Umbilical cord blood banking for unrelated transplantation: evaluation of cell separation and storage methods.

Cost-efficient umbilical cord blood (UCB) banking requires well-standardized methods of volume reduction and storage. To compare UCB fractionation using a technique of hydroxyethyl starch (HES) sedimentation with the Ficoll (double) and Percoll methods, 50 whole units was allocated randomly to each procedure. HES resulted in a significantly better recovery of mononuclear cells (87.5%), granulocyte/macrophage colony-forming units (CFU-GM) (88.4%), and CD34- cells (87.4%) and lesser volume reduction (85.5%). HES was the least laborious, time consuming, and expensive of the three procedures, costing 3.4- and 4.4-fold less than the Ficoll and Percoll methods, respectively. Five units processed by each method was frozen in 4.5-mL cryotubes under optimal conditions. After thawing, the greatest degree of recovery of viable nucleated cells and number of CFU-GM per unit were obtained using the HES procedure. Using 4.5-mL cryotubes, the calculated number of units that could be stored in 600-L containers was 3.8- and 2.2-fold higher for Ficoll- and Percoll-separated than for HES-separated units, respectively. Nevertheless, the higher direct costs of the density gradient separation procedures outweighed their lower storage cost. For long-term cryopreservation, we assessed the freezing of HES-processed units in 50-mL cryobags and their specifically designed canisters. We found cell recoveries similar to those obtained with cryotubes, but storage capacity was decreased. Special racks designed for these canisters resulted in a 5-fold increase over the number of units stored in standard cryobags. This system also is feasible for Percoll- and Ficoll-separated units, resulting in comparable storage costs for the three separation methods. We conclude that this HES procedure and the 50-mL cryobags constitute a cost-efficient system for large-scale UCB banking.

Splenic peliosis with spontaneous splenic rupture in a patient with immune thrombocytopenia treated with danazol.

We present a 79-year-old man diagnosed with immune thrombocytopenia (ITP), treated with danazol, who died as a result of a spontaneously ruptured spleen. The histopathological diagnosis was splenic peliosis. This patient presents a chronological association between the treatment with danazol and the development of peliosis, which suggests a clear cause-effect relationship. Facing an individual patient with ITP, clinicians should weigh the potential benefits of danazol with the possible development of serious complications, such as hepatic failure or splenic rupture due to peliosis.

Detection of maternal DNA in umbilical cord blood by polymerase chain reaction amplification of minisatellite sequences.

One of the concerns about the use of cord blood as a source of hematopoietic stem cells for allogeneic transplantation is the possibility of contamination by maternal cells which could cause life-threatening GVHD. We have assessed cord blood contamination using PCR analysis of several minisatellite regions to detect maternal DNA. Eighty mother-cord pairs were obtained for this study. In one case there were no specific maternal alleles at any loci and, therefore, cord blood could not be evaluated. Thus, there was a total of 79 informative cases for the detection of maternal cells in the fetal circulation. In most cases, the level of detection was between 0.5 and 1%. We detected maternal DNA in the cord blood sample in only one case (1.26%), and the analysis of dilution experiments led to an estimate of 0.5-1% maternal cells. In conclusion, using PCR amplification of hypervariable regions, maternal DNA is very rarely detected in the cord blood collected at birth, although this approach has a relatively low level of sensitivity.