[Hematology: large steps followed by a time of small steps].
Explore the source record for details and available documents.
Hematologic Diseases↗
Biomedical subjects
J Fehr
Publications and source records attributed to J Fehr.
Inhibition of leukocyte emigration induced during the systemic inflammatory reaction in vivo is not due to IL-8.
In keeping with the multistep model of leukocyte-endothelial cell interaction, stimulation of endothelium by cytokines or endotoxin (LPS) in vitro leads to selectin/integrin-mediated neutrophil adhesion, followed by neutrophil endothelial transmigration. The i.p. injection of LPS in vivo induces a systemic inflammatory reaction in a mouse model with generalized activation of both endothelial cells (up-regulation of adhesion molecules ICAM-1, VCAM-1, E-selectin) and neutrophils (up-regulation of Mac-1). However, no intravascular endothelial adhesion or tissue emigration of neutrophils can be observed. Even more importantly, the in vivo emigration of polymorphonuclear cells at sites of a local inflammatory reaction (IL-8, TNF, LPS) is totally inhibited when the mice are pretreated systemically with LPS, although the neutrophils respond fully to a rechallenge with LPS ex vivo, and endothelial adhesion molecules are further up-regulated locally. The systemic application of TNF also caused a total inhibition of neutrophil emigration. However, while anti-TNF mAb abrogated the inhibitory activity induced by TNF, they had no effect on systemic LPS. The systemic application of IL-8 did not inhibit neutrophil emigration, nor did the pretreatment of mice with anti-IL-8 mAb before the systemic application of LPS abrogate the inhibitory activity induced by LPS. Therefore, the putative inhibitor of neutrophil emigration, which may be of great physiologic importance, as it prevents in vivo the generalized emigration of activated neutrophils, most likely is not IL-8.
Animals↗
Aplastic anemia rescued by exhaustion of cytokine-secreting CD8+ T cells in persistent infection with lymphocytic choriomeningitis virus.
Aplastic anemia may be associated with persistent viral infections that result from failure of the immune system to control virus. To evaluate the effects on hematopoiesis exerted by sustained viral replication in the presence of activated T cells, blood values and bone marrow (BM) function were analyzed in chronic infection with lymphocytic choriomeningitis virus (LCMV) in perforin-deficient (P0/0) mice. These mice exhibit a vigorous T cell response, but are unable to eliminate the virus. Within 14 d after infection, a progressive pancytopenia developed that eventually was lethal due to agranulocytosis and thrombocytopenia correlating with an increasing loss of morphologically differentiated, pluripotent, and committed progenitors in the BM. This hematopoietic disease caused by a noncytopathic chronic virus infection was prevented by depletion of CD8+, but not of CD4+, T cells and accelerated by increasing the frequency of LCMV-specific CD8+ T cells in T cell receptor (TCR) transgenic (tg) mice. LCMV and CD8+ T cells were found only transiently in the BM of infected wild-type mice. In contrast, increased numbers of CD8+ T cells and LCMV persisted at high levels in antigen-presenting cells of infected P0/0 and P0/0 x TCR tg mice. No cognate interaction between the TCR and hematopoietic progenitors presenting either LCMV-derived or self-antigens on the major histocompatibility complex was found, but damage to hematopoiesis was due to excessive secretion and action of tumor necrosis factor (TNF)/lymphotoxin (LT)-alpha and interferon (IFN)-gamma produced by CD8+ T cells. This was studied in double-knockout mice that were genetically deficient in perforin and TNF receptor type 1. Compared with P0/0 mice, these mice had identical T cell compartments and T cell responses to LCMV, yet they survived LCMV infection and became life-long virus carriers. The numbers of hematopoietic precursors in the BM were increased compared with P0/0 mice after LCMV infection, although transient blood disease was still noticed. This residual disease activity was found to depend on IFN-gamma-producing LCMV-specific T cells and the time point of hematopoietic recovery paralleled disappearance of these virus-specific, IFN-gamma-producing CD8+ T cells. Thus, in the absence of IFN-gamma and/or TNF/LT-alpha, exhaustion of virus-specific T cells was not hampered.
Anemia, Aplastic↗
[Hematology: centuries: centuries of experiences/recent discoveries also cheaper].
Explore the source record for details and available documents.
Cost Savings↗
[Castleman's disease--a rare cause of a febrile state with lymphadenopathy].
HISTORY AND CLINICAL FINDINGS: A 26-year-old man had a prolonged fever, 10 kg weight loss and generalized lymphadenopathy, first diagnosed as a malignant lymphoma. On admission he was febrile and in a markedly reduced physical condition. Submandibular, angular, cubital and inguinal lymph nodes were slightly enlarged bilaterally. INVESTIGATIONS: Serology and blood cultures were negative. Sonography and computed tomography showed enlarged lymph nodes in the neck, mediastinum, axillae, retroperitoneum and mesentery. Biopsies of lymph nodes and bone marrow revealed changes characteristic of Castleman's disease. TREATMENT AND COURSE: Prednisone was administered, 20 mg daily for 20 days, the dose gradually reduced over 4 months. The fever ceased after 14 days and the patients's working capacity was fully restored after 7 weeks. CONCLUSION: In a case of prolonged fever of unknown cause Castleman's disease should be included in the differential diagnosis. It at first consists of polyclonal lymphatic proliferation. But transformation to malignant lymphoma and systemic Kaposi's sarcoma have been described in the disease's generalized form.
Adult↗
Virus-induced transient bone marrow aplasia: major role of interferon-alpha/beta during acute infection with the noncytopathic lymphocytic choriomeningitis virus.
The hematologic consequences of infection with the noncytopathic lymphocytic choriomeningitis virus (LCMV) were studied in wild-type mice with inherent variations in their interferon (IFN)-alpha/beta responder ability and in mutant mice lacking alpha/beta (IFN-alpha/beta R0/0) or gamma IFN (IFN-gamma R0/0) receptors. During the first week of infection, wild type mice demonstrated a transient pancytopenia. Within a given genetic background, the extent of the blood cell abnormalities did not correlate with the virulence of the LCMV isolate but variations were detected between different mouse strains: they were found to depend on their IFN-alpha/beta responder phenotype. Whereas IFN-gamma R0/0 mice were comparable to wild-type mice, IFN-alpha/beta R0/0 mice exhibited unchanged peripheral blood values during acute LCMV infection. In parallel, the bone marrow (BM) cellularity, the pluripotential and committed progenitor compartments were up to 30-fold reduced in wild type and IFN-gamma R0/0, but remained unchanged in IFN-alpha/beta R0/0 mice. Viral titers in BM 3 d after LCMV infection were similar in these mice, but antigen localization was different. Viral antigen was predominantly confined to stromal BM in normal mice and IFN-gamma R0/0 knockouts, whereas, in IFN-alpha/beta R0/0 mice, LCMV was detected in > 90% of megakaryocytes and 10-15% of myeloid precursors, but not in erythroblasts Although IFN-alpha/beta efficiently prevented viral replication in potentially susceptible hematopoietic cells, even in overwhelming LCMV infection, unlimited virus multiplication in platelet and myeloid precursors in IFN-alpha/beta R0/0 mice did not interfere with the number of circulating blood cells. Natural killer (NK) cell expansion and activity in the BM was comparable on day 3 after infection in mutant and control mice. Adaptive immune responses did not play a major role because comparable kinetics of LCMV-induced pancytopenia and transient depletion of the pluripotential and committed progenitor compartments were observed in CD8(0/0) and CD4(0/0) mice, in mice depleted of NK cells, in lpr mice, and in perforin-deficient (P0/0) mice lacking lytic NK cells. Thus, the reversible depression of hematopoiesis during early LCMV infection was not mediated by LCMV-WE-specific cytotoxic T lymphocyte, cytolysis, or secreted IFN-gamma from virally induced NK cells but was a direct effect of IFN-alpha/beta.
Acute Disease↗
The diagnostic value of the neutrophil left shift in predicting inflammatory and infectious disease.
The use of neutrophil left-shift parameters in the diagnosis of inflammatory and infective disease (ID) was evaluated. The level of C-reactive protein (CRP), currently the best quantitative parameter of inflammation, was used as the gold standard. Of 292 patients, 230 (79%) had a level of CRP of 1.0 mg/dL or greater and were classified as having inflammation, whereas 62 (21%) had normal levels. The neutrophil band count in each patient was determined by microscopic examination of 200 WBCs. The diagnostic value of the band count as an indicator for ID was evaluated in comparison to the WBC count, the neutrophil count, and the left-shift indicators of two automated hematologic analyzers, H*1 Technicon (Bayer Technicon Instruments, Tarrytown, NY) and Coulter MAX M (Coulter Electronics, Hialeah, Fla). When receiver operating characteristics were used, the band count was superior to the immature to total neutrophil count (I/T) ratio, the total WBC count, and the neutrophil count. The sensitivity and specificity in identifying ID at designated cutoff points were as follows: band count of 20% or greater of total WBC count (53% and 79%, respectively), I/T ratio of 0.25 or greater (59% and 63%), total WBC count of 9.6 x 10(6)/mL or greater (68% and 56%), and neutrophil count of 8.0 x 10(6)/mL or greater (60% and 58%). The performance of the H*1 Technicon left-shift flag was similar but slightly inferior to the band count (sensitivity, 44%; specificity, 79%), whereas the Coulter MAX M flags had a clearly higher sensitivity (79%) and lower specificity (53%). In addition, microscopic evaluation to determine the presence of reactive morphologic changes in neutrophils, such as toxic granules, Döhle bodies, and cytoplasmic vacuoles, had a high sensitivity (80%) but a low specificity (58%) in predicting ID. The diagnostic value of both microscopic and automated neutrophil left-shift parameters as indicators for ID is limited. Morphologic changes in neutrophils, however, either have a high specificity (band count) or a high sensitivity (toxic signs) in predicting ID and therefore may be a clinically useful tool.
Adolescent↗
Regulation and selectivity of leukocyte emigration.
Explore the source record for details and available documents.
Animals↗
Estimation of the lower limits of manual and automated platelet counting.
Most evaluators of automated or manual methods for platelet counting focus on characteristics such as imprecision, linearity, and carry over. The limits of the analytical procedure are usually not assessed. The limits of the different techniques are neither discussed in the literature nor do manufacturers of analytical systems supply these data. A new procedure is presented to assess the performance of the manual as well as the automated platelet count. This procedure allows, with defined statistical confidence (eg, 95%), the determination of (1) the limit of platelet detection (LD) at which signals of platelets can be discriminated from the system noise; (2) the lower limit of quantification (LLQ), at which a certain imprecision is not surpassed; and (3) the power of definition (PD) that defines the number of values that can be discriminated in a certain interval. For each value, the PD allows calculation of the two adjacent (lower and higher) values that are significantly (P > or = 0.95) different. For the manual count, LD was found to be 1.6 x 10(9) plt/L and the LLQ 6.9 x 10(9) plt/L. For the automated count with the Technicon H1, LD was 4.3 x 10(9) plt/L and LLQ 13.8 x 10(9) plt/L (CVmax = 15%). The PD in the range 20 to 100 x 10(9) plt/L is 8 for the automated and 7 for the manual count.
Analysis of Variance↗
Early diagnosis of low grade malignant lymphoma and chronic lymphocytic leukaemia. Verification of morphologically suspected malignancy in blood lymphocytes by flow cytometry.
According to international recommendations, the diagnosis of chronic lymphocytic leukaemia (CLL) is made on the grounds of persistent peripheral lymphocytosis or lymphocytic infiltration of the bone marrow. The appearance of morphologically atypical lymphocytes in low-grade malignant lymphoma (NHL) or CLL is easily overlooked, and is generally not regarded as a diagnostic criterion. We report 12 cases of CLL/NHL who were detected only by morphological screening of routine peripheral blood smears (83,400 blood smears). The diagnosis of CLL/NHL was not suggested by the patients' history, physical or other laboratory findings, and had not been contemplated by the physician in charge. Monoclonality of peripheral lymphocytes was confirmed by immunophenotyping and Southern blotting. The lymphoma was classified histologically according to the International Working Formulation (bone marrow biopsy). A monoclonal lymphatic population was not found by immunophenotyping in the blood of 11 patients whose lymphocytes were morphologically classified as activated-abnormal. However, 3 patients suspected to have NHL/CLL on morphological screening of blood smears had to be classified as benign after immunophenotyping. We conclude that morphological screening of routine blood smears is an inexpensive and easy additional screening method for CLL and low grade malignant NHL.
Aged↗
HB Hinwil or beta 38(C4)Thr-->Asn: a new beta chain variant detected in a Swiss family.
This paper reports a new hemoglobin variant which was identified while investigating the cause of a mild erythrocytosis. The abnormal beta-globin chain was detected by reversed phase chromatography. Mutation mapping of the beta-globin gene by polymerase chain reaction and denaturing gradient gel electrophoresis followed by sequence analysis revealed a C-->A transversion at codon 38, predicting a Thr-->Asn substitution. Tryptic peptide mapping by liquid chromatography electrospray mass spectrometry, followed by conventional Edman peptide sequence analysis, confirmed the predicted amino acid substitution. In contrast to the only other known mutation at codon 38, Hb Hazebrouck (Thr-->Pro), this hemoglobin is stable and shows elevated oxygen affinity.
Amino Acid Sequence↗
[Value of the blood picture and flow cytometry immunotyping in the early diagnosis of low-grade lymphoma].
Low-grade malignant non-Hodgkin lymphoma [NHL] and chronic lymphocytic leukemia [CLL] as its special form are slowly progressing malignancies which may present with lymphadenopathy, splenomegaly or, more rarely, hepatomegaly. The diagnosis is made by bone marrow or lymph node histology, while laboratory tests are relatively unspecific and may only hint towards the diagnosis. In contrast to high-grade malignant lymphoma, low-grade malignant NHL is often associated with the appearance of malignant lymphoma cells in peripheral blood. These malignant lymphocytes may be differentiated microscopically from normal lymphocytes, so that the diagnosis of NHL may be suspected not only because of clinical symptoms or lymphocytosis, which may present late in the natural history of the disease, but also on morphological grounds. Three types of low-grade malignant NHL cells may be recognized in peripheral blood: A mature appearing lymphocytic type with only slight alterations of the nucleus, a lymphoplasmocytic type, and a lymphocytic type with prominent alterations of the nucleus. The appearance of smudge cells and a monotony in lymphocyte morphology may serve as further diagnostic aids. Once the diagnosis has been suspected on morphological grounds, it may be verified in the case of B-cell lymphomas by flow cytometry. The clonality of T-cell lymphoproliferative disorders in addition has to be proven by demonstrating a clonal rearrangement of the T-cell receptor in Southern blots. An early diagnosis of low-grade malignant NHL may not only provide new insights into the natural history of monoclonal cytopathies but may also be of importance in the clinical management of patients.
Blood Cells↗
[Malignant hematologic diseases].
Explore the source record for details and available documents.
Hematologic Diseases↗
High grade malignant lymphoma with clinical characteristics and immunophenotype of natural killer cells.
The malignant proliferation of natural killer (NK) cells which are morphologically characterized as large granular lymphocytes (LGL) is a well known clinical entity which was named after its morphological appearance as LGL-leukemia/lymphoma. Similar to non-malignant NK-cells, these tumors can be divided into those which express the CD3-T-cell receptor complex and those which do not. The CD3-positive type of LGL-leukemia is immunophenotypologically characterized by the expression of CD16, and variably CD 56 and CD 57, and generally follows a more indolent course. In contrast, malignant proliferations of CD3-negative LGL express either CD16 or CD 56, and only occasionally CD 57 on their cell surface. Clinically, CD3-negative NK-lymphomas tend to progress rapidly. We report here the case of a high grade malignant lymphoma which was characterized by an immunophenotype typical for CD3-negative NK-cells (CD2+, CD3-, CD16+, CD56(+), CD57-). The disease proved to be rapidly fatal despite aggressive chemotherapy. Interestingly, the patient suffered from a high turn over pancytopenia, which also characterizes NK-cell leukemias/lymphomas of the LGL-type. However, our patient's lymphatic cells appeared highly immature, and cytoplasmic granules, characteristic for LGL-cells, could not be discerned either microscopically or electronmicroscopically. Furthermore, the malignant lymphatic population had the T-cell receptor beta-chain rearranged. We therefore concluded that our patient might have suffered from a malignant proliferation of a putative precursor cell intermediate between T-cells and NK-cells.
Adult↗
The influence of leukocyte filtration during cardiopulmonary bypass on postoperative lung function. A clinical study.
The accumulation of activated leukocytes in the pulmonary circulation plays an important role in the pathogenesis of lung dysfunction associated with cardiopulmonary bypass. Animal studies have demonstrated that the elimination of leukocytes from the circulation reduces postoperative lung injury and improves postoperative pulmonary function. We conducted a prospective randomized clinical study to evaluate whether postoperative lung function could be improved by use of a leukocyte filter during cardiopulmonary bypass. Elective coronary artery bypass grafting was done with a leukocyte-depleting arterial blood filter incorporated in the extracorporeal circuit (14 patients, leukocyte filter group) or without the filter (18 patients, control group). Blood samples collected at intervals before, during, and after operation were used for analysis of blood cell counts, elastase concentrations, and arterial blood gases. The use of the leukocyte filter caused no significant reduction in leukocyte count (p = 0.86). There were no differences in postoperative lung function between the groups, as assessed through (1) oxygenation index (290 for leukocyte filter group compared with 329 for control group, 95% confidence interval, 286 to 372, p = 0.21), (2) pulmonary vascular resistance (p = 0.10), and (3) intubation time (16.6 hours for leukocyte filter group versus 15.7 hours for control group, 95% confidence interval, 12.1 to 19.1 hours, p = 0.72). The levels of neutrophil elastase were significantly higher at the end of cardiopulmonary bypass in the leukocyte filter group (460 microgram/L in leukocyte filter group versus 230 microgram/L in control group, 95% confidence interval, 101 to 359 microgram/L, p = 0.003). We conclude that the clinical use of the present form of leukocyte-depleting filter did not improve any of the postoperative lung function parameters analyzed in this study.
Cardiopulmonary Bypass↗
GM-CSF-induced acute eosinophilic pneumonia.
There is increasing evidence that haemopoietic growth factors are effective in reversal of neutropenia associated with large granular lymphocytes (LGLs) proliferation. A 19-year-old woman with CD3+/TCR gamma delta+, CD4-, CD8- LGL proliferation and severe neutropenia repeatedly developed blood eosinophilia, fever and dyspnoea after administration of GM-CSF. Acute eosinophilic pneumonia with a lobar lung infiltrate pleural effusion, and marked bronchoalveolar lavage fluid eosinophilia was diagnosed. Treatment with corticosteroids and discontinuation of GM-CSF lead to rapid improvement. In addition, haematological analysis revealed that H*1 Technicon, a widely-used automated cell counter, may misinterpret eosinophils erroneously as neutrophils, therefore examination of blood smears to prevent eosinophil-mediated toxicity during GM-CSF treatment is recommended.
Acute Disease↗
Prediction of iron deficiency in chronic inflammatory rheumatic disease anaemia.
We prospectively studied 45 anaemic patients (37 women, 8 men) with chronic inflammatory rheumatic diseases. The combination of serum ferritin and CRP (as well as ESR) in its predictive capacity for bone marrow iron stores was examined. The relationship between other iron-related measurements (transferrin, transferrin saturation, soluble transferrin receptor, erythrocyte porphyrins and percentage of hypochromic/microcytic erythrocytes) and bone marrow iron stores was also investigated. Stainable bone marrow iron was taken as the most suitable standard to separate iron-deficient from iron-replete patients. 14 patients (31%) were lacking bone marrow iron. Regression analysis showed a good correlation between ferritin and bone marrow iron (adjusted R2 = 0.721, P < 0.0001). The combination of ferritin and CRP (ESR) did not improve the predictive power for bone marrow iron (adjusted R2 = 0.715) in this cohort of patients with low systemic inflammatory activity. With respect to the bone marrow iron content the best predictive cut-off value of ferritin was 30 micrograms/l (86% sensitivity, 90% specificity). The other iron-related parameters both individually and when combined were less powerful in predicting bone marrow iron than ferritin alone. Only zinc bound erythrocyte protoporphyrin in combination with ferritin slightly improved prediction (adjusted R2 = 0.731). A cut-off point of 11% hypochromic erythrocytes reached a high specificity (90%), but was less sensitive (77%).
Adult↗
Epinephrine test and plasma elastase as diagnostic tools in a patient with CD3+ large granular lymphocyte proliferation.
Large granular lymphocytes (LGL) proliferation is characterized by expansion of cytotoxic lymphocytes and associated with neutropenia. In a case of CD3+ LGL-proliferation the epinephrine stimulation test (EST) induced a striking elevation of CD3+, CD8+, CD57+ LGL in peripheral blood from 2.7 x 10(9)/l to 20 x 10(9)/l and might be an additional diagnostic tool in patients with normal or low absolute numbers of circulating LGL. After treatment with steroids, plasma elastase--a marker of neutrophil destruction--decreased from 162 to 40 micrograms/l (normal < 47 micrograms/l) which correlated well with a simultaneous increase in peripheral neutrophil counts from 0.14 to 1.0 x 10(9)/l. This finding supports the hypothesis that neutropenia in CD3+ LGL proliferation is due to neutrophil destruction, possibly mediated by LGL.
Aged↗