Cord Blood (CB) APGAR Score May Be Predictive of Transplant Related Mortality (TRM), Overall Survival (OS) and Disease-Free Survival (DFS) for Plasma Depleted/Reduced CB Products

CB potency is important for engraftment potential prediction and transplantation product selection and Nucleated cell (NC), CD34+ cell (CD34), and colony forming unit (CFU) doses have been used to measure such potency. TNC is widely used for CB selection; however its predictive value is not as robust as the progenitor cell measurements. In contrast, CFU and CD34 suffer from high inter-laboratory coefficient of variance - decreasing their utility as potency measures. Recently, the Duke Group proposed a CB APGAR scoring system composed of (a) a Pre-Cryopreserved Score (PCS) reflecting pre-freeze CFU, CD34, NC, and CB collected volume, as well as a (b) Composite Score (CS) which combines the PCS score with post-thaw NC, CD34, CFU and mononuclear cell dose. Based on single, myeloablative and first (SMF) transplants of largely pediatric patients performed at Duke and using mostly red cell reduced (RCR) CB, the PCS and CS scores were shown to be predictive of graft failure, neutrophil and platelet engraftment. Subsequently, the CB APGAR Score was further validated by us recently for engraftment prediction on a patient population with mostly adults, heavy representation of minority and international patients, and on both SMF transplants, and all transplants (All) using plasma depleted/reduced (PDR) CB products. We next examined if PCS and CS can correlate with relapse, transplant related mortality (TRM), overall (OS) and disease free survival (DFS) on the SMF patients transplanted with PDR CB products. The table below shows K-M probabilities of 100-day and 1-Year TRM, 1-Year OS, DFS and relapse for the various PCS and CS strata that had sufficient sample size. There appears to be no correlation between PCS/CS and relapse; however, both scores appear to be predictive of TRM, OS and DFS. We conclude that in addition to its utility as an easy-to-use engraftment prediction tool, the CB APGAR score may be predictive of TRM, OS and DFS for PDR CB transplanted for mixed adult and pediatric populations and for minority and international patients. This observation may further enhance the value of Duke CB APGAR as a reproducible and practical potency measurement for CB selection by transplant centers.Table 1CB APGAR Correlation with TRM, OS and DFS1-Year Relapse100-Day TRM1-Yr TRM1-Year OS1-Year DFSPCS <4.2516.7 ± 15.2%31.9 ± 10.1%31.9 ± 10.1%51.6 ± 10.6%48.9 ± 13.6%PCS ≥4.25 - <5.514.3 ± 13.2%No Events11.6 ± 7.8%79.3 ± 9.3%71.8 ± 14.0%PCS ≥5.5 - <7.75No EventsNo EventsNo Events92.3 ± 7.4%100%CS Score < 13.512.5 ± 11.7%25.4 ± 9.9%31.1 ± 10.7%51.3 ± 11.1%51.2 ± 14.1%CS Score ≥ 13.533.3 ± 27.2%No EventsNo Events82.4 ± 9.3%88.9 ± 10.5%HR (CS ≥13.5 vs <13.5)1.26 (0.08 - 20.61)Not ApplicableNot Applicable0.32 (0.10 - 1.00)0.13 (0.02 - 1.06) Open table in a new tab