James Kurtz

Platelet products prepared by different methods of sedimentation undergo platelet activation differently during storage

BACKGROUND: The activation marker CD40 ligand (CD40L) has recently been demonstrated to be released from the cytoplasm of platelets (PLTs) during storage. CD40L may be associated with some adverse transfusion reactions including febrile responses and transfusion‐related acute lung injury. CD62P has been traditionally measured to assess PLT activation. This study compares the surface levels of CD40L and CD62P and accumulation of the soluble forms of these activation markers in the plasma of stored PLTs, prepared by PLT‐rich plasma (PRP) or buffy coat (BC) methods and with two apheresis instruments.

Retention of cellular properties of PBPCs following liquid storage and cryopreservation

BACKGROUND: G–CSF‐mobilized PBPCs are routinely cryopreserved within 24 hours of collection. The ability to hold PBPCs for extended time would offer increased flexibility for patients and hospitals. Retention of PBPC properties following overnight shipping, extended liquid storage at 1 to 6°C, and cryopreservation was evaluated.

Multiple-laboratory comparison of in vitro assays utilized to characterize hematopoietic cells in cord blood.

BACKGROUND:  Understanding the variability in results obtained by multiple laboratories is important because cord blood units are distributed worldwide for transplantation.

Assessment of cord blood hematopoietic cell parameters before and after cryopreservation.

BACKGROUND: The testing of cord blood (CB) progenitor and stem cell units for transplantation suitability involves enumeration of total nucleated cells before freezing. CD34+ cell counts may also be a means of determining suitability. Studies have been conducted to evaluate how specific storage conditions influence cell counts.

Characterization of multiple CD34+ cell populations in cord blood.

Unlike granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood, which show a single homogeneous population of CD34(+) cells, umbilical cord blood (CB) CD34(+) cells are present as multiple populations, CD34(regular) and CD34(bright) (the latter comprising 7.0-58.2% of the total CD34(+) cells), using the ProCOUNT trade mark procedure or with anti-CD34 labeling of immunoselected cells. The CD34(regular) population contains cells with high forward scatter (CD34(regular)FSC(high)) and with low forward scatter (CD34(regular) FSC(low)). Immunomagnetically selected CD34(+) cells, sorted into CD34(regular), CD34(regular) FSC(high), CD34(regular)FSC(low), and CD34(bright) cell populations, were used in in vitro assays: only the CD34(regular)FSC(high) population transmigrated and showed growth of colony-forming unit (CFU) and long-term culture initiating cells (LTC-IC) colonies. The absolute number of CD34(+) cells in CB samples was determined by ProCOUNT trade mark and Stem Kit trade mark enumeration protocols. In liquid stored CB units, ProCOUNT trade mark and Stem Kit trade mark count differences are accounted for by the enumeration of CD34(bright) cells. Differences between ProCOUNT trade mark and Stem Kit trade mark counts using cryopreserved/thawed samples are accounted for by increased CD34(regular) FSC(low) cell numbers (2.0 +/- 1.4% in liquid stored and 27.8 +/- 14.6% in cryopreserved/thawed samples). The ProCOUNT trade mark assay includes the nonfunctional CD34(bright) and CD34(regular)FSC(low) cells as part of the CD34(+) cell count, thereby elevating the absolute number of CD34(+) cells. Using the Stem Kit trade mark assay method of gating, CD34(bright) and CD34(regular)FSC(low) cells are not counted. Our data indicate that the CD34(regular)FSC(high) cell population has functional characteristics based on the in vitro assays and a more accurate count of these cells can be achieved using the Stem Kit trade mark assay.

Effect of storage on levels of nitric oxide metabolites in platelet preparations

BACKGROUND: Nitric oxide (NO), a potent signaling molecule, is known to inhibit platelet (PLT) function in vivo. We investigated how the levels of NO and its metabolites change during routine PLT storage. We also tested whether the material of PLT storage containers affects nitrite content since many plastic materials are known to contain and release nitrite.

Storing apheresis platelets without agitation with simulated shipping conditions during two separate periods: immediately after collection and subsequently between Day 2 and Day 3

BACKGROUND: Apheresis platelet (PLT) units are not routinely agitated during transit. Our study compared the in vitro properties of apheresis PLT units that were stored with continuous agitation (CA) and without continuous agitation (WCA) during two separate periods, immediately after collection and between Day 2 and Day 3 of storage.

Comparison of total nucleated cell measurements of UC blood samples using two hematology analyzers.

BACKGROUND The total nucleated cell (TNC) content of umbilical cord blood (UCB) units currently serves as the most important measure for determining suitability for transplantation. Hence it is important that TNC measurements are performed in an accurate manner. TNC content is evaluated routinely by hematology analyzers (HA) as WBC counts. The objective of the study was to compare TNC content utilizing two different HA, one utilizing an impedance channel and optical channel, and the other using only an optical channel. METHODS The HA utilized in this study used two different modes of operation for lysis, regular mode (RM) and extended lysis mode (ELM). Cell-Dyn 3200 (CD3.2) utilizes optical technology for WBC measurements, involving WBC optical count (WOC) and nuclear optical count (NOC), whereas the Cell-Dyn 3700 (CD3.7) utilizes both the impedance (WIC) and optical technology (WOC) for WBC measurements. TNC content was determined with 17 identical samples using CD3.2 in one laboratory and CD3.7 in the other laboratory. Cord blood samples processed to concentrate nucleated cells by either of the laboratories were sent by overnight courier and assays were performed on the same day by both laboratories. RESULTS For CD3.7, the WOC values were consistently lower than the WIC using the regular mode, but showed no significant differences (P>0.05). The WIC and WOC values were comparable on using the ELM and RM. For CD3.2, WOC values using RM and NOC values using ELM showed no significant differences (P>0.05), even though the WOC measurement was lower than the NOC values for most samples. The best comparison of TNC measurement between the two HA could be achieved by comparing CD3.7-WIC with CD3.2-NOC values. The results were equivalent (P>0.05) and 12 of 17 samples had equal to or less than 10% difference (mean 9.5%). DISCUSSION TNC measurements of UCB samples were essentially identical using the WIC channel of the Cell-Dyn 3700 and the NOC channel of the Cell-Dyn 3200.

Comparison of the in vitro storage properties of Amicus apheresis platelets collected using single- and double-needle procedures from the same donors.

BACKGROUND: Amicus apheresis platelets (PLTs) can be collected using either a single‐ (SN) or a double‐needle (DN) procedure. To investigate whether the method of PLT collection using the same instrument influences PLT quality, the in vitro storage properties of Amicus PLTs were evaluated in the same donors collected by SN and DN procedures.

Characterizing the variation in pH measurements with apheresis platelets.

BACKGROUND: pH measurements of platelet (PLT) components remain a key parameter when assessing how storage and shipping conditions influence the retention of PLT properties. Studies were conducted to characterize variations in pH measured with two pH meters and a blood gas analyzer.