Interlaboratory assessment of a novel colony-forming unit assay: a multicenter study by the cellular team of Biomedical Excellence for Safer Transfusion (BEST) collaborative.

BACKGROUND: Interlaboratory scoring performances were determined using a traditional 14-day colony-forming unit (CFU) assay and a new 7-day CFU assay. STUDY DESIGN AND METHODS: Digital images of colonies were utilized to train personnel at each site. A central laboratory inoculated methylcellulose with progenitors and sent the samples by overnight courier to participating labs for plating. RESULTS: Colony counts from two digital images showed greater variability by novice counters (coefficients of variation [CV], 18.5 and 23.0%; n = 8) than for experienced staff (CV, 7.3 and 4.8%; n = 5). CFU assays plated immediately, 24 and 48 hours after methylcellulose inoculation displayed 39.5 CFU, 37.1 ± 10.6 (CV, 28%) and 34.8 ± 8.5 (CV, 24%) colonies for the 7-day assay and 39.5 CFU, 39.1 ± 9.9 (CV, 25%) and 37.1 ± 10.6 (CV, 28%) colonies for the 14-day assay, respectively. Overall, no significant differences in colony counts were noted between assays (p = 0.68). Also, no differences in CFU counts were seen when assays were set up immediately, 24 and 48 hours after methylcellulose inoculation (14-day p = 0.695; 7-day p = 0.632). CONCLUSION: Total CFUs obtained in 7- and 14-day CFU assays are comparable and show similar levels of interlaboratory variability. The major source of this variability is due to differences in how CFU plates are scored by individuals at different sites. UCB progenitor cells can be maintained in methylcellulose-based media at room temperature for up to 48 hours prior to transport without a significant loss in CFUs.

The new apheresis and blood and marrow transplantation-related current procedural terminology codes for payment of apheresis and blood and marrow transplantation services.

To address deficiencies in Current Procedural Terminology (CPT) codes that describe many of the clinical services offered to patients, several physicians in the blood and marrow transplantation and apheresis field joined with a coalition including the American Society of Hematology, American Society for Blood and Marrow Transplantation, American Association of Blood Banks, American Society of Clinical Oncology, American Society for Apheresis, National Marrow Donor Program, and American Red Cross to collaborate in addressing these deficiencies by designing new CPT codes. The CPT editorial panel approved 18 new or revised codes. All these codes were given permanent or temporary value by the relative value unit update committee, but not all values were approved by the Centers for Medicare & Medicaid Services (CMS), in particular, the cell-processing codes and the unrelated donor search code. Further discussions addressing these concerns are under way with the CMS. Use of these new codes allows apheresis and transplant centers to charge appropriately for these services. This will help transplant center contracts with CPT codes, with payers more specifically describing services offered to these patients. In turn, this will give better justification for payment. This may allow certain payments for services to increase and help transplant centers better allocate revenue from fixed global case rate payments. Details about the individual codes and their approval process are reviewed in this article.

Functional assessment and specific depletion of alloreactive human T cells using flow cytometry.

Human T-cell alloreactivity plays an important role in many disease processes, including the rejection of solid organ grafts and graft-versus-host disease (GVHD) following allogeneic stem cell transplantation. To develop a better understanding of the T cells involved in alloreactivity in humans, we developed a cytokine flow cytometry (CFC) assay that enabled us to characterize the phenotypic and functional characteristic of T cells responding to allogeneic stimuli. Using this approach, we determined that most T-cell alloreactivity resided within the CD4(+) T-cell subset, as assessed by activation marker expression and the production of effector cytokines (eg, tumor necrosis factor alpha [TNF]alpha) implicated in human GVHD. Following prolonged stimulation in vitro using either allogeneic stimulator cells or viral antigens, we found that coexpression of activation markers within the CD4(+) T-cell subset occurred exclusively within a subpopulation of T cells that significantly increased their surface expression of CD4. We then developed a simple sorting strategy that exploited these phenotypic characteristics to specifically deplete alloreactive T cells while retaining broad specificity for other stimuli, including viral antigens and third-party alloantigens. This approach also was applied to specifically enrich or deplete human virus-specific T cells.