Racial disparities in access to HLA-matched unrelated donor transplants: a prospective 1312-patient analysis.

Availability of 8/8 HLA-allele matched unrelated donors (URDs) is a barrier for ethnic and racial minorities. We prospectively evaluated receipt of 8/8 HLA-allele matched URD or either 7/8 URD or cord blood (CB) transplants by patient ancestry from 2005 to 2017. Matched URDs were given priority if they were available. Of 1312 patients, 723 (55%) received 8/8 URD, 219 (17%) 7/8 URD, 319 (24%) CB, and 51 (4%) had no 7/8 or 8/8 URD or CB graft. Europeans were more likely to receive an 8/8 URD transplant than non-Europeans (67% vs 33%) and less likely to have no URD or CB graft (1% vs 9%). Southern Europeans received 8/8 URD transplants (41%) at rates similar to those of Asians (34%) and white Hispanics (35%); Africans were the least likely (18%) to undergo 8/8 URD transplantation. CB and 7/8 URDs extended transplant access to all groups. In 742 recent patients, marked racial disparity in 8/8 URD access between groups observed in earlier years persisted with only a modest increase in the percentage of 8/8 URD transplants. Of 78 recent African patients, 46% received a CB transplant and 14% had no 7/8 or 8/8 URD or CB graft. Increasing registry size has not resolved the racial disparity in URD access, which emphasizes the importance of alternative graft sources.

Investigating the Association of Genetic Admixture and Donor/Recipient Genetic Disparity with Transplant Outcomes.

Disparities in survival after allogeneic hematopoietic cell transplantation have been reported for some race and ethnic groups, despite comparable HLA matching. Individuals' ethnic and race groups, as reported through self-identification, can change over time because of multiple sociological factors. We studied the effect of 2 measures of genetic similarity in 1378 recipients who underwent myeloablative first allogeneic hematopoietic cell transplantation between 1995 and 2011 and their unrelated 10 of 10 HLA-A, -B, -C, -DRB1, and-DQB1- matched donors. The studied factors were as follows (1) donor and recipient genetic ancestral admixture and (2) pairwise donor/recipient genetic distance. Increased African genetic admixture for either transplant recipients or donors was associated with increased risk of overall mortality (hazard ratio [HR], 2.26; P = .005 and HR, 3.09; P = .0002, respectively) and transplant-related mortality (HR, 3.3; P = .0003 and HR, 3.86; P = .0001, respectively) and decreased disease-free survival (HR, 1.9; P = .02 and HR, 2.46; P = .002 respectively). The observed effect, albeit statistically significant, was relevant to a small subset of the studied population and was notably correlated with self-reported African-American race. We were not able to control for other nongenetic factors, such as access to health care or other socioeconomic factors; however, the results suggest the influence of a genetic driver. Our findings confirm what has been previously reported for African-American recipients and show similar results for donors. No significant association was found with donor/recipient genetic distance.

Association of Socioeconomic Status with Outcomes of Autologous Hematopoietic Cell Transplantation for Multiple Myeloma.

Autologous hematopoietic cell transplantation (AHCT) is standard therapy for eligible patients with multiple myeloma. Health care disparities can influence transplantation outcomes. However, the association of socioeconomic status (SES), a major indicator of health care disparities, with outcomes in patients with myeloma after AHCT has not been previously described. We analyzed 346 consecutive AHCT recipients with myeloma who underwent transplantation between 2003 and 2013 in this retrospective cohort study. Zip code of residence at the time of AHCT was obtained to assess annual household income based on 2010 US census data (median, $49,054; range, $16,546 to $127,313). SES groups were divided into < $45,000 (low; n = 120), $45,000 to $60,000 (middle; n = 116), and > $60,000 (high; n = 110). The low-income cohort had smallest portion of Caucasians (69% versus 89% versus 91%); otherwise, patient, disease, and transplantation characteristics were comparable among cohorts or different without significant patterns found. Median follow-up was 49 months. There was no difference among SES groups in overall survival, progression-free survival, nonrelapse mortality, or relapse in univariate and multivariable analysis. Similarly, SES was not associated with survival in a subset analysis of 303 patients who had survived for 1 year after transplantation.

Spiritual Well-Being in Hispanic and Non-Hispanic Survivors of Allogeneic Hematopoietic Stem Cell Transplantation.

Research suggests that spiritual well-being positively contributes to quality of life during and following cancer treatment. This relationship has not been well-described in ethnically diverse survivors of allogeneic transplantation.  This study compares spiritual well-being and quality of life of Hispanic (n = 69) and non-Hispanic (n = 102) survivors. Hispanic participants were significantly younger and reported significantly greater spiritual well-being than non-Hispanic survivors. Survivors with higher spiritual well-being had significantly better quality of life. Meaning and Peace significantly predicted quality of life. Although Hispanic survivors report greater spiritual well-being, Meaning and Peace, irrespective of ethnicity, have a salutary effect on quality of life.

Cord Blood Banking in the Arab World: Current Status and Future Developments.

Umbilical cord blood transplants are now used to treat numerous types of immune- and blood-related disorders and genetic diseases. Cord blood (CB) banks play an important role in these transplants by processing and storing CB units. In addition to their therapeutic potential, these banks raise ethical and regulatory questions, especially in emerging markets in the Arab world. In this article, the authors review CB banking in five countries in the region, Jordan, Saudi Arabia, Egypt, Qatar, and the United Arab Emirates, selected for their different CB banking policies and initiatives. In assessing these case studies, the authors present regional trends and issues, including religious perspectives, policies, and demographic risk factors. This research suggests strong incentives for increasing the number of CB units that are collected from and available to Arab populations. In addition, the deficit in knowledge concerning public opinion and awareness in the region should be addressed to ensure educated decision-making.

Impact of race and ethnicity on outcomes and health care utilization after allogeneic hematopoietic cell transplantation.

Disparities in outcomes after hematopoietic cell transplant (HCT) are reported mostly by registry studies. We examined the association of self-reported race and ethnicity with outcomes and health care utilization after allogeneic HCT in a single center study. Clinical and socioeconomic data of 296 adult patients who underwent allogeneic HCT from November 2003 to October 2012 were analyzed. Survival was compared between non-Hispanic Whites (NHW) and minority patients using Cox proportional hazards regression. Some 73% of patients were NHW and 27% were racial/ethnic minority patients. More minority patients were younger and had lower socioeconomic status. Both unadjusted and adjusted overall and progression-free survival were comparable between the two groups. High risk disease, poor performance score and Medicare/Tricare were significant predictors of mortality. Health care utilization was comparable between the two groups. Homogeneity of medical care for allogeneic HCT may help overcome racial/ethnic disparities, but not those due to patients' primary insurance.

Racial disparities in hematopoietic cell transplantation in the United States.

Hematopoietic cell transplantation (HCT) is a highly specialized, expensive and resource-intense medical procedure that can be associated with racial disparities. We review the prevailing literature on racial disparities in HCT in the United States and describe areas for future research and interventions. We discuss the complexity of interpreting race as a biological and social determinant of disease in biomedical research, especially as it relates to HCT. In the United States, race is often a surrogate for socioeconomic, education and health insurance status. We also discuss some of the nuances to consider while reviewing the literature on racial disparities. Disparities by race exist in three areas related to HCT: donor availability, access to HCT and outcomes of HCT. African-Americans/Blacks have a lower likelihood of finding an unrelated donor. Race and ethnicity definitions are country-specific and reconciling race data can represent significant challenges to unrelated donor registries worldwide. African-Americans/Blacks do not have the same access to autologous and allogeneic HCT as Whites. Racial disparities in outcomes of HCT are more prevalent among allogeneic HCT than autologous HCT recipients. More research is required to understand the biological, social, cultural, medical and financial aspects of race that may influence access to HCT and survival after transplantation. Better understanding of racial disparities will minimize inequities, inform health policy, guide development of interventions targeted to eliminate disparities and ensure equitable access to HCT for all populations.

Ethnic differences in chronic health conditions after hematopoietic cell transplantation: a report from the Bone Marrow Transplant Survivor Study.

BACKGROUND: Hispanics have a greater risk of early treatment failure after hematopoietic stem cell transplantation (HCT) compared with non-Hispanic whites. However, long-term morbidity among Hispanics has not been described. METHODS: Health-related outcomes were examined in 159 Hispanic patients and 825 non-Hispanic white patients who underwent HCT between 1974 and 1998 and survived a mean of 8.7 years. Patients completed a detailed questionnaire about sociodemographic factors and the occurrence of chronic health conditions. RESULTS: Exposure to total body irradiation (TBI) (odds ratio [OR], 1.94; 95% confidence interval [CI], 1.06-3.56; P = .03), the presence of chronic graft versus host disease (GvHD) (OR, 3.99; 95% CI, 1.94-8.24; P = .002), and health insurance coverage (OR, 3.46; 95% CI, 1.5-8.01; P = .004), were associated significantly with severe/life-threatening conditions. Compared with non-Hispanic white patients, Hispanic patients were 53% less likely to report severe/life-threatening conditions (OR, 0.47; 95% CI, 0.27-0.83; P = .009) after adjusting for relevant clinical variables. This effect size was mitigated (OR, 0.56; 95%CI, 0.29-1.08; P = .08) after adjusting for health insurance coverage. CONCLUSIONS: Hispanics were less likely to report severe/life-threatening health conditions after HCT than non-Hispanic whites-a difference that decreased in magnitude and significance after taking health insurance into consideration. Although the current results confirmed the role of TBI and chronic GvHD, in the current study, the role of a lack of health insurance coverage was identified as a mediator of the lower prevalence of self-reported long-term morbidity in Hispanics.

Race and socioeconomic status influence outcomes of unrelated donor hematopoietic cell transplantation.

Success of hematopoietic cell transplantation (HCT) can vary by race, but the impact of socioeconomic status (SES) is not known. To evaluate the role of race and SES, we studied 6207 unrelated-donor myeloablative (MA) HCT recipients transplanted between 1995 and 2004 for acute or chronic leukemia or myelodysplastic syndrome (MDS). Patients were reported by transplant center to be White (n = 5253), African American (n = 368), Asian/Pacific-Islander (n = 141), or Hispanic (n = 445). Patient income was estimated from residential zip code at time of HCT. Cox regression analysis adjusting for other significant factors showed that African American (but not Asian or Hispanic) recipients had worse overall survival (OS) (relative-risk [RR] 1.47; 95% confidence interval [CI] 1.29-1.68, P < .001) compared to Whites. Treatment-related mortality (TRM) was higher in African Americans (RR 1.56; 95% CI 1.34-1.83, P < .001) and in Hispanics (RR 1.30; 95% CI 1.11-1.51, P = .001). Across all racial groups, patients with median incomes in the lowest quartile (<$34,700) had worse OS (RR 1.15; 95% CI 1.04-1.26, P = .005) and higher risks of TRM (RR 1.21; 1.07-1.36, P = .002). Inferior outcomes among African Americans are not fully explained by transplant-related factors or SES. Potential other mechanisms such as genetic polymorphisms that have an impact on drug metabolism or unmeasured comorbidities, socioeconomic factors, and health behaviors may be important. Low SES, regardless of race, has a negative impact on unrelated donor HCT outcomes.

Methodological and logistical considerations to study design and data collection in racial/ethnic minority populations evaluating outcome disparity in hematopoietic cell transplantation.

Outcome disparity associated with race or ethnicity in the United States has been observed in hematopoietic cell transplantation (HCT). The underlying reasons for such disparity are not known. In the United States, an optimal study of health care disparity by race or ethnicity involves consideration of both biologic and psychosocial determinants, which requires an adequately powered, prospective cohort study design. To better characterize the nature and quantify the magnitude of the many impediments relevant to conducting a successful prospective study involving racial or ethnic minorities in HCT, we conducted a feasibility study to help guide planning of a larger scale outcome and disparity study in HCT. The primary questions to be addressed in the study were: (1) can we establish a racially or ethnically diverse patient sample that will respond to a survey focused on sociodemographic, economic, health insurance, cultural, spiritual, and religious well-being, and social support information? (2) What is the retention rate in the study over time? (3) What is the quality of the data collected from the patients over time? The challenges we faced in conducting this multicenter feasibility study are summarized in this report. Despite the difficulty in conducting disparity studies in racial and ethnic minorities, such studies are essential to ensure that people of all ethnic and racial backgrounds have the best chance possible of benefiting from HCT.

Criteria for initiation and evaluation of minority donor programs and application to the example of donors of Turkish descent in Germany.

Minority donor programs aim to improve access to unrelated hematopoietic SCT for specific ethnic groups through directed donor recruitment. We have developed criteria for initiation and evaluation of such programs and applied them to the situation of donors of Turkish descent in Germany, as well as a program by DKMS German Bone Marrow Center that targets this group. Criteria for program initiation include the number of accessible minority donors, potential impact on the chances of finding matching donors, and general access to unrelated transplantation for patients of the targeted group. Success criteria comprise number and availability of recruited donors, the effect of these donors on the HLA phenotype distribution of a donor file, and the number of donations resulting from the program. More than 40 000 donors of Turkish descent have been recruited within the analyzed program to date. Recruited minority donors show more favorable demographic characteristics but lower availability rates than do German donors. Although HLA haplotype distributions of Turkish and German donors differ considerably, patients with common Turkish HLA phenotypes should benefit from the German donor pool even without a specific minority program. The analysis of donations from minority donors, however, shows specific benefits for patients with rare HLA phenotypes.

Frequency and targeted detection of HLA-DPB1 T cell epitope disparities relevant in unrelated hematopoietic stem cell transplantation.

The majority of unrelated donor (UD) hematopoietic stem cell (HSC) transplants are performed across HLA-DP mismatches, which, if involving disparity in a host-versus-graft (HVG) direction for an alloreactive T cell epitope (TCE), have been shown by our group to be associated with poor clinical outcome in 2 cohorts of patients transplanted for hematopoietic malignancies and beta-thalassemia, respectively. Using site-directed mutagenesis of DPB1*0901, we show here that the TCE is abrogated by the presence of amino acids LFQG in positions 8-11 of the DP beta-chain. Based on this and on alloreactive T cell responsiveness, we have determined the presence or absence of the TCE for 72 DPB1 alleles reported in the ethnic groups representative of the worldwide UD registries, and predict that 67%-87% (mean 77%) of UD recipient pairs will not present a DPB1 TCE disparity in the HVG direction. We developed and validated in 112 healthy Italian blood donors an innovative approach of DPB1 epitope-specific typing (EST), based on 2 PCR reactions. Our data show that DPB1 TCE disparities may hamper the clinical success of a considerable number of transplants when DPB1 matching is not included into the donor selection criteria, and that a donor without DPB1 TCE disparities in the HVG direction can be found for the majority of patients. Moreover, the study describes the first protocol of targeted epitope-specific DPB1 donor-recipient matching for unrelated HSC transplantation. This protocol will facilitate large-scale retrospective clinical studies warranted to more precisely determine the clinical relevance of DPB1 TCE disparities in different transplant conditions.