Racial and Socioeconomic Disparities in Long-Term Outcomes in ≥1 Year Allogeneic Hematopoietic Cell Transplantation Survivors: A CIBMTR Analysis.

Racial/ethnic minorities have demonstrated worse survival after allogeneic hematopoietic cell transplantation (HCT) compared to whites. Whether the racial disparity in HCT outcomes persists in long-term survivors and possibly may be even exacerbated in this population, which frequently transitions back from the transplant center to their local healthcare providers, is unknown. In the current study, we compared long-term outcomes among 1-year allogeneic HCT survivors by race/ethnicity and socioeconomic status (SES). The Center for International Blood and Marrow Transplant Research database was used to identify 5473 patients with acute myeloid leukemia, acute lymphocytic leukemia, chronic myeloid leukemia, or myelodysplastic syndromes who underwent their first allogeneic HCT between 2007 and 2017 and were alive and in remission for at least 1 year after transplantation. The study was restricted to patients who underwent HCT in the United States. SES was defined using patient neighborhood poverty level estimated from the recipient's ZIP code of residence; a ZIP code with ≥20% of persons below the federal poverty level was considered a high poverty area. The primary outcome was to evaluate the associations of race/ethnicity and neighborhood poverty level with overall survival (OS), relapse, and nonrelapse mortality (NRM). Cox regression models were used to determine associations of ethnicity/race and SES with OS, relapse, and NRM. Standardized mortality ratios were calculated to compare mortality rates of the study patients and their general population peers matched on race/ethnicity, age, and sex. The study cohort was predominately non-Hispanic white (n = 4385) and also included non-Hispanic black (n = 338), Hispanic (n = 516), and Asian (n = 234) patients. Overall, 729 patients (13%) resided in high-poverty areas. Significantly larger proportions of non-Hispanic black (37%) and Hispanic (26%) patients lived in high-poverty areas compared to non-Hispanic whites (10%) and Asians (10%) (P < .01). Multivariable analysis revealed no significant associations between OS, PFS, relapse, or NRM and race/ethnicity or poverty level when adjusted for patient-, disease- and transplantation-related covariates. Our retrospective cohort registry study shows that among adult allogeneic HCT recipients who survived at least 1 year in remission, there were no associations between race/ethnicity, neighborhood poverty level, and long-term outcomes.

Assessment of SARS-CoV-2 Immunity in Convalescent Children and Adolescents.

Persistence of protective immunity for SARS-CoV-2 is important against reinfection. Knowledge on SARS-CoV-2 immunity in pediatric patients is currently lacking. We opted to assess the SARS-CoV-2 adaptive immunity in recovered children and adolescents, addressing the pediatrics specific immunity towards COVID-19. Two independent assays were performed to investigate humoral and cellular immunological memory in pediatric convalescent COVID-19 patients. Specifically, RBD IgG, CD4+, and CD8+ T cell responses were identified and quantified in recovered children and adolescents. SARS-CoV-2-specific RBD IgG detected in recovered patients had a half-life of 121.6 days and estimated duration of 7.9 months compared with baseline levels in controls. The specific T cell response was shown to be independent of days after diagnosis. Both CD4+ and CD8+ T cells showed robust responses not only to spike (S) peptides (a main target of vaccine platforms) but were also similarly activated when stimulated by membrane (M) and nuclear (N) peptides. Importantly, we found the differences in the adaptive responses were correlated with the age of the recovered patients. The CD4+ T cell response to SARS-CoV-2 S peptide in children aged <12 years correlated with higher SARS-CoV-2 RBD IgG levels, suggesting the importance of a T cell-dependent humoral response in younger children under 12 years. Both cellular and humoral immunity against SARS-CoV-2 infections can be induced in pediatric patients. Our important findings provide fundamental knowledge on the immune memory responses to SARS-CoV-2 in recovered pediatric patients.

Estimation of optimal donor number in Bone Marrow Donor Registry: Hong Kong's experience.

Better outcome for hematopoietic stem cell transplantation (HSCT) requires optimal matching between donor and recipient at the HLA-A, -B, -C, and -DRB1 loci. This study estimates the likelihood of identifying HLA matched donors in Hong Kong. 7595 volunteer unrelated Chinese donors at the Hong Kong Bone Marrow Donor Registry were typed with HLA-A, -B, -C and -DRB1 genotypes. The matching probabilities for 8/8 and 7/8 HLA match via the matching models were determined. Based on current 100,000 donors in the HKBMDR, the matching probabilities are 45% at 8/8 HLA match and 65% at 7/8 match. By increasing the registry to 200,000, the likelihoods of match become 54% and 73% at 8/8 and 7/8 match stringencies respectively. Our findings may be helpful in planning future donor recruitment and HLA typing. A cost-effective Bone Marrow Donor Registry with a larger pool of donors could increase chance of matching and the success of HSCT.

Factors Influencing Hematopoietic Stem Cell Donation Intention in Hong Kong: A Web-Based Survey.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) has become increasingly common for treatment of severe hematological disorders. However, the number of compatible hematopoietic stem cell (HSC) donors is usually limited. Expanding donor pool size would enhance matching success by increasing donor frequency and introducing allelic diversity within the registry. Identifying factors that affect public willingness towards HSC donation allows better strategic recruitment planning to facilitate donor pool expansion. Previous studies in white populations showed knowledge, family attitude, trust towards the healthcare system, fear, self-identity, and social identity are important factors related to HSC donation intention. However, given the differences in cultural and society values that exist across different regions, in particular between the East and West, whether these factors influence HSC donation willingness in Hong Kong remained to be determined. The objective of this study was to identify factors associated with HSC donation motivation in Hong Kong. MATERIAL AND METHODS: A large-scale, cross-sectional, observational study involving 3479 local participants. RESULTS: There is a positive correlation of HSC donation intention with younger age (18-32, OR: 1.80, p≤0·001) and higher education (OR: 1·47, p≤0.001). Better HSCT knowledge is also related to greater HSC donation intention (OR: 2.55, p£0.001). CONCLUSIONS: Our data suggests HSCT education could help to improve donor recruitment and that more resources should be allocated for public education.