Lymphoblastic Transformation Research Articles

Allergological study in patients vaccinated against COVID-19 with suspected allergic reactions

BackgroundOne of the main barriers to vaccination against SARS-CoV-2 is the fear of developing hypersensitivity reactions to any of its components. Although these reactions are very rare, it is necessary to establish an effective protocol to detect patients at risk of developing them. The aim of this study was to evaluate hypersensitivity reactions in vaccinated patients in order to allow or not to complete the vaccination protocol.MethodsDescriptive and cross-sectional study in which patients with suspected hypersensitivity to SARS-CoV-2 vaccines were evaluated. All patients underwent skin prick test (SPT) and/or intradermal test (IDT) with the vaccines and their excipients. In patients with positive IDT with the vaccine, a histopathological and immunohistochemical study was performed by skin biopsy. A basophil activation test (BAT) and a lymphoblastic transformation test (LTT) were also performed.ResultsSixteen patients with suspected hypersensitivity to SARS-CoV-2 vaccine (12 received Comirnaty®, 3 received Vaxzevria®, and 1 received Spikevax®) were evaluated. Half had immediate hypersensitivity reactions and half had delayed reactions. All SPTs to excipients and vaccines were negative. IDTs with all excipients were negative. IDTs with vaccines were positive in 11 patients and negative in 5. The histological and immunohistochemical study of the two selected patients with positive IDT with vaccine showed T-lymphocyte involvement. BAT and LTT were negative in both cases. The vaccination protocol could be completed in 7 of 16 patients (44%) studied. The remaining 9 patients did not receive the second dose: 5 because vaccination was not required and 4 because they refused to be vaccinated.ConclusionsThanks to the allergological and immunohistochemical study, the vaccination protocol could be completed in about half of the patients who presented suspected hypersensitivity reactions to SARS-CoV-2 vaccines. IDTs with vaccines could be a valuable method for assessing the immunogenicity of the vaccines.

Myeloid Sarcoma of the Bladder in a Patient with Chronic myelomonocytic Leukaemia

Background Myeloid sarcoma is a rare extramedullary tumour of immature granulocytes, most commonly involving the skin, bone, lymph nodes, and soft tissue. It is usually associated with a diagnosis of relapsed or de novo acute myeloid leukaemia, acute lymphoblastic transformation of a myelodysplastic/myeloproliferative neoplasm, or can occur as isolated myeloid sarcoma. Case report A 66-year-old female with a 7-year history of stable chronic myelomonocytic leukaemia presents with urgency, frequency, dysuria symptoms, and without new constitutional symptoms. She is found to have atypical, multifocal lesions on the right posterolateral wall of the bladder with associated hydronephrosis. Pathology reveals the diagnosis as myeloid sarcoma; surprisingly, bone marrow evaluation does not show evidence of acute leukaemic transformation. Conclusions Myeloid sarcoma occurring in patients with chronic myelomonocytic leukaemia is extremely rare, and there are no cases reported in the English literature of these patients developing lesions in the bladder. The urological manifestations of an underlying haematological malignancy are best managed with a combination of systemic chemotherapy and allogeneic stem cell transplant, and in this case, the only surgical intervention required was ureteric stenting and tissue biopsy. Although rare, it is essential to consider alternative diagnoses when confronted with an atypical bladder tumour; failure to do so may result in patient harm by exposure to unnecessary intervention and delay to potentially curative treatment.

Comparing Tuberculin Anergy Skin Test Reactions and Lymphoblastic Transformation in Medical Student

Background: Tuberculin Skin Test (TST) reaction is an accepted screening test for diagnosing acute and latent Tuberculosis (TB) infection among at-risk populations. It is performed with a standard Protein Purified Derivative (PPD) solution. The skin reaction of PPD is unreliable to distinguish natural infection from the Bacillus Calmette Guerin (BCG) effect. The present survey aimed to determine the prevalence of Tuberculin Anergy (TA) reactions among medical students. Accordingly, we evaluated its sensitivity, specificity, and efficiency by applying the Recall Panel Antigen Test (RPAT) and the Lymphoblastic Transformation Test (LTT). Methods: The participants were sequentially enrolled in this study according to the designed protocol. The current study was conducted on healthy medical students before registering for the hospital training course. All research subjects were healthy, having a cicatrix of Bacillus Calmette Guerin (BCG) vaccination on the arm, and at a young age (20-24 years). Results: In total, 180 medical students met the inclusion criteria of the study. The study subjects’ Mean±SD age was 22±3.07 years (male=89, female=91). Moreover, 75 (42%) subjects presented a TA reaction in the first step of TST screening. Furthermore, 13 (64%) individuals presented a negative result of the RPAT. The sensitivity and specificity of the TST reactions, compared with the LTT were 100% and 94.4 %, respectively. Conclusion: Significant TA reactions were found among medical students with positive cicatrix post-vaccinated. The obtained data suggested that the BCG protection for individuals may be decreased as time expired. Consequently, the medical students will especially be at high risk for TB infection during the clinical training course. The collected data highlighted the patient-safety from the viewpoint of forensic medicine.

Severe Ocular Graft-Versus-Host Disease Successfully Treated with Amniotic Membrane Transplantation - Case Series

Ocular graft-versus-host disease (GVHD) has the potential to lead to serious vision impairment, restriction of daily activities and deterioration of quality of life of patients after allogeneic stem cell transplantation (allo-SCT). Amniotic membrane transplantation (AMT) is an established technique in the treatment of various diseases of the ocular surface. This method could provide new options in the management of otherwise disabling severe ocular GVHD.We report a case-series of four patients with severe ocular GVHD refractory to standard local and systemic therapy, successfully treated with AMT. First patient was a 26-year old male who underwent a related allo-SCT for lymphoblastic transformation of chronic myeloid leukemia (CML) and received three donor lymphocytes infusions (DLI) due to molecular relapse. Six months later he developed severe GVHD of the mouth and eye that gradually deteriorated, despite corticosteroid treatment and topical therapy, and finally led to corneal perforation. In this case AMT was used to successfully seal the corneal perforation and to avoid keratoplasty. Moreover, AMT led to a durable clinical improvement continuing for four years after the treatment without the need for systemic immunosuppression. The second patient was a 25-year old male, transplanted from an unrelated donor for a CML refractory to tyrosine kinase inhibitors, who received one DLI for mixed chimerism and consequently developed GVHD of the skin, liver, lungs and eyes. Ocular GVHD progressed despite local and triple systemic immunosuppressive treatment. In this case AMT was applied before severe corneal ulcerations developed and led to full clinical recovery. The third patient was a 32-year old female who underwent an unrelated myeloablative allo-SCT for myelofibrosis, complicated with acute liver GVHD and slow immune reconstitution. At day +150 she developed a disabling herpes keratitis and stomatitis which led to prolonged hospitalization and slow recovery. At day +280 her vision deteriorated again, this time with signs of severe ocular GVHD. We feared herpes reactivation and hesitated from increasing immunosuppression. With this rationale we decided to perform AMT which again led to significant clinical improvement. Finally, our fourth patient underwent unrelated allo-SCT in the age of 22 for high risk myelodysplastic syndrome complicated with toxic epidermal necrolysis (TEN) of the skin, mucosa and eye. In this case chronic GVHD of the eye developed eight months later and gradually progressed, partly due to patient's non-compliance with treatment. This time AMT was applied on two consecutive occasions resulting in a similarly impressive clinical effect. The latter two patients also had marked corneal vascularization possibly due to the preceding involvement of the eye with viral infection and TEN. This was efficiently treated with additional subconjunctival anti-VEGF injections. With a median follow-up of 15 months, all four patients remained clinically stable without recurrence of severe ocular GVHD.Amniotic membrane is rich in cytokines, growth factors and protease inhibitors and serves as a biological bandage that suppresses inflammation and promotes epithelialization. In our experience, beside acute healing of corneal ulcerations in severe ocular GVHD and preventing perforation, it has a durable effect and prevents GVHD recurrence. Moreover, with the use of AMT we can avoid systemic immunosuppression and decrease both the risk of infectious complications and recurrence of the primary malignancy in allo-SCT patients. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Transformation of de novo high-grade B cell lymphoma with MYC and BCL2 rearrangements to double-hit B lymphoblastic leukemia/lymphoma: a case report and review of literature

High-grade B cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements (“double-hit” lymphoma (DHL)/“triple-hit” lymphoma (THL)) are mature B cell neoplasms with highly aggressive clinical behavior and poor response to therapy. Lymphoblastic transformation of mature B cell neoplasms is an uncommon event that is best recognized for follicular lymphoma (FL). To our knowledge, only one case of “B lymphoblastic” transformation of de novo DHL has been reported in the literature. Here, we describe another case of such transformation. The patient was a 57-year-old man who presented with hypercalcemia, high lactate dehydrogenase (LDH), and multiple lytic bone lesions and was diagnosed with high-grade B cell lymphoma with MYC and BCL2 rearrangements. The neoplastic cells were positive for CD45, CD19, CD20, CD79a, PAX5, CD10, BCL6, and BCL2 and negative for CD34, CD99, and terminal deoxynucleotidyl transferase (TdT). The patient received chemotherapy followed by autologous stem cell transplant and achieved complete remission. Nine months after the initial presentation, he developed general weakness and found to have cytopenias and circulating blasts. Bone marrow examination revealed extensive involvement by a high-grade B cell neoplasm co-expressing PAX5, CD10, and BCL2, in addition to precursor markers TdT and CD99. There was loss of CD20, CD79a, and BCL6 expression, and CD34 remained negative. A diagnosis of B lymphoblastic leukemia/lymphoma (B-LBL) was established. Similar MYC and BCL2 rearrangements were identified. IGH gene rearrangement studies confirmed clonal relatedness. The patient passed away 3 days after bone marrow examination. This case represents an extremely rare case of DHL transformation to B-LBL.

Lymphoblastic Transformation of Follicular Lymphoma: A Case Report and Review of the Literature

Abstract Follicular lymphoma (FL) is one of the most common B-cell non-Hodgkin lymphomas in adults in the Western world. Prognosis is correlated with the clinical stage and histologic grade and, increasingly, the tumor genetic profile. A subset of patients with FL experiences histologic disease progression (ie, histologic transformation), of which the majority will demonstrate diffuse large B-cell lymphoma. We describe a patient initially diagnosed with low-grade FL with relapsed disease presenting as acute renal failure due to diffuse abdominal lymphadenopathy. Excisional biopsy of an inguinal lymph node at relapse showed high-grade areas with sheets of immature-appearing lymphoid cells adjacent to nodular areas characteristic of low-grade FL. Cells of both components were positive for BCL2 and CD19. The cells of the high-grade component were positive for CD99 and TdT and negative for CD20, whereas cells of the low-grade component were positive for CD20 and negative for CD99 and TdT. Fluorescence in situ hybridization studies demonstrated the IGH/BCL2 rearrangement in addition to an MYC rearrangement in both low- and high-grade components.

KRAS mutation in secondary malignant histiocytosis arising from low grade follicular lymphoma

BackgroundTransformation of follicular lymphoma most typically occurs as diffuse large B-cell lymphoma, however other forms of transformation such as classic Hodgkin lymphoma and lymphoblastic transformation can occur. Secondary malignant histiocytosis also represents a rare form of transformation, which is thought to occur due to a process of transdifferentiation whereby the lymphoma cells exhibit lineage plasticity and lose all evidence of B-cell phenotype and instead acquire the phenotype of a histiocytic neoplasm. Little is known about the underlying genetic alterations that occur during this unusual process. Comparative genetic analysis of pre- and post-transformation/transdifferentiation would be one tool by which we could better understand how this phenomenon occurs.Case presentationHere we report the clinical, immunophenotypic and genetic features of a rare case of secondary malignant histiocytosis, Langerhans cell-type (Langerhans cell sarcoma) arising from a previous low grade follicular lymphoma. FISH analysis confirmed the presence of IgH/BCL2 rearrangement in both the low grade follicular lymphoma (FL) and transformed Langerhans cells sarcoma (LCS) samples, demonstrating a clonal relationship. Comparative whole exome sequencing was then performed, which identified a KRAS p.G13D mutation in the LCS that was not present in the FL.ConclusionsThis report highlights genetic alterations, in particular an acquired somatic KRAS mutation, that may occur during transdifferentiation, with additional significance of KRAS mutation as a possible therapeutic target in cases which otherwise would have limited treatment options.

The Therapeutic Effect of ICAM-1-Overexpressing Mesenchymal Stem Cells on Acute Graft-Versus-Host Disease

Background/Aims: Mesenchymal stem cells (MSCs) do not readily migrate to appropriate sites, and this creates a major obstacle for their use in the treatment of graft-versus-host disease (GVHD). Intercellular adhesion molecule-1 (ICAM-1) can guide the homing of various immune cells to the proper anatomical location within secondary lymphoid organs (SLOs), which are the major niches for generating immune responses or tolerance. MSCs rarely migrate to SLOs after intravenous infusion, and are constitutively low expression of ICAM-1. So in our previous work, ICAM-1 was engineered into a murine MSC line C3H10T1/2 by retrovirus transfection system (ICAM-1MSCs). Here, we hypothesized that ICAM-1^highMSCs may significantly improve their immunomodulatory effect. Methods: We used different co-culture methods combined with real-time PCR and flow cytometry to evaluate ICAM-1^highMSCs immunomodulatory effect on dendritic cells (DCs) and T cells in vitro and in vivo. MSCs were labeled with carboxyfluorescein diacetate succinimidylester (CFSE) to detect its distribution in mouse model. Results: Our in vitro analyses revealed ICAM-1 MSCs could suppress DCs maturation according to co-culture methods and suppress the T cell immune response according to the mixed lymphocyte response (MLR) and lymphoblast transformation test (LTT) tests. We found that infusion of ICAM-1^highMSCs potently prolonged the survival of GVHD mouse model. The infused ICAM-1^highMSCs migrate to SLOs in vivo, and suppressed DCs maturation, suppressed CD4+ T cell differentiation to Th1 cells, and increased the ratios of Treg cells. Conclusions: Taken together, these data demonstrate that ICAM-1^highMSCs had an enhanced immunosuppressive effect on DCs and T cells, which may help explain the protective effect in a GVHD model. This exciting therapeutic strategy may improve the clinical efficacy of MSC-based therapy for GVHD.

Effect of Knockdown of Vascular Cell Adhesion Molecule-1 on the Immunologic Regulation Capacity of Murine Mesenchymal Stem Cells

To establish the stably lower expression of vascular cell adhesion molecule-1 (VCAM-1) in MSC cell line (C3H10T1/2) by siRNA technology, and explore the effect of knockdown of VCAM-1 on the immunologic regulation capacity of murine MSC. The mouse GV118-VCAM-1-RNAi retrovirus vector was constructed by gene recombination technology. The recombinant plasmid was identified by restriction analysis and sequencing, and then the recombinant plasmid GV118-VCAM-1-RNAi was transfected into 293 cells by Lipofectamine, and the supernatant was collected to transfect C3H10T1/2. Moreover, the VCAM-1 lower expression on MSC was evaluated by flow cytometry and fluorescent microscopy. The knockdown VCAM-1 MSC was sorted by flow cytometry. Furthermore, the inhibitory effect of the knockdown VCAM-1 MSC on lymphocyte proliferation was tested by lymphoblast transformation assay (LTT) and mixed lymphocyte reaction assay(MLR). The recombinant retroviral vector of knockdown VCAM-1 (GV118-VCAM-1-RNAi) was successfully constructed and transfected into mouse MSC cell line C3H10T1/2. The knockdown VCAM-1/MSC was obtained by flow cytometric sorting. The LTT and MLR assay showed that the immunosuppressive effect of MSC lower-expressing VCAM-1 dramatically decreased (P<0.05). Knockdown VCAM-1 in MSC can significantly down-regulate the inhibitory capability of MSC on the proliferation of T-cells. The data of this study laid an experimental foundation for studying effect of VCAM-1 transfecting into MSC on immune function.

XIV. The pathology of transformation of indolent B cell lymphomas.

XIV. The pathology of transformation of indolent B cell lymphomas.

Lymphoblastic transformation of follicular lymphoma: a clinicopathologic and molecular analysis of 7 patients.

Approximately 30% of patients with follicular lymphoma (FL) transform to a more aggressive malignancy, most commonly diffuse large B cell lymphoma. Rarely, FL transformation results in clinical findings, histology, and immunophenotype reminiscent of B-lymphoblastic leukemia/lymphoma. We report the largest series to date with detailed analysis of 7 such patients. Lymphoblastic transformation occurred on average 2 years after initial diagnosis of FL. Five patients had prior intensive chemotherapy. Two patients developed mature high-grade lymphoma, followed by the lymphoblastic transformation. FL had BCL2 gene rearrangement in 4 of 5 cases. High-grade transformation was accompanied by MYC gene rearrangement (5 of 5). Transformation was characterized by expression of TdT, loss of Bcl6, variable loss of immunoglobulin light chain, and persistence of Pax-5, Bcl2, and CD10. Whole-exome sequencing in 1 case revealed presence of several actionable mutations (CD79B, CCND3, CDK12). FL, aggressive mature B cell lymphoma, and lymphoblastic transformation were clonally related in 6 evaluable cases. After transformation, survival ranged from 1 to 14 months. Four patients died of disease, 2 were in remission after stem cell transplant, and 1 was alive with disease.

Bilineal T lymphoblastic and myeloid blast transformation in chronic myeloid leukemia with TP53 mutation—an uncommon presentation in adults

Bilineal blast transformation of myeloid and T lymphoid type is a rare event in chronic myeloid leukemia. Here, we report a case in which an adult presented with high white cell counts and lymphadenopathy. Bone marrow studies confirmed the presence of 9 and 22 chromosomal translocation, and a diagnosis of chronic myeloid leukemia in chronic phase was made. Examination of a lymph node showed both myeloid and T lymphoblastoid blast crisis. Molecular studies demonstrated the presence of BCR-ABL fusion transcripts in both the myeloid and the T lymphoblastic component, indicating that the myeloid and T lymphoid blast crisis components shared common progenitors. TP53 deletion was demonstrated by fluorescence in situ hybridization.

In vitro immunotoxicology of quantum dots and comparison with dissolved cadmium and tellurium

The increasing use of products derived from nanotechnology has raised concerns about their potential toxicity, especially at the immunocompetence level in organisms. This study compared the immunotoxicity of cadmium sulfate/cadmium telluride (CdS/Cd-Te) mixture quantum dots (QDs) and their dissolved components, cadmium chloride (CdCl2 )/sodium telluride (NaTeO3 ) salts, and a CdCl2 /NaTeO3 mixture on four animal models commonly used in risk assessment studies: one bivalve (Mytilus edulis), one fish (Oncorhynchus mykiss), and two mammals (mice and humans). Our results of viability and phagocytosis biomarkers revealed that QDs were more toxic than dissolved metals for blue mussels. For other species, dissolved metals (Cd, Te, and Cd-Te mixture) were more toxic than the nanoparticles (NPs). The most sensitive species toward QDs, according to innate immune cells, was humans (inhibitory concentration [IC50 ] = 217 μg/mL). However, for adaptative immunity, lymphoblastic transformation in mice was decreased for small QD concentrations (EC50 = 4 μg/mL), and was more sensitive than other model species tested. Discriminant function analysis revealed that blue mussel hemocytes were able to discriminate the toxicity of QDs, Cd, Te, and Cd-Te mixture (Partial Wilk's λ = 0.021 and p < 0.0001). For rainbow trout and human cells, the immunotoxic effects of QDs were similar to those obtained with the dissolved fraction of Cd and Te mixture. For mice, the toxicity of QDs markedly differed from those observed with Cd, Te, and dissolved Cd-Te mixture. The results also suggest that aquatic species responded more differently than vertebrates to these compounds. The results lead to the recommendation that mussels and mice were most able to discriminate the effects of Cd-based NPs from the effects of dissolved Cd and Te at the immunocompetence level.

Pediatric chronic myeloid leukemia with B-cell lymphoid blast crisis at presentation

TO THE EDITOR: Chronic Myeloid Leukemia (CML) is a rare hematological malignancy accounting for less than 3% of pediatric and adolescent leukemias, with an annual incidence of approximately 1 per million children and young people aged 20% blasts in the marrow or the presence of extra-medullary blast proliferation [3, 4]. Blast transformation of CML is lymphoid in 30% of cases and myeloid in the remaining 70%. We report the case of a 10-year-old boy who presented with a 6-week history of weight loss and left-sided upper abdominal pain. On examination, he was found to have substantial splenomegaly extending into the right iliac fossa. His full blood count showed a hemoglobin level of 6.6 g/dL, a platelet count of 148×109/L, and a total white cell count of 575×109/L. A differential count showed the following: blasts, 30%; promyelocytes, 6%; myelocytes, 24%; metamyelocytes, 11%; neutrophils, 7%; eosinophils, 9%; basophils, 3%; monocytes, 1%; and lymphocytes, 10% (Fig. 1). Flow cytometry of the blast population showed that the blasts expressed CD19, cyCD79a, CD10, HLA-DR, CD34, and TdT surface antigens. Chromosome analysis showed a t(9;22)(q34;q11) translocation consistent with a Philadelphia chromosome (Fig. 2A). Interphase fluorescence in situ hybridization (FISH) showed BCR-ABL1 fusion signals in 90% of the nuclei (Fig. 2B). A minor breakpoint cluster region (210 kDa) was confirmed using RT-PCR. In the absence of a documented CML-CP, distinguishing between lymphoid blast crisis of CML and a Philadelphia chromosome-positive ALL can be difficult. A diagnosis of CML in B-cell lymphoid blast crisis rather than de novo precursor B-cell ALL was made because of the concurrent presence of basophilia, a predominance of metamyelocytes and myelocytes, and the p210 BCR-ABL transcript. The patient did not have any additional chromosomal anomalies associated with advanced phase CML and was negative for IgH rearrangement on FISH analysis. Fig. 1 Blood film demonstrating chronic myeloid leukemia in lymphoid blast transformation. Fig. 2 (A) Karyotype showing t(9;22)(q34;q11) Philadelphia translocation. (B) Interphase FISH, Vysis dual-fusion probe set. Green: BCR; red: ABL1; yellow: fused BCR and ABL signals corresponding to der(9) and der(22) translocation products. The patient achieved a complete hematological response and a minor cytogenetic response following induction therapy comprising dexamethasone, vincristine, daunorubicin, asparaginase, and imatinib. Nonetheless, he subsequently died of idiopathic pneumonitis after allogeneic stem-cell transplantation. The progression from CML-CP to CML-BC in the pre-tyrosine kinase era is well described, but CML-BC at presentation in children is extremely rare. The case reported here adds to the literature on the simultaneous presence of features of both lymphoblastic transformation and CML at presentation in the absence of cytogenetic clonal evolution. Further research into the biology of the aggressive phase of CML is required to develop novel targets to improve outcomes.

MLPA is a powerful tool for detecting lymphoblastic transformation in chronic myeloid leukemia and revealing the clonal origin of relapse in pediatric acute lymphoblastic leukemia

Copy number alterations (CNAs) at 58 different loci have been investigated in 95 bone marrow or peripheral blood samples from patients with chronic myeloid leukemia (CML) or pediatric acute lymphoblastic leukemia (pALL) using multiplex ligation-dependent probe amplification (MLPA). In all but one case, the CNA profile correctly distinguished patients with CML who were in chronic phase from those in lymphoblast crisis. Within the chronic phase group, we could not separate patients resistant to imatinib therapy from those who were good responders. In our investigation of patients with pALL, a panel of MLPA probes broader than ever before was applied. Paired diagnostic and relapse samples from patients with pALL demonstrated clonally related or independent dominant clones, suggesting the presence of a pre-leukemic cell group. Identification of the origin of cell populations dominating at relapse will have a great effect on future treatment strategies. In summary, we have demonstrated the versatility of MLPA by using this cost-effective technique for two new applications.

ChemInform Abstract: Studies on Immunostimulating Derivatives: Synthesis of Some Pyrrolo(1, 2-c)pyrimidines.

In a search for potential immunomodulating agents novel pyrrolo[1, 2-c]pyrimidines were synthesized and their structures elucidated by spectroscopic means. Unfortunately, most of them were cytotoxic and devoid of effects on Tlymphocyte lymphoblastic transformation. Furthermore, they were inactive in the locomotor activity test in mice.

HIV-1 Rev–binding protein accelerates cellular uptake of iron to drive Notch-induced T cell leukemogenesis in mice

Somatic activating mutations in Notch1 contribute to the pathogenesis of T cell acute lymphoblastic lymphoma (T-ALL), but how activated Notch1 signaling exerts this oncogenic effect is not completely understood. Here we identify HIV-1 Rev-binding protein (Hrb), a component of the clathrin-mediated endocytosis machinery, as a critical mediator of Notch-induced T-ALL development in mice. Hrb was found to be a direct transcriptional target of Notch1, and Hrb loss reduced the incidence or delayed the onset of T-ALL in mouse models in which activated Notch1 signaling either contributes to or drives leukemogenesis. Consistent with this observation, Hrb supported survival and proliferation of hematopoietic and T cell precursor cells in vitro. We demonstrated that Hrb accelerated the uptake of transferrin, which was required for upregulation of the T cell protooncogene p21. Indeed, iron-deficient mice developed Notch1-induced T-ALL substantially more slowly than control mice, further supporting a critical role for iron uptake during leukemogenesis. Taken together, these results reveal that Hrb is a critical Notch target gene that mediates lymphoblast transformation and disease progression via its ability to satisfy the enhanced demands of transformed lymphoblasts for iron. Further, our data suggest that Hrb may be targeted to improve current treatment or design novel therapies for human T-ALL patients.

Myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1

The 2008 World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues introduced a new category for myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1.1 Many of these cases present as a myeloproliferative neoplasm, usually with eosinophilia. However, neoplasms associated with rearrangement of PDGFRA can present as acute myeloid leukemia or as T lymphoblastic lymphoma with eosinophilia.2 Neoplasms associated with rearrangement of FGFR1 even more frequently present as acute myeloid leukemia or T lymphoblastic lymphoma, in both instances with eosinophilia, and both T lymphoblastic and B lymphoblastic transformation of chronic eosinophilic leukemia have also been described.3–5 Because of the prominent lymphoid component these disorders have been assigned, in the WHO classification, to a specific category rather than being categorized as a myeloproliferative neoplasm. However, it should be noted that BCR-ABL1-positive chronic myelogenous leukemia is accepted as a bona fide myeloproliferative neoplasm and yet it too can undergo lymphoblastic transformation and even present as acute lymphoblastic leukemia with the underlying chronic myelogenous leukemia being revealed only after remission has been achieved.

Immunotoxicological effects of an activated-sludge-treated effluent on rainbow trout ( Oncorhynchus mykiss)

Municipal effluents are often treated by biological processes designed to enhance natural biodegradation that introduce important changes to the local bacterial community and contaminant status. The purpose of this study was to examine the immunotoxicological effects of an activated sludge treated urban effluent on rainbow trout ( Oncorhynchus mykiss). Trout specimens were exposed to increasing concentrations of the effluent at 0.1%, 1% and 10% v/v dilutions for 30 days at 15 °C. After the exposure period, the leukocytes were isolated from the anterior kidney and the following parameters were determined: phagocytic activity, lymphoblastic transformation and natural cytotoxic activity. The results revealed that phagocytic activity was not significantly affected by the biologically treated effluent. Natural cytotoxic activity was significantly increased at an effluent threshold concentration of 3% v/v at an effector/target cell ratio of 20:1 and 40:1. Stimulated lymphocyte T and B proliferation was significantly decreased at a threshold concentration of 0.3%. However, neither the unstimulated lymphocyte T nor lymphocyte B proliferation was significantly affected by effluent exposure. The results suggest that the activated-sludge-treated effluent increased cell-mediated cytotoxic activity with a concomitant decrease in cells responsible for antibody and cytokine production, indicating that the immune system of rainbow trout was directed towards the elimination of transformed cells, virus-infected cells and protozoan parasites at the expense of cytokine and antibody production.

The immunosuppressive effect of gossypol in mice is mediated by inhibition of lymphocyte proliferation and by induction of cell apoptosis

To investigate the immunosuppressive effect of gossypol in mice both in vitro and in vivo. The in vitro effect of gossypol on the proliferation of lymphocytes isolated from lymph nodes of BALB/c mice was determined by CFSE staining and by an MTS assay. Lymphocyte activation and lymphoblastic transformation were evaluated with immunostaining. Cell apoptosis was detected by Annexin-V and Hoechst 33342 staining. The in vivo immunosuppressive effect of gossypol on the DTH reaction was evaluated using a mouse DTH model induced by 2,4-dinitro-1-fluorobenzene (DNFB). The thickness of the ears was measured, and the histological changes of the mouse auricles were observed after hematoxylin-eosin staining. The proliferation capacity of lymphocytes from DTH mice was also assayed. In vitro, gossypol could significantly inhibit the proliferation of mouse lymphocytes stimulated with phorbol ester plus ionomycin in a dose-dependent manner. Although the expression of the early activation antigen CD69 was not affected, the lymphoblastic transformation of both T and B lymphocyte subsets was significantly suppressed by gossypol. Moreover, gossypol could induce apoptosis of lymphocytes, and the effect was time- and dose-dependent. In vivo, the DTH reaction in mice was markedly alleviated by gossypol injected intraperitoneally. Lymphocytes from drug-treated DTH mice had a reduced proliferation capacity as compared with lymphocytes from untreated DTH mice. Gossypol treatment also markedly reduced the number of infiltrated lymphocytes in the auricles of DTH mice. Gossypol exhibited immunosuppressive effects in mice, probably by inhibition of lymphocyte proliferation and by induction of cell apoptosis.