Caterina Tatarelli

Histone Deacetylase Inhibitor Valproic Acid Enhances the Cytokine-Induced Expansion of Human Hematopoietic Stem Cells

Ex vivo amplification of human hematopoietic stem cells (HSC) without loss of their self-renewing potential represents an important target for transplantation, gene and cellular therapies. Valproic acid is a safe and widely used neurologic agent that acts as a potent inhibitor of histone deacetylase activities. Here, we show that valproic acid addition to liquid cultures of human CD34+ cells isolated from cord blood, mobilized peripheral blood, and bone marrow strongly enhances the ex vivo expansion potential of different cytokine cocktails as shown by morphologic, cytochemical, immunophenotypical, clonogenic, and gene expression analyses. Notably, valproic acid highly preserves the CD34 positivity after 1 week (range, 40-89%) or 3 weeks (range, 21-52%) amplification cultures with two (Flt3L + thrombopoietin) or four cytokines (Flt3L + thrombopoietin + stem cell factor + interleukin 3). Moreover, valproic acid treatment increases histone H4 acetylation levels at specific regulatory sites on HOXB4, a transcription factor gene with a key role in the regulation of HSC self-renewal and AC133, a recognized marker gene for stem cell populations. Overall, our results relate the changes induced by valproic acid on chromatin accessibility with the enhancement of the cytokine effect on the maintenance and expansion of a primitive hematopoietic stem cell population. These findings underscore the potentiality of novel epigenetic approaches to modify HSC fate in vitro.

Absolute lymphocyte count is a prognostic factor in diffuse large B-cell lymphoma

imab is associated with a reduction in IgG antibodies to ADAMTS13. British Journal of Haematology, 136, 451–461. Yarranton, H., Lawrie, A.S., MacKie, I.J., Pinkoski, L., Corash, L. & Machin, S.J. (2005) Coagulation factor levels in cryosupernatant prepared from plasma treated with amotosalen hydrochloride (S-59) and ultraviolet A light. Transfusion, 45, 1453–1458.

Defective expression of the T‐cell receptor‐CD3 ζ chain in T‐cell acute lymphoblastic leukaemia

Summary. This study analysed the T‐cell receptor (TCR)‐CD3 ζ complex and the signal transduction apparatus of T‐acute lymphoblastic leukaemia (T‐ALL) blasts, and investigated the function of the ubiquitin‐proteasome system. In all nine T‐ALL samples studied, the leukaemic cells showed a marked reduction in the expression of the ζ chain, while a variety of tyrosine kinases (p56lck, ZAP70 and SYK) were normally present. There was no expression of the FcεRIγ chain. To confirm that this aberration was specific to immature T‐ALL blasts, we investigated two patients with lymphoproliferative disorders of granular lymphocytes (LDGL), characterized by the expansion of mature T lymphocytes and found normal ζ chain expression. The reduction of the ζ chain protein was not reversible after 72 h stimulation with the anti‐CD3 monoclonal antibody and interleukin 2, either alone or in combination. Northern blot analysis indicated that the reduced protein expression did not correspond to a defect at the mRNA level, nor were mutations in the coding region of the ζ chain found. We, therefore, hypothesized that the observed reduction of protein expression in T‐ALL blasts could be secondary to an increased degradation at the proteasome level. Following selective inhibition of the proteasome, a marked increase of the ζ chain expression was observed. Moreover, an increase in the surface expression of CD3 was also documented. Taken together, these results indicate that the expression of the ζ subunit of the TCR‐CD3 complex is consistently reduced in T‐ALL blasts and that degradation of the protein is mediated by the proteasome system.

FLT3 inhibition in t(4;11)+ adult acute lymphoid leukaemia

The present study was designed to investigate, in t(4;11)+ adult lymphoid leukaemia (ALL) blast cells, the pathogenetic role of the FLT3 protein, its level of mRNA and protein expression, the degree of constitutive phosphorylation, the possible presence of mutations of the sequence, the capacity of signal transduction and the potential therapeutic role of specific inhibitors. We evaluated nine adult ALL patients carrying this translocation. The increased FLT3 mRNA levels, determined by oligonucleotide microarray analysis, was in agreement with the increased protein expression evaluated by Western blot. The protein was constitutively phosphorylated in all cases analysed. Polymerase chain reaction detected no internal tandem duplication or point mutations. The signal transduction apparatus, after stimulation with the specific ligand, was preserved. We then investigated the effect of specific FLT3 inhibition on signal transduction and survival. The PKC412 inhibitor specifically inhibited ligand‐induced phosphorylation; the same inhibitor reduced the survival of leukaemic cells when compared with untreated cells. These data indicate that the FLT3 protein might play a role in this subgroup of ALL with a particularly poor prognosis. Specific inhibition of the kinase receptor must be hypothesised as an innovative therapeutic tool for t(4;11)+ ALL patients.

Clinicopathologic Characterization of Diffuse-Large-B-Cell Lymphoma with an Associated Serum Monoclonal IgM Component

Recently, diffuse-large-B-cell lymphoma (DLBCL) associated with serum IgM monoclonal component (MC) has been shown to be a very poor prognostic subset although, detailed pathological and molecular data are still lacking. In the present study, the clinicopathological features and survival of IgM-secreting DLBCL were analyzed and compared to non-secreting cases in a series of 151 conventional DLBCL treated with R-CHOP. IgM MC was detected in 19 (12.5%) out of 151 patients at disease onset. In 17 of these cases secretion was likely due to the neoplastic clone, as suggested by the expression of heavy chain IgM protein in the cytoplasm of tumor cells. In IgM-secreting cases immunoblastic features (p<.0001), non-GCB-type (p = .002) stage III-IV(p = .003), ≥2 extra nodal sites (p<.0001), bone-marrow (p = .002), central-nervous-system (CNS) involvement at disease onset or relapse (p<.0001), IPI-score 3–5 (p = .009) and failure to achieve complete remission (p = .005), were significantly more frequent. FISH analyses for BCL2, BCL6 and MYC gene rearrangements detected only two cases harboring BCL2 gene translocation and in one case a concomitant BCL6 gene translocation was also observed. None of the IgM-secreting DLBCL was found to have L265P mutation of MYD88 gene. Thirty-six month event-free (11.8% vs 66.4% p<.0001), progression-free (23.5% vs 75.7%, p<.0001) and overall (47.1% vs 74.8%, p<.0001) survivals were significantly worse in the IgM-secreting group. In multivariate analysis IgM-secreting (p = .005, expB = 0.339, CI = 0.160-0.716) and IPI-score 3–5 (p = .010, expB = 0.274, CI = 0.102–0.737) were the only significant factors for progression-free-survival. Notably, four relapsed patients, who were treated with salvage immmunochemotherapy combined with bortezomib or lenalidomide, achieved lasting remission. Our data suggests that IgM-secreting cases are a distinct subset of DLBCL, originating from activated-B-cells with terminally differentiated features, prevalent extra nodal dissemination and at high risk of CNS involvement.

Deferasirox chelation therapy in patients with transfusion-dependent MDS: a ‘real-world’ report from two regional Italian registries: Gruppo Romano Mielodisplasie and Registro Basilicata

Deferasirox (DFX) is an orally administered iron chelator approved for use in patients with transfusion‐dependent iron overload due to myelodysplastic syndromes (MDS). The safety and efficacy of DFX has been explored in clinical trial settings, but there is little data on unselected patients with MDS. The aim of this study was to retrospectively evaluate the safety, compliance, efficacy and effect on haematopoiesis of DFX in a large ‘real‐world’ MDS population. One hundred and eighteen patients with transfusion‐dependent MDS were treated with DFX across 11 centres in Italy. Serum ferritin levels, haematological response, dosing, adverse events and transfusion dependence were recorded at baseline, 3, 6, 12 and 24 months following initiation of treatment. DFX reduced mean serum ferritin levels from 1790 to 1140 ng/mL (P < 0.001), with 7.1% of patients achieving transfusion independence. Significant haematological improvement was seen in erythroid (17.6%), platelet (5.9%) and neutrophil counts (7.1%). Adverse events were reported in 47.5% of patients, including gastrointestinal and renal toxicity. Regression analysis showed that higher starting doses of DFX are associated with transfusion independence at 24 months. DFX is a safe, effective treatment for transfusion‐dependent MDS that can lead to transfusion independence and haematological improvement in a subset of patients.

Specific effects exerted by B-lymphoproliferative diseases on peripheral T-lymphocyte protein expression

A proteomic approach was applied to study the protein expression profile of peripheral T‐cells derived from patients at the onset of different B‐lymphoproliferative diseases, because a rising interest in specific actions played by T‐cells in such pathologies has emerged. Decreased levels of profilin‐1 and cofilin‐1 and increased levels of coronin1A and prohibitin were found in patients, compared with healthy controls. The protein‐protein interaction network of these proteins was studied using a web‐based bioinformatics tool, highlighting the actin cytoskeleton regulation as the main biological process involved in peripheral T‐cells of such patients. Unsupervised cluster analysis of protein expression data shows that the recorded alteration of T‐cell proteome was specifically induced by B‐cell pathologies.

Ethical questions in human clinical psychopharmacology: Should the focus be on placebo administration?

Of all ethical issues in clinical trial designs, only placebo use is dealt with acrimony and unwarranted, rhetoric emphasis. Many misconceptions are biased and may hamper research in the mechanisms of healing and recovery if placebo is banned from clinical trials, as some influential ethicists propose. Current treatments in psychiatry are by no means optimal and may vary in their effect across studies, rendering difficult to find the best available therapeutic method with which to compare new drugs. Because drugs possess specific mechanisms, it is not possible to compare drugs with different mechanisms as to their relevance in the pathophysiology of a given disorder. Placebo acts through non-specific mechanisms and is the ideal control for any disorder whose pathophysiology is relatively unknown and its treatment is still suboptimal. Sticking to short-term patient benefit in a trial reflects an individualistically oriented thinking in contemporary ethics and is likely to limit further research and efforts to better understand the mechanisms of disease and drug action, but also those related to general body reactance and self-healing, which are enhanced by placebo administration. Because in history ethics are swinging between two opposed views, it is possible that in the near future, the balance will move towards communitarianism, which is more likely to better serve long-term patient needs. Ethicists should also consider some other aspects of human experimentation, such as the consistency of research lines and the trend to substitute older drugs with their metabolites or enantiomers.

A case of resolution of an acute psychotic episode after high fever.

Fever (pyretotherapy) was used for psychosis during the turn of the 19th century, but pyretotherapy (ie, the treatment of a disorder by inducing fever) fell out of use after the introduction of convulsive methods. Here, we report on a case of schizoaffective disorder and review classical and recent literature on fever and psychosis. The patient developed auditory hallucinations, persecutory delusional ideas, and was terrified soon upon his arrival in a foreign country. After being treated for 12 days with olanzapine and haloperidol, he developed a fever due to urinary infection; his creatine phosphokinase levels were high, prompting the suspension of antipsychotics. Psychotic symptom resolution followed immediately fever abatement. Antipsychotics were reintroduced at lower dosages. He was discharged asymptomatic with a prescription of olanzapine 15 mg/day and haloperidol 3 mg/day. The time course of symptom resolution in this patient suggests that fever had a beneficial role in this case. The associations between body temperature changes and psychotic symptoms need to be further studied.

Systemic lupus erythematosus and myelofibrosis: a case report and revision of literature

Blood cytopenia represents one of the diagnostic criteria for systemic lupus erythematosus (SLE) and may occur as the first symptom of the disease. Antibody-mediated peripheral destruction of blood cells is the main cause of cytopenia observed in patients affected by SLE, however, inflammatory anemia, nutritional deficiencies, immunosuppressive therapy and, more rarely, myelofibrosis (MF) have also been documented. In the literature, 45 cases of autoimmune MF (AIMF) and SLE have been previously reported. Here the 46th case of a 43-year-old female with a SLE and an underhand cytopenia, with a review of the literature.