Impact On Mother-Baby Parameters in Total Nuclear and CD34+ Cell Count in Umbilical Cord Blood Banking.

Umbilical cord blood (UCB) has become an easily, available and viable source of hematopoeitic stem cells for transplant. The main limitation factor for its wide use is cell dose. Previous studies have showed that certain physiological parameters pertaining to either the baby or the mother impact in the UCB cell yields.

The aim of our study was to compare five physiological parameters pertaining to the mother or baby (mother`s age [MA], gestational age at delivery [GA], baby`s gender [G], baby`s birth weight [BW] and type of delivery [TD]) with total nuclear cells (TNC) and CD34 + cells recovery. We also evaluated the impact of time from collection to processing (TCP) on CD45+ cells viability.

UCB product collection was performed after the baby's delivery, while the placenta was still in uterus, either from vaginal or cesarean deliveries. Collection bags that were used contained 35 mL of CFDA-1 (CFD with Adenina) as anticoagulant. Cord blood units (CBU) were processed in our institution under local and international regulations regarding cord blood banking. Usual techniques with HES 6% for red cell depletion and 4°C centrifugation for plasma depletion were used. Twenty-five ml, EVA, two-compartment cord blood cells freezing bags (Pall Medical) were used for a final CBU volume of 20.5 ml combined with Dextran 40/40 and DMSO for cryopreservation. A sample was removed for flow cytometric analysis (BD FACSCan) and to determine the TNC (Cell-dyn 1200). Cultures pre and post CBU handling were done. Freezing took place in a controlled-rate freezer according to standard protocol before storage in liquid nytrogen.

From May 2004 to Jun 2009, a total of 4,262 continous UCB collections were performed in our institution throught the Peruvian Republic. Seventy-eight percent of the CBU were collected by cesarean; median TCP was 30 hours 58 minutes. The mean CBU volume and TNC count were 81.8 ml and 8.63 × 108 respectively. The colected volume was greater in cesarean than vaginal delivery (85.3 ml vs 78.9, F=30.82, p<0.001). TNC counts collected were directly correlated with GA: in preterm delivery (<37sem) was 7.13×108, in term delivery (>=37sem) was 9.93×108. TNC counts were directly correlated with BW (F=325, p<0.001) while the MA had inverse correlation (F=8.05, p=0.005); regarding TD there was a significant mayor TNC count in the vaginal vs. cesarean group (10.49×108 vs. 9.22×108, F=48.207, p<0.001); while it was a trend for major TNC count in females vs. males babies (9.82×108 vs. 9.13×108, p=0.059). CD34+ cells count was directly correlated with BW (F=70.1, p<0.001). The strongest correlation was with GA (in preterm: 61.99 CD34+/ul and in term delivery: 84.67 CD34+/ul, F=27.62 p=<0.001); moreover, there was association between CD34+ cells count with TD (vaginal: 87.88 CD34+/ul vs cesarean: 80.26 CD34+/ul, F=5.327 p=0.02). There was not association either with G (females: 79.97 CD34+/ul vs males: 83.48 CD34+/ul, F=1.668 p=0.197) neither MA (F=1.82, p=0.177). There was a significant difference between CD34+ viability cells among CBU with less than 48 hours or more of TCP (99.6% vs. 99.4%, p=0.019); this difference was stronger when the CD45+ viability was evaluated (93.35% vs. 90.14%, p<0,001).

TNC and CD34+ UCB cells are influenced by many variables related to the mother and the baby. It looks like on time female babies with good weight, born to a younger mother and from a vaginal delivery reach highest TNC count. CD34+ cells count was directly correlated with BW and CD34+ viability is mainly influenced by the time from collection to processing

No relevant conflicts of interest to declare.