Effect of cord blood processing on transplantation outcomes after single myeloablative umbilical cord blood transplantation.

Variations in cord blood manufacturing and administration are common, and the optimal practice is not known. We compared processing and banking practices at 16 public cord blood banks (CBB) in the United States and assessed transplantation outcomes on 530 single umbilical cord blood (UCB) myeloablative transplantations for hematologic malignancies facilitated by these banks. UCB banking practices were separated into 3 mutually exclusive groups based on whether processing was automated or manual, units were plasma and red blood cell reduced, or buffy coat production method or plasma reduced. Compared with the automated processing system for units, the day 28 neutrophil recovery was significantly lower after transplantation of units that were manually processed and plasma reduced (red cell replete) (odds ratio, .19; P = .001) or plasma and red cell reduced (odds ratio, .54; P = .05). Day 100 survival did not differ by CBB. However, day 100 survival was better with units that were thawed with the dextran-albumin wash method compared with the "no wash" or "dilution only" techniques (odds ratio, 1.82; P = .04). In conclusion, CBB processing has no significant effect on early (day 100) survival despite differences in kinetics of neutrophil recovery.

A survey of transfusion practices in pediatric hematopoietic stem cell transplant patients.

Until recovery of hematopoiesis, pediatric hematopoietic stem cell transplant (HSCT) patients are dependent on red blood cell and platelet transfusions to avoid the complications associated with anemia and thrombocytopenia, respectively. Despite the fact that these patients are high utilizers of blood components, there are no evidence-based guidelines regarding optimal transfusion practices in this patient population. A web-based survey was designed to examine current transfusion thresholds used by institutions that perform pediatric HSCT. This survey was sent to department directors identified through the Children's Oncology Group directory with a response rate of 69%. The majority of institutions use 8 g/dL as the hemoglobin threshold for red blood cell transfusions (60%), but a significant minority use 7 g/dL (25%). With respect to platelet transfusion thresholds, 47% of respondents report using 20×10/L and 44% use 10×10/L. Respondents were also asked about specific clinical scenarios that would prompt an increase in a patient's threshold. This survey revealed that there is variation in transfusion practices among pediatric HSCT institutions with respect to both baseline transfusion threshold and what prompts an increase in threshold. Future clinical trials are needed to determine optimal transfusion thresholds in pediatric HSCT patients, which can lead to improved standardization in practices.

An Immune Recovery-Based Revaccination Protocol for Pediatric Hematopoietic Stem Cell Transplant Recipients: Revaccination Outcomes Following Pediatric HSCT.

Following hematopoietic stem cell transplant (HSCT), patients are at increased risk of vaccine-preventable diseases (VPDs) and experience worse outcomes of VPDs compared to immunocompetent patients. Therefore, patients are routinely vaccinated post-HSCT to restore VPD immunity. Published guidelines recommend revaccination based on time post-HSCT, although optimal revaccination timing and the value of using other clinical and laboratory variables to guide revaccination remain unclear. An institutional immune recovery-based protocol to guide timing of revaccination is used at Children's Hospital Colorado. This protocol incorporates time from transplant, time off immunosuppressive therapy and intravenous immunoglobulin replacement, absence of active graft-versus-host disease (GVHD), and minimum absolute CD4 count, absolute lymphocyte count (ALC), and immunoglobulin G (IgG) levels. The objective of this study is to evaluate the performance of this immune recovery-based revaccination protocol by determining rates of seroprotective vaccine responses achieved and describing demographic, clinical, and laboratory markers associated with protective antibody titers post-revaccination. Rates of seroprotection following revaccination were retrospectively determined for patients who received autologous or allogeneic HSCTs at Children's Hospital Colorado from 2007 to 2017. Percent seropositivity after revaccination was determined for ten VPDs: measles, mumps, rubella, varicella, tetanus, diphtheria, Haemophilus influenzae type B (Hib), poliovirus, hepatitis B virus (HBV), and Streptococcus pneumoniae. The impact of covariates, including post-HSCT vaccine timing, patient demographics, clinical features (diagnosis, donor and conditioning regimen data, GVHD, cytomegalovirus disease), and laboratory parameters (CD4 count, ALC, IgG level), on rates of seroprotection post-revaccination was determined using Wilcoxon rank sum, Fisher's exact, or chi-square tests, as appropriate. One hundred-twelve unique patients among 427 HSCT recipients had available data for both revaccination timing and vaccine titers. Among these, high rates of seroprotection were achieved after revaccination for rubella (100%), diphtheria (100%), tetanus (100%), and Hib (98%). More modest rates of seroprotection were achieved after revaccination with HBV (87%) and pneumococcal conjugate (85%) vaccines. Seroprotection was lower after revaccination with measles (76%), pneumococcal polysaccharide (72%), mumps (67%), and varicella (25%) vaccines. Greater rates of seroprotection were associated with younger age (hepatitis B vaccine, P = .04), lack of prior rituximab treatment (pneumococcal conjugate vaccine, P = .005), lack of total body irradiation (pneumococcal conjugate vaccine, P = .03), and receipt of a non-cord blood transplant (pneumococcal polysaccharide vaccine, P = .04). These results suggest that a revaccination protocol that incorporates both time post-HSCT and patient-specific indicators of immunologic recovery can achieve high rates of seroprotection against most VPDs. Seroprotection rates for HBV and PCV were notably among the highest reported in children post-HSCT, suggesting that an immune recovery-based protocol may improve seroprotection for some VPDs that frequently are associated with lower vaccine responses post-HSCT. Seroprotection rates for other VPDs remained suboptimal after revaccination. Therefore, evaluation of additional strategies, such as the use of novel markers of immune competence and new vaccines, to further optimize protection against VPDs in this population is warranted.

Abnormal infant pulmonary function in young children with neuroendocrine cell hyperplasia of infancy.

RATIONALE: Lung function in children with neuroendocrine cell hyperplasia of infancy (NEHI) and correlations with future clinical outcomes are needed to guide clinical management. OBJECTIVE: To compare results of infant pulmonary function tests (IPFTs) in children with NEHI to disease control (DC) subjects and to correlate NEHI IPFTs with future outcomes. METHODS: We performed a retrospective, single center study of IPFT in subjects diagnosed by lung biopsy (NEHI) or clinically (NEHI syndrome) and in DC subjects evaluated for cancer or pre-hematopoietic stem cell transplantation (HSCT). Raised volume rapid thoracoabdominal compression (RVRTC) and plethysmography were performed on all infants and evaluated for quality. Standard spirometry measures, room air oxygen saturations (RA O2 sat), and weight percentiles were collected during follow up. MEASUREMENTS AND MAIN RESULTS: Fifty-seven IPFTs were performed in 15 NEHI, 22 NEHI syndrome, and 20 DC subjects. RVRTC and FRC measurements were obtained in 85% or more of subjects in all groups. Significant airflow limitation (FEV0.5 P-value ≤ 0.01) and air trapping (FRC P-value ≤ 0.01) were seen in NEHI and NEHI syndrome subjects compared to DCs. No significant correlations were found between IPFT, oxygen use, RA O2 sat, and weight at the time of the IPFTs. Initial FEV0.5 and FRC z-scores correlated with RA O2 sat (r = 0.60 and -0.49) at short-term follow up (6-12 months). Most measurements of RVRTC correlated with FEV1 (n = 5) measured 4-5 years later (r > 0.50). CONCLUSIONS: IPFTs in NEHI subjects are feasible, demonstrate significant obstruction and air trapping, and correlate with future RA O2 sat and FEV1 . IPFTs may provide valuable clinical information when caring for NEHI patients. Pediatr Pulmonol. 2013; 48:1008-1015. © 2012 Wiley Periodicals, Inc.