Stéphane Morisset

Serotyping of Toxoplasma gondii: striking homogeneous pattern between symptomatic and asymptomatic infections within Europe and South America

Field isolates of Toxoplasma gondii in Europe and North America have been grouped into three clonal lineages that display different virulence in mice. Whether the genetic structure of the parasite is related to clinical expression in humans has not yet been demonstrated. We developed an enzyme-linked immunosorbent assay which uses lineage-specific, polymorphic polypeptides derived from the dense granule antigens, GRA5 and GRA6. Our goal was to compare serotypical patterns observed in asymptomatic versus symptomatic (ocular disease and severe infection in human immunodeficiency virus (HIV)-positive patients) infections among patients from Europe and South America. Independent of the clinical presentation of the disease, serotypes differed according to geographical origin, with a homogeneous distribution of serotype II in Europe and of serotypes I and III in South America. We conclude that GRA5-GRA6 serotyping is an interesting tool to study serotype prevalence in populations but it is not an accurate marker of pathogenicity of Toxoplasma infection in humans.

Allogeneic stem cell transplantation for patients harboring T315I BCR-ABL mutated leukemias

T315I(+) Philadelphia chromosome-positive leukemias are inherently resistant to all licensed tyrosine kinase inhibitors, and therapeutic options remain limited. We report the outcome of allogeneic stem cell transplantation in 64 patients with documented BCR-ABL(T315I) mutations. Median follow-up was 52 months from mutation detection and 26 months from transplantation. At transplantation, 51.5% of patients with chronic myeloid leukemia were in the chronic phase and 4.5% were in advanced phases. Median overall survival after transplantation was 10.3 months (range 5.7 months to not reached [ie, still alive]) for those with chronic myeloid leukemia in the blast phase and 7.4 months (range 1.4 months to not reached [ie, still alive]) for those with Philadelphia chromosome-positive acute lymphoblastic leukemia but has not yet been reached for those in the chronic and accelerated phases of chronic myeloid leukemia. The occurrence of chronic GVHD had a positive impact on overall survival (P = .047). Transplant-related mortality rates were low. Multivariate analysis identified only blast phase at transplantation (hazard ratio 3.68, P = .0011) and unrelated stem cell donor (hazard ratio 2.98, P = .011) as unfavorable factors. We conclude that allogeneic stem cell transplantation represents a valuable therapeutic tool for eligible patients with BCR-ABL(T315I) mutation, a tool that may or may not be replaced by third-generation tyrosine kinase inhibitors.

Achieving deeper molecular response is associated with a better clinical outcome in chronic myeloid leukemia patients on imatinib front-line therapy

Sustained imatinib treatment in chronic myeloid leukemia patients can result in complete molecular response allowing discontinuation without relapse. We set out to evaluate the frequency of complete molecular response in imatinib de novo chronic phase chronic myeloid leukemia patients, to identify base-line and under-treatment predictive factors of complete molecular response in patients achieving complete cytogenetic response, and to assess if complete molecular response is associated with a better outcome. A random selection of patients on front-line imatinib therapy (n=266) were considered for inclusion. Complete molecular response was confirmed and defined as MR 4.5 with undetectable BCR-ABL transcript levels. Median follow up was 4.43 years (range 0.79–10.8 years). Sixty-five patients (24%) achieved complete molecular response within a median time of 32.7 months. Absence of spleen enlargement at diagnosis, achieving complete cytogenetic response before 12 months of therapy, and major molecular response during the year following complete cytogenetic response was predictive of achieving further complete molecular response. Patients who achieved complete molecular response had better event-free and failure-free survivals than those with complete cytogenetic response irrespective of major molecular response status (95.2% vs. 64.7% vs. 27.7%, P=0.00124; 98.4% vs. 82.3% vs. 56%, P=0.0335), respectively. Overall survival was identical in the 3 groups. In addition to complete cytogenetic response and major molecular response, further deeper molecular response is associated with better event-free and failure-free survivals, and complete molecular response confers the best outcome.

The impact of HLA matching on long-term transplant outcome after allogeneic hematopoietic stem cell transplantation for CLL: a retrospective study from the EBMT registry

We analyzed 368 chronic lymphocytic leukemia patients who underwent allogeneic hematopoietic stem cell transplantation reported to the EBMT registry between 1995 and 2007. There were 198 human leukocyte antigen (HLA)-identical siblings; among unrelated transplants, 31 were well matched in high resolution (‘well matched’ unrelated donor, WMUD), and 139 were mismatched (MM), including 30 matched in low resolution; 266 patients (72%) received reduced-intensity conditioning and 102 (28%) received standard. According to the EBMT risk score, 11% were in scores 1–3, 23% in score 4, 40% in score 5, 22% in score 6 and 4% in score 7. There was no difference in overall survival (OS) at 5 years between HLA-identical siblings (55% (48–64)) and WMUD (59% (41–84)), P=0.82. In contrast, OS was significantly worse for MM (37% (29–48) P=0.005) due to a significant excess of transplant-related mortality. Also OS worsened significantly when EBMT risk score increased. HLA matching had no significant impact on relapse (siblings: 24% (21–27); WMUD: 35% (26–44), P=0.11 and MM: 21% (18–24), P=0.81); alemtuzumab T-cell depletion and stem cell source (peripheral blood) were associated with an increased risk. Our findings support the use of WMUD as equivalent alternative to HLA-matched sibling donors for allogeneic HSCT in CLL, and justify the application of EBMT risk score in this disease.

High DNA Methyltransferase DNMT3B Levels: A Poor Prognostic Marker in Acute Myeloid Leukemia

It has been recently shown that DNA methyl transferase overexpression is correlated with unfavourable prognosis in human malignancies while methylation deregulation remains a hallmark that defines acute myeloid leukemia (AML). The oncogenic transcription factor EVI1 is involved in methylation deregulation and its overexpression plays a major role for predicting an adverse outcome. Moreover, the identification of DNMT3A mutations in AML patients has recently been described as a poor prognostic indicator. In order to clarify relationship between these key actors in methylation mechanisms and their potential impact on patient outcomes, we analysed 195 de novo AML patients for the expression of DNMT3A, 3B (and its non-catalytic variant 3BNC) and their correlations with the outcome and the expression of other common prognostic genetic biomarkers (EVI1, NPM1, FLT3ITD/TKD and MLL) in adult AML. The overexpression of DNMT3B/3BNC is (i) significantly correlated with a shorter overall survival, and (ii) inversely significantly correlated with event-free survival and DNMT3A expression level. Moreover, multivariate analysis showed that a high expression level of DNMT3B/3BNC is statistically a significant independent poor prognostic indicator. This study represents the first report showing that the overexpression of DNMT3B/3BNC is an independent predictor of poor survival in AML. Its quantification should be implemented to the genetic profile used to stratify patients for therapeutical strategies and should be useful to identify patients who may benefit from therapy based on demethylating agents.

Risk factors for invasive aspergillosis in acute myeloid leukemia patients prophylactically treated with posaconazole.

Invasive aspergillosis (IA) is an important cause of morbidity and mortality in neutropenic patients with hematological malignancies. To investigate the immediate and mid-term benefits of posaconazole prophylaxis in AML patients undergoing first induction chemotherapy and to study the infection risk factors, we prospectively studied the IA incidence in these patients at our hospital between years 2007 and 2008; then we compared them to a matched control group without prophylaxis. There were 55 and 66 patients in each group respectively. At day 32 post-induction, two probable cases (3.6%) were scored in the prophylaxis group compared to 8 cases (12.1%) in the control group (4 possible and 4 probable). At day 100, it reached 7.27% and 15.5% respectively. Kaplan-Meier analysis at day 100 showed lower mortality rate in the prophylaxis group compared to the control group [3.64% (n = 2, none due to IA) and 10.61% (n = 7, four due to IA) respectively, P = 0.002]. Multivariate analysis showed age and lack of response to induction as independent infection risk factors. Posaconazole prophylaxis resulted in lower incidence of IA and significantly improved survival. Patients age and response to induction treatment are two independent infection risk factors, and need more attention during future clinical trials linked to antifungal prophylaxis.

Double umbilical cord blood transplantation for hematological malignancies: a long- term analysis from the SFGM-TC registry.

Allogeneic hematopoietic stem cell (HSC) transplantation is a curative treatment for many hematologic malignancies for which umbilical cord blood (UCB) represents an alternative source of HSCs. To overcome the low cellularity of one UCB unit, double UCB transplantation (dUCBT) has been developed in adults. We have analyzed the outcome of 136 patients who underwent dUCBT reported to the SFGM-TC registry between 2005 and 2007. Forty-six patients received myeloablative regimens, and 90 patients received reduced-intensity conditioning regimens. There were 84 cases of leukemia, 17 cases of non-Hodgkin lymphoma, 11 cases of myeloma, and 24 other hematologic malignancies. At transplantation, 40 (29%) patients were in complete remission. At day 60 after transplantation, the cumulative incidence of neutrophil recovery was 91%. We observed one UCB unit domination in 88% of cases. The cumulative incidence of day 100 acute graft-versus-host disease, chronic graft-versus-host disease, transplant-related mortality, and relapse at 2 years were 36%, 23%, 27%, and 28% respectively. After a median follow-up of 49.5 months, the 3-year probabilities of overall and progression-free survival were 41% and 35%, respectively, with a significant overall survival advantage when male cord engrafted male recipients. We obtained a long-term plateau among patients in complete remission, which makes dUCBT a promising treatment strategy for these patients.

Evolving strategies with immunomodulating drugs and tandem autologous/allogeneic hematopoietic stem cell transplantation in first line high risk multiple myeloma patients.

We prospectively evaluated in high-risk myeloma patients the efficacy and toxicity of tandem autologous hematopoietic stem cell transplantation (auto-HSCT) followed by reduced-intensity conditioning (RIC) and allogeneic (allo)-HSCT with bortezomib and donor lymphocyte infusions introduction after allo-HSCT (group 1). Results were compared with results from tandem auto-RIC-allo-HSCT without bortezomib (group 2). Groups 1 and 2 were compared to matched patients not receiving allo-HSCT from the Intergroupe Francophone du Myélome prospective studies. Allo-HSCT groups included 25 patients (12 in group 1, 13 in group 2). All patients engrafted. There were 8 acute GVHD (7 grade II [3 in group 1], 1 grade III in group 1)] and 11 chronic GVHD (3 limited [in group 1], 8 extensive [1 in group 1]). Matched population included 36 controls for group 1 and 39 for group 2. After a median follow-up of 55 months (range, 3-142 months), median overall survival was not reached in group 1 versus 65 months (51-not reached [NR]) in its matched group (p = 0.027); it was 96 months (49-NR) in group 2 versus 91 months (32-NR) in its matched group (p = 0.77). Median progression-free survival was 49 months (29-NR) in group 1 and was 25 months (range, 21-35 months) in its matched group (p = 0.0045); it was 31 months (22-NR) in group 2 and 28 months (range, 21-40 months) in its matched group (p = 0.0776). Tandem auto-RIC-allo-HSCT including new molecules and immunomodulation after transplantation could be used as a first-line treatment for high-risk myeloma patients.

Impact of anti-HLA antibodies on allogeneic hematopoietic stem cell transplantation outcomes after reduced-intensity conditioning regimens

Anti-human leukocyte antigen (HLA) antibodies are associated with several complications in solid organ transplantations, but their impact after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is not yet well defined. To evaluate the relevance of anti-HLA antibodies, we have retrospectively analyzed 107 peripheral blood allo-HSCTs after reduced-intensity conditioning regimen between 2005 and 2010. Acute myeloid leukemia and multiple myeloma were the most frequent malignancies in the cohort. The detection of anti-HLA antibodies was systematically performed in all patients before transplantation. Anti-HLA antibodies were present in 24 patients (22%). There was no significant impact of anti-HLA antibodies on engraftment, incidence of relapse, and incidence of acute graft-vs-host disease. The presence of anti-HLA antibodies was associated with significantly worse overall survival (p = 0.006) and event-free survival (p = 0.024) after stratification on sex. The 3-year probability of overall survival was 34% without anti-HLA antibodies and 16% in their presence. Patients with anti-HLA antibodies had a higher transplant-related mortality associated with life-threatening vascular complications. Our study supports that anti-HLA antibodies should be tested and considered as an important impacting factor for transplantation outcomes after reduced-intensity conditioning allo-HSCT. We recommend its consideration before allo-HSCT in the donor-recipient selection parameters.

Prospective study of erythropoietin use on quality of life and cost effectiveness in acute myeloid leukemia and allogeneic hematopoietic stem cell transplantation patients

Despite frequent anemia and multiple transfusions in patients undergoing chemotherapy and allogeneic hematopoietic stem cell transplantation (allo‐HSCT) for acute myeloid leukemia , recommendations for use of erythropoiesis‐stimulating agents (ESAs) in these populations are still missing. The primary objective was the effect of ESA administration on patients quality of life (QoL). Secondary objectives were hemoglobin (Hb) recovery, red blood cell (RBC) transfusions, overall survival, and event‐free survival.