To date, hematopoietic stem and progenitor cells from human umbilical cord blood (CB) have been employed in approximately 90 allogeneic (56 sibling and 34 unrelated) matched and mismatched transplantations worldwide with easy and successful restoration of hematopoiesis. Requests for stem cell preparations from CB will continue to increase. Thus, as a pilot study, the examination and standardization of unrelated cord blood-derived stem cell preparations and banking as well as their biologic characterization were initiated. Up to October 1995, a total of 574 samples [mean volume 79 +/- 26 ml, total nucleated cells (NC) 8.5 +/- 5 x 10(8), BFU-E 9.5 +/- 8.6 x 10(5), CFU-GM 5.7 +/- 6.3 x 10(5), CFU-GEMM 1.6 +/- 1.9 x 10(5)] from cord-derived or placental-derived residual blood have been defined by hematologic, immunologic, and microbiologic criteria. These CB samples were collected from the umbilical cord vein immediately after vaginal full-term delivery (n = 450) or cesarean section (n = 124) and stored frozen in liquid nitrogen. Seven percent of all samples collected could not be considered for potential transplants because of volumes < 40 ml. Only 5.0 ml of a CB sample is required for routine laboratory testing, consisting of HLA class I typing, HLA class II typing by sequence-specific oligonucleotide probes (PCR-SSOP), ABO typing, sterility control, assessment of progenitor and stem cells by colony-forming and LTC-IC assays, and CD34+ status. To assess the potential problem of contaminating maternal cells, a PCR was performed on 7 representative samples. During the initial 6 months of the unrelated CB collection program, a median bacterial contamination rate of 18% (20% skin flora species, 80% perineal flora species) was encountered, which has since been reduced to < 1% through practical experience. With regard to viral infections, maternal sera was tested for HBsAg (0.6% positive), anti-HCV (0%), anti-HAV (IgG 18%, IgM 0%), anti-HIV-1-2 (0%), anti-EBV (IgG 98%, IgM 0%), anti-HTLVI-II (0%), anti-CMV (IgG 43%, IgM 0.4%), toxoplasmosis (46%) and syphilis (0%). In addition, all cord blood samples were tested by PCR for CMV infection. With regard to its clinical relevance, it is important that only 0.3% of all the samples were positive for CMV by this sensitive method. This may represent a critical advantage of CB grafts over bone marrow (BM) since, in contrast, > 40% of the unrelated BM donors have been identified to be positive for CMV. An additional advantage of CB is that since 20% of CB samples were collected from ethnic minorities, it appears possible to balance common HLA types and uncommon HLA types represented in this group. In summary, with the extensive practical experience of the obstetric collection team as well as the stem cell-processing laboratory, it appears feasible to obtain a 90% yield of unrelated CB-derived stem cell preparations for banking, which clearly should meet the medical and regulatory qualification criteria required for clinical transplantation. To test the feasibility of hematopoietic ...

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To date, human umbilical cord blood (CB) has been employed successfully in well over 1000 allogeneic (unrelated and sibling) stem cell transplantations. Because of primary limitations in volume and cell numbers, over 90% of these transplantations were performed in children. Therefore requests for well standardised cord blood units of high quality are now increasing constantly. Examination and standardisation of unrelated and related cord blood stem cell preparations and banking as well as their biological characterisation was already initiated in Düsseldorf in 1992. Hitherto a total of 3236 CB samples with a mean volume of 89 +/- 25 ml, a mean total number of nucleated cells (NC) of 10 +/- 5 x 10(8) and a mean number of CFU-GM of 6 +/- 5 x 10(5) have also been validated by haematological, immunological and microbiological criteria. In addition to that, 97 directed CB donations of siblings with a clinical indication have been characterised and banked along the same lines. All CB units were collected from the umbilical cord vein immediately after vaginal full term delivery or caesarean section, then frozen and stored in liquid nitrogen. 1940 CB units were stored unseparated, the other 1296 were volume reduced using Hetastarch (HES) with a mean recovery of 85 +/- 13% of the nucleated cells, 86 +/- 12% and 84 +/- 13% for CFC and CD34+ cells, respectively. Only 5.0 ml of a CB sample is required for routine laboratory testing as there are HLA-class I typing, HLA-class II typing by sequence specific oligonucleotide probes (PCR-SOP), ABO typing, sterility control, assessment of progenitor and stem cells by colony forming assays, and CD34+ status as well as certain viral infections such as CMV, Hepatitis B, C, HIV, Parvo B19 by PCR technology before releasing the CB unit for transplantation. For apparent viral infections, maternal sera obtained at birth were tested for HBsAg, anti-HBc, anti-HCV, -HAV-(IgG, IgM), -HIV-1-2, -EBV- (IgG, IgM), -HTLVI-II, -CMV (IgM, IgG), toxoplasmosis and syphilis. Within the last three years a total of 4860 preliminary searches and 680 extended unit reports were submitted to the CB bank Düsseldorf by fax or World Wide Web. So far 68 unrelated and 3 related CB units were delivered. From these 70 have been transplanted in 30 different transplant centres world-wide. Until now the evaluation of the first 53 unrelated CB-transplantations was performed together with the EUROCORD transplant registry. Three patients were excluded from the analysis, since they received an unrelated CB-transplant for non-engraftment after previous allotransplants. The median patient age of these 50 patients was 5.0 years (range 0.3-44), the median weight 18 kg (range 4-70 kg). The majority of the patients transplanted for malignancies (66%) suffered from ALL (n = 19), AML (n = 7), CML (n = 4) and lymphoma (n = 2) with two third (75%) in an intermediate (2nd CR) or advanced stage of disease (> 2nd CR); 13 patients had metabolic diseases and immunodeficiencies and three had aplastic anaemia. All CB samples as well as th...

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