Pneumocystis Pneumonia After Allogeneic Hematopoietic Cell Transplantation: A Case-Control Study on Epidemiology and Risk Factors on Behalf of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation.

Pneumocystis pneumonia (PCP) is a life-threatening complication after allogeneic hematopoietic cell transplantation (allo-HCT). However, allo-HCT procedures have evolved toward older patients, unrelated donors, and reduced-intensity conditioning, possibly modifying the risks. Polymerase chain reaction (PCR), widely used nowadays, is more sensitive than microscopy diagnostic methods. This study aimed to assess the factors associated with PCP in allo-HCT recipients within 2 years of HCT and managed according to current procedures. This multicenter, nested case-control study included PCP cases diagnosed by PCR, cytology, or immunofluorescence on bronchoalveolar lavage fluid between 2016 and 2018. Two controls per case were selected from the ProMISe registry and matched for the center, transplant date, and underlying disease. Fifty-two cases and 104 controls were included among the 5452 patients who underwent allo-HCT in the participating centers. PCP occurred at a median of 11.5 months after transplantation. The mortality rate was 24% on day 30 after the PCP diagnosis and 37% on day 90. The clinical presentation and mortality rates of the 24 patients diagnosed using only PCR were not different from those diagnosed with microscopy methods. Our study demonstrates a substantial incidence of, and mortality from, PCP, after allogeneic HCT despite well-established prophylactic approaches. In our experience, PCP nowadays occurs later after transplant than previously reported, justifying the prolongation of prophylaxis after six months in many cases. Allo-HCT recipients diagnosed with PCR as the only PCP marker should benefit from specific treatment as for other patients.

Comparison of efficacy and toxicity according to etoposide and cytarabine dosing in BEAM conditioning followed by autologous stem cell transplantation in Hodgkin lymphoma.

The combination of carmustine, etoposide, cytarabine, and melphalan (BEAM) followed by autologous stem cell transplantation (ASCT) is a commonly used intensification regimen for patients with Hodgkin lymphoma. As etoposide and cytarabine dosing are not defined, we conducted a retrospective, multicenter study, to compare efficacy and toxicity in 130 patients with Hodgkin lymphoma receiving etoposide and cytarabine at either 200 mg/m2/d (n = 50), 400 mg/m2/d (n = 35), or etoposide 200 mg/m2/d and cytarabine 400 mg/m2/d (n = 45). Progression-free survival and overall survival were not associated with the intensity of conditioning. Increased conditioning intensity was associated with longer duration of thrombocytopenia, a higher number of transfused RBC and platelet units and a higher frequency of mucositis, but serious adverse events or infectious complications were not increased. The intensity of BEAM regimen was not associated with survival but with the rate of cytopenia and mucositis advocating for the use of lower dosing in frail patients.

Toxicity Profile According to Etoposide and Cytarabine Dosing in Patients with Lymphoma Receiving Autologous Stem Cell Transplantation Following BEAM Conditioning.

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is part of the treatment strategy for some patients with high-risk lymphoma by improving survival with an acceptable toxicity profile. Although the BEAM (BCNU, etoposide, cytarabine, and melphalan) intensification regimen is the most used, the optimal dosing for each drug is unclear. Here, we retrospectively compared the outcome of 110 patients receiving higher (400 mg/m2, n = 69) or lower (200 mg/m2, n = 41) etoposide and cytarabine doses in our institution between 2012 and 2019. Patients in the BEAM 200 group experienced less toxicity with reduced fever duration (P < 0.001), number of platelet transfusions (P = 0.008), antibiotic duration (P < 0.001), antifungal therapy (P < 0.001), and mucositis (P < 0.001) whereas length of stay, admission to the intensive care unit, and in-hospital mortality were not different between groups. Progression-free survival (PFS) was non-significantly lower in the BEAM 200 group (36-month PFS, 68% vs. 80%, P = 0.053) whereas OS was similar between the two groups (36-month OS, 87% vs. 91%, respectively, P = 0.12). Albeit a non-significant reduction in PFS, BEAM 200 conditioning intensity was associated with a reduced toxicity profile.

Relationship between comorbidities, mutational profile, and outcome after intensive chemotherapy in patients older than 60 years with acute myeloid leukemia: Assessment of different risk scores.

The aim of this study was to evaluate how comorbidities and molecular landscape relate to outcome in patients with acute myeloid leukemia (AML) aged 60 years or older who received intensive induction therapy. In 91 patients, 323 mutations were identified in 77 genes by next-generation sequencing, with a median of four mutations per patient, with NPM1, FLT3, TET2, and DNMT3A being the most frequently mutated genes. A multistate model identified FLT3, IDH2, RUNX1, and TET2 mutations as associated with a higher likelihood of achieving complete remission while STAG2 mutations were associated with primary refractory disease, and DNMT3A, FLT3, IDH2, and TP53 mutations with mortality after relapse. Ferrara unfitness criteria and performance status were the best predictors of short-term outcome (area under the curve = 82 for 2-month survival for both parameters), whereas genomic classifications better predicted long-term outcome, with the Patel risk stratification performing the best over the 5-year follow-up period (C-index = 0.63 for event-free and overall survival). We show that most genomic prognostic classifications, mainly used in younger patients, are useful for classifying older patients, but to a lesser extent, because of different mutational profiles. Specific prognostic classifications, incorporating performance status, comorbidities, and cytogenetic/molecular data, should be specifically designed for patients over 60 years.

Daunorubicin and Its Active Metabolite Pharmacokinetic Profiles in Acute Myeloid Leukaemia Patients: A Pharmacokinetic Ancillary Study of the BIG-1 Trial.

Daunorubicin pharmacokinetics (PK) are characterised by an important inter-individual variability, which raises questions about the optimal dose regimen in patients with acute myeloid leukaemia. The aim of the study is to assess the joint daunorubicin/daunorubicinol PK profile and to define an optimal population PK study design. Fourteen patients were enrolled in the PK ancillary study of the BIG-1 trial and 6-8 samples were taken up to 24 h after administration of the first dose of daunorubicin (90 mg/m2/day). Daunorubicin and daunorubicinol quantifications were assessed using a validated liquid chromatography technique coupled with a fluorescence detector method. Data were analysed using a non-compartmental approach and non-linear mixed effects modelling. Optimal sampling strategy was proposed using the R function PFIM. The median daunorubicin and daunorubicinol AUC0-tlast were 577 ng/mL·hr (Range: 375-1167) and 2200 ng/mL·hr (range: 933-4683), respectively. The median metabolic ratio was 0.32 (range: 0.1-0.44). Daunorubicin PK was best described by a three-compartment parent, two-compartment metabolite model, with a double first-order transformation of daunorubicin to metabolite. Body surface area and plasma creatinine had a significant impact on the daunorubicin and daunorubicinol PK. A practical optimal population design has been derived from this model with five sampling times per subject (0.5, 0.75, 2, 9, 24 h) and this can be used for a future population PK study.

Serum phosphate level and its kinetic as an early marker of acute kidney injury in tumor lysis syndrome.

INTRODUCTION: Acute kidney injury (AKI) is a major cause of mortality in tumor lysis syndrome. The biochemical parameters and kinetics of tumor lysis syndrome remain poorly described. Particularly, whether blood serum phosphate variations may help in the identification and management of patients who will eventually develop AKI remains to be studied. METHODS: In this retrospective study, we included patients with tumor lysis syndrome episodes without AKI at diagnosis, and analyzed serum phosphate kinetic, clinical and tumor lysis syndrome biochemical variables to identify factors associated with AKI onset, and determine threshold values of phosphatemia associated with AKI development. RESULTS: One hundred thirty tumor lysis syndrome episodes occurred in 120 patients during an 11-year period at the University Hospital of Angers. AKI developed in 56 tumor lysis syndrome episodes. In multivariable analysis, among the analyzed factors, only an increase in serum phosphate levels (before AKI diagnosis), exposure to platinum salts and an increase in LDH levels were associated with AKI development. Before AKI onset, a serum phosphate cut-off of 2.1 mmol/L was not effective in predicting AKI development (sensitivity 48%, specificity 84%, area under the receiver operating characteristic curve (AUC) 0.63 [0.52-0.74]). No other biochemical parameters were effective to better predict AKI occurrence. CONCLUSION: This work suggests that increases in serum phosphate and LDH appear to be early and reliable biomarkers of AKI in tumor lysis syndrome. No valuable threshold value of serum phosphate was found to effectively predict AKI. This work is the basis for further prospective controlled studies on phosphate monitoring and phosphate lowering therapies to prevent AKI during tumor lysis syndrome.

Antifungal Prophylaxis in AML Patients Receiving Intensive Induction Chemotherapy: A Prospective Observational Study From the Acute Leukaemia French Association (ALFA) Group.

BACKGROUND: Although recommended in patients with acute myeloblastic leukaemia (AML) after induction chemotherapy, real-life use of antifungal prophylaxis (AFP) is different among centres. MATERIALS AND METHODS: This is an ancillary study to a randomized trial on intensive induction chemotherapy in AML patients (ALFA-0702/NCT00932412), where AFP with posaconazole was recommended. IFIs were graded by investigators and by central reviewers according to the revised EORTC definitions. Experts conclusions were compared to the investigators' ones. RESULTS: A total of 677 patients were included. Four AFP strategies were reported: Group-1: no AFP (n = 203, 30%), Group-2: posaconazole (n = 241, 36%), Group-3: posaconazole with other AFP (n = 142, 21%), Group-4: other AFP (n = 91, 13%). Experts graded more IFI than investigators: proven/probable IFI, 9.0% (n = 61) versus 6.2% (n = 42). The cumulative incidence at day60 of probable/proven IFI was 13.9% (Group-1); 7.9% (Group-2); 5.6% (Group-3); and 6.6% (Group-4). IFI onset was 26 (19-31) days after induction in Groups 2-3, versus 16 (9-25) days in Group 1 and 20 (12-24) days in Group 4 (P< .001). After a median follow-up of 27.5 months (0.4-73.4), the mortality rate was 38.3%, with 5.4% attributed to IFI. In multivariate analysis, IFI occurrence was an independent risk of death (HR5.63, 95%-CI 2.62-12.08, P< .001). EORTC recommendations were applied in only 57% of patients. In patients without IFI, the rate of AML complete remission was higher. CONCLUSIONS: In AML patients, AFP delayed the onset of IFI in addition of decreasing their rate. The frequent misidentification of IFI impacts their appropriate management according to recommendations. hematological remission was more frequent in patients without IFI.

Impact of allogeneic stem cell transplantation comorbidity indexes after haplotransplant using post-transplant cyclophosphamide.

BACKGROUND: Three different scoring systems have been developed to assess pre-transplant comorbidity in allogeneic hematopoietic stem cell transplantation (Allo-HSCT): the Hematopoietic Cell Transplantation-Specific Comorbidity Index, the Comorbidity/Age index, and the Augmented Comorbidity/Age index. All were devised to predict overall survival (OS) and disease-free survival (DFS) survivals and non-relapse mortality (NRM) in patients receiving HLA-matched Allo-HSCT, but their performance has scarcely been studied in the haploidentical Allo-HSCT setting with post-transplant cyclophosphamide, a procedure in constant expansion worldwide. METHODS: To address this issue, their impact on survivals and NRM was examined in a cohort of 223 patients treated with haploidentical Allo-HSCT in four different centers. RESULTS: With a median follow-up of 35.6 months, 3-year OS, DFS, and NRM were 48.1% ± 4%, 46.3% ± 4%, and 30.0% ± 3%, respectively. No impact was found for any of the three comorbidity scores in univariate analysis. In multivariate analyses, the only three factors associated with lower OS were DRI (p < 0.001), an older age of recipients (≥55 years old, p = 0.02) and of donors (≥40 years old, p = 0.005). Older donor age was also associated with lower DFS and higher NRM. CONCLUSION: The comorbidity scores do not predict survivals nor NRM in haploidentical Allo-HSCT with PTCY, suggesting that pre-transplant comorbidities should not be a contra-indication to this procedure.

Risk of infection according to the gamma globulin level in the 100 days following allogeneic stem cell transplantations.

BACKGROUND: Immunoglobulin replacement therapy is recommended in case of severe hypogammaglobulinemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the supposed increased risk of infection in case of hypogammaglobulinemia has not been confirmed in allo-HSCT. In this study, we assessed the relationship between the gamma globulin level and the risk of infection during the 100 days following the allo-HSCT. METHODS: We gathered the weekly laboratory tests from day 7 to day 100 of 76 allograft patients, giving a total of 1 044 tests. 130 infections were documented clinically, by imaging, or microbiologically. RESULTS: Average gamma globulin levels between D-7 and D100 did not differ between patients with or without infection (642 ± 232 and 671 ± 246 mg/dL, respectively, P = .65). Gamma globulin level <400 mg/dl was not associated with the occurrence of infection between the test studied and the next one (aOR 1.33 [0.84-2.15], P = .24). The gamma globulin level was not predictive of bacterial or fungal infections (AUC 0.54 [95%CI: 0.47-0.61]) nor of viral reactivations (AUC 0.51 [95%CI: 0.43-0.60]). CONCLUSIONS: This confirmed that the humoral deficiency is a minor part of the immune deficiency in the 100 days post-transplant. This questions the relevance of the indications of immunoglobulin substitution during this period.

Early Post-Transplantation Serum Ferritin Level Predicts Survival in Recipients of Haploidentical Stem Cell Transplantation Using Post-Transplantation Cyclophosphamide as Graft-versus-Host Disease Prophylaxis.

The negative impact of high serum ferritin level (SFL) before and after allogeneic hematopoietic cell transplantation (allo-HSCT) on outcomes is well recognized. However, it is poorly documented in adults undergoing haploidentical HSCT (haplo-HSCT) with post-transplantation cyclophosphamide (PTCY) for hematologic malignancies. The main objective was to assess the impact of pretransplantation and post-transplantation SFL on overall survival (OS), disease-free survival (DFS), and nonrelapse mortality (NRM) in patients undergoing haplo-HSCT with PTCY. The secondary objective was to identify factors associated with outcomes after transplantation by comparing SFL with other parameters related to the status of patients or donors. This multicentric retrospective study included 223 consecutive patients who underwent haplo-HSCT with PTCY in 4 French centers (Nantes, Angers, Besançon, and Brest) between October 2013 and January 2020. The impact of SFL on OS, DFS, and NRM at different time points was assessed based on receiver operating characteristic curves. With a median follow-up of 37.6 months (interquartile range, 23.5 to 51.0 months), 3-year OS, DFS, and NRM were 48.1 ± 4%, 46.3 ± 4%, and 30.0 ± 3%, respectively. Pretransplantation SFL had no impact on outcomes irrespective of the cutoff tested. Considering patients alive at 3 months post-transplantation, an SFL ≥3500 µg/L at 3 months was statistically significantly associated with worse 3-year OS (32.7 ± 8.7% versus 53.4 ± 7.2%; P = .01) and DFS (30.1 ± 8.2% versus 53.1 ± 7.1%; P = .008), with a trend toward higher NRM (33.2 ± 8.6% versus 17.6 ± 5.4%; P = .10). Similarly, high SFL (≥2700 µg/L) at 6 months post-transplantation was associated with worse 3-year OS (56.1 ± 9.1% versus 79.2 ± 6.0%; P = .02) and DFS (53.6 ± 8.7% versus 74.9 ± 6.2%; P = .01), with a trend toward higher NRM (21.4 ± 7.4% versus 8.2 ± 4.0%; P = .10). In multivariate analysis, high 3-month and 6-month FL remained associated with lower OS and DFS, with a trend toward higher NRM. Pretransplantation SFL appears to have no impact on outcomes in haplo-HSCT with PTCY, in contrast to what is documented in the matched allo-HSCT setting. In contrast, in the haplo-HSCT setting, high SFL early post-transplantation is associated with lower survival and a trend toward higher NRM.

Oncogenetic landscape and clinical impact of IDH1 and IDH2 mutations in T-ALL.

IDH1 and IDH2 mutations (IDH1/2Mut) are recognized as recurrent genetic alterations in acute myeloid leukemia (AML) and associated with both clinical impact and therapeutic opportunity due to the recent development of specific IDH1/2Mut inhibitors. In T-cell acute lymphoblastic leukemia (T-ALL), their incidence and prognostic implications remain poorly reported. Our targeted next-generation sequencing approach allowed comprehensive assessment of genotype across the entire IDH1 and IDH2 locus in 1085 consecutive unselected and newly diagnosed patients with T-ALL and identified 4% of, virtually exclusive (47 of 49 patients), IDH1/2Mut. Mutational patterns of IDH1/2Mut in T-ALL present some specific features compared to AML. Whereas IDH2R140Q mutation was frequent in T-ALL (25 of 51 mutations), the IDH2R172 AML hotspot was absent. IDH2 mutations were associated with older age, an immature phenotype, more frequent RAS gain-of-function mutations and epigenetic regulator loss-of-function alterations (DNMT3A and TET2). IDH2 mutations, contrary to IDH1 mutations, appeared to be an independent prognostic factor in multivariate analysis with the NOTCH1/FBXW7/RAS/PTEN classifier. IDH2Mut were significantly associated with a high cumulative incidence of relapse and very dismal outcome, suggesting that IDH2-mutated T-ALL cases should be identified at diagnosis in order to benefit from therapeutic intensification and/or specific IDH2 inhibitors.

[Transition to adulthood: An essential period in the follow up of young patients]. / La transition vers l'âge adulte: une période charnière dans la prise en charge continue des jeunes patients.

In recent decades, follow-up of cancer survivors has taken on its full meaning with the gradual improvement in the survival of children and adolescents with cancer. This follow-up is associated specially for adolescents with a multitude of transitions: the transition from therapeutic management to the monitoring for possible relapse, the transition into long-term follow-up after childhood cancer, the transition from a pediatric system to an adult care system. If this transition can be perceived as difficult by patients, it gives young people the opportunity to access more autonomous follow-up and support in becoming an adult. Supporting the transition should make caregivers attentive to this time of consolidation of adolescence, favorable to the emergence of a sense of stable, mature identity that guarantees a certain autonomy. This is a key to a successful transition limiting breakdown of care and promoting "the work of the disease". The double contribution of adult and pediatric oncology provides support tailored to these psychic and societal issues. AYA teams can actively participate in this process by facilitating the acculturation of pediatric and adult care teams to the specificity of this group, thus allowing a continuum of care.

Slower degradation rate of cytarabine in blood samples from acute myeloid leukemia by comparison with control samples.

PURPOSE: Cytarabine, a key chemotherapy agent for acute myeloid leukemia (AML) treatment, is deaminated into inactive uracil-arabinoside by cytidine deaminase. This deamination leads to samples stability issues with respect to clinical pharmacokinetic trials. The aim of our study was to study in vitro cytarabine stability in blood samples obtained from AML patients. METHODS: Cytarabine quantification was performed using a fully validated LC/MS/MS method. In vitro cytarabine stability was assessed at room temperature over 24 h in samples coming from 14 AML patients and 7 control patients (CTRL) with no hematological malignancy. In vitro concentrations versus time data were analyzed using a noncompartmental approach. RESULTS: Cytarabine in vitro area under the curve (AUCIVlast) was 22-fold higher in AML samples as compared to CTRL samples (AML mean (standard deviation (SD)), 51,829 (27,004) h ng/mL; CTRL mean (SD), 2356 (1250) h ng/mL, p = 0.00019). This increase was associated with a prolonged in vitro degradation half-life (t1/2IVdeg AML mean (SD), 15 (11.8) h; CTRL mean (SD), 0.36 (0.37) h, p = 0.0033). Multiple linear regression analysis showed that AML diagnosis significantly influenced t1/2IVdeg and AUCIVlas relationship. CONCLUSION: Cytarabine stability is higher in AML than in CTRL samples. The absence of correlation between t1/2IVdeg and AUCIVlast in AML samples suggests that in vitro cytarabine degradation in AML is complex. These results open perspectives including the evaluation of the clinical relevance and the involved molecular mechanisms.

Vasculitis associated with myelodysplastic syndrome and chronic myelomonocytic leukemia: French multicenter case-control study.

INTRODUCTION: Our objective was to evaluate characteristics, treatment and outcome of vasculitis associated with myelodysplastic syndrome (MDS) and chronic myelomonicytic leukemia (CMML) PATIENTS AND METHODS: Retrospective descriptive analysis of MDS/CMML-related vasculitis and comparison with MDS/CMML patients without dysimmune features. RESULTS: Seventy patients with vasculitis and MDS/CMML were included, with median age of 71.5 [21-90] years and male/female ratio of 2.3. Vasculitis was diagnosed prior to MDS/CMML in 31 patients (44%), and after in 20 patients. In comparison with MDS/CMML without autoimmune/inflammatory features, vasculitis with MDS/MPN showed no difference in MDS/CMML subtypes distribution nor International Prognostic Scoring System and CMML-specific prognostic (IPSS/CPSS) scores. Vasculitis subtypes included Giant cell arteritis in 24 patients (34%), Behçet's-like syndrome in 11 patients (20%) and polyarteritis nodosa in 6 patients (9%). Glucocorticoids (GCs) were used as first-line therapy for MDS/CMML vasculitis in 64/70 patients (91%) and 41 (59%) received combined immunosuppressive therapies during the follow-up. After a median follow-up of 33.2 months [1-162], 31 patients (44%) achieved sustained remission. At least one relapse occurred in 43 patients (61%). Relapse rates were higher in patients treated with conventional Disease Modifying Anti-Rheumatic Drug (DMARDs) (odds ratio 4.86 [95% CI 1.38 - 17.10]), but did not differ for biologics (odds ratio 0.59 [95% CI 0.11-3.20]) and azacytidine (odds ratio 1.44 [95% CI 0.21-9.76]) than under glucocorticoids. Overall survival in MDS/CMML vasculitis was not significantly different from MDS/CMML patients without autoimmune/inflammatory features (p = 0.5), but acute leukemia progression rates were decreased (log rank <0.05). CONCLUSION: This study shows no correlation of vasculitis diagnoses with subtypes and severity of MDS/CMML, and no significant impact of vasculitis on overall survival. Whereas conventional DMARDs seem to be less effective, biologics or azacytidine therapy could be considered for even low-risk MDS/CMML vasculitis.

Analysis of a cohort of 279 patients with hairy-cell leukemia (HCL): 10 years of follow-up.

In total, 279 patients with hairy-cell leukemia (HCL) were analyzed, with a median follow-up of 10 years. Data were collected up to June 2018. We analyzed responses to treatment, relapses, survival, and the occurrence of second malignancies during follow-up. The median age was 59 years. In total, 208 patients (75%) were treated with purine analogs (PNAs), either cladribine (159) or pentosatin (49), as the first-line therapy. After a median follow-up of 127 months, the median overall survival was 27 years, and the median relapse-free survival (RFS) was 11 years. The cumulative 10-year relapse incidence was 39%. In patients receiving second-line therapy, the median RFS was 7 years. For the second-line therapy, using the same or another PNA was equivalent. We identified 68 second malignancies in 59 patients: 49 solid cancers and 19 hematological malignancies. The 10-year cumulative incidences of cancers, solid tumors, and hematological malignancies were 15%, 11%, and 5.0%, respectively, and the standardized incidence ratios were 2.22, 1.81, and 6.67, respectively. In multivariate analysis, PNA was not a risk factor for second malignancies. HCL patients have a good long-term prognosis. PNAs are the first-line treatment. HCL patients require long-term follow-up because of their relatively increased risk of second malignancies.

R-DHA-oxaliplatin (R-DHAOx) versus R-DHA-cisplatin (R-DHAP) regimen in B-cell lymphoma treatment: A eight-year trajectory study.

BACKGROUND: The R-DHAP regimen (rituximab, cisplatin, dexamethasone, and high-dose cytarabine) is standardly used to treat relapsed Non-Hodgkin lymphoma (NHL). Despite scarce data, cisplatin is frequently substituted with oxaliplatin (R-DHAOx) to avoid nephrotoxicity. We compared nephrotoxicity of cisplatin and oxaliplatin based on creatinine-based trajectory modeling. METHODS: All patients with NHL treated by R-DHAP or R-DHAOx in Angers hospital between January 01, 2007, and December 31, 2014, were included. Patients received cisplatin 100 mg/m2 or oxaliplatin 130 mg/m2 (d1) with cytarabine (2000 mg/m2 , two doses, d2), dexamethasone (40 mg, d1-4), and rituximab (375 mg/m2 , d1). Creatinine levels were recorded before each cycle. Individual profiles of trajectories were clustered to detect homogeneous patterns of evolution. RESULTS: Twenty-two patients received R-DHAP, 35 R-DHAOx, 6 switched from R-DHAP to R-DHAOx due to nephrotoxicity. Characteristics of patients were similar between two groups. Patients receiving R-DHAP experienced more severe renal injury than patients receiving R-DHAOx (68% vs. 7.7%, P < .001). Two homogeneous clusters appeared: cluster A, with a majority of R-DHAOx (32, 91.4%), was less nephrotoxic than B, with a majority of R-DHAP (19, 86.4%), with a decreased average serum creatinine level (P < .0001). There were no other differences between clusters. CONCLUSIONS: Our study confirms that R-DHAOx regimen causes less nephrotoxicity than R-DHAP regimen.

Quantitative chimerism in CD3-negative mononuclear cells predicts prognosis in acute myeloid leukemia patients after hematopoietic stem cell transplantation.

Relapse is a major complication of acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (SCT). The objective of our study was to evaluate chimerism monitoring on the CD3-negative mononuclear cells by RQ-PCR to predict relapse of patients allografted for AML and to compare its performance with WT1 quantification. A cohort of 100 patients undergoing allogenic SCT for AML was retrospectively analyzed in a single institution. Patients without complete chimerism, defined as less than 0.01% of recipient's DNA in CD3-negative cells, had a significantly higher risk of relapse and a lower overall survival (p < 0.001). An increase in the percentage of recipient DNA in CD3-negative cells was associated with an increased risk of relapse (p < 0.001) but not with overall survival. Comparable performances between monitoring of CD3-negative cell chimerism and WT1 expression to predict relapse was observed up to more than 90 days before hematological relapse, with sensitivity of 82% and 78%, respectively, and specificity of 100% for both approaches. Quantitative specific chimerism of the CD3-negative mononuclear fraction, enriched in blastic cells, is a new and powerful tool for monitoring measurable residual disease and could be used for AML patients without available molecular markers.