Real-world data showing trends and outcomes by race and ethnicity in allogeneic hematopoietic cell transplantation: a report from the Center for International Blood and Marrow Transplant Research

BACKGROUND

Use of human leukocyte antigen (HLA)-mismatched donors could enable more patients with ethnically diverse backgrounds to receive allogeneic hematopoietic cell transplantation (HCT) in the United States. However, real-world trends and outcomes following mismatched donor HCT for diverse patients remain largely undefined.

OBJECTIVE

To determine whether mismatched donor platforms have increased access to allogeneic HCT for ethnically diverse patients, particularly through the application of novel graft-versus-host disease (GvHD) prophylaxis regimens, and if outcomes for diverse patients were comparable to those of non-Hispanic White patients.

DESIGN

Observational cross-sectional study using real-world data from the Center for International Blood and Marrow Transplant Research (CIBMTR) registry. All patients receiving their first allogeneic HCT in the U.S. from 2009-2020 with focus on transplants performed in 2020 were included. Data from patients receiving allogeneic HCT using bone marrow, peripheral blood or cord blood from HLA-matched or mismatched related and unrelated donors was analyzed. Specifically, relative proportions of allogeneic HCT were generated as percent of total for donor type and for patient age, disease indication, GvHD prophylaxis, and race and ethnicity. Causes of death were summarized using frequencies, and the Kaplan-Meier estimator was used for estimating overall survival.

RESULTS

Compared to matched related donor and matched unrelated donor HCT, more ethnically diverse patients received mismatched unrelated donor, haploidentical donor, and cord blood HCT. Matched unrelated donor remains the most common donor type, but use of haploidentical donors has increased significantly over the last 5 years. Paralleling the increase in haploidentical HCT is the increased use of post-transplant cyclophosphamide (PTCy) as GvHD prophylaxis. Relative to older transplant eras, the most contemporary transplant era associates with the highest survival rates following allogeneic HCT irrespective of patient race and ethnicity. However, disease relapse remains the primary cause of death for both adult and pediatric allogeneic HCT recipients by donor type and across all patient race and ethnicity groups.

CONCLUSIONS

Ethnically diverse patients are undergoing allogeneic HCTs at higher rates largely through the use of alternative donor platforms incorporating PTCy. Maintaining access to potential life-saving allogeneic HCT using alternative donors and novel GvHD prophylaxis strategies and improving HCT outcomes, particularly disease relapse, are urgent clinical needs.

Updated Trends in Hematopoietic Cell Transplantation in the United States with an Additional Focus on Adolescent and Young Adult Transplantation Activity and Outcomes

Hematopoietic cell transplantation (HCT) has been successfully used to treat many malignant and nonmalignant conditions. As supportive care, donor selection, and treatment modalities evolve, documenting HCT trends and outcomes is critical. This report from the Center for International Blood and Marrow Transplant Research (CIBMTR) provides an update on current transplantation activity and survival rates in the United States. Additional data on the use and outcomes of HCT in the adolescent and young adult (AYA) population are included. AYA patients more frequently receive peripheral blood stem cell grafts than pediatric patients, which may reflect differences in practice in pediatric versus adult treatment centers. The proportions of donor types also differ those in adult and pediatric populations. Outcomes for patients in the AYA age range are similar to those of pediatric patients for acute myelogenous leukemia but worse for acute lymphoblastic leukemia. Outcomes for both leukemias are better in AYA patients compared with older adults. Comparing the time periods 2000 to 2009 and 2010 to 2019 revealed significant improvement in overall survival across the age spectrum, but the greatest improvement in the AYA age group.

High-performance liquid-chromatographic determination of free nicotinic acid and its metabolite, nicotinuric acid, in plasma and urine

We report a liquid-chromatographic procedure for determining free nicotinic acid and a metabolite, nicotinuric acid, in plasma and urine. Five-tenths milliliter of urine or deproteinized plasma is evaporated and the residue analyzed isocratically by reversed-phase ion-pair chromatography, with measurement of the eluted nicotinic acid and nicotinuric acid at 254 nm. Nicotinic acid, nicotinuric acid, and the internal standard (isonicotinic acid) have retention times of 7.8, 8.4, and 6.8 min, respectively, in plasma, and 12.3, 13.1, and 10.8 min in urine, because of double column length. Day-to-day reproducibilities (CV) for nicotinic acid and nicotinuric acid within 7.5% are attainable for the concentration ranges 0.1--20 mg/liter, equivalent to 0.81--162 micromol of nicotinic acid and 0.55--11 micromol of nicotinuric acid per liter for plasma; in urine for the range 0.5--100 mg/liter, equivalent to 4--810 micromol of nicotinic acid and 2.8--555 micromol of nicotinuric acid per liter. Metabolites of nicotinic acid such as nicotinamide, N-methylnicotinamide, 2-hydroxypyridine-5-carboxylic acid, and other structurally related substances do not interfere.

High-performance liquid-chromatographic determination of free nicotinic acid and its metabolite, nicotinuric acid, in plasma and urine

We report a liquid-chromatographic procedure for determining free nicotinic acid and a metabolite, nicotinuric acid, in plasma and urine. Five-tenths milliliter of urine or deproteinized plasma is evaporated and the residue analyzed isocratically by reversed-phase ion-pair chromatography, with measurement of the eluted nicotinic acid and nicotinuric acid at 254 nm. Nicotinic acid, nicotinuric acid, and the internal standard (isonicotinic acid) have retention times of 7.8, 8.4, and 6.8 min, respectively, in plasma, and 12.3, 13.1, and 10.8 min in urine, because of double column length. Day-to-day reproducibilities (CV) for nicotinic acid and nicotinuric acid within 7.5% are attainable for the concentration ranges 0.1--20 mg/liter, equivalent to 0.81--162 micromol of nicotinic acid and 0.55--11 micromol of nicotinuric acid per liter for plasma; in urine for the range 0.5--100 mg/liter, equivalent to 4--810 micromol of nicotinic acid and 2.8--555 micromol of nicotinuric acid per liter. Metabolites of nicotinic acid such as nicotinamide, N-methylnicotinamide, 2-hydroxypyridine-5-carboxylic acid, and other structurally related substances do not interfere.

Gas-liquid chromatographic determination of nicotine and cotinine in plasma

We report a procedure for determining nicotine and cotinine in plasma. Nicotine is extracted from 1 ml of plasma with diethyl ether, back extracted, and analyzed by gas-liquid chromatography with a nitrogen/phosphorus detector. Nicotine and its internal standard, modaline, had retention times of 1.9 and 2.9 min, respectively. Cotinine is then extracted from the same plasma with dichloromethane and similarly analyzed. Cotinine and its internal standard, lidocaine, had retention times of 3.8 and 4.9 min. Day-to-day reproducibilities (CV) within 14% for nicotine and within 6% for cotinine are attainable for the respective concentration ranges 1-100 microgram/liter and 1-200 microgram/liter. Nornicotine and related alkaloids do not interfere. The sensitivity was such that less than 0.1 microgram (0.62 nmol) of nicotine and 0.1 microgram (0.62 nmol) of nicotine and 0.1 microgram (0.57 nmol) of cotinine could be detected per liter.

Gas-liquid chromatographic determination of nicotine and cotinine in plasma

We report a procedure for determining nicotine and cotinine in plasma. Nicotine is extracted from 1 ml of plasma with diethyl ether, back extracted, and analyzed by gas-liquid chromatography with a nitrogen/phosphorus detector. Nicotine and its internal standard, modaline, had retention times of 1.9 and 2.9 min, respectively. Cotinine is then extracted from the same plasma with dichloromethane and similarly analyzed. Cotinine and its internal standard, lidocaine, had retention times of 3.8 and 4.9 min. Day-to-day reproducibilities (CV) within 14% for nicotine and within 6% for cotinine are attainable for the respective concentration ranges 1-100 microgram/liter and 1-200 microgram/liter. Nornicotine and related alkaloids do not interfere. The sensitivity was such that less than 0.1 microgram (0.62 nmol) of nicotine and 0.1 microgram (0.62 nmol) of nicotine and 0.1 microgram (0.57 nmol) of cotinine could be detected per liter.