hematocrit, higher pre-harvest platelet count and higher pre-harvest white blood cell count predicted significantly higher TNC concentration of marrow products. When comparing predictive models that incorporate these characteristics, the cvLASSO and bootstrapped OLS provided the best fit. We now supply these formulae to be validated in other datasets prior to clinical use.\n\n\nCONCLUSIONS\nTNC concentration in marrow products can be predicted using donor characteristics, most of which are readily available during the donor clinical assessment. The ability to predict marrow allograft TNC concentrations can optimize collection volumes during a harvest.