Umbilical Cord Blood statistics
The number of cord blood donations either to public or private bank is rapidly growing in the USA and all over the world.
UCB donation numbers and statistical data
By taking in consideration statistical data relative to CB application and to histocompatibility between cell donors and recipients, it is possible to provide some useful informations about the importance of CB-SCs for transplantation procedures in regenerative medicine [48]. The high efficiency recovery relative to all functional types of CB-derived-SCs has been stated formally in literature [32; 45; 48; 49]. Today, it is not possible to establish which is the real number of CB donations in the world, but it is possible to report some highly respectable data relative to trustworthy experiences by remarkable Scientific Institutions such as Scientific Societies, for instance:
- Eurocord (http://www.eurocord.org/),
- Netcord
- National Cord Blood Program (http://www.nationalcordbloodprogram.org/). The donations numbers relative to Eurocord are 300000 (http://www.eurocord.org/) and the close collaboration with Netcord CB banks and EBMT centers, starting from 1988 to March 2009, has reported 5223 CB transplantations to the Eurocord registry from 238 EBMT (68% of cases) and 199 non-EBMT (29% of cases) centers from 47 European and non European countries [50](http://www.eurocord.org/).
Eurocord database increases each year with approximately 400 cases reported [50] (http://www.eurocord.org/), but it is important to report that BMDW has declared that in its own database there are 400000 UCB unit available [51] (http://www.bmdw.org/). The inventory numbers relative to Netcord are available: at June 2009, the inventory NETCORD/FACT accredited are 131424 unit; the inventory not NETCORD/FACT accredited are 65111 unit, total inventory 196535 unit; 6353 UCB unit NETCORD/FACT accredited have been released for transplantation procedures, while 2042 UCB unit not NETCORD/FACT accredited have been released for transplantation procedures, total UCB unit released for transplants is 8395 (https://www.netcord.org/inventory.html). National Cord Blood Program has reported that the harvested donations are 33000 unit. This Scientific Institution has declared that the number of CB transplants throughout the world are 6000 thus far 2008 (http://www.nationalcordbloodprogram.org/). These data are relative to CB public banks with references relative to related or unrelated allogeneic transplantation procedures [50]. CB-SCs can be cryopreserved also in private banks: in this case, the decisive good deed is between storage for autologous or eterologous use [40]. The collections performed in private CB banks as autologous preservation are not reported as public data, while the ones accredited as eterologous donation are reported to the public database registry. The total UCB units released by private CB banks for autologous, allogeneic and supportive autologous transplantations, thus far September 2009, are 392. Each year about 1.5 million people develop diseases curable with CB-SCs, but in the world 95% of UCB units are thrown away as biological discard yet [50; 52] Another discriminant pushing for the storage of UCB is the probability to find a compatible UCB or BM for transplantation, which range is from 1/50000 to 1/100000 [52].
UCB outcome
All outcomes relative to CB-SCs transplantations are due to their own intrinsic features and to 20 years experience formally stated in literature [51]. The first positive outcome has been provided by Gluckman E. et al. in 1989 [53]. The hematopoietic reconstitution by means of CB-SCs HLA-identical sibling in a child with Fanconi’s anemia was a brilliant success also in follow-up [51]. By the way, to date CB-SCs have been established as curative for a very heteroegenous panel of selected malignant and non-malignant pathologies [54], but CB-SCs outcomes are still mainly related to hematological malignancies [52; 55; 56; 57]. Recently, some interesting initial clinical results and preclinical studies have been reported in literature about CB-SCs in non-hematological diseases such as cerebral palsies [54] and type 1 diabetes (T1D), inherited biochemical disease such as mucopolysaccharidosis, glycoproteinosis and sphingolipidosis [58] and in cerebral adrenoleukodystrophy. These non-hematological applications should be evaluated for risk and benefits based on many factors including status of disease, functional status, donor availability and quality of graft. Outcomes relative to CB-SCs in hematological applications are based on surrogate end-points indicating the recovery of neuthrophils and platelets counts (absolute neuthrophils count of at least 500 per mm3 on 3 consecutive days, platelet count of at least 20000 per mm3 in the absence of platelet transfusions) [52; 55; 57]. In summary in hematological diseases it can be stated that UCB offers a significant risk decrease of transplant-related mortality due to the finest CB-SCs HLA-matching together with a lower relapse rate and higher cell doses available, and CB-SCs are becoming a real alternative to bone marrow transplantation [52; 55; 57].
Allogeneic versus autologous transplant
In 1997, Gluckman E. et al. has established the first positive outcome relative to CB-SCs related and unrelated donors [52]. This outcome has been provided by studying 143 transplantation procedures performed in 45 transplantation centers and with 12 years of follow-up. Among 143 patients, 78 recipients of CB-SCs related donors and 65 recipients of CB-SCs unrelated donors were analyzed. The Kaplan-Meier established the rate of Survival at one year as 63% for recipients CB-SCs related donors and as 29% for recipients CB-SCs unrelated donors (Figure 2A). Younger age, lower weight, transplant from HLA-identical donor together with cytomegalovirus-negative serologic results in recipient have been established as favorable prognostic factors. Among 143 patients, at least grade II GvHD rate was 9% in 60 recipients HLA-matched and 50% in 18 recipients HLA-mismatched (Figure 2B). Patients that received a cell dose >37 10×106 nucleated cells/kg showed the best neutrophil recovery [52]. Further comparison studies have been performed on large amount of young and adult recipients. For instance, 503 children with acute leukaemia and transplanted with unrelated CB-SCs were compared with outcomes of 282 bone marrow recipients [55]. In this case UCB recipients received grafts that were HLA-matched (n=35) or HLA-mismatched for 1 (n=201) or 2 antigens (n=267) (typing at antigen level HLA-A, HLA-B and allele level for HLA-DRB1); bone marrow recipients received grafts that were matched at the allele level HLA-A, HLA-B, HLA-C and HLA-DRB (n=116), or mismatched (n=166). This study showed that by using CB-SCs HLA-matched and 1- or 2-antigen HLA mismatched there is a decrease risk of transplant-related mortality [55]. In summary we can confirm that compared with HLA-matched unrelated BM transplant, cord blood has several advantages such as better long-term immune recovery resulting in a similar long-term survival [50] (Figure 2C).
