Acute Trypanosoma cruzi infection is associated with anemia, thrombocytopenia, leukopenia, and bone marrow hypoplasia: reversal by nifurtimox treatment

In the present work we show that acute infection of C3H mice with the CL strain of Trypanosoma cruzi is characterized by an exponential growth of parasites and high mortality accompanied by anemia, thrombocytopenia, leukopenia, and bone marrow hypoplasia. Administration of nifurtimox, a trypanocydal drug currently in clinical use at different days postinfection, modulates parasitemia and prevents mortality. More importantly, none of blood and bone marrow alterations were observed in nifurtimox-treated animals when treatment was initiated early in infection, one or seven days postinoculation. The bone marrow alterations were characterized by a decrease in the total number cells as well in the number of megakaryoblasts and erythroblasts. Transfer experiments of bone marrow cells from infected mice to noninfected lethally irradiated recipients revealed a poor marrow-repopulating activity. The colony forming units-spleen assay confirmed the depression of committed clonal progenitors cells and revealed a decreased number of granulocyte/macrophage, megacariocyte and erythrocyte colonies. In summary, this is the first report showing that acute T. cruzi infection results in profound alterations of the hematopoietic system and that these alterations can be prevented by nifurtimox treatment.     

A Study of Cytological Changes in the Bone Marrow of Patients with Severe Fever with Thrombocytopenia Syndrome

Background

Peripheral blood leucopenia and thrombocytopenia are the main manifestations in severe fever with thrombocytopenia syndrome (SFTS) patients. However, the underlying causes are poorly understood. Therefore, we aimed to investigate cytology of bone marrow samples collected from SFTS patients.

Methods

10 SFTS patients were identified by typical clinical manifestations, detection of peripheral blood leucopenia and thrombocytopenia, and nucleic acid-based detection of the newly identified bunyavirus. SFTS patients, along with 10 participants with acute aplastic anemia and 10 healthy volunteers were enrolled in this study after written informed consent to undergo bone marrow cytological examination.

Results

We observed similar bone marrow properties in SFTS patients and healthy volunteers, significantly different from the characteristics observed in acute aplastic anemia patients.

Conclusion

Similarities between bone marrow samples collected from SFTS patients and healthy volunteers suggest that peripheral blood leucopenia and thrombocytopenia do not result from bone marrow cell plasticity.     

Peripheral Blood and Bone Marrow Abnormalities in the Acquired Immunodeficiency Syndrome

In reviewing the peripheral hematologic manifestations, bone marrow changes and clinical course in 41 consecutive patients with acquired immunodeficiency syndrome (AIDS), frequent findings included anemia (95%), leukopenia (76%), bone marrow hypercellularity (73%) and pancytopenia (41%). These hematologic abnormalities were not clearly associated with specific clinical manifestations of AIDS, but support the conclusion that the hematopoietic system is a target organ in AIDS. The mechanisms of these abnormalities still need to be evaluated. Clinicians should be aware of these commonly encountered changes.     

Bone marrow depressant and leukemogenic actions of benzene

Chronic benzene toxicity is expressed as bone marrow depression resulting in leucopenia, anemia or thrombocytopenia. With continued exposure the disease progresses to pancytopenia resulting from a bone marrow aplasia. In recent years evidence has accumulated implicating benzene in the etiology of leukemias in workers in industries where benzene was heavily used. It has been suggested that leukemia is as frequent a cause of death from chronic benzene exposure as is aplastic anemia. This review explores some current ideas on the mechanisms by which benzene may produce these diseases and emphasizes recent work suggesting that the causative agent is a metabolite of benzene.     

Acute dyspnoea and single tracheal localisation of mantle cell lymphoma

We report a case of a 48-year-old Chinese female with end-stage renal disease and chronic anemia on hemodialysis. Clonazepam was prescribed for myoclonus disorder two weeks prior to her hospitalization. Subsequently, she was hospitalized for neutropenic fever with thrombocytopenia and worsening anemia. Bone marrow examination demonstrated a markedly hypocellular marrow (10-20% total cellularity). Clonazepam was discontinued, with gradual improvement of thrombocytopenia, and neutropenia in 1-2 weeks. To our knowledge, this is the first reported case of pancytopenia associated with clonazepam. We recommend patients taking clonazepam to be monitored with regular complete blood count to check for clinically significant pancytopenia or thrombocytopenia.     

Conversion of polycythemia vera to refractory anemia with hyperplastic bone marrow.

Clinical and morphologic findings in the conversion of treated polycythemia vera to pancytopenia with hyperplastic bone marrow (refractory anemia or pancytopenia with hyperplastic bone marrow) are described in light of our own observation. The nomenclature associated with this condition (pancytopenia, chronic erythroleukemia, preleukemia) is not uniform, whereas the morphologic findings are virtually identical. Some patients subsequently develop acute leukemia. The prognosis in cases of refractory anemia with hyperplastic bone marrow following polycythemia vera is, independent of the subsequent acute leukemia, invariably terminal.     

Various indicators of humoral immunity in patients with hematopoietic hypoplasia after bone marrow transplantation]

The authors examined 65 patients with hypoplasia of the hemopoiesis following bone marrow transplantation. To patients of the 1st group the bone marrow was chosen by erythrocytic antigens only, and to patients of the 2nd group both by erythrocytic and by leukocytic antigens. The data obtained pointed to the reduction of isoimmunization to the antigens of leukocytes and platelets in the patients with hypoplasia of the hemopoiesis following transplantation of the histocompatible bone marrow, in comparison with the patients in whom the bone marrow was chosen only by erythrocytic antigens alone.     

Transient pancytopenia. A report from the International Agranulocytosis and Aplastic Study

From a population-based study on the incidence of potentially drug-associated blood dyscrasias 28 cases were identified with pancytopenia. Who recovered within 90 days after diagnosis. Early recovery occurred more frequently in patients showing normal or increased cellularity of the bone marrow than in patients with bone marrow hypoplasia. Median recovery times of leukocytes were 14 and 10 days and of platelets 21 and 9 days in patients with and without bone marrow hypoplasia, respectively. Age and sex distribution were similar in both groups. Of 28 patients, 11 reported a period of fever before onset of pancytopenia. Sixteen patients in whom information on drug use was available had taken a median of 4 drugs before the onset of symptoms that were related to pancytopenia. From these results we present the hypothesis that transient pancytopenia with or without marrow hypoplasia can be the expression of the same type of bone marrow injury and that drugs or viral infections should be considered as etiological factors.     

Rasa3 Controls Megakaryocyte Rap1 Activation,Integrin Signaling and Differentiation into Proplatelet

Rasa3 is a GTPase activating protein of the GAP1 family which targets Ras and Rap1. Ubiquitous Rasa3 catalytic inactivation in mouse results in early embryonic lethality. Here, we show that Rasa3 catalytic inactivation in mouse hematopoietic cells results in a lethal syndrome characterized by severe defects during megakaryopoiesis, thrombocytopenia and a predisposition to develop preleukemia. The main objective of this study was to define the cellular and the molecular mechanisms of terminal megakaryopoiesis alterations. We found that Rasa3 catalytic inactivation altered megakaryocyte development, adherence, migration, actin cytoskeleton organization and differentiation into proplatelet forming megakaryocytes. These megakaryocyte alterations were associated with an increased active Rap1 level and a constitutive integrin activation. Thus, these mice presented a severe thrombocytopenia, bleeding and anemia associated with an increased percentage of megakaryocytes in the bone marrow, bone marrow fibrosis, extramedular hematopoiesis, splenomegaly and premature death. Altogether, our results indicate that Rasa3 catalytic activity controls Rap1 activation and integrin signaling during megakaryocyte differentiation in mouse.     

Facial paralysis and lymphocytic facial neuritis in a rhesus macaque (Macaca mulatta) positive for simian retrovirus type D2

Simian retrovirus type D (SRVD) is a naturally occurring betaretrovirus in nonhuman primates of the genus Macaca. Infection can lead to a variety of clinical, hematologic, and histopathologic abnormalities. We report an unusual clinical presentation of facial paralysis and histologic lymphocytic neuritis in an SRVD type 2 (SRVD2)-infected rhesus macaque (Macaca mulatta) with a catheter-associated vena caval thrombus, anemia, thrombocytopenia, and multisystemic lymphoid hyperplasia. At initial presentation, a right atrial mass was detected by echocardiography. The macaque was clinically asymptomatic but had persistent anemia, thrombocytopenia, hyperglobulinemia, and later neutropenia. It was seropositive for SRV and PCR-positive for SRVD 2. Approximately 1 mo after initial presentation, the macaque developed right facial paralysis and was euthanized. Histologic lesions included lymphoplasmacytic aggregates affecting multiple organs, consistent with SRV-related lymphoid hyperplasia. The right facial nerve showed lymphoplasmacytic inflammation. The nerve itself was negative immunohistochemically for SRV antigen, but antigen was present infrequently in pericapillary lymphoid cells within the facial nerve and abundantly within lymphoid aggregates in the adjacent parotid salivary gland, bone marrow, and soft tissue. Known neurotropic viruses could not be identified. Given the widespread inflammation in this macaque, particularly in the area surrounding the facial nerve, lymphocytic neuritis and facial paralysis likely were an indirect effect of SRV infection due to local extension of SRV-related inflammation in the surrounding tissue.     

Epigenetic and microenvironmental alterations in bone marrow associated with ROS in experimental aplastic anemia

Aplastic anemia or bone marrow failure often develops as an effect of chemotherapeutic drug application for the treatment of various pathophysiological conditions including cancer. The long-term bone marrow injury affects the basic hematopoietic population including hematopoietic stem/progenitor cells (HSPCs). The present study aimed in unearthing the underlying mechanisms of chemotherapeutics mediated bone marrow aplasia with special focus on altered redox status and associated effects on hematopoietic microenvironment and epigenetic status of hematopoietic cells. The study involves the development of busulfan and cyclophosphamide mediated mouse model for aplastic anemia, characterization of the disease with blood and marrow analysis, cytochemical examinations of bone marrow, flowcytometric analysis of hematopoietic population and microenvironmental components, determination of ROS generation, apoptosis profiling, expressional studies of Notch-1 signaling cascade molecules, investigation of epigenetic modifications including global CpG methylation of DNA, phosphorylation of histone-3 with their effects on bone marrow kinetics and expressional analysis of the anti-oxidative molecules viz; SOD-2 and Sdf-1. Severe hematopoietic catastrophic condition was observed during aplastic anemia which involved peripheral blood pancytopenia, marrow hypocellularity and decreased hematopoietic stem/progenitor population. Generation of ROS was found to play a central role in the cellular devastation in aplastic marrow which on one hand can be correlated with the destruction of hematopoiesis supportive niche components and alteration of vital Notch-1 signaling and on other hand was found to be associated with the epigenetic chromatin modifications viz; global DNA CpG hypo-methylation, histone-3 phosphorylation promoting cellular apoptosis. Decline of anti-oxidant components viz; Sdf-1 and SOD-2 hinted towards the irreversible nature of the oxidative damage during marrow aplasia. Collectively, the findings hinted towards the mechanistic correlation among ROS generation, microenvironmental impairment and epigenetic alterations that led to hematopoietic catastrophe under aplastic stress. The findings may potentiate successful therapeutic strategy development for the dreadful condition concerned.     

Use of mean platelet volume improves detection of platelet disorders

Classification of platelet disorders has been based on the platelet count. Addition of a second variable, mean platelet volume (MPV), to the routine blood count allows classification of patients into 9 categories: high, low, or normal MPV, and high, low or normal platelet count. We studied 1,244 adult inpatients. 1,134 had both platelet values normal. 11 patients had high MPV and low platelet count: all had hyperdestructive causes. 15 patients had high MPV and normal platelet count: 12 had heterozygous thalassemia, and three had iron deficiency. Seven patients had high MPV and high platelet count: causes included myeloproliferative disorders, inflammation, iron deficiency, and splenectomy, 25 patients had high platelet counts and normal MPV: the causes were inflammation, infection, sickle cell anemia, iron deficiency, or chronic myelogenous leukemia. 52 patients had an MPV that was inappropriately low for the platelet count (high, normal, or low). All had sepsis, splenomegaly, aplastic anemia, chronic renal failure, or a disease being treated with myelosuppressive drugs. High MPV thus appears correlated with myeloproliferative disease or thalassemia; and low MPV, with cytotoxic drugs or marrow hypoplasia. Addition of MPV to the platelet count allows subtler disorders to be detected (when the platelet count is normal), and allows distinction of the cause of thrombocytopenia.     

Quantitative analytical technique applied to histopathology of birds infected experimentally by the virus of chicken anemia virus

This research was conducted on ten glass slides selected from the histopathology evaluation chickens. Five slides of control's chickens healthy and five slides of chickens infected experimentally with chicken anemia virus (CAV slide) between one and twenty-one days post infection (PI), they were analyzed in magnifications of 200x and 400x. Histopathology showed severe bone marrow hypoplasia to complete aplasia, fully depletion of the erythrocytic and granulocytic series, both accompanied by space occupying adipocytic replacement. Foci of erythropoietic hyperplasia with intense mielopoietic activity, some hemocytoblast increased of size, with large nucleus. A quantitative analytical technique by Positive Pixel Count Algorithm was applied. It demonstrated that measures area stained of control slides were higher than CAV slides (Average: 61% vs. 25%, respectively). So, the control slides showed strong positivity, due to the presence of bigger quantity of cells of erythrocytic and granulocytic series. The CAV slides of seven days PI had high positivity (average: 94%), it was explained because the chicken anemia virus takes place severe lesions between ten to seventeen days PI, after 21 days PI the cellular regeneration is observed that is evidenced by means of focuses of erythroblastoid cells hyperplasia. This technique demonstrates in a quantitative way the severe decrease of the cellular components of the bone marrow in presence of the infection for CAV, supporting with numeric data the histology image evaluated by the pathologist. Therefore, it can be used as support to the histopathology of field samples to evaluate the presence of lesions taken place by CAV and this way to improve the quality and efficiency of the veterinary pathology services.     

Replication of Colorado tick fever virus within human hematopoietic progenitor cells.

Significant neutropenia, as well as thrombocytopenia and a mild anemia, occurs in patients infected with Colorado tick fever virus. In this study, human bone marrow CD34+ cells and KG-1a cells, a human hematopoietic progenitor cell line, were infected in vitro with Colorado tick fever virus. The time course and morphological appearance of viral replication in human progenitor cells were similar to those seen in erythroblasts and in HEL cells and suggest one possible mechanism for the clinical hematologic findings.     

Changes in hemopoietic and regulator levels in mice during fatal or nonfatal malarial infections. II. Nonerythroid populations

Levels of mature lymphocytes, granulocytes, macrophages, platelets, their progenitor cells, and cytokines were monitored in the blood, marrow, and spleen during fatal or nonfatal murine malarial infections. In all four malaria models, before anemia developed, there was a lymphopenia, a rapid lymphocyte depletion in the marrow with a compensating rise in spleen lymphocytes, thrombocytopenia with increased megakaryocytic progenitor cell numbers, and monocyte increases in the bone marrow and later the spleen. The development of anemia was associated with a monocytosis and neutropenia, an increase in granulomonocytic progenitor cells in the spleen, and a reduction of spleen lymphocytes. Spleen granulocytes, monocytes, and their progenitor cells increased two- to threefold more in nonfatal than in fatal malaria and the spleen lymphocyte pool became severely depleted in fatal malaria. The data suggest that a defective effector cell response was of importance for the fatal outcome of the disease. Other than an early rise in serum macrophage colony stimulating factor levels in fatal infections, changes in levels of the regulators of these effector cells did not correlate well with the outcome of the infection.     

Chronic anemia and effects of iron supplementation in a research colony of adult Rhesus macaques (Macaca mulatta)

A cohort of rhesus macaques used in neuroscience research was found at routine examinations to have chronic anemia (spun Hct less than 30%). Four anemic (Hct, 24.8% ± 3.4%) and 10 control (39.6% ± 2.9%) macaques were assessed to characterize the anemia and determine probable cause(s); some animals in both groups had cephalic implants. Diagnostic tests included CBC, bone marrow evaluations, iron panels, and serum erythropoietin and hepcidin concentrations. Serum iron and ferritin were 15.8 ± 11.1 μg/dL and 103.8 ± 53.1 ng/mL, respectively, for the anemic group compared with 109.8 ± 23.8 μL/dL and 88.5 ± 41.9 ng/mL, respectively, for the control group. Erythropoietin levels were 16.2 to over 100 mU/mL for the anemic macaques compared with 0 to 1.3 mU/mL for the control group. Hepcidin results were similar in both groups. Because the findings of low iron, high erythropoietin, and normal hepcidin in the anemic macaques supported iron-deficiency anemia or anemia of chronic disease combined with iron-deficiency anemia, a regimen of 4 doses of iron dextran was provided. In treated macaques, Hct rose to 36.3% ± 6.8%, serum iron levels increased to 94.0 ± 41.9 μg/dL, and erythropoietin levels fell to 0.15 to 0.55 mU/mL. Maintenance of normal Hct was variable between macaques and reflected individual ongoing clinical events.     

Cytogenetic damage of bone marrow cells produced by chronic alcohol consumption

Pair-feeding of rats with nutritionally adequate liquid diets containing 36% of total energy either as ethanol or as additional carbohydrate (in the controls) resulted in blood ethanol concentrations similar to those observed in alcoholics. Alcohol feeding for six weeks increased the frequency of micronuclei in bone marrow erythrocytes, an index of chromosomal damage in precursor cells. This was associated with bone marrow hypoplasia and erythrocyte macrocytosis, alterations commonly found in alcoholics. By contrast, acute ethanol administration produced no changes in the bone marrow. Cytogenetic damage of stem cells could lead to alterations persisting after alcohol withdrawal beyond the life span of effector cells.     

Progenitor white cells and serum inhibitors in patients with bone marrow aplasia.

In patients with various blood diseases, especially with bone marrow hypoplasia following parameters were determined: presence of antibodies against autologous bone marrow, number of granulocyte-progenitor cells in short term bone marrow cultures and stimulating or inhibiting factors in patient's serum influencing the proliferative activity of bone marrow colonies. The results as well as possible clinical aspects are discussed.     

四物汤对再生障碍性贫血小鼠骨髓细胞增殖的影响研究

目的研究四物汤对再生障碍性贫血（AA）小鼠骨髓细胞体外增殖的影响,探讨其治疗AA的机制。方法采用流式细胞仪、骨髓造血祖细胞培养等技术,检测四物汤对AA小鼠骨髓细胞的增殖变化。结果 四物汤能促进骨髓有核细胞进入G2／S期、增加CFU—GM、CFU-E、BFU-E集落数,且与自然恢复组有明显增强的差异。结论 四物汤在体内有促进AA小鼠骨髓细胞增殖的作用,为补血药治疗AA提供了实验与理论依据。