Impact of melphalan day -1 vs day -2 on outcomes after autologous stem cell transplant for multiple myeloma

Background

Melphalan is the most common conditioning regimen used prior to autologous stem cell transplant (ASCT); however, there are varying data on optimal melphalan timing prior to transplant for best safety and efficacy. Historically, ASCT conditioning consisted of melphalan 200 mg/m2 on day 2 (D-2) (48 h prior to ASCT), but many institutions have since adopted a melphalan protocol with administration on day 1 (D-1) (24 h prior to SCT) or split dosing over the 2 days. The optimal timing of melphalan has yet to be determined.

Methods

In this single-center retrospective study, we analyzed transplant outcomes for patients between March 2011 and September 2020 admitted for high-dose, single-agent melphalan 200 mg/m2 on D-1 vs. D-2. The primary outcomes were time to neutrophil and platelet engraftment. Secondary outcomes include incidence of hospital readmission within 30 days, 2-year progression-free survival, and 2-year overall survival.

Results

A total of 366 patients were studied (D-2 n = 269 and D-1 n = 97). The incidence of high-risk cytogenetics was similar between the two groups (37% vs. 40%). Median days to absolute neutrophil count engraftment was similar at 11 days in the D-2 and D-1 cohort (n = 269, range 0-14, IQR 11-11 vs. n = 97, range 0-14, IQR 11-12). Median days to platelet engraftment >20,000/mcL was 18 days for D-2 melphalan (range: 0-28, IQR 17-20) versus 19 days for D-1 melphalan (range: 0-32, IQR 17-21). Overall survival at 2 years post-transplant was similar in both cohorts (94%; p = 0.76), and PFS was 70% in D-2 compared with 78% in D-1 (p = 0.15). In a multivariable model including age and performance status, hospital readmission within 30 days of transplant was higher in the D-1 cohort (odds ratio 1.9; p = 0.01).

Conclusion

This study demonstrates similar neutrophil and platelet engraftment in D-1 and D-2 melphalan cohorts with similar 2-year PFS and OS. Either D-2 or D-1 melphalan dosing schedule is safe and effective.

High Cutaneous Amphiregulin Expression Predicts Fatal Acute Graft‐versus‐Host Disease

Background

Amphiregulin (AREG) is increased in circulation in acute graft‐versus‐host disease (aGVHD) and is associated with poor steroid response and lower survival. The expression of AREG in aGVHD target organs and its association with clinical outcomes are unknown.

Methods

We performed AREG immunohistochemical staining on skin specimens from 67 patients with aGVHD between the years 2010 and 2015. Two blinded reviewers assessed AREG expression and scored specimens with a semiquantitative scale ranging from 0 (absent) to 4 (most intense).

Results

Median AREG score of aGVHD cases was 3. Sixteen of 67 (23.9%) aGVHD cases had an AREG >3. High skin AREG expression (>3 vs. ≤3) was associated with increased overall clinical grade of aGVHD (52.9% vs. 33.4% clinical grade III‐IV, p = 0.02), reduced 3‐year overall survival (OS; 13% vs. 61%, p < 0.01), and increased 3‐year non‐relapse mortality (NRM; 56% vs. 20%, p = 0.05).

Conclusion

High skin AREG immunohistochemical expression is associated with high clinical grade aGVHD, poor OS, and increased NRM.

Comparative analysis of antibiotic exposure association with clinical outcomes of chemotherapy versus immunotherapy across three tumour types

Background

In solid tumours, antibiotic use during immune checkpoint inhibitor (ICI) treatment is associated with shorter survival. Following allogeneic haematopoietic cell transplantation (allo-HCT), antibiotic-induced gut microbiome alterations are associated with risk of relapse and mortality. These findings suggest that the gut microbiota can modulate antitumour immune response across tumour types, though it is not clear if the impact on outcomes is specific to immune therapy. An important limitation of previous studies is that the analysis combined all antibiotic exposures irrespective of the antibiotic spectrum of activity. Whether antibiotic exposure during induction chemotherapy in acute myeloid leukaemia (AML) affects risk of relapse is also unknown.

Patients and methods

We performed a single-centred retrospective analysis of antibiotic exposures in metastatic/advanced non-small cell lung cancer (NSCLC) and renal cell cancer (RCC) receiving ICI and newly diagnosed AML patients receiving induction chemotherapy achieving a complete remission 1. Antibiotic use within 4 weeks before and 6 weeks after the ICI initiation were included. In AML patients, antibiotic exposures between days 1 and 28 of induction were collected. Antibiotics were a priori stratified based on spectrum of activity. Primary outcomes of interest were progression-free survival (PFS), overall survival (OS) in NSCLC and RCC and relapse-free survival (RFS) in AML.

Results

140 patients with NSCLC, 55 with RCC and 143 with AML were included. In multivariable analysis, PFS and OS were shorter in NSCLC patients who received broad-spectrum anti-anaerobes (PFS, HR=3.2, 95% CI 1.6 to 6.2, p<0.01; OS, HR=1.7, 95% CI 0.8 to 3.6, p=0.19) or ‘other’ antibiotics (vancomycin-predominant) (PFS, HR=2.4, 95% CI 1.3 to 4.6, p<0.01; OS, HR=2.4, 95% CI 1.2 to 4.7, p=0.01). In RCC, patients who received penicillins/penicillin-class/early-generation cephalosporins had shorter PFS (HR=3.6, 95% CI 1.7 to 7.6, p<0.01) but similar OS (p=0.37). In the AML cohort, none of the exposures were associated with RFS.

Conclusion

In contrast to AML, antibiotic exposures in solid tumours affected clinical outcomes. The presence of an allogeneic effect (allo-HCT) or an augmented immune system (checkpoint blockade) may be necessary for microbiota mediation of relapse risk.

Transfusion burden following reduced intensity allogeneic hematopoietic cell transplantation: Impact of donor type

BACKGROUND

Transfusions are essential for allogeneic hematopoietic cell transplant (HCT), yet they are influenced by graft, donor, and other factors.

STUDY DESIGN

We analyzed transfusions in 165 adult reduced intensity HCTs (2016-2019): HLA matched sibling donor (MSD) (n = 59), matched URD (n = 25), UCB (n = 33), and haploidentical (haplo, n = 48) detailing the cumulative incidence of platelet and RBC transfusion independence, total transfusions (day-10 to day+100) plus transfusion densities (per week) over 110 days.

RESULTS

Platelet recovery to 20 × 10⁹ /L by 6 months occurred in 39/48 (81.25%) haplo recipients (median 33 [range, 0-139]) days vs. 58/59 (98.3%) MSD (median 10 [0-37]), 21/25 (84%) matched URD (median 20 [0-153]), and 29/33 (87.87%) UCB (median 48 [29-166]) days, p < .01. Regression analysis demonstrated a lower likelihood of prompt platelet recovery in matched URD, UCB, or haplo HCTs vs. MSD. Recovery to platelet independence was quickest in MSD (median 8 days [range 0-94]), vs. URD (median 16 days [0-99]), UCB (median 57 [0-94]), or haplo (median 45 [12-97]) days, p < .01. Platelet needs were unaffected by age, conditioning, or acute GVHD. RBC transfusion independence was achieved in 78% of MSD, 64% URD, and 82% UCB, though less frequent (58%) and slowest in haplo recipients, p < .01. All haplo and UCB recipients required platelet transfusions vs. only 51% of MSD and 76% of URD. RBC needs were highest in UCB and haplo HCTs.

DISCUSSION

The transplant donor influences the transfusion burden with greater platelet and RBC needs in haplo and UCB HCT which directly contributes to increased cost of care.

Outcomes of chronic graft-versus-host disease following matched sibling donor versus umbilical cord blood transplant

We compared chronic graft-versus-host disease (cGvHD) following umbilical cord blood (UCBT) and matched sibling donor peripheral blood transplant (MSD). 145 patients (2010-2017) with cGvHD after MSD (n = 104) and UCBT (n = 41) were included. Prior acute GvHD was less frequent in MSD (55% vs. 85%; p = 0.01). Severe cGvHD (32% vs. 15%, p = 0.01) and de-novo onset (45% vs. 15%, p < 0.01) were more frequent following MSD. Liver was more frequently involved in MSD recipients (38% vs. 6%); and GI in UCBT (33% vs. 63%), both p < 0.01. Overall response (CR + PR) was similar between both cohorts. 2-year CR was higher in UCBT (14% vs 33%, p = 0.02). Karnofsky score (KPS) ≥ 90 at cGvHD diagnosis was associated with higher odds of response (95%CI: 1.42-10, p < 0.01). The cumulative incidence of durable discontinuation of immune-suppressive therapy, failure-free survival (FFS) and NRM at 2-years were similar between cohorts. KPS < 90 (95%CI: 3.1-24.9, p < 0.01) and platelets <100 × 10e9/L (95%CI: 1.25-10, p = 0.01) were associated with higher risk of NRM. UCBT patients were more likely to have a prior acute GvHD, less severe cGvHD and more likely to attain CR. Despite differences, both cohorts had similar NRM and FFS. High-risk groups, including those with platelets <100 × 10e9/L and KPS < 90, need careful monitoring and intensified therapy.

Prophylactic Foscarnet for Human Herpesvirus 6: Effect on Hematopoietic Engraftment after Reduced-Intensity Conditioning Umbilical Cord Blood Transplantation

The high incidence of human herpesvirus-6 (HHV-6) reactivation, potentially interfering with engraftment after umbilical cord blood (UCB) hematopoietic cell transplantation (HCT), remains a major challenge. To potentially address this problem, we evaluated the effect of prophylactic foscarnet administered twice daily beginning on day +7 and continuing through engraftment in 25 patients. To determine the impact of foscarnet on HHV-6, engraftment, and other transplantation outcomes, we compared results in 61 identically treated patients with hematologic malignancies. Treatment and control groups underwent reduced-intensity conditioning UCB HCT with a conditioning regimen of fludarabine, cyclophosphamide, and total body irradiation 200 cGy with or without antithymocyte globulin (ATG), using sirolimus plus mycophenolate mofetil immune suppression. The treatment and control groups were similar in terms of age, disease risk, use of ATG, Hematopoietic Cell Transplantation Comorbidity Index, and graft CD34 cell dose; however, foscarnet-treated patients were less likely to receive a double UCB graft and to be treated more recently (2016 to 2018). The cumulative incidence of HHV-6 reactivation by day +100 was 63% for all patients (95% confidence interval [CI], 51% to 75%) and was not significantly different between the 2 groups. HHV-6 reactivation occurred at a median of 34 days in the foscarnet group and 25.5 days in the control group. The incidence of neutrophil engraftment at day 42 was higher in the foscarnet group compared with the control group (96%; [95% CI, 83% to 100%] versus 75% [95% CI, 64% to 85%]; P< .01). The cumulative incidence of platelet engraftment by 6 months was 92% (95% CI, 69% to 100%) for the foscarnet group versus 75% (95% CI, 60% to 90%) for the control group (P= .08), and multivariate analysis identified the use of foscarnet as an independent predictor of better platelet engraftment. No patients died as a result of graft failure in recipients of foscarnet, whereas 5 patients died from graft failure in the control group. Six-month overall survival (OS) and nonrelapse mortality (NRM) were better in the foscarnet group (96% versus 72% [P= .02] and 4% versus 18% [P= .07], respectively). Even though foscarnet prophylaxis did not prevent HHV-6 viremia, we observed a delay in time to HHV-6 reactivation, a trend toward differences in engraftment, NRM, and OS compared with historical controls.

Hematopoietic Cell and Solid Organ Transplantation in the Same Patient: Long-Term Experience at the University of Minnesota

There is a growing population of transplant survivors receiving both a solid organ transplantation (SOT) and a hematopoietic cell transplantation (HCT). This group remains underreported and not well described. We conducted a single-center retrospective study aimed at assessing safety and long-term survival outcomes of 40 patients receiving both HCT and SOT at the University of Minnesota. Twenty-seven patients underwent HCT followed by SOT (13 kidney, 10 lung, 2 liver, 1 heart, 1 heart/kidney) with a median age of 40 years (range, 5 to 72) at the time of SOT at a median of 88 months (range, 24 to 302) following the HCT. The 1-, 5-, and 10-year overall survival (OS) from the SOT was 93%, 76%, and 49%, respectively, with only 4 organ failures reported. Thirteen other patients received a HCT following a prior kidney (n = 8), liver (n = 4), or pancreas/kidney (n = 1) SOT with a median age of 42 years (range, 3 to 66) at the time of the HCT and a median 154 months (range, 1 to 304) from the SOT. The 1-, 5-, and 10-year OS from HCT were 46%, 46%, and 17% respectively. In patients receiving SOT followed by HCT, survival outcomes were better in kidney transplant recipients and patients subsequently requiring an autologous rather than an allogeneic HCT. There were no HCT engraftment failures. Our findings show that in a select patient population, undergoing a second transplant at a specialized center can lead to favorable outcomes with long-term survival and low incidence of graft rejection, organ failure, and malignant disease relapse. A large-scale study is needed to determine the incidence and risk factors preferred for a successful subsequent SOT or HCT. Those studies are crucial to further guide selection and management of patients who would benefit most from a second transplant.

Evaluation of post-thaw CFU-GM: clinical utility and role in quality assessment of umbilical cord blood in patients receiving single unit transplant

BACKGROUND

The CFU assay is considered the only in vitro assay that assesses the biologic function of hematopoietic stem and progenitor cells (HSPC).

STUDY DESIGN AND METHODS

To investigate the impact of post-thaw CFU-GM counts on the quality of umbilical cord blood (UCB), we studied transplant outcomes in 269 patients receiving single UCB transplant. We also correlated the post-thaw CFU-GM counts of 1912 units with the pre-freeze and post-thaw graft characteristics, hoping to optimize selection criteria of UCB. Data analysis included: total nucleated cells, viability, CD34+, nucleated red blood cells (NRBC), hematocrit, frozen storage time, and cord blood bank (CBB).

RESULTS

We demonstrated an association between post-thaw CFU-GM dose and the speed of neutrophil and platelet engraftment (p < 0.01). Higher post-thaw CFU-GM dose showed an increased benefit for neutrophil and platelet engraftment (p < 0.01). Post-thaw CD34+ cell dose and CFU-GM dose were strongly correlated (r = 0.78). However, CFU-GM dose showed additional benefit for patients receiving the lowest quartile of CD34+ dose. HLA disparity did not adversely impact either neutrophil or platelet engraftment. Post-thaw CFU-GM/million nucleated cells plated showed moderate correlation with pre-freeze and post-thaw CD34+ and weak correlation with other parameters. Post-thaw CFU-GM was not influenced by storage time, but was impacted by the CBB from which the unit is obtained (p < 0.01).

CONCLUSION

Post-thaw CFU-GM is an effective measure of the quality and efficacy of the UCB graft, particularly adding valuable clinical information when the CD34+ cell dose is low. Consideration of pre-freeze CD34+ cell content and CBB as additional selection criteria is warranted.

Dose Escalation of Total Marrow Irradiation in High-Risk Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Patients with refractory leukemia or minimal residual disease (MRD) at transplantation are at increased risk of relapse. Augmentation of irradiation, especially to sites of disease (ie, bone marrow) is one potential strategy for overcoming this risk. We studied the feasibility of radiation dose escalation in high-risk patients using total marrow irradiation (TMI) in a phase I dose-escalation trial. Four pediatric and 8 adult patients received conditioning with cyclophosphamide and fludarabine in conjunction with image-guided radiation to the bone marrow at 15 Gy and 18 Gy (in 3-Gy fractions), while maintaining the total body irradiation (TBI) dose to the vital organs (lungs, hearts, eyes, liver, and kidneys) at <13.2 Gy. The biologically effective dose of TMI delivered to the bone marrow was increased by 62% at 15 Gy and by 96% at 18 Gy compared with standard TBI. Although excessive dose-limiting toxicity, defined by graft failure or excessive specific organ toxicity, was not encountered, 3 of 6 patients experienced treatment-related mortality at 18 Gy. Thus, we halted enrollment at this dose level and treated an additional 4 patients at 15 Gy. The 1- year overall survival was 42% (95% confidence interval [CI], 15%-67%) and disease-free survival was 22% (95% CI, 4%-49%). The rate of relapse was 36% (95% CI, 10%-62%), and nonrelapse mortality was 42% (95% CI, 14%-70%). This study shows that TMI dose escalation to 15 Gy is feasible with acceptable toxicity in pediatric and adult patients with high-risk leukemia undergoing umbilical cord blood and sibling donor transplantation.

MDS disease characteristics, not donor source, predict hematopoietic stem cell transplant outcomes

Myelodysplastic syndrome (MDS) is a heterogeneous group of hematological malignancies with considerably variable prognoses and curable only with hematopoietic cell transplantation (HCT). Few studies comparing MDS HCT outcomes between sibling and umbilical cord blood (UCB) donors exist. Using the University of Minnesota Blood and Marrow Transplant (BMT) database, we retrospectively analyzed HCT outcomes among 89 MDS patients undergoing either sibling or double UCB HCT in 2000–2013. We observed similar survival, relapse and non-relapse mortality between sibling and UCB donor sources. Relapse was increased in those with monosomal karyotype (P=0.04) and with reduced intensity conditioning (P<0.01). In summary, our data highlight similar MDS HCT outcomes regardless of donor source and support the use of UCB as an alternative donor when a sibling is unavailable.

Marrow damage and hematopoietic recovery following allogeneic bone marrow transplantation for acute leukemias: Effect of radiation dose and conditioning regimen

BACKGROUND AND PURPOSE

Total body irradiation (TBI) is a common component of hematopoietic cell transplantation (HCT) conditioning regimens. Preclinical studies suggest prolonged bone marrow (BM) injury after TBI could contribute to impaired engraftment and poor hematopoietic function.

MATERIALS AND METHODS

We studied the longitudinal changes in the marrow environment in patients receiving allogeneic HCT with myeloablative (MA, n=42) and reduced intensity (RIC, n=56) doses of TBI from 2003-2013, including BM cellularity, histologic features of injury and repair, hematologic and immunologic recovery.

RESULTS

Following MA conditioning, a 30% decrease in the marrow cellularity persisted at 1 year post-transplant (p=0.03). RIC HCT marrow cellularity transiently decreased but returned to baseline by 6 months even though the RIC group received mostly umbilical cord blood (UCB) grafts (82%, vs. 17% in the MA cohort, p<0.01). There was no evidence of persistent marrow vascular damage or inflammation. Recipients of more intensive conditioning did not show more persistent cytopenias with the exception of a tendency for minimal thrombocytopenia. Immune recovery was similar between MA and RIC.

CONCLUSIONS

These findings suggest that TBI associated with MA conditioning leads to prolonged reductions in marrow cellularity, but does not show additional histological evidence of long-term injury, which is further supported by similar peripheral counts and immunologic recovery.

Myeloablative, but not Reduced-Intensity, Conditioning Overcomes the Negative Effect of Flow-Cytometric Evidence of Leukemia in Acute Myeloid Leukemia

Stringent complete remission (CR) in acute myeloid leukemia (AML) requires the absence of both morphologic and flow cytometric evidence of disease. We have previously shown that persistent AML detected by flow cytometry (FC+) before reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (alloHCT) was associated with significantly increased relapse, shorter disease-free survival (DFS), and poorer overall survival (OS), independent of morphologic blast count. We evaluated the effect of FC status on outcomes of alloHCT for AML after either myeloablative conditioning (MAC) or RIC regimens in 203 patients (MAC, n = 80, and RIC, n = 123) with no morphologic evidence of persistent AML pretransplant on marrow biopsy. The allografts included 130 umbilical cord blood (UCB) and 73 sibling donors. We performed central review of pretransplant standard sensitivity FC to identify detectable FC+. Twenty-five patients were FC+, including 15 (18.7%) receiving MAC and 10 (8.1%) RIC alloHCT. Among RIC patients FC+ was associated with significantly inferior relapse, DFS, and OS (multiple regression HR, 3.8; 95% CI, 1.7 to 8.7; P < .01 for relapse; HR, 2.9; 95% CI, 1.4 to 5.9; P < .01 for DFS; and HR, 3.4; 95% CI, 1.7 to 7; P < .01 for OS). In contrast, FC+ status was not associated with relapse or decreased OS after MAC. These data suggest that MAC, but not RIC, overcomes the negative effect of pretransplant FC+ after sibling or UCB alloHCT. Therefore, a deeper pretransplant leukemia-free state is preferred for those treated with RIC.

Higher Dose of Mycophenolate Mofetil Reduces Acute Graft-versus-Host Disease in Reduced-Intensity Conditioning Double Umbilical Cord Blood Transplantation

Mycophenolate mofetil (MMF) is frequently used in hematopoietic cell transplantation (HCT) for graft-versus-host disease (GVHD) prophylaxis and to facilitate engraftment. We previously reported that a higher level of mycophenolic acid can be achieved with an MMF dose of 3 g/day than with 2 g/day. Here, we retrospectively compared clinical outcomes of reduced-intensity conditioning (RIC) double umbilical cord blood (dUCB) HCT recipients receiving cyclosporine A with MMF 2 g (n = 93) versus 3 g (n = 175) daily. Multiple regression analysis adjusted for antithymocyte globulin in the conditioning revealed that MMF 3 g/day led to a 49% relative risk (RR) reduction in grade II to IV acute GVHD rate (RR, .51; 95% confidence interval, .36 to .72; P < .01). However, the higher MMF dose was not protective for chronic GVHD. Additionally, MMF dose was not an independent predictor of neutrophil engraftment or treatment-related mortality at 6 months or 2-year post-transplantation disease relapse, disease-free survival, or overall survival. Higher MMF dose did not increase risk of infectious complications, and infection-related mortality was similar for both MMF doses. Our data indicate that MMF 3 g/day reduces the risk of acute GVHD without affecting other clinical outcomes and should be used for GVHD prophylaxis after RIC dUCB transplantation.

Iron overload in allogeneic hematopoietic cell transplantation outcome: a meta-analysis

An elevated ferritin level before allogeneic hematopoietic cell transplantation (HCT) is an adverse prognostic factor for overall survival (OS) and nonrelapse mortality. Because ferritin is an imperfect surrogate of iron stores, the prognostic role of iron overload remains unclear. We conducted a patient-level meta-analysis of 4 studies that used magnetic resonance imaging to estimate pre-HCT liver iron content (LIC). An elevated LIC was not associated with a significant increase in mortality: the hazard ratio (HR) for mortality associated with LIC > 7 mg/g dry weight (primary endpoint) was 1.4 (P = .18). In contrast, ferritin >1000 ng/mL was a significant prognostic factor (HR for mortality, 1.7; P = .036). There was, however, no significant association between ferritin > 2500 and mortality. This meta-analysis suggests that iron overload, as assessed by LIC, is not a strong prognostic factor for OS in a general adult HCT population. Our data also suggest that ferritin is an inadequate surrogate for iron overload in HCT.

Myeloablative cord blood transplantation in adults with acute leukemia: comparison of two different transplant platforms

We compared the clinical outcomes of adults with acute leukemia that received single-unit umbilical cord blood transplantation (sUCBT) after conditioning with a busulfan/antithymocyte globulin (BU-ATG)-based regimen at University Hospital La Fe (n = 102) or double-unit UCBT (dUCBT) after conditioning with a total body irradiation (TBI)-based regimen at the University of Minnesota (n = 91). Nonrelapse mortality, relapse and disease-free survival were similar in the 2 groups. Multivariate analyses, showed more rapid neutrophil (hazard ratio [HR], .6; 95% confidence interval [CI], .45 to .80; P = .0006) and platelet recovery (HR, .59; 95% CI, .43 to.83; P = .002) after the BU-ATG-based conditioning and sUCBT. Although there was a lower risk of acute graft-versus-host disease (GVHD) grade II to IV (HR, 2.81; 95% CI, 1.75 to 4.35; P < .001) after BU-ATG and sUCBT, the incidences of grade III to IV acute and chronic GVHD were similar between the 2 groups. Regarding disease-specific outcomes, disease-free survival in both acute myeloid leukemia and acute lymphoblastic leukemia (ALL) patients were not significantly different; however, a significantly lower relapse rate was found in patients with ALL treated with TBI and dUCBT (HR, .3; 95% CI, .12 to .84; P = .02). In the context of these specific treatment platforms, our study demonstrates that sUCB and dUCBT offer similar outcomes.

Highly Variable Mycophenolate Mofetil Bioavailability Following Nonmyeloablative Hematopoietic Cell Transplantation

This study determined the oral bioavailability of mycophenolic acid, the active metabolite of mycophenolate mofetil, in patients undergoing nonmyeloablative hematopoietic cell transplantation. Eighteen adults receiving a preparative regimen containing fludarabine, cyclophosphamide, and total body irradiation were studied. Immune suppression consisted of cyclosporine and mycophenolate 1 g twice daily. Pharmacokinetic variability was high after intravenous and oral dosing. Intravenous dosing resulted in a median area under the curve (AUC) of 28.3 microg x h/mL (range, 9.96-70.4) and an oral AUC of 16.7 microg x h/mL (range, 9.38-35.3). Cmax after intravenous and oral dosing was 12.18 and 5.29 microg/mL, respectively. The median oral bioavailability was 72.3% (20.5%-172%), with 8-fold variability. Five patients (28%) had an oral bioavailability < or = 50%. At time of oral pharmacokinetics, 15 patients (83%) had an AUC(0-12) < 30 microg x h/mL. The initial oral dose should be at least 25% greater than the intravenous dose with follow-up assessment of plasma concentrations.

Prolonged subcutaneous administration of 852A, a novel systemic toll-like receptor 7 agonist, to activate innate immune responses in patients with advanced hematologic malignancies

The toll-like receptor (TLR) 7 agonist 852A, a small-molecule imidazoquinoline, stimulates plasmacytoid dendritic cells to produce multiple cytokines. We conducted a Phase II study of 852A in patients with recurrent hematologic malignancies. The primary objective was assessing the activity of 852A administered subcutaneously twice weekly for 12 weeks. Secondary objectives were assessing the safety of 852A and its ability to activate the immune system with prolonged dosing. Patients with relapsed hematologic malignancies of any age with adequate organ function were eligible. Patients initiated dosing at 0.6 mg/m(2) twice weekly and escalated by 0.2 mg/m(2) after every two doses as tolerated to a target dose of 1.2 mg/m(2) . Patients with responses or stable disease were eligible for additional cycles. Seventeen patients (15 males) entered the study: 6 with AML, 5 ALL, 4 NHL, 1 Hodgkin's lymphoma, and 1 multiple myeloma. The mean age was 41 years (12-71 years). The median number of prior chemotherapy regimens was 5 (range = 1-14). Thirteen patients completed all 24 injections. Grade 3-4 toxicities included nausea, dyspnea, fever, myalgia, malaise, and cough. Responses included one complete response (ALL), one partial response (AML), two stable disease (AML and NHL), and 9 progressive disease. This is the first in-human hematologic malignancy trial of a subcutaneously (SC) delivered TLR7 agonist using a prolonged dosing schedule. 852A was safely administered up to 1.2 mg/m(2) twice weekly with evidence of sustained tolerability and clinical activity in hematologic malignancies. Systemic TLR agonists for the treatment of hematologic malignancies warrant further study.

Successful remission rates and survival after lymphodepleting chemotherapy and donor lymphocyte infusion for relapsed hematologic malignancies postallogeneic hematopoietic cell transplantation

Few therapeutic strategies exist for hematologic malignancies relapsing post allogeneic hematopoietic cell transplantation. We present outcomes on 35 patients with nonchronic myelogenous leukemia (CML) hematologic malignancies, the majority having acute myelogenous leukemia (AML) or myelodysplastic syndromes/myeloproliferative disorders (MDS/MPD) (n = 22) receiving lymphodepleting chemotherapy followed by donor lymphocyte infusion (DLI) at 2 T cell dose levels (0.5 and 1.0 × 10(8) CD3/kg). Forty-nine percent of patients achieved complete remission (CR), with a median duration of remission of 6 months (range: 2-71+). CR rates were similar between the 2 groups. The incidence of acute graft-versus-host disease (aGVHD) of any grade was 49%. We saw a higher incidence of grade II-IV aGVHD, with a rate of 66% using the higher-dose DLI (grade III, 33% and grade 4, 20%) versus only 25% (10% grade III-IV) with the lower-dose DLI (P = .06). Overall survival at 1 and 2 years was 30% (95% confidence interval [CI], 16%-45%) and 19% (95% CI, 8%-34%); however, for those achieving CR, 1- and 2-year survival was improved at 44% (95% CI, 20%-66%) and 28% (95% CI, 8%-52%) (P = .03), respectively. These results demonstrate that DLI after lymphodepleting chemotherapy for relapsed hematologic malignancies results in frequent CRs. The lower DLI dose regimen improved the tolerability of this therapeutic approach, with modest rates of severe aGVHD.

Diagnosis of myelodysplastic syndrome among a cohort of 119 patients with fanconi anemia: morphologic and cytogenetic characteristics

Predisposition to myelodysplastic syndrome (MDS) and acute leukemia is a hallmark of Fanconi anemia (FA). Morphologic criteria for MDS in FA are not well established, nor is the significance of clonal chromosomal abnormalities. We reviewed bone marrow samples of 119 FA patients: 23 had MDS, with the most common subtype refractory cytopenia with multilineage dysplasia. The presence of MDS was highly correlated with the presence of clonal abnormalities. Neutrophil dysplasia and increased blasts were always associated with the presence of a clone, in contrast with dyserythropoiesis. The most frequent clones had gains of 1q and 3q and/or loss of 7. Karyotype complexity also correlated with MDS. One third of patients with 3q as a sole abnormality had no MDS; patients with 3q and an additional abnormality all had MDS. The data provide a rationale for integrating cytogenetic findings with independently evaluated morphologic findings for monitoring bone marrow status in FA.

Pre-transplant risk factors affecting outcome in Hurler syndrome

Allogeneic transplantation remains the standard of care for patients with Hurler syndrome. As enzyme replacement therapy (ERT) has become available, controversy has emerged in regards to whether the use of enzyme in the peri-transplant period is appropriate. An analysis was performed on 74 patients with Hurler syndrome transplanted at the University of Minnesota between 1990 and 2003, before our use of ERT associated with transplant, with the intention of determining if patients at higher risk during the transplant can be identified based on evaluations and events before transplantation. Age, the presence of hydrocephalus, a history of cardiovascular issues or upper airway obstruction before transplant was not associated with significant differences in survival. In contrast, patients who had a history of lower airway disease, including reactive airway disease or bronchiolitis, or a history of pneumonia, had a significantly inferior outcome based on OS. The risk for serious respiratory complications was also assessed by evaluating the incidence of intubation. Overall, 31% of these patients were intubated. The risk of intubation was higher in older patients and in those with a history of lower airway disease. These findings have implications for the care of patients with high-risk features.

Comparison of two mycophenolate mofetil dosing regimens after hematopoietic cell transplantation

Mycophenolic acid (MPA) is the active component of mycophenolate mofetil (MMF). Low MPA exposure is associated with a higher incidence of acute GVHD and possibly worse engraftment. Therapeutic plasma targets have been proposed in hematopoietic cell transplantation (HCT), however, are difficult to achieve in adult patients with MMF doses of 2 g/day. Mycophenolate pharmacokinetics was prospectively studied in adults undergoing nonmyeloablative HCT who received MMF 3 g/day with CYA. The first 15 individuals received 1.5 g every 12 h and the second 15 received 1 g every 8 h. Sampling was performed in each patient with i.v. and oral administration. There were no differences in total or unbound MPA 24-h cumulative area under the curves (AUCs), concentrations at steady state (Css) or troughs between the two dosing regimens (all P>0.01). The previously proposed total MPA Css target of 3 microg/ml and trough >or=1 micro/ml were achieved in only 13-27% and 20-53% of patients, respectively, on 3 g/day. However, the 3 g/day regimens readily achieved satisfactory unbound 24-h cumulative AUC targets of 0.600 microg(*)h/ml in 87-100% of subjects. There appears to be no significant difference in daily MPA exposure when MMF of 3 g/day is divided into two or three equal doses.

High prevalence of iron overload in adult allogeneic hematopoietic cell transplant survivors

Allogeneic hematopoietic cell transplant (HCT) recipients frequently need red blood cell transfusions, and can be at risk for developing iron overload. We studied the prevalence of iron overload in 56 adult allogeneic HCT patients who had survived for a median of 28 (range: 12-151) months from transplant. Patients were initially screened with serum ferritin, and those with serum ferritin >1000 ng/mL underwent R2 magnetic resonance imaging (MRI) of the liver, a sensitive and specific noninvasive imaging technique to measure liver iron concentration (LIC). Iron overload was defined as LIC above normal (>1.8 mg/g dry weight). Nineteen patients had serum ferritin >1000 ng/mL with a median LIC of 7.0 (range: 1.8-28.3) mg/g. The overall prevalence of iron overload was 32% (95% confidence intervals, 20%-46%). The LIC on MRI was moderately correlated with serum ferritin (rho = .47). Iron overload is a frequent complication of allogeneic transplantation. Serum ferritin is a good screening test but does not reliably predict tissue iron overload, and estimation of LIC should be considered before initiating therapy. More studies are needed to determine the impact of iron overload on long-term morbidity and mortality in allogeneic transplant survivors.

Fludarabine vs cladribine plus busulfan and low-dose TBI as reduced intensity conditioning for allogeneic hematopoietic stem cell transplantation: a prospective randomized trial

Purine analogs are often used for conditioning preceding allogeneic hematopoietic stem cell transplantation (HCT). We prospectively tested fludarabine (Flu) 40 mg/m(2)/day x 5 days vs cladribine (Clad) 10 mg/m(2)/day x 5 days plus oral busulfan (1 mg/kg q6 h x 2 days) and total body irradiation 200 cGy in 32 recipients of matched sibling and unrelated donor (URD) HCT. Patients were similar in age (median 52 years), diagnosis, extensive pre-HCT therapy (56 vs 63%), and high-risk disease status (81 vs 93%). Neutrophil engraftment was prompt (median 11 vs 12 days), but early graft failure using Clad halted randomization. Platelet recovery was prompt (median Flu 18 vs Clad 24 days). Graft-versus-host disease (GVHD) after Flu vs Clad was similar; (acute grade II/IV 56 vs 69%, P=0.26; chronic 50 vs 31%, P=0.27). Nonrelapse mortality (Flu 25 vs Clad 38%, P=0.47) and progression-free survival at 3 years were similar as well. Multivariate analyses showed slightly, but not significantly lower relative risk (RR) of neutrophil engraftment with Clad (RR 0.6 (95% CI 0.2-1.3) P=0.16) and with URD RR 0.4 (0.2-1.0) P=0.04). Older patients with advanced hematologic malignancies achieve satisfactory outcomes using either of these reduced intensity conditioning regimens.

Marked increased risk of Epstein-Barr virus-related complications with the addition of antithymocyte globulin to a nonmyeloablative conditioning prior to unrelated umbilical cord blood transplantation

Umbilical cord blood (UCB) is increasingly used as an alternative source of hematopoietic stem cells for transplantation for patients who lack a suitable sibling donor. Despite concerns about a possible increased risk of Epstein-Barr virus (EBV) posttransplantation lymphoproliferative disorder (PTLD) after UCB transplantation, early reports documented rates of PTLD comparable to those reported after HLA-matched unrelated marrow myeloablative (MA) transplantations. To further investigate the incidence of EBV PTLD after UCB transplantation and potential risk factors, we evaluated the incidence of EBV-related complications in 335 patients undergoing UCB transplantation with an MA or nonmyeloablative (NMA) preparative regimen. The incidence of EBV-related complications was a 4.5% overall, 3.3% for MA transplantations, and 7% for NMA transplantations. However, the incidence of EBV-related complications was significantly higher in a subset of patients treated with an NMA preparative regimen that included antithymocyte globulin (ATG) versus those that did not (21% vs 2%; P < .01). Nine of 11 patients who developed EBV PTLD were treated with rituximab (anti-CD20 antibody), with the 5 responders being alive and disease free at a median of 26 months. Use of ATG in recipients of an NMA preparative regimen warrants close monitoring for evidence of EBV reactivation and potentially preemptive therapy with rituximab.

Cerebral X-linked adrenoleukodystrophy: the international hematopoietic cell transplantation experience from 1982 to 1999

Cerebral X-linked adrenoleukodystrophy (X-ALD) is a disorder of very-long-chain fatty acid metabolism, adrenal insufficiency, and cerebral demyelination. Death occurs within 2 to 5 years of clinical onset without hematopoietic cell transplantation (HCT). One hundred twenty-six boys with X-ALD received HCT from 1982 to 1999. Survival, engraftment, and acute graft-versus-host disease were studied. Degree of disability associated with neurologic and neuropsychological function and cerebral demyelination were evaluated before and after HCT. Complete data were available and analyzed for 94 boys with cerebral X-ALD. The estimated 5- and 8-year survival was 56%. The leading cause of death was disease progression. Donor-derived engraftment occurred in 86% of patients. Demyelination involved parietal-occipital lobes in 90%, leading to visual and auditory processing deficits in many boys. Overall 5-year survival of 92% in patients with 0 or 1 neurologic deficits and magnetic resonance imaging (MRI) severity score less than 9 before HCT was superior to survival for all others (45%; P <.01). Baseline neurologic and neuropsychological function, degree of disability, and neuroradiologic status predicted outcomes following HCT. In this first comprehensive report of the international HCT experience for X-ALD, we conclude that boys with early-stage disease benefit from HCT, whereas boys with advanced disease may be candidates for experimental therapies.

Progenitor content of autologous grafts: mobilized bone marrow vs mobilized blood

The progenitor content of autologous peripheral blood progenitor and stem cell collections is a major determinant of prompt hematopoietic recovery following autologous stem cell transplantation. We analyzed unstimulated bone marrow (BM) and peripheral blood (PB) apheresis products in comparison to those collected following G-CSF or GM-CSF stimulation. We quantitated their committed (CFU-GM) and primitive (long-term culture-initiating cells, LTC-IC) progenitors in relation to hematologic recovery in 63 patients undergoing autografting for lymphoid malignancies. G-CSF, but not GM-CSF, substantially enriched the committed progenitor content (2.5-3.6-fold) of both PB and BM grafts. G-CSF also enriched the LTC-IC content of BM and PB compared to control grafts. GM-CSF augmented (11.5-fold) the LTC-IC content of stimulated BM, but not GM-CSF-mobilized PB. Neutrophil recovery was substantially quicker in recipients of BM or PB mobilized with G-CSF or GM-CSF. In contrast, red cell and platelet recovery was accelerated in recipients of GM-CSF-stimulated BM (but not PB) and G-CSF-stimulated PB (but not BM). No direct correlation between progenitor dose and hematopoietic recovery for neutrophils, platelets or red cells was observed. Cytokine stimulation can augment the committed and more primitive multilineage progenitor content of BM and PB grafts, to a differing extent. The uncertain relationship with multilineage myeloid recovery emphasizes the limitations in using clonogenic progenitor analyses to assess the adequacy of an autologous graft prior to transplantation.

A comparison of related donor peripheral blood and bone marrow transplants: importance of late-onset chronic graft-versus-host disease and infections

Peripheral blood hematopoietic stem cell (PBSC) transplants have been shown to result in more rapid engraftment than standard bone marrow transplants (BMTs). Little comparative data exist regarding complications in patients receiving transplants using these stem cell sources. In our study, 97 adults with advanced hematologic malignancies who received allogeneic PBSC transplants were compared with 97 adults who received allogeneic BMTs using identical preparative regimens and support parameters. The incidence of systemic infections and other major complications occurring within the first year after transplantation were calculated in both groups. Proportional hazard analysis was used to examine risk factors for death and complications in both groups. Patients receiving PBSC transplants had more rapid neutrophil (17 days versus 24 days; P <.001) and platelet engraftment (28 days versus 47 days; P <.001) than BMT recipients. The survival rate at 2 years was 38% in PBSC transplant recipients and 28% in marrow recipients (P =.08). There was no difference in rates of grade II to IV acute graft-versus-host disease (GVHD) between groups (PBSC 46%, BMT 51%; P =.3). PBSC transplant recipients were more likely to develop chronic GVHD after 180 days (hazard ratio 2.2; P =.05). Accompanying this "late-onset chronic GVHD," a pattern of more frequent late systemic fungal and cytomegalovirus infections was observed in PBSC transplant recipients. In conclusion, although PBSC transplant recipients engraft more quickly than BMT recipients and have somewhat better 2-year survival rates, they develop more frequent late-onset chronic GVHD and may have more late fungal and cytomegalovirus infections than marrow recipients. Further studies must examine this late-onset chronic GVHD and better characterize immune reconstitution in PBSC transplant recipients to understand their effects on patient recovery.

Evaluation of KIR ligand incompatibility in mismatched unrelated donor hematopoietic transplants. Killer immunoglobulin-like receptor

One of the functions of HLA class I alleles is interaction with natural killer (NK) cells. Receptors termed killer immunoglobulin-like receptors (KIRs) on NK cells recognize groups of HLA class I alleles, and interaction between receptor and class I allele inhibits reactivity of the NK cell. Failure to recognize the appropriate KIR ligand on a mismatched cell can trigger NK cell elimination of that target cell. Recent analysis of haploidentical hematopoietic transplantations has shown a reduction of graft failure, graft-versus-host disease, and relapse in those with KIR ligand incompatibility in the graft-versus-host direction. In this study we analyzed the effect of KIR ligand incompatibility on outcomes of unrelated donor bone marrow transplantations. The data show no advantage for KIR ligand incompatibility in this clinical setting as assessed by HLA-Bw4 and HLA-C alleles. It is possible that there will be a benefit of NK cell alloreactivity if strategies of haploidentical transplantation are used: high stem cell doses, extensive T-cell depletion, and no postgrafting immune suppression.

Low incidence of Epstein-Barr virus-associated posttransplantation lymphoproliferative disorders in 272 unrelated-donor umbilical cord blood transplant recipients

Umbilical cord blood (UCB) is being increasingly used for transplantation, but the ability of neonatal T cells to regulate Epstein-Barr virus (EBV)-associated lymphoproliferation is unknown. Because UCB transplantation (UCBT) is associated with a relatively low infused dose of donor T cells, frequent donor-recipient HLA disparity, and use of antithymocyte globulin during conditioning, we hypothesized that the risk of EBV-associated posttransplantation lymphoproliferative disorders (EVB-PTLD) after UCBT may be increased. To investigate the incidence of EBV-PTLD after UCBT, we analyzed 272 unrelated-donor UCBTs performed from August 1993 to December 1999 at Duke University Medical Center and the University of Minnesota. Five cases of EBV-PTLD were identified, with a cumulative incidence of 2% (95% confidence interval, 0.3%-3.7%) at 2 years. EBV-PTLD affected UCB recipients aged 1 to 49 years (median, 8 years), with 4 patients undergoing transplantation for leukemia and 1 for immunodeficiency. Patients received UCB grafts that were HLA matched (n = 1) or mismatched at 1 (n = 1) or 2 (n = 3) HLA loci. Diagnoses occurred at 4 to 14 months (median, 6 months) after UCBT, with 4 of 5 patients having preceding grade II to IV acute graft-versus-host disease and 1 being diagnosed at autopsy. Treatment of 4 patients consisted of withdrawal of immunosuppressive treatment and administration of rituximab, with 2 of 4 patients responding. Thus, the incidence of EBV-PTLD after unrelated-donor UCBT appears similar to that observed after transplantation using unrelated bone marrow (BM) and compares favorably with unrelated-donor T-cell-depleted BM transplantation. Because adoptive immunotherapy with donor lymphocytes is not an available option for recipients of unrelated-donor UCBT, new therapeutic strategies are needed, and rituximab appears promising.

Survival after transplantation of unrelated donor umbilical cord blood is comparable to that of human leukocyte antigen-matched unrelated donor bone marrow: results of a matched-pair analysis

Umbilical cord blood (UCB) is being increasingly used for hematopoietic stem cell transplantation and has been associated with a reduced incidence of severe graft-versus-host disease (GVHD). To further investigate the relative merits of unrelated donor UCB versus bone marrow (BM), a matched-pair analysis comparing the outcomes of recipients of 0 to 3 human leukocyte antigen (HLA)-mismatched UCB and HLA-A, B, DRB1-matched BM was performed. UCB patients, who received cyclosporine (CSA) and methylprednisolone (MP), were matched for age, diagnosis, and disease stage with BM patients, who received either methotrexate (MTX) and CSA (26 pairs) or T-cell depletion (TCD) and CSA/MP (31 pairs). Patients were predominantly children (median age, 5 years) undergoing transplantation for malignancy, storage diseases, BM failure, and immunodeficiency syndromes between 1991 and 1999. Although neutrophil recovery was significantly slower after UCB transplantation, the probability of donor-derived engraftment at day 45 was 88% in UCB versus 96% in BM-MTX recipients (P =.41) and 85% in UCB versus 90% in BM-TCD recipients (P =.32), respectively. Platelet recovery was similar in UCB versus BM pairs. Furthermore, incidences of acute and chronic GVHD were similar in UCB and BM recipients, with 53% of UCB versus 41% of BM-MTX recipients alive (P =.40) and 52% of UCB versus 56% of BM-TCD recipients alive at 2 years (P >.80), respectively. These data suggest that despite increased HLA disparity, probabilities of engraftment, GVHD, and survival after UCB transplantation are comparable to those observed after HLA-matched BM transplantation. Therefore, UCB should be considered an acceptable alternative to HLA-matched BM for pediatric patients.

Late outcomes after bone marrow transplant for aplastic anaemia

Allogeneic transplantation is effective in reconstituting haemopoiesis in severe aplastic anaemia (SAA). We report long-term health-related outcomes in 37 children and young adults with SAA transplanted between 1975 and 1996. The median length of follow-up was 17 years (range, 4-25 years). Using a case-control design, late social and medical outcomes in transplant recipients were compared with 146 control subjects matched for gender and age. The majority of patients received an irradiation-containing preparative regimen. There were no significant differences in the self-rating of health status between transplant recipients and controls (P = 0.8), with 71% reporting their health status as excellent and 29% as good compared with 74% and 26% of controls. They demonstrate the same normal psychosexual function as their peers and have similar educational achievements and employment history. Transplant recipients and controls are equally likely to have held a job or be currently employed and there are no significant differences in their personal income (OR = 0.60, 95% CI = 0.11-3.37). Although transplant recipients have had problems related to health insurance policies, the majority have adequate health insurance coverage. There were no differences in chronic health problems between transplant recipients and control subjects, except for expected increases in cataracts, short stature in men, hypothyroidism and gonadal dysfunction. Using self-assessment, these transplant recipients indicated an excellent level of satisfaction and social integration, showing transplantation to be an effective long-term therapy for SAA.

Impact of birthweight on healthcare charges within a managed care organization

OBJECTIVE

To determine the rate of low-birthweight (LBW) births and the association of LBW with utilization and healthcare charges in a managed care organization.

DESIGN

Observational study of computerized and medical record data.

PATIENTS AND METHODS

We assessed the rate of LBW (weight < 2500 g) for singleton infants born during 1993 and 1995 at 2 hospitals (1993, N = 3212; 1995, N = 3073). For a subset of infants born during 1995 (n = 1273), we examined differences in utilization and medical charges, by birthweight category (moderately LBW [MLBW; 1500 to 2499 g] vs normal birthweight [NBW]), at 1 year postdischarge.

RESULTS

In both 1993 and 1995, 3% of singleton infants were LBW infants, and 2% to 3% were macrosomic (> or = 4500 g). Complete data for analyses of utilization and healthcare charges were available on 1273 infants who were enrolled for the entire postdischarge year. The use of outpatient, emergency department (ED), and subspecialty care by MLBW infants and by NBW infants was similar. However, MLBW was associated with an increased rate of rehospitalization during the first year of birth (P < .01). MLBW infants' medical care charges were 46% higher than those of NBW infants (P = .0125).

CONCLUSIONS

MLBW infants and NBW infants had similar outpatient and ED service use during the first year after hospital discharge. Excess charges incurred by MLBW infants were primarily due to higher rates of rehospitalization. Of the 38 admissions, 21 were related to infection or fear of infection, and 4 were due to congenital malformations.

Response to thalidomide therapy in refractory chronic graft-versus-host disease

Chronic graft-versus-host disease (GVHD) refractory to standard immunosuppressive therapy remains a major cause of morbidity and mortality after allogeneic bone marrow transplantation (BMT). Thalidomide may be effective in some patients with high-risk or refractory chronic GVHD. We report a single-institution study of thalidomide in 37 BMT patients with extensive chronic GVHD refractory to standard immunosuppressive therapy. Acute GVHD occurred in 34 (91%) of patients and evolved progressively into chronic GVHD in 23 (62%) patients. Thalidomide was added to standard immunosuppressive therapy a median of 11 months (range 0-105 months) after the diagnosis of chronic GVHD. Fourteen of 37 (38%) patients responded after introduction of thalidomide (one complete, 13 partial). Ten of 21 (46%) children and four of 16 (25%) adults responded. Responses were seen in eight of 17 (47%) recipients of related donor marrow and six of 20 (30%) recipients of unrelated donor marrow. Eight of 23 (34%) patients with progressive onset of chronic GVHD showed a response. There were no deaths among the responders. The remaining 23 patients (62%) did not respond and of these only two survive, one with progressive scleroderma, and the other with bronchiolitis obliterans. Chronic GVHD with associated infection (most commonly disseminated fungal infection) was a major contributor to mortality in all cases. Overall, after initiation of thalidomide, the 2-year Kaplan-Meier survival was 41% (95% C.I. 24%-59%). We conclude that thalidomide is a useful and well-tolerated therapy for patients with previously treated refractory chronic GVHD, including those with progressive onset of chronic GVHD, recipients of unrelated donor marrow, and children. Earlier introduction of thalidomide as an adjunct to standard immunosuppressive therapy may lead to more frequent responses and possible better survival.

Busulfan pharmacokinetics do not predict relapse in acute myeloid leukemia

The purpose of this study was to evaluate the influence of busulfan (BU) pharmacokinetics on survival, grades II-IV acute graft-versus-host disease (GVHD), non-relapse mortality (NRM) and relapse in a group composed of 45 children (<18 years) and seven adults with acute myeloid leukemia (AML) in first complete remission and undergoing hematopoietic stem cell transplantation (SCT). Fifty-two patients underwent autologous (n = 25) or allogeneic (n = 27) SCT. The median age was 8.9 years (range 0.6-53 years). Conditioning therapy consisted of BU and cyclophosphamide. Improved disease-free survival was found in those patients with a steady-state concentration of BU (CssBU) below the median (<578 mg/ml, P = 0.05), and the same trend was noted for overall survival (P = 0.07). This was secondary to a higher incidence of NRM in the group of patients with CssBU above the median (P = 0.06). There was no significant correlation with CssBU and relapse (P = 0.31). No association between CssBU and GVHD was found in allogeneic patients (P = 0.30). Relapse was evaluated among the subgroups of age (< or >10 years) and transplant type (allogeneic or autologous) with no statistically significant association observed among these factors. Multiple regression analysis for relapse revealed no significant correlation with CssBU above or below the median, age, or transplant type. In this study, CssBU below the median did not correlate with an inferior outcome for patients with AML. Pharmacokinetic dosing of BU may be important for prevention of NRM but does not appear to influence the risk of relapse in this largely pediatric population with AML.

Increasing incidence of diffuse alveolar hemorrhage following allogeneic bone marrow transplantation: cryptic etiology and uncertain therapy

Diffuse alveolar hemorrhage (DAH) is a non-infectious pulmonary complication of bone marrow transplantation (BMT) with resultant high mortality. It reportedly occurs primarily in autologous recipients. We examined the incidence of DAH in our center in order to assess potential risk factors and develop preventive strategies. Between 1991 and 1997, 23 cases of DAH occurred in 922 adult patients (2.5%) receiving BMT for hematological malignancy. Strikingly, 12 cases occurred in 1997 with the majority in recipients of allogeneic matched sibling donor stem cells. Treatment with high-dose steroids, 250 mg to 2 g/day, in 15 patients led to transient improvement in 10 patients, but 21 of the 23 patients required mechanical ventilation. Mortality was high with 17 patients (74%) dying a median of 39 days (range 22-47) post transplant; a median of 17 days post onset of DAH (range 5-34). Six patients are alive with a median follow-up of 18 months (range 12-60). No recognizable alteration in supportive care, conditioning regimen, GVHD prophylaxis or cytokine usage was associated with this striking increase in the frequency of DAH after allografting. Further follow-up is required to establish whether this increase in the incidence of DAH in allogeneic transplantation is an isolated occurrence or an ongoing problem. If indeed there is a real increase in the incidence of this complication, then efforts need to be directed towards elucidating a possible cause or risk factors. We offer the possibility that a new unidentified infection, undetected by current microbiological tests might contribute to this striking increase in DAH. These data, while not establishing a cause, suggest a markedly augmented risk of DAH in allogeneic BMT. In addition, high-dose corticosteroids have only limited efficacy as therapy for DAH after allotransplantation. Further investigation into the pathogenesis of this syndrome is essential as is prompt and immediate consideration of DAH in all patients with respiratory compromise early after BMT.

Thrombopoietic cytokines in relation to platelet recovery after bone marrow transplantation

In order to evaluate the importance of different thrombopoietic stimulatory cytokines in accelerating platelet recovery after bone marrow transplantation (BMT), we assayed serial plasma concentrations of three cytokines, thrombopoietin (TPO), interleukin-6 (IL-6), and IL-11 through the course of platelet nadir and recovery after BMT. Both mean TPO and IL-6 levels showed a marked rise and later fall preceding or coincident with the platelet nadir and recovery, suggesting their potential role as circulating regulators or stimulators of thrombopoiesis. In contrast, IL-11 levels remained remarkably constant through the whole course suggesting that this cytokine, though capable of stimulating thrombopoiesis, does not serve as a circulating regulator of platelet production. Additionally, we assayed the levels of these three cytokines following initial platelet transfusion to assess the capacity of transfused platelets to adsorb these thrombopoietic cytokines from the plasma and reduce their circulating levels, thus potentially modifying their availability for stimulating megakaryocyte proliferation. No consistent falls in TPO, IL-6 or IL-11 levels were observed following the initial two platelet transfusions. These data support the importance of circulating TPO and IL-6 as hormones capable of stimulating platelet production. Their physiologic relevance as in vivo regulators of thrombopoiesis and clinical utility for therapy of thrombocytopenia need further investigation.

Pulmonary cytolytic thrombi: a newly recognized complication of stem cell transplantation

Over the past 5 years we have recognized a new pulmonary complication of hematopoietic stem cell transplantation (HSCT) associated with fever and pulmonary nodules termed 'pulmonary cytolytic thrombi' (PCT). Retrospective analysis of medical and radiographic records and pathologic material from 13 HSCT recipients with PCT and a review of the Blood and Marrow Transplant Database for all patients with radiographic evidence of pulmonary nodules or who underwent open-lung biopsy from 1 January 1993 to 31 December 1998 (n = 1228) were performed. The median age of patients with PCT was 11.9 years (range, 1.3-29.7 years). All patients developed fever at a median of 72 days (range, 8-343 days) post transplant, followed by pulmonary nodules on chest CT. Eleven patients were receiving therapy for active GVHD (acute, grades I-IV (n = 10); extensive chronic (n = 1)). Biopsy of the pulmonary nodules revealed a unique pattern of necrotic, basophilic thromboemboli with amorphous material suggestive of cellular breakdown products. This was descriptively labeled 'pulmonary cytolytic thrombi'. Immunohistochemical staining revealed entrapped leukocytes and disrupted endothelium, but was negative for histiocytes. Cultures and immunohistochemical stains were negative for infectious agents. Empiric therapy included systemic corticosteroids (n = 9) and amphotericin (n = 7). Nine patients survive with resolution of PCT at a median follow-up of 1.5 years. Bone Marrow Transplantation (2000) 25, 293-300.

Autologous stem cell transplantation for high-risk pediatric solid tumors

Many solid tumors exhibit a steep dose-response to alkylating agents, and autologous stem cell transplantation (ASCT) allows escalation of the chemotherapy dose for treatment of high risk solid tumors. We have transplanted 24 children and young adults with relapsed or metastatic solid tumors on two consecutive ASCT protocols consisting primarily (protocol MT 8911) or exclusively (MT 9408) of alkylating agents. The median time to neutrophil engraftment was 21 days in protocol MT 8911 (no prophylactic use of growth factors) and 14 days in MT 9408 (G-CSF, 5 microg/kg, started on day 0). Disease-free survival estimated by the Kaplan-Meier method is 39% (95% CI: 19-59%) at 2 years after transplant and 34% (95% CI: 14-54%) at 4 years after transplant. Six of the nine patients with metastatic or relapsed disease that were transplanted while in complete remission (four patients with Ewing's sarcoma family of tumors and two patients with anaplastic Wilms tumor) are alive and disease-free with a median follow-up of 37 months (range 20-74 months). The estimated 4 year survival for patients receiving a transplant while in high risk remission was 78% (95% CI: 51-100%). In contrast, 13/15 patients that were transplanted while in partial remission died because of progressive disease or transplant-related complications. There were three transplant-related deaths (12.5%), including one patient with multiorgan failure, and two patients with complications of hepatic veno-occlusive disease. Our data indicate that autologous stem cell transplantation should be considered for consolidation therapy of high risk and relapsed pediatric patients with solid tumors who have achieved complete remission.

High spontaneous IL-10 production in unrelated bone marrow transplant recipients is associated with fewer transplant-related complications and early deaths

Interleukin 10 (IL-10) is a potent inhibitor of proliferative T cell responses toward alloantigens, and suppresses the production of pro-inflammatory cytokines which are important in cellular activation and recruitment to sites of inflammation. Because of these properties, we hypothesized that high IL-10 production in patients prior to BMT may predict a better outcome. To investigate this, peripheral blood mononuclear cells (PBMNC) were obtained from 58 recipients (11 autologous, 25 related donor (RD), and 22 unrelated donor (URD)), prior to conditioning therapy. PBMNC were cultured for 24 h in the presence and absence of lipopolysaccharide (LPS) and culture supernatants were assayed for IL-10 using an ELISA method. Spontaneously produced and LPS-stimulated IL-10 levels were correlated with the development of transplant-related complications (TRC) including grade II-IV acute GVHD, veno-occlusive disease, idiopathic pneumonia syndrome and multi-organ dysfunction syndrome, and with death before day 100. For the autologous group, there were no TRC and only one death prior to day 100; therefore, no statistical comparisons to IL-10 levels could be made. In the RD group, 36% developed one or more TRC and 24% died before day 100; however, there were no statistically significant associations between spontaneous or LPS-induced IL-10 levels. In URD patients 41% developed TRC and 55% died prior to day 100. In this group, higher levels of spontaneous IL-10 production were associated with a lower overall occurrence of TRC (P = 0.03) and early death (P = 0.04). Our data would indicate that higher levels of IL-10 production prior to URD BMT may predict fewer TRC, as well as early deaths. The hypothesis that high IL-10 production prior to BMT may decrease complications following URD BMT warrants further testing.

B cell lymphoproliferative disorders following hematopoietic stem cell transplantation: risk factors, treatment and outcome

Twenty-six cases of B cell lymphoproliferative disorder (BLPD) were identified among 2395 patients following hematopoietic stem cell transplants (HSCT) for which an overall incidence of BLPD was 1.2%. The true incidence was probably higher, since 9/26 of the diagnoses were made at autopsy. No BLPD was observed following autologous HSCT, so risk factor analyses were confined to the 1542 allogeneic HSCT. Factors assessed were HLA-mismatching (> or = 1 antigen), T cell depletion (TCD), presence of acute GvHD (grades II-IV), donor type (related vs unrelated), age of recipient and donor, and underlying disease. Factors found to be statistically significant included patients transplanted for immune deficiency and CML, donor age > or = 18 years, TCD, and HLA-mismatching, with recipients of combined TCD and HLA-mismatched grafts having the highest incidence. Factors found to be statistically significant in a multiple regression analysis were TCD, donor age and immune deficiency, although 7/8 of the patients with immunodeficiencies and BLPD received a TCD graft from a haploidentical parent. The overall mortality was 92% (24/26). One patient had a spontaneous remission, but subsequently died >1 year later of chronic GVHD. Thirteen patients received therapy for BLPD. Three patients received lymphocyte infusions without response. The only patients with responses and longterm survival received alpha interferon (alphaIFN). Of seven patients treated with alphaIFN there were four responses (one partial and three complete). These data demonstrate that alphaIFN can be an effective agent against BLPD following HSCT, if a timely diagnosis is made.

Comparative analysis of autografting in chronic myelogenous leukemia: effects of priming regimen and marrow or blood origin of stem cells

The aims of this study were (1) to evaluate the effect of intermediate (cyclophosphamide alone) or intensive (mitoxantrone, cytosine arabinoside, cyclophosphamide) priming on the cytogenetic response in mobilized bone marrow (BM) or peripheral blood (PB) progenitors in patients with chronic myelogenous leukemia (CML), (2) to determine the incidence of cytogenetic remissions after mobilized progenitor transplantation in CML, and (3) to determine the effect of in vivo priming on the ability to select Philadelphia chromosome-negative (Ph-negative) CD34(+)HLA-DR- cells from mobilized BM or PB in quantities sufficient for transplantation. Between February 1994 and March 1997, 44 patients were enrolled in three sequential protocols. Although the duration of neutropenia after only cyclophosphamide mobilization was shorter, clinical morbidity for the intermediate and intensive priming protocols was similar. Cytogenetic responses in mobilized PB progenitors were similar after mobilization with either intermediate or intensive chemotherapy. The degree of Ph negativity in the mobilized product correlated with disease stage at the time of mobilization (early chronic phase [ECP] > late CP > accelerated phase). Cytogenetic responses after transplantation with mobilized progenitors obtained after the different regimens were similar. The cytogenetic status of the graft predicted the cytogenetic status of marrow obtained 3 weeks after transplantation whereas cytogenetic responses 3, 6, and 12 months after transplantation correlated with the number of BCR/ABL-negative CD34(+)HLA-DR- cells, but not the number of Ph-negative metaphases in the graft. In patients with ECP CML, mobilized PB collections yielded significantly more CD34(+)HLA-DR- cells than from steady state or mobilized BM. CD34(+)HLA-DR- cells were Ph negative and polyclonal (X-chromosome inactivation) in the majority of ECP CML patients, before and after mobilization and irrespective of the mobilization regimen. Because infusion of large numbers of Ph-negative CD34(+)HLA-DR- cells predicted superior outcome after transplantation, approaches in which CD34(+)HLA-DR- cells are selected from mobilized PB may result in longer lasting and clinically significant cytogenetic responses after transplantation.