The SLC40A1 R178Q mutation is a recurrent cause of hemochromatosis and is associated with a novel pathogenic mechanism.

Hemochromatosis type 4 is one of the most common causes of primary iron overload, after HFE-related hemochromatosis. It is an autosomal dominant disorder, primarily due to missense mutations in SLC40A1 This gene encodes ferroportin 1 (FPN1), which is the sole iron export protein reported in mammals. Not all heterozygous missense mutations in SLC40A1 are disease-causing. Due to phenocopies and an increased demand for genetic testing, rare SLC40A1 variations are fortuitously observed in patients with a secondary cause of hyperferritinemia. Structure/function analysis is the most effective way of establishing causality when clinical and segregation data are lacking. It can also provide important insights into the mechanism of iron egress and FPN1 regulation by hepcidin. The present study aimed to determine the pathogenicity of the previously reported p.Arg178Gln variant. We present the biological, clinical, histological and radiological findings of 22 patients from six independent families of French, Belgian or Iraqi decent. Despite phenotypic variability, all patients with p.Arg178Gln had elevated serum ferritin concentrations and normal to low transferrin saturation levels. In vitro experiments demonstrated that the p.Arg178Gln mutant reduces the ability of FPN1 to export iron without causing protein mislocalization. Based on a comparative model of the 3D structure of human FPN1 in an outward facing conformation, we argue that p.Arg178 is part of an interaction network modulating the conformational changes required for iron transport. We conclude that p.Arg178Gln represents a new category of loss-of-function mutations and that the study of "gating residues" is necessary in order to fully understand the action mechanism of FPN1.

Second tyrosine kinase inhibitor discontinuation attempt in patients with chronic myeloid leukemia.

BACKGROUND: Several studies have demonstrated that approximately one-half of patients with chronic myeloid leukemia (CML) who receive treatment with tyrosine kinase inhibitors (TKIs) and achieve and maintain a deep molecular response (DMR) are able to successfully discontinue therapy. In patients who have a molecular relapse, a DMR is rapidly regained upon treatment re-initiation. METHODS: The authors report the results from RE-STIM, a French observational, multicenter study that evaluated treatment-free remission (TFR) in 70 patients who re-attempted TKI discontinuation after a first unsuccessful attempt. After the second TKI discontinuation attempt, the trigger for treatment re-introduction was the loss of a major molecular response in all patients. RESULTS: The median follow-up was 38.3 months (range, 4.7-117 months), and 45 patients (64.3%) lost a major molecular response after a median time off therapy of 5.3 months (range, 2-42 months). TFR rates at 12, 24, and 36 months were 48% (95% confidence interval [CI], 37.6%-61.5%), 42% (95% CI, 31.5%-55.4%), and 35% (95% CI, 24.4%-49.4%), respectively. No progression toward advanced-phase CML occurred, and no efficacy issue was observed upon TKI re-introduction. In univariate analysis, the speed of molecular relapse after the first TKI discontinuation attempt was the only factor significantly associated with outcome. The TFR rate at 24 months was 72% (95% CI, 48.8%-100%) in patients who remained in DMR within the first 3 months after the first TKI discontinuation and 36% (95% CI, 25.8%-51.3%) for others. CONCLUSIONS: This study is the first to demonstrate that a second TKI discontinuation attempt is safe and that a first failed attempt at discontinuing TKI does not preclude a second successful attempt. Cancer 2017;123:4403-10. © 2017 American Cancer Society.

Severe chronic primary neutropenia in adults: report on a series of 108 patients.

Severe chronic primary neutropenia (CPN) is a rare entity, and long-term outcome and risk factors for infections in severe CPN adults have not been described to date. We report the characteristics and outcomes of 108 severe adult CPN patients enrolled in a multi-institutional observational study. Severe CPN adults were mostly female (78%), and median age at diagnosis was 28.3 years. Diagnosis was fortuitous in 62% of cases. The median absolute neutrophil count (ANC) at diagnosis was 0.4 × 10(9)/L, and median ANC without granulocyte colony-stimulating factor (G-CSF) during follow-up was 0.5 × 10(9)/L. Twenty-three of 66 (34.8%) evaluable patients had neutrophil autoantibodies, and 6 of 47 (12.8%) a T-cell clone. The presence of neutrophil autoantibodies or T-cell clone was not associated with any specific clinical or biological characteristics. No death or hematologic malignancies occurred, and 44 severe bacterial infections were reported in 27 patients with a median follow-up of 8.3 years. Fifty patients received G-CSF either sporadically (n = 24) or continuously (n = 26) and responded (96%). Nineteen patients received immunosuppressive therapies: overall response (OR) was 41%, and median duration of response was 3 months. At diagnosis, the only predictive factor for the occurrence of severe bacterial infections was an ANC count below 0.2 × 10(9)/L (OR, 0.76). Severe CPN in adults is characterized by a female predominance and a benign outcome with a low rate of severe bacterial infections and no secondary malignancies. G-CSF is efficient and well tolerated but is not required in a majority of patients.

Peripheral blood 8 colour flow cytometry monitoring of hairy cell leukaemia allows detection of high-risk patients.

Although purine analogues have significantly improved the outcome of hairy cell leukaemia (HCL) patients, 30-40% relapse, illustrating the need for minimal residual disease (MRD) markers that can aid personalized therapeutic management. Diagnostic samples from 34 HCL patients were used to design an 8-colour flow cytometry (8-FC) tube for blood MRD (B/RD) analysis (188 samples) which was compared to quantitative IGH polymerase chain reaction (Q-PCR) on 83 samples and to qualitative consensus IGH PCR clonality analysis on 165 samples. Despite heterogeneous HCL phenotypes at diagnosis, discrimination from normal B lymphocytes was possible in all cases using a single 8-FC tube, with a robust sensitivity of detection of 10(-4) , comparable to Q-PCR at this level, but preferable in terms of informativeness, simplicity and cost. B/RD assessment of 15 patients achieving haematological complete remission after purine analogues was predictive of a clinically significant relapse risk: with a median follow-up of 95 months; only one of the nine patients with reproducible 8-FC B/RD levels below 10(-4) (B/RD(neg) ) relapsed, compared to 5/6 in the B/RD(pos) group (P = 0.003). These data demonstrate the clinical interest of a robust 8-FC HCL B/RD strategy that could become a surrogate biomarker for therapeutic stratification and new drug assessment, which should be evaluated prospectively.

Early posttransplantation donor-derived invariant natural killer T-cell recovery predicts the occurrence of acute graft-versus-host disease and overall survival.

Invariant natural killer T (iNKT) cells can experimentally dissociate GVL from graft-versus-host-disease (GVHD). Their role in human conventional allogeneic hematopoietic stem cell transplantation (HSCT) is unknown. Here, we analyzed the post-HSCT recovery of iNKT cells in 71 adult allografted patients. Results were compared with conventional T- and NK-cell recovery and correlated to the occurrence of GVHD, relapse, and survival. We observed that posttransplantation iNKT cells, likely of donor origin, recovered independently of T and NK cells in the first 90 days after HSCT and reached greater levels in recipient younger than 45 years (P = .003) and after a reduced-intensity conditioning regimen (P = .03). Low posttransplantation iNKT/T ratios (ie, < 10(-3)) were an independent factor associated with the occurrence of acute GVHD (aGVHD; P = .001). Inversely, reaching iNKT/T ratios > 10(-3) before day 90 was associated with reduced nonrelapse mortality (P = .009) without increased risk of relapse and appeared as an independent predictive factor of an improved overall survival (P = .028). Furthermore, an iNKT/T ratio on day 15 > 0.58 × 10(-3) was associated with a 94% risk reduction of aGVHD. These findings provide a proof of concept that early postallogeneic HSCT iNKT cell recovery can predict the occurrence of aGVHD and an improved overall survival.

Hsp70 regulates erythropoiesis by preventing caspase-3-mediated cleavage of GATA-1.

Caspase-3 is activated during both terminal differentiation and erythropoietin-starvation-induced apoptosis of human erythroid precursors. The transcription factor GATA-1, which performs an essential function in erythroid differentiation by positively regulating promoters of erythroid and anti-apoptotic genes, is cleaved by caspases in erythroid precursors undergoing cell death upon erythropoietin starvation or engagement of the death receptor Fas. In contrast, by an unknown mechanism, GATA-1 remains uncleaved when these cells undergo terminal differentiation upon stimulation with Epo. Here we show that during differentiation, but not during apoptosis, the chaperone protein Hsp70 protects GATA-1 from caspase-mediated proteolysis. At the onset of caspase activation, Hsp70 co-localizes and interacts with GATA-1 in the nucleus of erythroid precursors undergoing terminal differentiation. In contrast, erythropoietin starvation induces the nuclear export of Hsp70 and the cleavage of GATA-1. In an in vitro assay, Hsp70 protects GATA-1 from caspase-3-mediated proteolysis through its peptide-binding domain. The use of RNA-mediated interference to decrease the Hsp70 content of erythroid precursors cultured in the presence of erythropoietin leads to GATA-1 cleavage, a decrease in haemoglobin content, downregulation of the expression of the anti-apoptotic protein Bcl-X(L), and cell death by apoptosis. These effects are abrogated by the transduction of a caspase-resistant GATA-1 mutant. Thus, in erythroid precursors undergoing terminal differentiation, Hsp70 prevents active caspase-3 from cleaving GATA-1 and inducing apoptosis.

Discontinuation of imatinib in patients with chronic myeloid leukaemia who have maintained complete molecular remission for at least 2 years: the prospective, multicentre Stop Imatinib (STIM) trial.

BACKGROUND: Imatinib treatment significantly improves survival in patients with chronic myeloid leukaemia (CML), but little is known about whether treatment can safely be discontinued in the long term. We aimed to assess whether imatinib can be discontinued without occurrence of molecular relapse in patients in complete molecular remission (CMR) while on imatinib. METHODS: In our prospective, multicentre, non-randomised Stop Imatinib (STIM) study, imatinib treatment (of >2 years duration) was discontinued in patients with CML who were aged 18 years and older and in CMR (>5-log reduction in BCR-ABL and ABL levels and undetectable transcripts on quantitative RT-PCR). Patients who had undergone immunomodulatory treatment (apart from interferon α), treatment for other malignancies, or allogeneic haemopoietic stem-cell transplantation were not included. Patients were enrolled at 19 participating institutions in France. In this interim analysis, rate of relapse was assessed by use of RT-PCR for patients with at least 12 months of follow-up. Imatinib was reintroduced in patients who had molecular relapse. This study is registered with ClinicalTrials.gov, number NCT00478985. FINDINGS: 100 patients were enrolled between July 9, 2007, and Dec 17, 2009. Median follow-up was 17 months (range 1-30), and 69 patients had at least 12 months follow-up (median 24 months, range 13-30). 42 (61%) of these 69 patients relapsed (40 before 6 months, one patient at month 7, and one at month 19). At 12 months, the probability of persistent CMR for these 69 patients was 41% (95% CI 29-52). All patients who relapsed responded to reintroduction of imatinib: 16 of the 42 patients who relapsed showed decreases in their BCR-ABL levels, and 26 achieved CMR that was sustained after imatinib rechallenge. INTERPRETATION: Imatinib can be safely discontinued in patients with a CMR of at least 2 years duration. Imatinib discontinuation in this setting yields promising results for molecular relapse-free survival, raising the possibility that, at least in some patients, CML might be cured with tyrosine kinase inhibitors.

Cryptococcus gattii in Patients with Lymphoid Neoplasms: An Illustration of Evolutive Host-Fungus Interactions.

Recent outbreaks of Cryptococcus gattii (CG) infections in North America have sparked renewed interest in the pathogenic potential of CG, and have underscored notable differences with Cryptococcus neoformans in terms of geographic distribution, pathogen virulence, and host susceptibility. While cases of CG are increasingly reported in patients with a wide variety of underlying conditions, only very few have been reported in patients with lymphoid neoplasms. Herein, we report a case of autochthonous CG meningitis in a patient receiving ibrutinib for chronic lymphocytic leukemia in France, and review available data on the clinical epidemiology of CG infections in patients with lymphoid neoplasms. We also summarise recent data on the host responses to CG infection, as well as the potential management pitfalls associated with its treatment in the haematological setting. The clinical epidemiology, clinical presentation, and course of disease during infections caused by CG involve complex interactions between environmental exposure to CG, infecting genotype, pathogen virulence factors, host susceptibility, and host immune responses. Future treatment guidelines should address the challenges associated with the management of antifungal treatments in the onco-haematological setting and the potential drug-drug interactions.

Rituximab efficacy and safety in adult splenectomy candidates with chronic immune thrombocytopenic purpura: results of a prospective multicenter phase 2 study.

Whether rituximab could effectively and safely avoid splenectomy for adults with chronic immune thrombocytopenic purpura (ITP) remains unresolved. A multicenter, prospective, open-label, single-arm, phase 2 trial was conducted to assess rituximab safety and efficacy in adult splenectomy candidates with chronic ITP. Sixty patients with chronic (>or= 6 months) ITP and platelet counts less than 30 x 10(9)/L received a weekly intravenous infusion of rituximab (375 mg/m(2)) for 4 weeks. All other ITP treatments were stopped. A good response was defined as a platelet count 50 x 10(9)/L or more, with at least a doubling of the initial value at 1 and 2 years after the first rituximab infusion. Patients who required another treatment during follow up were considered nonresponders. Sixteen patients experienced transient side effects that necessitated treatment discontinuation for only 1. Good 1-year responses were obtained in 40% of the patients (24/60 [95% confidence interval: 28%-52%]). At 2 years, 33.3% (20/60 patients) had good responses and 6.7% (4/60) had sustained platelet counts of 30 x 10(9)/L or more without treatment. Thirty-six (60%) patients failed to respond; 25 underwent splenectomy. Based on these results, rituximab was an apparently safe and effective splenectomy-avoiding option in some adults with chronic ITP. This trial is registered at http://clinicaltrials.gov as NCT00225875.

The human spleen is a major reservoir for long-lived vaccinia virus-specific memory B cells.

The fact that you can vaccinate a child at 5 years of age and find lymphoid B cells and antibodies specific for this vaccination 70 years later remains an immunologic enigma. It has never been determined how these long-lived memory B cells are maintained and whether they are protected by storage in a special niche. We report that, whereas blood and spleen compartments present similar frequencies of IgG(+) cells, antismallpox memory B cells are specifically enriched in the spleen where they account for 0.24% of all IgG(+) cells (ie, 10-20 million cells) more than 30 years after vaccination. They represent, in contrast, only 0.07% of circulating IgG(+) B cells in blood (ie, 50-100,000 cells). An analysis of patients either splenectomized or rituximab-treated confirmed that the spleen is a major reservoir for long-lived memory B cells. No significant correlation was observed between the abundance of these cells in blood and serum titers of antivaccinia virus antibodies in this study, including in the contrasted cases of B cell-depleting treatments. Altogether, these data provide evidence that in humans, the two arms of B-cell memory--long-lived memory B cells and plasma cells--have specific anatomic distributions--spleen and bone marrow--and homeostatic regulation.

[Criteria for suspecting a myelodysplastic syndrome]. / Sur quels critères suspecter un syndrome myélodysplasique?

The myelodysplastic syndromes are a group of heterogeneous acquired and clonal disorders that are characterized by the intramedullar, abnormal death of myeloid progenitors leading to peripheral variable cytopenias. Progressive, aregenerative anemia irresponsive to B12, folates or iron supplementation often constitutes the initial complaint. The diagnosis that may be difficut relies to a careful analysis of bone marrow aspirate morphology Classification system is based on cytogenetic abnormalities, and both the number of lineage involved, and bone marrow blasts. It is predictive for the risk of transformation in secondary acute myeloid leukemia.

Evaluation of Residual Disease and TKI Duration Are Critical Predictive Factors for Molecular Recurrence after Stopping Imatinib First-line in Chronic Phase CML Patients.

PURPOSE: Tyrosine kinase inhibitor (TKI) discontinuation is an emerging goal in chronic myelogenous leukemia (CML) management and several studies have demonstrated the feasibility of safely stopping imatinib. A sustained deep molecular response on long-term TKI is critical prior to attempting treatment-free remission. Reproducible results from several studies reported recently, failed to identify robust and reproducible predictive factors for the selection of the best candidates for successful TKI cessation. PATIENTS AND METHODS: We conducted a prospective national phase II study evaluating the cessation of imatinib after at least 2 years of MR4.5 obtained on imatinib first-line in patients with chronic phase CML. RESULTS: A total of 218 patients with de novo chronic phase CML were involved in the study. The median follow-up after imatinib cessation was 23.5 (1-64) months, 2 patients died from unrelated causes, and 107 experienced a confirmed increase in BCR-ABL1 levels defined as molecular recurrence. The molecular recurrence-free survival was 52% [95% confidence interval (CI), 45%-59%] at 6 months, and 50% (95% CI, 43%-57%) at 24 months. Droplet digital PCR (ddPCR) was used to evaluate more accurately low levels of BCR-ABL1 in 175 of 218 patients at imatinib cessation. To apply positive BCR-ABL1/ABL1 ratios on the international scale (IS), a conversion factor was calculated for ddPCR and the significant cut-off point was established at 0.0023%IS. In a multivariate analysis, the duration of TKI (≥74.8 months) and ddPCR (≥0.0023%IS) were the two identified predictive factors of molecular recurrence, with P = 0.0366 (HR, 0.635; 95% CI, 0.415-0.972] and P = 0.008 (HR, 0.556; 95% CI, 0.360-0.858), respectively. CONCLUSIONS: We conclude that the duration of TKI and residual leukemic cell load as determined by ddPCR are key factors for predicting successful treatment-free remission for patients with de novo chronic phase CML.See related commentary by Yan et al., p. 6561.

Pure red-cell aplasia and antierythropoietin antibodies in patients treated with recombinant erythropoietin.

BACKGROUND: Within a period of three years, we identified 13 patients in whom pure red-cell aplasia developed during treatment with recombinant human erythropoietin (epoetin). We investigated whether there was an immunologic basis for the anemia in these patients. METHODS: Serum samples from the 13 patients with pure red-cell aplasia were tested for neutralizing antibodies that could inhibit erythroid-colony formation by normal bone marrow cells in vitro. The presence of antierythropoietin antibodies was identified by means of binding assays with the use of radiolabeled intact, deglycosylated, or denatured epoetin. RESULTS: Serum from all 13 patients blocked the formation of erythroid colonies by normal bone marrow cells. The inhibition was reversed by epoetin. Antibodies from 12 of the 13 patients bound only conformational epitopes in the protein moiety of epoetin; serum from the remaining patient bound to both conformational and linear epitopes in erythropoietin. In all the patients, the antibody titer slowly decreased after the discontinuation of treatment with epoetin. CONCLUSIONS: Neutralizing antierythropoietin antibodies and pure red-cell aplasia can develop in patients with the anemia of chronic renal failure during treatment with epoetin.

Regression of splenic lymphoma with villous lymphocytes after treatment of hepatitis C virus infection.

BACKGROUND: Some epidemiologic studies suggest a link between hepatitis C virus (HCV) infection and some B-cell non-Hodgkin's lymphomas. We undertook this study after a patient with splenic lymphoma with villous lymphocytes had a hematologic response after antiviral treatment of HCV infection. METHODS: Nine patients who had splenic lymphoma with villous lymphocytes and HCV infection were treated with interferon alfa-2b (3 million IU three times per week) alone or in combination with ribavirin (1000 to 1200 mg per day). The outcomes were compared with those of six similarly treated patients with splenic lymphoma with villous lymphocytes who tested negative for HCV infection. RESULTS: Of the nine patients with HCV infection who received interferon alfa, seven had a complete remission after the loss of detectable HCV RNA. The other two patients had a partial and a complete remission after the addition of ribavirin and the loss of detectable HCV RNA. One patient had a relapse when the HCV RNA load again became detectable in blood. In contrast, none of the six HCV-negative patients had a response to interferon therapy. CONCLUSIONS: In patients with splenic lymphoma with villous lymphocytes who are infected with HCV, treatment with interferon can lead to regression of the lymphoma.

Diffuse large B-cell lymphoma in hyperimmunoglobulinemia E syndrome.

We report a case of diffuse large B-cell lymphoma occurring in a patient with the hyperimmunoglobulinemia E syndrome, a rare immune disorder defined by elevated immunoglobulin E levels and recurrent bacterial and fungal infections often manifesting as cold abscesses. This case further supports the notion that patients with hyperimmunoglobulinemia E have an increased risk of lymphoid malignancies and should be closely monitored. Despite a theoretic risk of severe infectious complications, chemotherapy was well tolerated and resulted in a sustained complete remission.

Long-Term Follow-Up of the French Stop Imatinib (STIM1) Study in Patients With Chronic Myeloid Leukemia.

Purpose Imatinib (IM) can safely be discontinued in patients with chronic myeloid leukemia (CML) who have had undetectable minimal residual disease (UMRD) for at least 2 years. We report the final results of the Stop Imatinib (STIM1) study with a long follow-up. Patients and Methods IM was prospectively discontinued in 100 patients with CML with UMRD sustained for at least 2 years. Molecular recurrence (MR) was defined as positivity of BCR-ABL transcript in a quantitative reverse transcriptase polymerase chain reaction assay confirmed by a second analysis point that indicated an increase of one log in relation to the first analysis point at two successive assessments or loss of major molecular response at one point. Results The median molecular follow-up after treatment discontinuation was 77 months (range, 9 to 95 months). Sixty-one patients lost UMRD after a median of 2.5 months (range, 1 to 22 months), and one patient died with UMRD at 10 months. Molecular recurrence-free survival was 43% (95% CI, 33% to 52%) at 6 months and 38% (95% CI, 29% to 47%) at 60 months. Treatment was restarted in 57 of 61 patients with MR, and 55 patients achieved a second UMRD with a median time of 4 months (range, 1 to 16 months). None of the patients experienced a CML progression. Analyses of the characteristics of the study population identified that the Sokal risk score and duration of IM treatment were significantly associated with the probability of MR. Conclusion With a median follow-up of more than 6 years after treatment discontinuation, the STIM1 study demonstrates that IM can safely be discontinued in patients with a sustained deep molecular response with no late MR.

Dramatic clinical efficacy of cladribine in Rosai-Dorfman disease and evolution of the cytokine profile: towards a new therapeutic approach.

Rosai-Dorfman disease (RDD) is a rare disorder, often benign but with possible life-threatening prognosis. In most cases, specific treatment is not necessary; when required, the management of RDD is not codified to date, and various chemotherapies have been shown to be ineffective. Here, we report a patient with RDD who presented a dramatic and sustained response with cladribine. Analysis of the cytokine profile evolution shows a clear correlation between serum levels of TNF-alpha and IL-6 and disease activity. Our findings show the promising efficacy of cladribine and suggest that therapies targeting specifically cytokines might be useful in some cases of active RDD.

A double-blind low dose-finding phase II study of granulocyte colony-stimulating factor combined with chemotherapy for stem cell mobilization in patients with non-Hodgkin's lymphoma.

The aim of the study was to define the minimal effective dose (MED) of granulocyte colony-stimulating factor (G-CSF) among five daily doses following chemotherapy for peripheral blood stem cell (PBSC) collection. Twenty-five patients were included in this double-blind dose-finding phase II study conducted according to a two-stage Bayesian design. The estimated probabilities of success for PBSC collection for the G-CSF doses of 50, 75, 100, 125 and 150 microg/m2/day were 84%, 87.7%, 91%, 93.9 and 96.4%, respectively. Low G-CSF doses may be used with a similar probability of success as conventional doses and could allow significant savings.