Machine learning analysis of humoral and cellular responses to SARS-CoV-2 infection in young adults.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces B and T cell responses, contributing to virus neutralization. In a cohort of 2,911 young adults, we identified 65 individuals who had an asymptomatic or mildly symptomatic SARS-CoV-2 infection and characterized their humoral and T cell responses to the Spike (S), Nucleocapsid (N) and Membrane (M) proteins. We found that previous infection induced CD4 T cells that vigorously responded to pools of peptides derived from the S and N proteins. By using statistical and machine learning models, we observed that the T cell response highly correlated with a compound titer of antibodies against the Receptor Binding Domain (RBD), S and N. However, while serum antibodies decayed over time, the cellular phenotype of these individuals remained stable over four months. Our computational analysis demonstrates that in young adults, asymptomatic and paucisymptomatic SARS-CoV-2 infections can induce robust and long-lasting CD4 T cell responses that exhibit slower decays than antibody titers. These observations imply that next-generation COVID-19 vaccines should be designed to induce stronger cellular responses to sustain the generation of potent neutralizing antibodies.

Vaccines against the original strain of SARS-CoV-2 provide T cell memory to the B.1.1.529 variant.

BACKGROUND: The SARS-CoV-2 variant B.1.1.529 potentially escapes immunity from vaccination via a heavily mutated Spike protein. Here, we analyzed whether T cell memory towards the B.1.1.529 Spike protein is present in individuals who received two or three doses of vaccines designed against the original Wuhan strain of SARS-CoV-2. METHODS: PBMCs were isolated from two- and three-times vaccinated study participants and incubated in vitro with peptide pools of the Spike protein derived from sequences of the original Wuhan or the B.1.1.529 strains of SARS-CoV-2. Activated antigen-specific T cells were detected by flow cytometry. In silico analyses with NetMHCpan and NetMHCIIpan were used to determine differences in MHC class presentation between the original strain and the B.1.1.529 strain for the most common MHCs in the European-Caucasian population. RESULTS: Here we show, that both CD4 and CD8 responses to the B.1.1.529 Spike protein are marginally reduced compared to the ancestor protein and a robust T cell response is maintained. Epitope analyses reveal minor differences between the two SARS-CoV-2 strains in terms of MHC class presentations for the MHC-alleles being most common in the European-Caucasian population. CONCLUSIONS: The memory T cell response induced via first generation vaccination remains robust and is mostly unaffected by B.1.1.529 mutations. Correspondingly, in silico analyses of MHC presentation of epitopes derived from the B.1.1.529 Spike protein shows marginal differences compared to the ancestral SARS-CoV-2 strain.

Vaccination against SARS-CoV-2 results in the production of proteins called antibodies, that bind and inactivate the virus, and cells that help to eliminate it from the body in a future encounter, such as memory T cells. Both antibodies and memory T cells remain in the body after vaccination with memory T cells being present for longer than antibodies. Here, we determined that even though most of the first generation vaccines were created to prevent infection with the original SARS-CoV-2 virus, the memory T cells generated by this vaccination can also detect the omicron variant.

Rapid Manufacturing of Highly Cytotoxic Clinical-Grade SARS-CoV-2-specific T Cell Products Covering SARS-CoV-2 and Its Variants for Adoptive T Cell Therapy.

Objectives: Evaluation of the feasibility of SARS-CoV-2-specific T cell manufacturing for adoptive T cell transfer in COVID-19 patients at risk to develop severe disease. Methods: Antiviral SARS-CoV-2-specific T cells were detected in blood of convalescent COVID-19 patients following stimulation with PepTivator SARS-CoV-2 Select using Interferon-gamma Enzyme-Linked Immunospot (IFN-γ ELISpot), SARS-CoV-2 T Cell Analysis Kit (Whole Blood) and Cytokine Secretion Assay (CSA) and were characterized with respect to memory phenotype, activation state and cytotoxic potential by multicolor flow cytometry, quantitative real-time PCR and multiplex analyses. Clinical-grade SARS-CoV-2-specific T cell products were generated by stimulation with MACS GMP PepTivator SARS-CoV-2 Select using CliniMACS Prodigy and CliniMACS Cytokine Capture System (IFN-gamma) (CCS). Functionality of enriched T cells was investigated in cytotoxicity assays and by multiplex analysis of secreted cytotoxic molecules upon target recognition. Results: Donor screening via IFN-γ ELISpot allows for pre-selection of potential donors for generation of SARS-CoV-2-specific T cells. Antiviral T cells reactive against PepTivator SARS-CoV-2 Select could be magnetically enriched from peripheral blood of convalescent COVID-19 patients by small-scale CSA resembling the clinical-grade CCS manufacturing process and showed an activated and cytotoxic T cell phenotype. Four clinical-grade SARS-CoV-2-specific T cell products were successfully generated with sufficient cell numbers and purities comparable to those observed in donor pretesting via CSA. The T cells in the generated products were shown to be capable to replicate, specifically recognize and kill target cells in vitro and secrete cytotoxic molecules upon target recognition. Cell viability, total CD3+ cell number, proliferative capacity and cytotoxic potential remained stable throughout storage of up to 72 h after end of leukapheresis. Conclusion: Clinical-grade SARS-CoV-2-specific T cells are functional, have proliferative capacity and target-specific cytotoxic potential. Their function and phenotype remain stable for several days after enrichment. The adoptive transfer of partially matched, viable human SARS-CoV-2-specific T lymphocytes collected from convalescent individuals may provide the opportunity to support the immune system of COVID-19 patients at risk for severe disease.

A multicenter prospective, randomized, placebo-controlled phase II/III trial for preemptive acute graft-versus-host disease therapy.

Acute graft-versus-host disease (aGvHD) contributes to about 50% of transplant-related mortality (non-relapse mortality) after allogeneic hematopoietic stem cell transplantation (HSCT). Here the predictive value of a urinary proteomic profile (aGvHD_MS17) was tested together with preemptive prednisolone therapy. Two-hundred and fifty-nine of 267 patients were eligible for analysis. Ninety-two patients were randomized upon aGvHD_MS17 classification factor above 0.1 to receive either prednisolone (2-2.5 mg/kg, N = 44) or placebo (N = 47; N = 1 randomization failure) for 5 days followed by tapering. The remaining 167 patients formed the observation group. The primary endpoint of the randomized trial was incidence of aGvHD grade II between randomization and day +100 post HSCT. Analysis of the short-term preemptive prednisolone therapy in the randomized patients showed no significant difference in incidence or severity of acute GvHD (HR: 1.69, 95% CI: 0.66-4.32, P = 0.27). Prednisolone as preemptive treatment did not lead to an increase in relapse (20.2% in the placebo and 14.0% in the prednisolone group (P = 0.46)). The frequency of adverse events was slightly higher in the placebo group (64.4% versus 50%, respectively). Taken together, the results of the Pre-GvHD trial demonstrated the feasibility and safety of preemptive prednisolone treatment in the randomized patients.

Does rehabilitation pose a risk to patients suffering from haemato-oncological diseases? Results of a monocentric, retrospective analysis in Germany.

OBJECTIVE: Patients suffering from haemato-oncological diseases tend to have a weakened immune system after the end of their therapy. To avoid infections, patients are advised to limit contact with other people. This poses the question whether a stay at a rehabilitation facility can be recommended. METHODS: We report about 134 rehabilitation stays of patients. Premature discontinuation of the rehabilitation stay was selected as the criterion for a serious complication during the rehabilitation, and the underlying reasons were analysed. RESULTS: Compared to the discontinuation rates of patients suffering from solid tumours (2.4%), the percentage of haemato-oncological patients ending prematurely their rehabilitation stay (8.2%) is significantly increased. This rises to 17.1% for patients who have undergone an allogeneic stem cell transplantation. The analysis of the discontinuation reasons revealed that they were not directly connected to the rehabilitation. Apart from the already known risk factors for premature termination of the rehabilitation stay, we have identified the period (days) between the last therapy and the beginning of the rehabilitation stay as a risk factor. CONCLUSIONS: We show for the first time that a rehabilitation stay does not pose additional risks for patients suffering from haemato-oncological diseases.

Imatinib in myeloid/lymphoid neoplasms with eosinophilia and rearrangement of PDGFRB in chronic or blast phase.

We evaluated clinical characteristics and outcome on imatinib of 22 patients with myeloid/lymphoid neoplasms with eosinophilia and rearrangement of PDGFRB. Median age was 49 years (range 20-80), 91% were male. Fifteen different PDGFRB fusion genes were identified. Eosinophilia was absent in 4/19 (21%) cases and only 11/19 (58%) cases had eosinophils ≥1.5×109/L. On imatinib, 17/17 (100%) patients in chronic phase achieved complete hematologic remission after median 2 months (range 0-13)​. Complete cytogenetic remission and/or complete molecular remission by RT-PCR were achieved in 12/13 (92%) and 12/14 patients (86%) after median 10 (range 3-34) and 19 months (range 7-110), respectively. In patients with blast phase (myeloid, n = 2; lymphoid, n = 3), treatment included combinations of imatinib (n = 5), intensive chemotherapy (n = 3), and/or allogeneic stem cell transplantation (n = 3). All 3 transplanted patients (complex karyotype, n = 2) experienced early relapse. Initially, patients were treated with imatinib 400 mg/day (n = 15) or 100 mg/day (n = 7), the dose was reduced from 400 mg/day to 100 mg/day during follow-up in 9 patients. After a median treatment of 71 months (range 1-135), the 5-year survival rate was 83%; 4/22 (18%) patients died (chronic phase; n = 2; blast phase, n = 2) due to progression (n = 3) or comorbidity while in remission (n = 1). Of note, 3/4 patients had a complex karyotype. In summary, the most important characteristics of myeloid/lymphoid neoplasms with rearrangement of PDGFRB include (a) male predominance, (b) frequent lack of hypereosinophilia,

Hematopoietic stem-cell transplantation for advanced systemic mastocytosis.

PURPOSE: Advanced systemic mastocytosis (SM), a fatal hematopoietic malignancy characterized by drug resistance, has no standard therapy. The effectiveness of allogeneic hematopoietic stem-cell transplantation (alloHCT) in SM remains unknown. PATIENTS AND METHODS: In a global effort to define the value of HCT in SM, 57 patients with the following subtypes of SM were evaluated: SM associated with clonal hematologic non-mast cell disorders (SM-AHNMD; n = 38), mast cell leukemia (MCL; n = 12), and aggressive SM (ASM; n = 7). Median age of patients was 46 years (range, 11 to 67 years). Donors were HLA-identical (n = 34), unrelated (n = 17), umbilical cord blood (n = 2), HLA-haploidentical (n = 1), or unknown (n = 3). Thirty-six patients received myeloablative conditioning (MAC), and 21 patients received reduced-intensity conditioning (RIC). RESULTS: Responses in SM were observed in 40 patients (70%), with complete remission in 16 patients (28%). Twelve patients (21%) had stable disease, and five patients (9%) had primary refractory disease. Overall survival (OS) at 3 years was 57% for all patients, 74% for patients with SM-AHNMD, 43% for those with ASM, and 17% for those with MCL. The strongest risk factor for poor OS was MCL. Survival was also lower in patients receiving RIC compared with MAC and in patients having progression compared with patients having stable disease or response. CONCLUSION: AlloHCT was associated with long-term survival in patients with advanced SM. Although alloHCT may be considered as a viable and potentially curative therapeutic option for advanced SM in the meantime, given that this is a retrospective analysis with no control group, the definitive role of alloHCT will need to be determined by a prospective trial.

Outcome of patients with abnl(17p) acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation.

Patients with acute myeloid leukemia (AML) and abnormalities of chromosome 17p (abnl(17p)) are at high-risk of treatment failure. Poor outcomes have been reported with conventional chemotherapy. To accurately define the outcome after allogeneic hematopoietic stem cell transplantation (HSCT) in patients with abnl(17p) AML, we analyzed the results of patients with this abnormality who received an allogeneic HSCT between January 2000 and December 2010 in 1 of 4 well-defined cohorts (Fred Hutchinson Cancer Research Center, Haemato Oncology Foundation for Adults in the Netherlands, Study Alliance Leukemia, German Cooperative Transplant Study Group). Data of 201 patients with a median age of 54 years were evaluable. At the time of analysis, 30 patients were alive with a median follow-up of 30 months. The 3-year probability of overall survival (OS) was 15% (95% confidence interval [CI], 10-20). The cumulative incidence of relapse at 3 years was 49% (95% CI, 42-56). Notably, almost 70% of all relapses occurred within the first 6 months after HSCT. Patients who were transplanted in first complete remission (CR1) had superior OS compared with those with advanced disease (22% vs 9%, P < .001). Our findings confirm the high-risk of treatment failure in abnl(17p) AML even after allogeneic HSCT in CR1. Although allogeneic HSCT remains a valid option in CR1, alternative treatment strategies are needed for the remaining patients.

Consensus on the histopathological evaluation of liver biopsies from patients following allogeneic hematopoietic cell transplantation.

After allogeneic hematopoietic cell transplantation (alloHCT) liver biopsy is performed for enigmatic liver disorders when noninvasive diagnostic steps have failed in establishing a definitive diagnosis. This document provides an updated consensus on the prerequisites for proper evaluation of liver biopsies in alloHCT patients and the histological diagnostic criteria for liver graft-versus-host disease (GvHD). The Working Group's recommendations for the histological diagnosis of liver GvHD were derived from the peer-reviewed literature and from the consensus diagnosis of a total of 30 coded liver biopsies. Acceptance of the recommendations was tested by a survey distributed to all HCT centers in Austria, Germany and Switzerland. Consensus was achieved for biopsy indications, methods of sample acquisition and processing, reporting and interpretation of biopsy findings. As GvHD is variably treated and the treatment modalities have changed over time, the panel endorses the use of more frequent biopsies in clinical studies in order to improve the present challenging clinical and diagnostic situation.

Reduced-intensity conditioning versus standard conditioning before allogeneic haemopoietic cell transplantation in patients with acute myeloid leukaemia in first complete remission: a prospective, open-label randomised phase 3 trial.

BACKGROUND: Reduced-intensity conditioning regimens have been developed to minimise early toxic effects and deaths after allogeneic haemopoietic cell transplantation. However, the efficacy of these regimens before this procedure has not been investigated in a randomised trial. In this prospective, open-label randomised phase 3 trial we compared a reduced-intensity fludarabine-based conditioning regimen with a standard regimen in patients with acute myeloid leukaemia in first complete remission. METHODS: Patients were aged 18-60 years and had intermediate-risk or high-risk acute myeloid leukaemia (defined by cytogenetics) in first complete remission; an available HLA-matched sibling donor or an unrelated donor with at least nine of ten HLA alleles; and adequate renal, cardiac, pulmonary, and neurological function. Between Nov 15, 2004, and Dec 31, 2009, patients were randomly assigned (1:1, by a computer-based minimisation procedure that balanced patients for age, cytogenetic risk, induction therapy, and donor type) to receive either reduced-intensity conditioning of four doses of 2 Gy of total-body irradiation and 150 mg/m(2) fludarabine or standard conditioning of six doses of 2 Gy of total-body irradiation and 120 mg/kg cyclophosphamide. All patients were given ciclosporin and methotrexate as prophylaxis against graft-versus-host disease. Neither investigators nor patients were blinded to study treatment. Our primary endpoint was the incidence of non-relapse mortality, analysed in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT00150878. FINDINGS: The trial was stopped early on Dec 31, 2009, because of slow accrual of patients. 99 patients were randomly assigned to receive reduced-intensity conditioning and 96 to receive standard conditioning. The incidence of non-relapse mortality did not differ between the reduced-intensity and standard conditioning groups (cumulative incidence at 3 years 13% [95% CI 6-21] vs 18% [10-26]; HR 0·62 [95% CI 0·30-1·31]). Relapse incidence (cumulative incidence 3 years 28% [95% CI 19-38] vs 26% [17-36]; HR 1·10 [95% CI 0·63-1·90]), disease-free survival (3 year disease-free survival 58% [95% CI 49-70] vs 56% [46-67]; HR 0·85 [95% CI 0·55-1·32]), and overall survival (3 year overall survival 61% [95% CI 50-74] vs 58% [47-70]; HR 0·77 [95% CI 0·48-1·25]) did not differ significantly between groups. Grade 3-4 of oral mucositis was less common in the reduced-intensity group than in the standard conditioning group (50 patients in the reduced-intensity conditioning group vs 73 patients in the standard conditioning group); the frequency of other side-effects such as graft-versus-host disease and increased concentrations of bilirubin and creatinine did not differ significantly between groups. INTERPRETATION: Reduced-intensity conditioning results in a similar incidence of non-relapse mortality and reduced toxic effects compared with standard conditioning without affecting survival outcomes, and thus could be preferentially used in patients younger than 60 years with acute myeloid leukaemia transplanted in first complete remission.

Outcome of high-risk acute myeloid leukemia after allogeneic hematopoietic cell transplantation: negative impact of abnl(17p) and -5/5q-.

The European LeukemiaNet classification combines a heterogeneous group of aberrations as adverse-risk abnormalities. Our goal was to investigate the outcomes associated with distinct high-risk chromosomal abnormalities in acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (HSCT). We performed a retrospective cohort analysis in patients with high-risk AML who received first, HLA-compatible, allogeneic HSCT between January 2005 and December 2008. Data from 236 patients with a median age of 55 years were included. Because complex karyotype (CK), -5/5q-, and abnl(17p) are overlapping categories, a hierarchical classification system based on the presence or absence of abnl(17p) and -5/5q- was developed. Patients with abnl(17p) had a 2-year event-free survival (EFS) of 11% (95% confidence interval [CI], 0%-25%), patients with -5/5q- but no abnl(17p) a 2-year EFS of 29% (95% CI, 14%-44%), and patients with adverse-risk AML but neither of the 2 marker lesions a 2-year EFS of 49% (95% CI, 39%-59%). Notably, complex and monosomal karyotypes lost their prognostic value when these marker lesions were excluded. In conclusion, hierarchical classification of adverse-risk karyotypes by 2 marker lesions, abnl(17p) and -5/5q-, is effective in prognostication of the outcome of allogeneic HSCT in AML.

High single-drug activity of nelarabine in relapsed T-lymphoblastic leukemia/lymphoma offers curative option with subsequent stem cell transplantation.

Nelarabine, a purine analog with T-cell specific action, has been approved for relapsed/refractory T-cell acute lymphoblastic leukemia/lymphoma (ALL/LBL). This is a report of a single-arm phase 2 study conducted in adults (18-81 years of age) with relapsed/refractory T-ALL/LBL. After 1 or 2 cycles, 45 of 126 evaluable patients (36%) achieved complete remission (CR), 12 partial remission (10%), and 66 (52%) were refractory. One treatment-related death was observed, and 2 patients were withdrawn before evaluation. A total of 80% of the CR patients were transferred to stem cell transplantation (SCT). Overall survival was 24% at 1 year (11% at 6 years). After subsequent SCT in CR, survival was 31% and relapse-free survival 37% at 3 years. Transplantation-related mortality was 11%. Neurologic toxicities of grade I-IV/grade III-IV were observed in 13%/4% of the cycles and 16%/7% of the patients. This largest study so far with nelarabine in adults showed impressive single-drug activity in relapsed T-ALL/T-LBL. The drug was well tolerated, even in heavily pretreated patients. A high proportion of CR patients were transferred to SCT with low mortality but a high relapse rate. Exploration of nelarabine in earlier stages of relapse (eg, increasing minimal residual disease), in front-line therapy, and in combination is warranted.

Therapy of sclerodermatous chronic graft-versus-host disease with mammalian target of rapamycin inhibitors.

This retrospective study analyzes 34 patients with severe sclerodermatous chronic graft-versus-host disease (cGVHD) treated with inhibitors of the mammalian target of rapamycin (mTOR-I). Twelve patients received mTOR-I as monotherapy and 22 a combination therapy. Four patients also received extracorporal photopheresis. mTOR-I were applied as first-line therapy (n = 15) or in refractory disease (n = 19). Drug doses were adjusted to low therapeutical levels (3-8 ng/mL). Six and 20 patients had a complete and a partial response, respectively, with an overall response rate of 76%. Two additional patients had stable disease. Six refractory patients required alternative therapy. Comedication, especially steroids, could be tapered and stopped in a significant number of patients. No difference in response was observed in everolimus- and sirolimus-treated patients. Major adverse events possibly related to mTOR-I were hyperlipidemia and impaired wound healing. Two patients developed thrombotic microangiopathy. Eight patients died, 5 of the nonresponders (cGVHD; n = 3, infection; n = 2) and 3 of the responders (relapse of the underlying malignancy; n = 1, secondary malignancy; n = 1, unknown cause; n = 1). Twenty-six of the 34 patients remain alive, 18 still on therapy with mTOR-I. Median follow-up for surviving patients is 723 days (range 88-1621). The overall survival at 3 years since mTOR-I is 72%. In conclusion, mTOR-I seem to be an effective and well-tolerated treatment option for patients with sclerodermatous cGVHD.

Impact of JAK2V617F mutation status, allele burden, and clearance after allogeneic stem cell transplantation for myelofibrosis.

Allogeneic stem cell transplantation (ASCT) after reduced-intensity conditioning has become a reasonable treatment option for patients with advanced myelofibrosis. The role of characteristic molecular genetic abnormalities, such as JAK2V617F on outcome of ASCT, is not yet elucidated. In 139 of 162 myelofibrosis patients with known JAK2V617F mutation status who received ASCT after reduced-intensity conditioning, the impact of JAK2 genotype, JAK2V617F allele burden, and clearance of mutation after ASCT was evaluated. Overall survival was significantly reduced in multivariate analysis in patients harboring JAK2 wild-type (hazard ratio = 2.14, P = .01) compared with JAK2 mutated patients. No significant influence on outcome was noted for the mutated allele burden analyzed either as continuous variable or after dividing into quartiles. Achievement of JAK2V617F negativity after ASCT was significantly associated with a decreased incidence of relapse (hazard ratio = 0.22, P = .04). In a landmark analysis, patients who cleared JAK2 mutation level in peripheral blood 6 months after ASCT had a significant lower risk of relapse (5% vs 35%, P = .03). We conclude that JAK2V617F-mutated status, but not allele frequency, resulted in an improved survival and rapid clearance after allografting reduces the risk of relapse.

Allogeneic stem cell transplantation after reduced-intensity conditioning in patients with myelofibrosis: a prospective, multicenter study of the Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation.

From 2002 to 2007, 103 patients with primary myelofibrosis or postessential thrombocythemia and polycythemia vera myelofibrosis and a median age of 55 years (range, 32-68 years) were included in a prospective multicenter phase 2 trial to determine efficacy of a busulfan (10 mg/kg)/fludarabine (180 mg/m(2))-based reduced-intensity conditioning regimen followed by allogeneic stem cell transplantation from related (n = 33) or unrelated donors (n = 70). All but 2 patients (2%) showed leukocyte and platelet engraftment after a median of 18 and 22 days, respectively. Acute graft-versus-host disease grade 2 to 4 occurred in 27% and chronic graft-versus-host disease in 43% of the patients. Cumulative incidence of nonrelapse mortality at 1 year was 16% (95% confidence interval, 9%-23%) and significantly lower for patients with a completely matched donor (12% vs 38%; P = .003). The cumulative incidence of relapse at 3 years was 22% (95% confidence interval, 13%-31%) and was influenced by Lille risk profile (low, 14%; intermediate, 22%; and high, 34%; P = .02). The estimated 5-year event-free and overall survival was 51% and 67%, respectively. In a multivariate analysis, age older than 55 years (hazard ratio = 2.70; P = .02) and human leukocyte antigen-mismatched donor (hazard ratio = 3.04; P = .006) remained significant factors for survival. The study was registered at www.clinicaltrials.gov as #NCT 00599547.

Dose-dense induction with sequential high-dose cytarabine and mitoxantone (S-HAM) and pegfilgrastim results in a high efficacy and a short duration of critical neutropenia in de novo acute myeloid leukemia: a pilot study of the AMLCG.

Dose density during early induction has been demonstrated to be one of the prime determinants for treatment efficacy in acute myeloid leukemia (AML). The German AML Cooperative Group has therefore piloted a dose-dense induction regimen sequential high-dose AraC and mitoxantrone followed by pegfilgrastim (S-HAM) in which 2 induction cycles are applied over 11 to 12 days instead of 25 to 29 days as used in conventional double induction, thereby increasing dose density 2-fold. Of 172 de novo AML patients (excluding acute promyelocytic leukemia), 61% reached a complete remission, 22% a complete remission with incomplete peripheral recovery, 7% had persistent leukemia, 10% died (early death) resulting in an overall response rate of 83%. Kaplan-Meier estimated survival at 2 years was 61% for the whole group (patients with unfavorable karyotypes, 38%; patients with favorable karyotypes, 69%; patients with intermediate karyotypes, 75%) after S-HAM treatment. Importantly, the compression of the 2 induction cycles into the first 11 to 12 days of treatment was beneficial for normal hematopoiesis as demonstrated by a significantly shortened duration of critical neutropenia of 31 days compared with 46 days after conventionally timed double induction.

Matched unrelated or matched sibling donors result in comparable survival after allogeneic stem-cell transplantation in elderly patients with acute myeloid leukemia: a report from the cooperative German Transplant Study Group.

PURPOSE: In patients with acute myeloid leukemia (AML), differential indications for matched sibling and unrelated hematopoietic stem-cell transplantation (HCT) are considered, and arbitrary age limits for HCT exist. We sought to determine whether donor type is a prognostic factor in elderly patients in the era of high-resolution DNA-based HLA typing. PATIENTS AND METHODS: We performed univariate and multivariate analyses of event-free survival (EFS) and overall survival (OS) in patients older than 50 years with standard- or high-risk AML who had received an allogeneic HCT between 1995 and 2005. Available DNA from donors and recipients of unrelated HCT was retyped so that the HLA-A, -B, -C, and -DRB1 alleles could be characterized in detail. Unrelated donors (UDs) were classified as matched (8/8), possibly matched (matched, but incomplete information), partially matched (one mismatch), or poorly matched (two or more mismatches) according to the final typing results. RESULTS: Data from 368 patients with a median age of 57 years (range, 50 to 73 years) were included. Multivariate Cox regression analysis revealed that patients' disease status at HCT (P < .001) and the cytogenetic risk (P < .001) highly significantly predicted EFS and OS. Compared with patients with matched sibling donors, the adjusted relative risk of EFS was 0.7 (95% CI, 0.4 to 1.1) for patients with matched UDs and 1.0 (95% CI, 0.7 to 1.6) for patients with partially matched UDs. CONCLUSION: Donor type is not a major prognostic factor for HCT in elderly patients with standard- or high-risk AML.