Double unrelated reduced-intensity umbilical cord blood transplantation in adults

Umbilical cord blood (UBC) stem cells are a useful stem cell source for patients without matched related or unrelated donors. Adult transplantation with single UBC units is associated with high transplantation-related mortality (TRM). In most cases, mortality is due to infection related to slow engraftment and immunoincompetence. In this study, we used a reduced-intensity conditioning regimen of fludarabine, melphalan, and antithymocyte globulin followed by 2 partially matched UBC units. The UBC units were a 4/6 HLA match or better with each other and with the patient and achieved a minimum precryopreservation cell dose of 3.7 x 10(7) nucleated cells/kg. A total of 21 patients (median age, 49 years) were treated. The median time to an absolute neutrophil count > 0.5 x 10(9)/L was 20 days, and the median time to an unsupported platelet count > 20 x 10(9)/L was 41 days. Two patients experienced primary graft failure and underwent a second UBC transplantation. One patient had a late graft failure. Acute graft-versus-host disease (GVHD) grade II-IV occurred in 40% of patients. The 100-day TRM was 14%, and the 1-year disease-free survival was 67%. Mixed chimerism was associated with a higher risk of chronic GVHD. Our findings indicate that adult patients can tolerate double UBC transplantation well and achieve sustained antitumor responses using this reduced-intensity conditioning regimen.

Outcomes of 122 diverse adult and pediatric cord blood transplant recipients from a large cord blood bank

BACKGROUND

Umbilical cord blood is a useful stem cell source for some patients. The American Red Cross Cord Blood Program was established as a national network of cord blood banks. Nine thousand cord blood units were cryopreserved for transplant use.

STUDY DESIGN AND METHODS

This report summarizes the experience with the first 125 cord blood units that have been distributed for transplant for 122 patients at 36 different transplant centers worldwide. Patients were treated with a variety of conditioning regimens.

RESULTS

Most patients had acute myelogeneous leukemia (21%), genetic disorders (22%), or acute lymphoblastic leukemia (18%). The median age of the patients was 11 years with a range of 2 months to 63 years. The patients ranged in size from 3 to 120 kg (median, 39 kg). The median number of days to neutrophil engraftment was 22, and the median number of days to platelet engraftment was 63. Thirty percent of patients experienced Grades III to IV acute graft-versus-host disease (GVHD). Survival at 1 year after transplant was 35 percent, with recurrent disease the major cause of death. In multivariate analysis, only age less than 18 years was a significant predictor for improved survival. Forty-two percent of patients were non-Caucasian. Engraftment, GVHD, survival, and disease-free survival were similar among Caucasian and non-Caucasian patients.

CONCLUSION

Umbilical cord blood serves as a satisfactory stem cell source for a diverse group of pediatric and adult patients.

Adhesion receptor expression by CD34+ cells from peripheral blood or bone marrow grafts: correlation with time to engraftment

OBJECTIVE

This study was undertaken to define the pattern of cell adhesion receptor expression by the CD34+ progenitor cells from mobilized peripheral blood and bone marrow from normal and autologous donors, and to correlate the adhesion receptor profile with time to blood cell recovery for patients undergoing autologous transplant.

METHODS

Blood cell recovery was determined by absolute neutrophil count (> 500/microL), time to last red cell transfusion, and platelet count (> 50,000/microL and > 100,000/microL). The analysis for expression of adhesion receptors alphaL (CD11a), alpha2 (CD49b), alpha3 (CD49c), alpha4 (CD49d), alpha5 (CD49e), alpha6 (CD49f), beta1 (CD29), L-selectin (CD62L), ICAM-1 (CD54), PECAM-1 (CD31), HCAM (CD44), and P-selectin (CD62P) was performed by two-color flow cytometry. The Kruskal-Wallis test and Spearman's rank correlation were used for statistical analysis.

RESULTS

Statistical analysis of adhesion expression by the CD34+ population for patients undergoing autologous transplant demonstrated that the higher percent expression of PECAM-1 correlated with longer time to platelet recovery (> 100,000/microL, p = 0.049). In contrast, the higher the percent expression of alpha6 (p = 0.013) and the increased density of expression of alpha2 (p = 0.035), alpha3 (p = 0.023), alpha4 (p = 0.044), beta1 (p = 0.027), and ICAM-1 (p = 0.010) correlated with shorter time to platelet recovery. Neutrophil recovery time decreased with increased density of expression of alphaL (p = 0.014) and P-selectin (p = 0.007) receptors. Increased density of expression of CD44 (HCAM) was associated with longer time to red blood cell recovery (p = 0.05).

CONCLUSION

These data suggest that upregulation of specific adhesion receptors or selection of certain cell populations could result in earlier blood cell recovery after transplant.

Treatment-related myelodysplasia/AML in a patient with a history of breast cancer and an oligodendroglioma treated with temozolomide: case study and review of the literature

The emergence of temozolomide as an effective alkylating agent with little acute toxicity or cumulative myelosuppression has led to protracted courses of chemotherapy for many patients with gliomas. Secondary, or treatment-related, myelodysplasia (t-MDS) and acute myelogenous leukemia (t-AML) are life-threatening complications of alkylating chemotherapy and have been reported in patients with primary brain tumors. We describe a case of temozolomide-related t-MDS/AML and discuss the clinical features of this condition. Administration of an alkylating agent in patient populations with long median survivals must be undertaken with an understanding of the potential for this treatment complication.

Cellular immune therapy for refractory cancers: novel therapeutic strategies

OBJECTIVE

Allogeneic stem cell transplantation is curative for certain cancers, but the high doses of chemotherapy and radiotherapy may lead to toxicity. This review summarizes the field of cellular immune therapy using very-low-dose conditioning for refractory cancers.

METHODS

In our initial study, we treated 25 patients with refractory cancers with 100 cGy total body irradiation followed by allogeneic, nonmobilized peripheral blood cells. Eighteen patients received sibling and seven patients received unrelated cord blood stem cells.

RESULTS

None of the 13 patients with solid tumors achieved donor chimerism or had a sustained response. Twelve patients with hematologic malignancies were treated, 1 received a cord blood transplant and 11 received sibling donor cells. Nine of these 11 patients achieved donor chimerism, ranging from 5% to 100%. Four patients had sustained complete remission of their cancers. The patients who received cord blood transplants did not respond. Development of chimerism correlated with total previous myelotoxic chemotherapy (p < 0.001). We review additional studies in this area, including data in the haploidentical and unrelated donor setting. The data presented comprises studies performed at the four institutions represented by the authors, and a review of other pertinent studies in this area.

CONCLUSIONS

Cellular immune therapy is an emerging application of transplantation therapy, which may be appropriate for refractory cancers. New studies in solid tumors, and with alternative donors, will expand the application of this new and promising treatment.

Outcome of unrelated transplants in patients with multiple myeloma

The outcome of patients with multiple myeloma treated with standard therapy is disappointing, with a historical median survival of 3 years. Although high-dose therapy with autologous stem cell transplant has improved treatment outcomes, cure is unlikely. Allogeneic transplant provides a tumor-free graft and a graft-versus-myeloma effect. However, only a minority of patients has a compatible sibling donor. Unrelated hematopoietic stem cell transplant is another option. We analyzed the outcome of patients who received an unrelated bone marrow transplant facilitated by the National Marrow Donor Program (NMDP). Between 1989 and 2000, 71 patients received a myeloablative unrelated transplant for multiple myeloma; 70 patients consented for this analysis. The median recipient age was 44 years. A total of 31% of patients had received a prior autologous transplant. In all, 91% of patients engrafted. The 3-year cumulative incidence estimate of relapse was 34+/-10%. The incidence of Grade II-IV GVHD was 47%. The Kaplan-Meier estimate for overall survival at 5 years was 9+/-7%. The 100-day treatment-related mortality was 42%. In multivariate analysis, only a male donor was a significant predictor for survival. Better strategies are needed to treat patients with multiple myeloma, perhaps by using less-toxic, nonmyeloablative conditioning regimens.

New trends in umbilical cord blood transplantation

Since the first report of a successful umbilical cord blood transplantation in 1988, there has been great interest in the use of cord blood as an alternative stem cell source to treat cancer and genetic diseases. More than 4000 cord blood transplantations have been performed worldwide. In this review, the scientific rationale for this therapy, as well as related preclinical studies, cord blood banking issues, and ethical concerns, will be addressed. Results of studies in both pediatric and adult transplantation will be discussed. Finally, new indications for cord blood use and emerging technologies will be addressed.

Low dose total body irradiation followed by allogeneic lymphocyte infusion for refractory hematologic malignancy--an updated review

Allogeneic stem cell transplantation is curative for certain cancers, but the high doses of chemotherapy and radiotherapy used in conventional myeloablative conditioning regimens may lead to severe toxicity. In our initial study, we treated 25 patients with refractory cancers with 100 cGy total body irradiation (TBI) followed by allogeneic, non mobilized peripheral blood cells. Eighteen patients received sibling and 7 patients received unrelated cord blood stem cells. None of the 13 patients with solid tumors achieved donor chimerism or had a sustained response. Twelve patients with hematologic malignancies were treated, 1 received a cord blood transplant and 11 received sibling donor cells. Nine of these 11 patients achieved donor chimerism, ranging from 5% to 100%. Four patients had sustained complete remission of their cancers, and 2 are long-term survivors. The development of chimerism correlated with total previous myelotoxic chemotherapy (p < 0.001). This technique is now being extended into the haploidentical setting.

Autologous Stem-Cell Transplantation Can Be Performed Safely Without the Use of Blood-Product Support

Purpose

Autologous stem-cell transplantation has been shown to be a curative procedure for a variety of leukemias and lymphomas. Most transplants require RBC and platelet support. We report the ability to perform autologous transplantation without blood-product support.

Subjects and Methods

In this study, we treated 26 patients with religious objection to blood products with autologous stem-cell support without the use of any blood products. Patients received a combination of granulocyte colony-stimulating factor (G-CSF), erythropoietin, and interleukin-11 or G-CSF alone to mobilize stem cells. Post-transplant patients received intravenous iron, erythropoietin, G-CSF, and epsilon aminocaproic acid.

Results

There were two major bleeding complications (8%), with two treatment-related deaths (8%). There were three minor bleeding complications (12%). The median fall in hemoglobin level was 4.7 g/dL; the median hemoglobin level 30 days after transplantation was 9.2 g/dL. The median total number of days with platelet count less than 10 × 109/L was 4 days; the median days to platelet recovery greater than 20 × 109/L was 12 days.

Conclusion

Autologous stem-cell transplantation can be performed safely without the use of any blood products.

Autologous stem cell transplantation in multiple myeloma patients <60 vs >/=60 years of age

The role of autologous stem cell transplantation (AuSCT) in older multiple myeloma patients is unclear. Using data from the Autologous Blood and Marrow Transplant Registry, we compared the outcome of 110 patients >/=the age of 60 (median 63; range 60-73) years, undergoing AuSCT with that of 382 patients <60 (median 52; range 30-59) years. The two groups were similar except that older patients had a higher beta(2)-microglobulin level at diagnosis (P=0.016) and fewer had lytic lesions (P=0.007). Day 100 mortality was 6% (95% confidence interval 4-9) and 1-year treatment-related mortality (TRM) was 9% (6-13) in patients <60 years, compared with 5% (2-10) and 8% (4-14), respectively, in patients >/=60 years. The relapse rate, progression-free survival (PFS) and overall survival (OS) in the two groups were also similar. Multivariate analysis of all patients identified only an interval from diagnosis to AuSCT >12 months and the use of two prior chemotherapy regimens within 6 months of AuSCT as adverse prognostic factors. Our results indicate that AuSCT can be safely performed in selected older patients: the best results were observed in patients undergoing AuSCT relatively early in their disease course.

Racial diversity with high nucleated cell counts and CD34 counts achieved in a national network of cord blood banks

Banked, unrelated, partially HLA-matched, umbilical cord blood is an alternative stem cell source for patients in need of transplantation therapy who lack traditionally matched donors. A presumed advantage of cord blood is the ability to increase recruitment of donors of minority ethnic backgrounds. The American Red Cross Cord Blood Program was established in 1999 with 6 banks and 10 collection sites throughout the country. Cord blood donors self-report racial designations on questionnaires, and donor race was collected from each site. Postprocessing nucleated cell counts and CD34(+) counts were obtained on the cord blood units, and results from each racial group (white, black, Asian, Hispanic, and Native American) were compared in the natural logarithmic scale by using analysis of variance. A total of 18878 donors consented: 64% white, 16% black, 12% Hispanic, 4% Asian, 1% Native American, and 3% other. The Detroit area consented the highest percentage of black donors (87%), San Diego consented the highest percentage of Hispanic donors (59%), and Oakland consented the highest percentage of Asian donors (15%). Seven thousand eight hundred sixty-six cord blood units have been banked for transplantation. The mean preprocessing nucleated cell count was 1220 x 10(6) (range, 327-7300 x 10(6)). There was no difference among racial groups when controlled for site (P =.395). The mean CD34(+) count was 3.28 x 10(6). Blacks had a significantly lower CD34(+) count than the other racial/ethnic groups in the Midwest, Northwest, and North Carolina collection sites. A racially diverse cord blood bank can be achieved. Nucleated cell counts were similar among the different racial/ethnic groups. CD34(+) counts were lower for blacks in some collection sites.

Racial and ethnic composition of volunteer cord blood donors: comparison with volunteer unrelated marrow donors

BACKGROUND

Umbilical cord blood is an alternative peripheral blood progenitor cell source for patients who need transplantation. A presumed advantage of cord blood is the ability to increase minority recruitment.

STUDY DESIGN AND METHODS

The racial composition of five member cord blood banks of the National Marrow Donor Program (NMDP) was compared, representing 9020 cord blood donors with NMDP marrow donors from comparable geographic areas, representing 417,676 donors. Cord blood and marrow donors self-reported racial designations on questionnaires. Donor statistics were compared with baseline racial data of deliveries from participating hospitals for cord blood donors and with geographic census data for marrow donors.

RESULTS

The California, Florida, and Massachusetts cord blood banks recruited a lower percentage of minorities than the corresponding marrow donor centers. In New York and Colorado, minority recruitment was equivalent. In California, Florida, Massachusetts, and New York, the cord blood banks recruited a lower percentage of minorities than those delivering at the respective hospitals. The cord blood banks in California, Colorado, Florida, and Massachusetts recruited a lower percentage of minorities compared with delivery data than the corresponding marrow donor centers compared with census population (p < 0.001). In New York, the percentages were similar.

CONCLUSION

The problem of insufficient minority recruitment of cord blood has not yet been solved. Better strategies are needed to recruit minority donors.

Low-dose total body irradiation followed by allogeneic lymphocyte infusion may induce remission in patients with refractory hematologic malignancy

Allogeneic stem cell transplantation is curative for certain cancers, but the high doses of chemotherapy/radiotherapy lead to toxicity. Here, we treat patients with refractory cancer with 100 cGy total body irradiation (TBI) followed by infusion of nonmobilized pheresed allogeneic peripheral blood cells. Twenty-five patients, with a median age of 47 years, with refractory cancers were enrolled. Eighteen patients received sibling and 7 received unrelated cord blood cells. Donor chimerism was assessed at weeks 1, 2, 3, 4, and 8 after transplantation. Seven patients with solid tumors received a sibling transplant and 6 received a cord blood transplant; none achieved donor chimerism, but 1 treated at the higher dose level of 1 x 10(8) CD3+ cells/kg had a transient nodal response. Twelve patients with hematologic malignancies were treated; 1 received a cord blood transplant and 11 received sibling donor cells. Nine of these 11 patients achieved donor chimerism, ranging from 5% to 100%. Four patients had sustained complete remission of their cancers, including one patient with transient 5% donor chimerism. The development of chimerism correlated with hematologic malignancy (P <.001), total previous myelotoxic chemotherapy (P <.001), T-cell dose (P =.03), and graft-versus-host disease (P =.01). Tumor response correlated with donor chimerism (P =.01). Engraftment was achieved in patients with hematologic malignancies who had been heavily pretreated, suggesting the degree of immunosuppression may be a determinant of engraftment. Low-dose TBI and allogeneic lymphocyte infusion may induce remission in patients with refractory hematologic malignancy.

Prospective evaluation of antiemetic outcome following high-dose chemotherapy with hematopoietic stem cell support

Considerable progress has been made in improving the control of chemotherapy-induced emesis. The impact of available antiemetic options for patients receiving stem cell transplants is unclear, as few prospective data have been collected. We prospectively evaluated antiemetic outcome in patients receiving stem cell transplantation over a 7-day period following the initiation of chemotherapy. The primary endpoints were the number of emetic episodes and the extent of nausea measured on a four-point scale. Eighty-two patients were evaluated. Ninety-five percent of patients had nausea during the first week of treatment; 80% had at least one emetic episode. The percentage of patients with emesis was as follows: day 1: 13%, day 2: 21%, day 3: 30%, day 4: 38%, day 5: 44%, day 6: 39%, day 7: 18%. In multivariate analysis, gender, emesis with prior chemotherapy, history of morning or motion sickness, type of transplant (auto vs allo), use of total body irradiation, or use of dexamethasone did not effect emesis control. Most patients receiving high-dose chemotherapy experience incompletely controlled emesis. Control of nausea and emesis progressively worsened with each subsequent day following initiation of chemotherapy, reaching a nadir on day 5. New treatment approaches are needed to improve emesis control in this patient population.

Variables to predict engraftment of umbilical cord blood into immunodeficient mice: usefulness of the non-obese diabetic--severe combined immunodeficient assay

Umbilical cord blood is an alternative stem cell source for patients without matched family donors. In this study, we examined several parameters that have not been studied in detail -- radiation dose, cell dose, age of mice, and maternal and neonatal characteristics of the cord blood donor -- that affect engraftment of cord blood in non-obese diabetic-severe combined immunodeficient (NOD--scid) mice. Engraftment, measured using flow cytometry analyses of human CD45(+) cells, was highest in 400 cGy-treated mice. Successful engraftment was demonstrated up to 6 months, with a mean engraftment of 31% (range 0--67%) of human cells in recipient bone marrow. Engraftment was skewed to B lymphocytes. The radiation dose of 350 cGy resulted in superior survival of the murine recipients compared with 400 cGy (P = 0.03). The sex of the NOD--scid recipients had a significant effect on survival (female superior to male, P = 0.01), but not on engraftment. There were high levels of variability among different cord units and among animals injected with the same cord unit. This variability may limit the clinical usefulness of the NOD--scid mice as hosts for the quantification of human stem cells.

Autotransplants for Hodgkin's disease in first relapse or second remission: a report from the autologous blood and marrow transplant registry (ABMTR)

Although patients with relapsed Hodgkin's disease have a poor prognosis with conventional therapies, high-dose chemotherapy and autologous hematopoietic stem cell transplantation (autotransplantation) may provide long-term progression-free survival. We reviewed data from the Autologous Blood and Marrow Transplant Registry (ABMTR) to determine relapse, disease-free survival, overall survival, and prognostic factors in this group of patients. Detailed records from the ABMTR on 414 patients with Hodgkin's disease in first relapse (n = 295) or second complete remission (CR) (n = 119) receiving an autotransplant from 1989 to 1995 were reviewed. Median age was 29 (range, 7-64) years. Median time from diagnosis to relapse was 18 (range, 6-219) months; median time from relapse to transplant was 5 (range, <1-215) months. Most patients received high-dose chemotherapy without total body irradiation for conditioning (n = 370). The most frequently used high-dose regimen was cyclophosphamide, BCNU, VP-16 (CBV) (n = 240). The graft consisted of bone marrow (n = 246), blood stem cells (n = 112), or both (n = 56). Median follow-up was 46 (range, 5-96) months. One hundred-day mortality (95% confidence interval) was 7 (5-9)%. One hundred and sixty-five of 295 patients (56%) transplanted in relapse achieved CR after autotransplantation. Of these, 61 (37%) recurred. Twenty-four of 119 patients (20%) transplanted in CR recurred. The probability of disease-free survival at 3 years was 46 (40-52)% for transplants in first relapse and 64 (53-72)% for those in second remission (P < 0.001). Overall survival at 3 years was 58 (52-64)% after transplantation in first relapse and 75 (66-83)% after transplantation in second CR (P < 0.001). In multivariate analysis, Karnofsky performance score <90% at transplant, abnormal serum LDH at transplant, and chemotherapy resistance were adverse prognostic factors for outcome. Progression of Hodgkin's disease accounted for 69% of all deaths. Autotransplantation should be considered for patients with Hodgkin's disease in first relapse or second remission. Future investigations should focus on strategies designed to decrease relapse after autotransplantation, particularly in patients at high risk for relapse.

Bigger is better: maternal and neonatal predictors of hematopoietic potential of umbilical cord blood units

Umbilical cord blood (CB) is a useful stem cell source for patients without matched family donors. CB banking is expensive, however, because only a small percentage of the cord units stored are used for transplantation. In this study, we determined whether maternal factors, such as race, age, and smoking status have an effect on laboratory parameters of hematopoietic potential, such as viability, cell counts, CD34+ cell counts, and CFU-GM. We studied the effect of neonatal characteristics such as birth order, birth weight, gestational age, and sex of the baby on the same laboratory parameters. Race and maternal age had no effect on these laboratory parameters. In multivariate analysis, babies of longer gestational age had higher cell counts, but lower CD34+ cell counts and CFU-GM. Bigger babies had higher cell counts, more CD34+ cells, and more CFU-GM. Women with fewer previous live births also produced cord units with higher cell counts, CFU-GM, and CD34+ cell counts. Specifically, each 500 g increase in birth weight contributed to a 28% increase in CD34+ cell counts, each week of gestation contributed to a 9% decrease in CD34+cell counts, and each previous birth contributed to a 17% decrease in CD34+ cell counts (all P < 0.05). These data may be used to select the optimal cord blood donors and allow CB banks efficient resource allocation.

Manipulation of the stem cell as a target for hematologic malignancies

Hematologic malignancies affect more than 80,000 patients in the United States each year. Some patients with lymphoma and leukemia are cured with conventional chemotherapy treatments. For others, autologous or allogeneic bone marrow transplantation may be the best therapeutic option. This chapter will explore novel therapies for the hematologic malignancies, using the stem cell as a target. We review work in the murine model looking at (1) the phenotype of the engrafting cells, (2) stem cell competition and host stem cells, (3) allochimerism with low-dose total body irradiation, and (4) the tolerance approach with costimulator blockade. Human data, including stem cell migration, adhesion receptor expression, and manipulations for gene therapy, are reviewed. The NOD/scid mouse model serves as a bridge between the basic bench work and human clinical trials, and we discuss applications related to umbilical cord blood and gene therapy, as well as discuss the inherent variability of this system. Finally, we address unique clinical applications in gene therapy, high-dose cell transplants, minimal myeloablation, and cellular immune therapy as approaches to treatment of for patients with hematologic malignancies.

Successful autologous bone marrow transplant without the use of blood product support

We describe a successful autologous bone marrow transplant without the use of any blood products. The patient had relapsed large cell lymphoma. He was a Jehovah's Witness and would not accept transfusions of red blood cells or platelets. He enrolled in our Bloodless Medicine and Surgery Program and was maintained on a regimen of erythropoietin, iron, Amicar, and G-CSF throughout the transplant. He tolerated the transplant well and is alive with no evidence of disease 10 months after autografting.

Safety and cost of hyperhydration for the prevention of hemorrhagic cystitis in bone marrow transplant recipients

Hemorrhagic cystitis is a major cause of morbidity after bone marrow transplantation. Traditional methods of prevention have included mesna (2-mercaptoethane sodium sulfonate) and bladder irrigation. We report the use of hyperhydration as an alternative to these prophylactic measures. One hundred consecutive patients who underwent autologous or allogeneic bone marrow transplantation received high dose cyclophosphamide with hyperhydration using 5% dextrose normal saline at the rate of 250 ml/h and furosemide to maintain a urine output of >150 ml/h. Seventy-one of these patients also received high dose cyclophosphamide as mobilization chemotherapy. There were no episodes of hemorrhagic cystitis following mobilization chemotherapy. The incidence of hemorrhagic cystitis after transplant conditioning was 7% with 2 patients developing clinically significant hemorrhagic cystitis; one was a severe episode. The cost of hyperhydration was US$ 20 per course as opposed to US$ 1,500 per course for mesna, based on acquisition costs at our institution. We conclude that hyperhydration is a safe, inexpensive means of preventing hemorrhagic cystitis associated with high dose cyclophosphamide in bone marrow transplant recipients.

Coverage of bone marrow transplant patients: a survey of American and Canadian institutions

Personnel involved in supportive care of bone marrow transplant (BMT) patients include fellows (F), medical house-staff (HS), nurse practitioners (NP), physician assistants (PA), and moonlighting physicians (MP). We have obtained surveys from 108 American and Canadian transplant centers on the composition of inpatient support teams. Eighty-seven percent of institutions responding to the survey were university-based programs. Eighty-eight percent of the centers performed both allogeneic and autologous transplants, and 60% performed unrelated donor grafts. The mean number of transplants performed annually at each center was 101 (range 4-515). For daytime coverage, the percent of programs involving F, HS, NP, PA, or MP was 57, 50, 35, 25, and 0%, respectively, and for nighttime coverage, the composition was 50, 56, 7, 6, and 13%, respectively. Medical HS were incorporated into the care of BMT patients at some level in 93% of the programs. Involvement by HS included full 24-hour coverage (44%), full nighttime coverage (8%), stat coverage (18%), and code blue only coverage (21%). HS involvement was similar in small and large transplant programs. HS were more involved in university-based programs. Programs on the East Coast had more HS involvement, with 54% of the programs reporting full 24-hour coverage by HS compared with 32% of the programs in the Pacific region. Coverage of transplant patients varies throughout the country, and nonphysician providers are often used. HS are more active in university-based programs, and their role is similar in both large and small programs.