Montserrat Torrebadell

B cell–helper neutrophils stimulate the diversification and production of immunoglobulin in the marginal zone of the spleen

Neutrophils utilize immunoglobulins (Igs) to clear antigen, but their role in Ig production is unknown. Here we identified neutrophils around the marginal zone (MZ) of the spleen, a B cell area specialized in T-independent Ig responses to circulating antigen. Neutrophils colonized peri-MZ areas after post-natal mucosal colonization by microbes and enhanced their B-helper function upon receiving reprogramming signals from splenic sinusoidal endothelial cells, including interleukin 10 (IL-10). Splenic neutrophils induced Ig class switching, somatic hypermutation and antibody production by activating MZ B cells through a mechanism involving the cytokines BAFF, APRIL and IL-21. Neutropenic patients had fewer and hypomutated MZ B cells and less preimmune Igs to T-independent antigens, which indicates that neutrophils generate an innate layer of antimicrobial Ig defense by interacting with MZ B cells.Neutrophils use immunoglobulins to clear antigen, but their role in immunoglobulin production is unknown. Here we identified neutrophils around the marginal zone (MZ) of the spleen, a B cell area specialized in T cell–independent immunoglobulin responses to circulating antigen. Neutrophils colonized peri-MZ areas after postnatal mucosal colonization by microbes and enhanced their B cell–helper function after receiving reprogramming signals, including interleukin 10 (IL-10), from splenic sinusoidal endothelial cells. Splenic neutrophils induced immunoglobulin class switching, somatic hypermutation and antibody production by activating MZ B cells through a mechanism that involved the cytokines BAFF, APRIL and IL-21. Neutropenic patients had fewer and hypomutated MZ B cells and a lower abundance of preimmune immunoglobulins to T cell–independent antigens, which indicates that neutrophils generate an innate layer of antimicrobial immunoglobulin defense by interacting with MZ B cells.

Erythropoietin treatment of the anaemia of myelofibrosis with myeloid metaplasia: results in 20 patients and review of the literature

Recombinant human erythropoietin (rHuEPO) is an effective treatment for the anaemia that occurs secondary to various conditions, but its role in myelofibrosis with myeloid metaplasia (MMM) is not well established. rHuEPO, at an initial dose of 10 000 U thrice a week, was given to 20 patients with MMM and anaemia. Complete response (CR) was defined as transfusion cessation with normal haemoglobin (Hb) levels and partial response (PR) as a transfusion decrease ≥50% and Hb > 10 g/dl maintained for at least 8 weeks. Nine patients (45%) showed a favourable response to treatment, including four CR and five PR, four of whom have maintained their response at a median follow‐up of 12·5 months (range: 4–21 months) from the start of treatment. The pretreatment factors associated with a favourable response were lack of transfusion requirement (P = 0·002) and higher Hb at start treatment of (P = 0·01). An analysis of the present series (n = 20) and 31 patients from the literature identified 28 (55%) favourable responses to rHuEPO, including 16 CR and 12 PR. In the multivariate analysis, serum erythropoietin level <125 U/l was found to be associated with a favourable response to rHuEPO, whereas lack of transfusional support had borderline significance.

Favorable outcome of patients with acute myeloid leukemia harboring a low-allelic burden FLT3-ITD mutation and concomitant NPM1 mutation: relevance to post-remission therapy

Risk associated to FLT3 internal tandem duplication (FLT3-ITD) in patients with acute myeloid leukemia (AML) may depend on mutational burden and its interaction with other mutations. We analyzed the effect of FLT3-ITD/FLT3 wild-type (FLT3wt) ratio depending on NPM1 mutation (NPM1mut) in 303 patients with intermediate-risk cytogenetics AML treated with intensive chemotherapy. Among NPM1mut patients, FLT3wt and low ratio (<0.5) subgroups showed similar overall survival, relapse risk, and leukemia-free survival, whereas high ratio (≥0.5) patients had a worse outcome. In NPM1wt AML, FLT3-ITD subgroups showed a comparable outcome, with higher risk of relapse and shortened overall survival than FLT3wt patients. Allogeneic stem cell transplantation in CR1 was associated with a reduced relapse risk in all molecular subgroups with the exception of NPM1mut AML with absent or low ratio FLT3-ITD. In conclusion, effect of FLT3 burden is modulated by NPM1 mutation, especially in patients with a low ratio.

Long-term results of thalidomide in refractory and relapsed multiple myeloma with emphasis on response duration

Objective: Thalidomide administered as a single agent produces a response rate of about 40% in patients with refractory or relapsed multiple myeloma (MM). The aim of our study was to determine the quality and duration of such responses.

Kinetics of recovery of dendritic cell subsets after reduced-intensity conditioning allogeneic stem cell transplantation and clinical outcome

Background and Objectives Dendritic cells (DC) play a critical role in the regulation of alloimmune responses and might influence the outcome of allogeneic stem cell transplantation (allo-SCT). We studied the clinical relevance of early reconstitution of DC after reduced-intensity conditioning allo-SCT (allo-RIC). Design and Methods This study included 79 adult patients undergoing allo-RIC from HLA-identical siblings. Peripheral blood samples were drawn from patients at 1 month (+1m) and 3 months (+3m) after the transplant. DC were identified as positive for HLA-DR and negative for CD3, CD19, CD14 and CD56. The expression of CD33, CD123 and CD16 was used to identify myeloid DC, plasmacytoid DC and CD16+ DC subpopulations, respectively. Results Patients whose DC count at +1m was lower than the median had a higher probability of treatment-related mortality (TRM) (60% vs 12%; p=0.02), poorer overall survival (OS) (15% vs 45%; p=0.002) and worse event-free survival (EFS) (20% vs 38%; p=0.03). A multivariate analysis confirmed that low DC counts had a detrimental effect on OS (RR 3.2; p=0.007), relapse (RR 4.1; p=0.01), and EFS (RR 6; p=0.001). Low CD16+ DC counts were observed to have a detrimental effect on EFS, which was due to both a higher incidence of deaths caused by infections (50% vs 0%, p=0.05) and a higher incidence of relapse (57% vs 50%; p=0.03). Indeed, the number of CD16+ DC at +3 m was the most important prognostic factor for EFS (RR 6; p=0.001). Interpretations and Conclusions This study shows the clinical importance of DC recovery, especially of the CD16+ DC subset, in the outcome of patients treated with allo-RIC.

The prognostic value of multilineage dysplasia in de novo acute myeloid leukemia patients with intermediate-risk cytogenetics is dependent on NPM1 mutational status.

To the editor: The prognostic significance of multilineage dysplasia (MLD) in acute myeloid leukemia patients with intermediate-risk cytogenetics (IR-AML) presenting as de novo disease is unclear.[1][1]–[4][2] Falini et al have recently analyzed the biologic and prognostic significance of MLD in

Multiplex real-time PCR for prompt diagnosis of an outbreak of human parainfluenza 3 virus in children with acute leukemia.

IntroductionHuman parainfluenza virus type 3 (HPIV-3) causes significant morbimortality in immunocompromised patients. Outbreaks of severe pneumonitis have been previously described in this setting.Materials and methodsRetrospective observational study in children diagnosed with acute leukemia and a documented HPIV-3 infection in the context of a nosocomial outbreak occurred in a single center.ResultDuring summer 2012, an HPIV-3 infection was detected in six hospitalized children with acute leukemia. All the patients had respiratory symptoms and one of them suffered from parotitis.ConclusionEarly diagnoses using multiplex real-time polymerase chain reaction (PCR) let us control this outbreak. A phylogenetic analysis confirmed person-to-person transmission of a single HPIV-3 variant.

Outcome and toxicities associated to chemotherapy in children with acute lymphoblastic leukemia and Gilbert syndrome. Usefulness of UGT1A1 mutational screening.

Acute lymphoblastic leukemia (ALL) is the most frequent cancer in childhood. Although intensive chemotherapy has improved survival in those patients, important side effects, including hyperbilirubinemia, are frequent. Gilbert syndrome (GS) is a frequent condition that causes a reduction in glucuronidation and intermittent hyperbilirubinemia episodes. This could provoke a greater exposure to some cytotoxic agents used in ALL, increasing the risk of toxicity. On the other hand, unexplained hyperbilirubinemia could lead to unnecessary modifications or even treatment withdrawals, which could increase the risk of relapse, but data regarding this in ALL pediatric population are scarce.

Refining the diagnosis and prognostic categorization of acute myeloid leukemia patients with an integrated use of cytogenetic and molecular studies.

Significant progress in the understanding of the genetic basis of acute myeloid leukemia (AML) has been made during the last 30 years. The aim of the present study was to assess whether the detection of recurrent gene rearrangements by fluorescent in situ hybridization (FISH) studies and NPM1 and FLT3 gene mutations by molecular studies added clinically relevant information to the karyotype in 113 AML patients. Thus, FISH and molecular studies were found to add new information in 22 and 55% of the patients, respectively, particularly in cases with normal karyotype (NK) or when a cytogenetic analysis failed. Patients with NK changed their genetic risk group to favorable in 27 and 29% of cases using FISH and molecular biology studies, respectively. Our results demonstrate that molecular biology and FISH studies provide relevant information in AML and should be routinely performed.

A 4-gene expression prognostic signature might guide post-remission therapy in patients with intermediate-risk cytogenetic acute myeloid leukemia

Abstract In intermediate-risk cytogenetic acute myeloid leukemia (IRC-AML) patients, novel biomarkers to guide post-remission therapy are needed. We analyzed with high-density arrays 40 IRC-AML patients who received a non-allogeneic hematopoietic stem-cell transplantation-based post-remission therapy, and identified a signature that correlated with early relapse. Subsequently, we analyzed selected 187 genes in 49 additional IRC-AML patients by RT-PCR. BAALC, MN1, SPARC and HOPX overexpression correlated to refractoriness. BAALC or ALDH2 overexpression correlated to shorter overall survival (OS) (5-year OS: 33 ± 8.6% vs. 73.7 ± 10.1%, p = .006; 32 ± 9.3% vs. 66.4 ± 9.7%, p = .016), whereas GPR44 or TP53INP1 overexpression correlated to longer survival (5-year OS: 66.7 ± 10.3% vs. 35.4 ± 9.1%, p = .04; 58.3 ± 8.2% vs. 23.1 ± 11.7%, p = .029). A risk-score combining these four genes expression distinguished low-risk and high-risk patients (5-year OS: 79 ± 9% vs. 30 ± 8%, respectively; p = .001) in our cohort and in an independent set of patients from a public repository. Our 4-gene signature may add prognostic information and guide post-remission treatment in IRC-AML patients.