With only a few exceptions, parents who decided to have their children participate in the infusion study exhibited similar demographic and cord blood storage characteristics as parents who declined to have their children receive infusion. Children who did not receive infusion were diagnosed with T1D for 1.5 more years than those who received infusion. It is plausible that these parents thought that the longer duration of their child’s diabetes combined with the experimental nature of the study would not result in outcomes worthy of using the stored cord blood. Our sample was also comprised of families who had higher socioeconomic backgrounds who likely had more disposable income. However, children who did not receive infusion were more likely to have both parents working outside of the home, which may have impacted their flexibility about taking time off from work and willingness to travel long distances to participate in the infusion study.
Almost all of the parents who decided to have their children participate in the infusion study had an available supply of their child’s umbilical cord blood which was stored in a private cord blood bank. There was one exception – a family donated their child’s umbilical cord blood to a public bank and was able to retrieve it for use in the infusion study. Given the current costs associated with privately banking cord blood, it may be that the demographic characteristics of samples comprising umbilical cord studies will be restricted to those with the financial means to store their child’s cord blood. Alternative paradigms such as a combined public-private cord blood storage partnership could not only provide affordable storage options to all parents, but could also result in increased participation in future umbilical cord blood based studies as the science of autologous cord blood therapies advances.
Overall, attitudes about research were positive. Many of the parents from both groups (children who received infusion and those that did not) who completed our survey indicated that they had participated in prior research studies. Although a small proportion learned of the infusion study from their child’s physician, the majority of parents learned about the study by conducting an internet search of ongoing research studies. This suggests that parents who stored their children’s cord blood were highly motivated, but that there may also be untapped potential participants who are not aware of such studies or who do not have available resources to find studies.
Upon entry into the infusion study, parents who decided to have their children participate were explicitly informed, and great care was taken to ensure their understanding that infusion would not lead to a cure of T1D. Yet, almost 50% of the parents who decided to have their children receive infusion indicated that one of the reasons they enrolled was based on hope that their child would be cured. This highlights that despite our best efforts to minimize expectations, parents were optimistic for a cure. Although this may be a common parental reaction, investigators need to be aware that many parents will hope for a cure even when curing the disease is not the focus of the study [13
There were a few important consequences of parents’ decisions to have, or not have children undergo infusion. All parents were faced with having to potentially exhaust their supply of cord blood and this dilemma remained the primary reason cited for those who declined to have their children receive infusion. The most common private cord blood storage techniques currently involve storage of 80% or more of the total nucleated cells initially collected in one vial with the remaining 20% being stored in two smaller aliquots typically reserved for testing of sterility, viability, and human leukocyte antigen confirmation. Because current Food and Drug Administration approved protocols do not allow thawing and refreezing a portion of cells, families participating in our trial were often faced with the dilemma of using 80% or more of their child’s cord blood. Notably, however, 50% of the parents who enrolled in the infusion study had cord blood remaining upon completion of the study and chose to continue storing it despite the fact that it was often too few cells to be used for current standard of care therapies. The experimental nature of the study was another reason cited for declining infusion. Although parents who declined to have their children participate in the infusion study were positive and optimistic about the general benefits of research and its potential to cure T1D, they were also generally satisfied with their decision to decline infusion. Those who consented to have their children undergo infusion were also satisfied with their decision – even if they exhausted their supply of umbilical cord blood. In addition, the majority of parents who did not deplete their child’s cord blood supply indicated that they would consider being in another study that required its use.
Nevertheless, the manner in which umbilical cord blood is currently stored has implications for the design of future studies. Many of the parents who declined to have their children undergo infusion stated they would have participated in the infusion if multiple aliquots had been available. Once cell expansion techniques are perfected, storage of multiple aliquots could allow parents to participate in a research study while preserving some of the supply for future use. In fact, parents who declined to have their children undergo infusion also indicated that they were worried about using their entire supply of cord blood on an experimental study that might not lead to a cure, which would eliminate them from being able to participate in a future study that could lead to a cure. Companies and public storage facilities may need to consider storing multiple aliquots so that parents have more options regarding allocation of their children’s cord blood. In the combined public-private cord blood storage partnership previously mentioned, donors might be required to participate in a national or international registry and release units for allogeneic use in patients in whom the unit could provide a standard of care therapy. At the same time, donors would be given the option of retrieving their own unit should relevant autologous cord blood based therapies be developed.
Limitations of the current study are noteworthy. Rates of participation in the current study were lower for those who declined infusion as compared to those who received infusion, which limits the generalizability of the sample. In addition, children were in generally good metabolic control and they engaged in frequent blood glucose monitoring, which suggests a self-selection bias and also limits the generalizability of participants who seek participation in cord blood studies. Although participation in the infusion study required lengthy travel, multiple study visits, and missed work days, more than 95% of parents who decided to have their children participate indicated that they liked being in the study and that their decision to participate was a good one. As evidenced by the high satisfaction ratings in this survey study, parents of young children with T1D are eager to explore safe and potentially effective therapies to interdict the autoimmune process. That said, lack of clear efficacy data, cost of private cord blood storage, and limited cell number for both current and future studies, result in difficult decision making processes for parents of children with T1D. While our efforts are not yet able to provide clear direction for these families, these data establish a baseline for parental concerns and experiences for participation in cell based therapies in children with T1D.