Commensal Cryptosporidium colonization elicits a cDC1-dependent Th1 response that promotes intestinal homeostasis and limits other infections

Cryptosporidium can cause severe diarrhea and morbidity, but many infections are asymptomatic. Here, we studied the immune response to a commensal strain of Cryptosporidium tyzzeri (Ct-STL) serendipitously discovered when conventional type 1 dendritic cell (cDC1)-deficient mice developed cryptosporidiosis. Ct-STL was vertically transmitted without negative health effects in wild-type mice. Yet, Ct-STL provoked profound changes in the intestinal immune system, including induction of an IFN-γ-producing Th1 response. TCR sequencing coupled with in vitro and in vivo analysis of common Th1 TCRs revealed that Ct-STL elicited a dominant antigen-specific Th1 response. In contrast, deficiency in cDC1s skewed the Ct-STL CD4 T cell response toward Th17 and regulatory T cells. Although Ct-STL predominantly colonized the small intestine, colon Th1 responses were enhanced and associated with protection against Citrobacter rodentium infection and exacerbation of dextran sodium sulfate and anti-IL10R-triggered colitis. Thus, Ct-STL represents a commensal pathobiont that elicits Th1-mediated intestinal homeostasis that may reflect asymptomatic human Cryptosporidium infection.

Efficient targeted integration directed by short homology in zebrafish and mammalian cells

Efficient precision genome engineering requires high frequency and specificity of integration at the genomic target site. Here, we describe a set of resources to streamline reporter gene knock-ins in zebrafish and demonstrate the broader utility of the method in mammalian cells. Our approach uses short homology of 24-48 bp to drive targeted integration of DNA reporter cassettes by homology-mediated end joining (HMEJ) at high frequency at a double strand break in the targeted gene. Our vector series, pGTag (plasmids for Gene Tagging), contains reporters flanked by a universal CRISPR sgRNA sequence which enables in vivo liberation of the homology arms. We observed high rates of germline transmission (22-100%) for targeted knock-ins at eight zebrafish loci and efficient integration at safe harbor loci in porcine and human cells. Our system provides a straightforward and cost-effective approach for high efficiency gene targeting applications in CRISPR and TALEN compatible systems.

Megakaryocytes and Platelets as the Main Cause for Vascular Events in Chronic Myeloproliferative Disorders

Megakaryocytes are part of clonal hematopoiesis in chronic myeloproliferative disorders and are responsible for most of the clinical complications in this disease. About 30-40% of patients with polycythemia vera (PV) and essential thrombocythemia (ET) suffer from thrombotic complications, and microcirculatory disorders are common. Spontaneous bleeding mainly from the gastrointestinal tract is another complication that is especially prevalent in myelofibrosis and advanced stages of chronic myeloid leukemia.

In vivo, the bone marrow is hypercellular and the concentration of megakaryocytes increased with characteristic morphological abnormalities. Megakaryocytes are enlarged and ploidy is increased in PV and ET but small mononuclear cells with decreased ploidy are a feature of CML. Despite spontaneous growth in cul-ture, megakaryocytes in chronic MPD are hypersensitive to added interleukin-3, interleukin-6 and GM-CSF.

Platelets released from these megakaryocytes show abnormal morphology and ultrastructure, reflected in loss of storage granules and organelles, increased volume distribution and low buoyant density. Uptake, storage and secretion of platelet dense granule constituents is abnormal, and the plasma levels of platelet specific proteins which may also include growth factors for fibroblasts are elevated. At high platelet counts, spontaneous aggregation is observed, whereas agonist-induced aggregation in vitro with adrenaline, ADP and collagen is often defective. Platelet thromboxane generation may be stimulated, and production along the lipoxygenase pathway is decreased. Abnormalities of glycoprotein receptors and decreased fibrinogen binding have been reported but their clinical significance is uncertain. Several observations suggest that not only receptor defects but ineffective intracellular signalling may be responsible for platelet function abnormalities.

No single underlying defect has been discovered that could explain this variety of pathological findings. Moreover, a combination of intrinsic megakaryocyte abnormalities and increased susceptibility of platelets to activation makes it difficult to differentiate secondary phenomena from effects of clonal hematopoiesis. How-ever, there are some clinical guidelines for therapy.

Most elderly patients will be treated with cytoreductive therapy. Alkylating drugs and 32P have been shown to be leukemogenic, but even hydroxyurea may have a 10% incidence of leukemia induction after long-term therapy. Therapy with platelet-inhibitory drugs is often not sufficient to control thrombosis, and may aggravate a bleeding tendency, so that younger patients with PV and ET are increasingly treated with anagrelide or interferon alpha (A-IFN). Anagrelide is a quinazolin derivative that specifically inhibits megakaryocytopoiesis, while A-IFN may suppress clonal hematopoiesis by an unknown mechanism.

Ultratrace voltammetric determination of DNA-bound platinum in patients after administration of oxaliplatin

Oxaliplatin, a novel diaminocyclohexane-platinum complex, is used for the treatment of metastatic colorectal cancer. The amount of DNA-adduct formation of this drug in white blood cells of patients is determined after isolation of the DNA by density gradient centrifugation and a four-step solid phase extraction procedure. DNA is quantified by UV spectrometry, and platinum is determined after mineralization of the DNA sample by adsorptive stripping voltammetry (formazone method). It is possible to determine Pt-nucleotide ratios in clinical samples down to five Pt atoms in 10(8) nucleotides, and the dynamic range of the method covers three orders of magnitude. An absolute amount of 25 microg of DNA is sufficient for such measurements. With the method described, the time-dependent formation of oxaliplatin DNA adducts can be monitored in clinical studies, which may help us to understand inter-individual differences in the responses of patients to oxaliplatin-based therapy.

Primary non-Hodgkin's lymphoma of bone: three cases and a short review of the literature

Primary non-Hodgkin's lymphoma of bone (PLB) is a rare entity. We present three new cases and a review of the literature. If PLB is suspected radiologically, the diagnosis must be confirmed by open biopsy. Histopathologically, PLB usually represents diffuse large B-cell lymphoma or lymphoma of the follicular center type. The extent of local disease manifestation, additional skeletal involvement, and the presence or absence of lymphadenopathy is assessed by radiological examination. Localized stages of the disease require involved-field radiotherapy (45-50 Gy) to the entire bone that is affected. Regional lymphatics must also be irradiated. Radiotherapy may be required immediately to prevent pathological fractures. In the few cases of more widespread skeletal or extraskeletal involvement, radiotherapy of the major site of manifestation may be followed by a "watch-and-wait" strategy until progression of the disease becomes apparent. In cases of intermediate or high-grade lymphoma of bone, combined radiochemotherapy is the treatment of choice for all stages. Six to eight cycles of chemotherapy (usually the CHOP regimen) are recommended for remission induction. This is followed by involved-field radiotherapy with 45-50 Gy. High-dose chemotherapy with autologous stem cell support is an option if there is no satisfactory response to conventional chemotherapy, or if early relapse occurs.

Hemoglobinopathy York [beta146 (HC3) His==>Pro]: first report of a family history

The rare hemoglobinopathies with abnormal oxygen binding are usually characterized by erythropoietin-mediated erythrocytosis. Bare et al. first described a hemoglobinopathy with mild erythrocytosis in a 22-year-old Caucasian woman in 1976. These authors called the abnormal hemoglobin Hb York. Hb York is characterized by a mutation at the beta146 position that changes histidine into proline. A second case of Hb York was observed by Kosugi et al. in 1983. To the best of our knowledge, no further cases have been reported. We have encountered a new case of Hb York, which was detected by agar gel electrophoresis at pH 6.0. Analysis of DNA sequences revealed a CAC-->CCC mutation in codon 146. The proportion of Hb York was approximately 50%. Analysis of oxygen transport function showed a leftward shift of the sigmoidal O2-dissociation curve. P50 was reduced to 15.5 mmHg. Investigation of family members revealed Hb York in the patient's sister, two daughters and a grandson. In retrospect, the mother of the patient may also have been affected. The mode of inheritance is autosomal dominant.

Diagnosis, pathogenesis and treatment of the myeloproliferative disorders essential thrombocythemia, polycythemia vera and essential megakaryocytic granulocytic metaplasia and myelofibrosis

According to strict clinical, hematological and morphological criteria, the Philadelphia (Ph) chromosome negative chronic myeloproliferative disorders essential thrombocythemia (ET), polycythemia vera (PV), and agnogenic myeloid (megakaryocytic/granulocytic) metaplasia (AMM) or idiopathic myelofibrosis (IMF) are three distinct disease entities with regard to clinical manifestations, natural history and outcome in terms of life expectancy. As clonality studies have clearly demonstrated that fibroblast proliferation in AMM, as well as in many other conditions such as advanced stages of Ph(+)-essential thrombocythemia, Ph(+)-granulocytic leukemia, and Ph(-)-polycythemia vera, is polyclonal indicating that myelofibrosis is secondary to the megakaryocytic granulocytic metaplasia in these various conditions, AMM is illogically labeled as IMF. As abnormal megakaryocytic granulocytic metaplasia is the essential feature preceding the early prefibrotic stage of AMM, the term essential megakaryocytic granulocytic metaplasia (EMGM) can readily be used to characterize this condition more appropriately at the biological level. Clinical, hematological and morphological characteristics, in particular megakaryocytopoiesis and bone marrow cellularity, reveal diagnostic features, which enable a clear-cut distinction between ET, PV and EMGM or classical IMF. The characteristic increase and clustering of enlarged megakaryocytes with mature cytoplasm and multilobulated nuclei and their tendency to cluster in a normal or only slightly increased cellular bone marrow represent the hallmark of ET. The characteristic increase and clustering of enlarged mature and pleiomorphic megakaryocytes with multilobulated nuclei and proliferation of erythropoiesis in a moderate to marked hypercellular bone marrow with hyperplasia of dilated sinuses are the specific diagnostic features of untreated PV. EMGM, including the early prefibrotic stages as well as the various myelofibrotic stages of classical IMF appear to be a distinct neoplastic dual proliferation of abnormal megakaryopoiesis and granulopoiesis. The histopathology of the bone marrow in prefibrotic EMGM and in classical IMF is dominated by atypical, enlarged and immature megakaryocytes with cloud-like immature nuclei, which are not seen in ET and PV at diagnosis and during follow-up. Myelofibrosis in ET, PV and EMGM is graded into: no reticulin fibrosis (MF0), early reticulin fibrosis (MF1), advanced reticulin sclerosis with minor or moderate collagen fibrosis (MF2) and advanced collagen fibrosis with osteosclerosis (MF3). Myelofibrosis is not a feature of ET at diagnosis and during long-term follow-up. Myelofibrosis may be present in a minority of PV-patients at diagnosis and usually becomes apparent during long-term follow-up in the majority of PV-patients. Myelofibrosis secondary to the abnormal megakaryocytic and granulocytic myeloproliferation constitutes a prominent feature in the majority of EMGM/IMF at time of diagnosis and usually progresses more or less rapidly during the natural history of the disease. Life expectancy is normal in ET, normal during the 1st ten years and compromised during the 2nd ten years follow-up in PV, but significantly shortened in the prefibrotic stage of EMGM as well as in the various myelosclerotic stages of classical IMF. First line treatment options in prospective randomized clinical trials of newly diagnosed MPD-patients are control of platelet function with low-dose aspirin versus reduction of platelet count with anagrelide, interferon or hydroxyurea in ET; control of platelet and erythrocyte counts by interferon alone versus bloodletting plus hydroxyurea on indication in PV; interferon versus no treatment in the early stages of EMGM; a wait and see strategy in the fibrotic stages of EMGM or classical IMF with favorable prognostic factors, and bone marrow transplantation in classical IMF with poor prognostic factors at presentation or during short-term follow-up.

Diagnosis, pathogenesis and treatment of the myeloproliferative disorders essential thrombocythemia, polycythemia vera and essential megakaryocytic granulocytic metaplasia and myelofibrosis

According to strict clinical, hematological and morphological criteria, the Philadelphia (Ph) chromosome negative chronic myeloproliferative disorders essential thrombocythemia (ET), polycythemia vera (PV), and agnogenic myeloid (megakaryocytic/granulocytic) metaplasia (AMM) or idiopathic myelofibrosis (IMF) are three distinct disease entities with regard to clinical manifestations, natural history and outcome in terms of life expectancy. As clonality studies have clearly demonstrated that fibroblast proliferation in AMM, as well as in many other conditions such as advanced stages of Ph(+)-essential thrombocythemia, Ph(+)-granulocytic leukemia, and Ph(-)-polycythemia vera, is polyclonal indicating that myelofibrosis is secondary to the megakaryocytic granulocytic metaplasia in these various conditions, AMM is illogically labeled as IMF. As abnormal megakaryocytic granulocytic metaplasia is the essential feature preceding the early prefibrotic stage of AMM, the term essential megakaryocytic granulocytic metaplasia (EMGM) can readily be used to characterize this condition more appropriately at the biological level. Clinical, hematological and morphological characteristics, in particular megakaryocytopoiesis and bone marrow cellularity, reveal diagnostic features, which enable a clear-cut distinction between ET, PV and EMGM or classical IMF. The characteristic increase and clustering of enlarged megakaryocytes with mature cytoplasm and multilobulated nuclei and their tendency to cluster in a normal or only slightly increased cellular bone marrow represent the hallmark of ET. The characteristic increase and clustering of enlarged mature and pleiomorphic megakaryocytes with multilobulated nuclei and proliferation of erythropoiesis in a moderate to marked hypercellular bone marrow with hyperplasia of dilated sinuses are the specific diagnostic features of untreated PV. EMGM, including the early prefibrotic stages as well as the various myelofibrotic stages of classical IMF appear to be a distinct neoplastic dual proliferation of abnormal megakaryopoiesis and granulopoiesis. The histopathology of the bone marrow in prefibrotic EMGM and in classical IMF is dominated by atypical, enlarged and immature megakaryocytes with cloud-like immature nuclei, which are not seen in ET and PV at diagnosis and during follow-up. Myelofibrosis in ET, PV and EMGM is graded into: no reticulin fibrosis (MF0), early reticulin fibrosis (MF1), advanced reticulin sclerosis with minor or moderate collagen fibrosis (MF2) and advanced collagen fibrosis with osteosclerosis (MF3). Myelofibrosis is not a feature of ET at diagnosis and during long-term follow-up. Myelofibrosis may be present in a minority of PV-patients at diagnosis and usually becomes apparent during long-term follow-up in the majority of PV-patients. Myelofibrosis secondary to the abnormal megakaryocytic and granulocytic myeloproliferation constitutes a prominent feature in the majority of EMGM/IMF at time of diagnosis and usually progresses more or less rapidly during the natural history of the disease. Life expectancy is normal in ET, normal during the 1st ten years and compromised during the 2nd ten years follow-up in PV, but significantly shortened in the prefibrotic stage of EMGM as well as in the various myelosclerotic stages of classical IMF. First line treatment options in prospective randomized clinical trials of newly diagnosed MPD-patients are control of platelet function with low-dose aspirin versus reduction of platelet count with anagrelide, interferon or hydroxyurea in ET; control of platelet and erythrocyte counts by interferon alone versus bloodletting plus hydroxyurea on indication in PV; interferon versus no treatment in the early stages of EMGM; a wait and see strategy in the fibrotic stages of EMGM or classical IMF with favorable prognostic factors, and bone marrow transplantation in classical IMF with poor prognostic factors at presentation or during short-term follow-up.

Dyshematopoiesis in de novo acute myeloid leukemia: cell biological features and prognostic significance

Dyshematopoiesis was found in 44 (42.3%) of 104 cases of de novo acute myeloid leukemia (AML). Dyshematopoietic AML (dys-AML) and AML without hematopoietic dysplasia (non-dys-AML) were compared with regard to biological, hematological, immunophenotypic, and cytogenetic parameters as well as prognostic criteria. Median age of patients was 55 years in both groups. In dys-AML, the median leukocyte count (p = 0.04), peripheral blast (p = 0.02) and medullary blast cell count (p < 0.001) were significantly decreased, whereas the median platelet count (p - 0.04) was increased. Immunophenotyping demonstrated that leukemic blast cells in dys-AML more frequently expressed the adhesion molcules CD54 (p = 0.05) and CD58 (p = 0.08) than leukemic cells in non-dys-AML. Cytogenetically, we distinguished two karyotypic patterns, one group with a normal karyotype or prognostically favorable single chromosome aberrations ("P(0)-karyotype"), and another one with unfavorable single aberrations or complex aberrations ("P(1)-karyotype"). The incidence of these groups was not significantly different between dys-AML and non-dys-AML. Complete remission rate (CRR) after induction chemotherapy (p = 0.03) and overall survival time (OS; p = 0.03) were significantly lower in dys-AML. In addition, median disease free survival (DFS; p = n.s.) was inferior compared to non-dys-AML. In the dys-AML as well as in the non-dys-AML patient group, CRR, DFS, and OS were decreased in the P(1)-compared to the P(0)-subgroup. We conclude that dyshematopoietic AML is characterized by specific cell biological features and that hematopoietic and cytogenetic status represent complementary prognostic factors in de novo AML.

Plasma levels of D-dimer and circulating endothelial adhesion molecules in veno-occlusive disease of the liver following allogeneic bone marrow transplantation

Veno-occlusive disease (VOD) of the liver is a frequent and life-threatening complication of BMT. Recently, successful treatment by t-PA has been reported but has been compromised by fatal bleeding events. Therefore, t-PA application should be restricted to patients with severe VOD. However, moderate and severe forms of VOD are difficult to distinguish in early stages. We analyzed plasma levels of cross-linked fibrin degradation products (D-dimer) and soluble endothelial adhesion molecules such as sE-selectin, sVCAM-1 and sICAM-1 in 10 consecutive patients undergoing allogeneic BMT to evaluate their use in identifying severe forms of VOD. During the observation period, 4 episodes of VOD occurred, 2 of which were fatal due to early onset of multiorgan failure. Concentrations of D-dimer generally increased after transplantation. However, there was an additional significant increase in D-dimer levels during severe VOD. Thus, D-dimer levels above 1000 microg/l were only found in 2 cases with severe VOD and fatal outcome. When compared with bilirubin concentrations substantial increases of D-dimers appeared earlier during the course of severe VOD. In contrast, VOD episodes were not accompanied by significant increases in sE-selectin, sVCAM-1 and sICAM-1 levels. It is concluded that measurement of D-dimer concentrations may aid accuracy to the early diagnosis of severe VOD.

Idarubicin, melphalan and cyclophosphamide: an intensified high-dose regimen for the treatment of myeloma patients

Following conventional chemotherapy, eight myeloma patients presenting with advanced tumor stages were treated with an intensified high-dose regimen and autologous peripheral blood stem cell transplantation. High-dose chemotherapy consisted of idarubicin 20 mg/m2 on days -13, -12 and -11, melphalan 100 mg/m2 on days -5 and -4 and cyclophosphamide 60 mg/kg (plus mesna 60 mg/kg) on days -3 and -2 (IMC). Seven patients achieved a complete remission or a very good partial remission (reduction of M-component > or =90%). There were no toxic deaths. Severe mucositis and fever of unknown origin were seen in all patients. Reversible supraventricular tachycardias without clinical signs of cardiac failure occurred in five patients. One patient developed a persistent deterioration of cardiac function. We surmise that high-dose chemotherapy with IMC is very effective and well tolerated in myeloma patients.

Pseudomonas aeruginosa blepharoconjunctivitis during cytoreductive chemotherapy in a woman with acute lymphocytic leukemia

Patients undergoing chemotherapy regimens for hematologic malignancies are prone to develop unusual and potentially life-threatening infections during periods of leukopenia- induced immunosuppression. We report the case of a woman who received consolidation chemotherapy for acute lymphocytic leukemia and acquired necrotizing Pseudomonas aeruginosa blepharoconjunctivitis of the right eye during a period of mild leukopenia. The infection led to severe orbital and periorbital inflammation, spreading down to the neck. High-dose antibiotic treatment with ceftazidime and tobramycin combined with granulocyte cell-stimulating factor cleared the infection after several days, but plastic surgery was needed to restore normal eye closure.

Lymphoid myelofibrosis associated with high grade B cell lymphoma of the liver: morphological, cytogenetic, and clinical features

Severe pancytopenia associated with moderate hepatosplenomegaly, increased serum lactic dehydrogenase (LDH) levels, and hypogammaglobulinemia were found in a young male patient. Bone marrow histology showed extensive fibrosis, hypoplasia of erythro- and granulocytopoiesis, and hyperplasia of megakaryocytopoiesis associated with histiocytic fat cell phagocytosis and infiltration of abnormal lymphocytes, compatible with lymphoid myelofibrosis. Striking chromosomal aberrations indicating karyotype evolution were also demonstrated by cytogenetic analyses (47, XY, +3 / 47, XY, +3, 1p+ / 46, XO, +3, 1p+, -Y). The clinical course was characterized by cyclic febrile episodes accompanied by excessive increase of serum LDH levels and leukocyte counts, and decrease of platelet counts, followed by spontaneous regression. Further diagnostic procedures, including two liver biopsies and computed tomography, did not detect any manifestation of lymphoma. Eventually, the patient developed rapidly progressive, lethal pulmonary aspergillosis. At autopsy, high grade B cell lymphoma of the liver was found. In this case, the lymphoid myelofibrosis seen on bone marrow biopsy may be considered as a manifestation of "discordant" bone marrow histology related to high grade lymphoma. With respect to the cyclic clinical course, a possible role of apoptotic mechanisms in the physiopathology of this disorder is reviewed.

Increases of sICAM-1 during neutropenic pneumonia in leukemic patients

Aggressive chemotherapy of leukemia increases the risk of severe infections during treatment-induced myelosuppression. However, the assessment of an infectious origin of neutropenic fever is often difficult. Leukocyte adhesion molecules such as E-selectin, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) are involved in early inflammatory response. We studied plasma concentrations of their soluble isoforms during 48 treatment courses with myeloablative chemotherapy in 32 leukemic patients. There were 35 febrile episodes during neutropenia. Pneumonia was clinically and microbiologically documented in 15 cases, six had proven infections but normal chest radiograph, and 14 were classified as fever of unknown origin. Longitudinal studies revealed a sustained increase of sICAM-1 plasma levels associated with pneumonia. Increase of sICAM-1 plasma levels distinguished patients with pneumonia from those with fever not related to pneumonia (positive predictive value 0.87, negative predictive value 0.94). Plasma levels of sICAM-1 were elevated in both, fungal and non-fungal pneumonia. Increases of sICAM-1 paralleled first radiographic evidence of pulmonary infiltrations in most cases. In contrast, no elevation of sVCAM-1 or sE-selectin was documented during febrile events prior to recovery of leukocyte counts.

Relation of platelet abnormalities to thrombosis and hemorrhage in chronic myeloproliferative disorders

The chronic myeloproliferative disorders (MPD), predominantly polycythemia vera and essential thrombocythemia, are characterized by a high incidence of thromboembolic and, to a lesser degree, hemorrhagic complications. The disease process in chronic MPD affects a pluripotent progenitor cell and results in trilineage hematopoietic proliferation. Clonal involvement of megakaryocytopoiesis is regarded as the main origin of thromboembolism in MPD and results in abnormal platelet production. These platelets show increased size heterogeneity and ultrastructural abnormalities, and their function in vitro is in many ways impaired with a high degree of individual variability. Elevated levels of platelet-specific proteins, increased thromboxane generation, and expression of activation-dependent epitopes on the platelet surface are common on chronic MPD, and may reflect an inappropriate state of platelet activation. Although a variety of platelet receptor deficiencies and some defects of intracellular signaling pathways have been identified, the different platelet defects in MPD could not be traced back to an underlying general pathogenetic mechanism. On progression of chronic MPD to more advanced stages of the disease, the number of platelet abnormalities tend to increase. Cytoreductive drugs may partly improve platelet dysfunction, and platelet inhibitory agents reduce symptoms of platelet activation. However, neither of these therapeutic principles is able to normalize platelet function in MPD. As an alternative to conventional treatment, specific suppression of clonal megakaryocyte growth and recovery of polyclonal hematopoiesis may be achieved by biologic agents such as interferon alpha. Such treatment strategies may prevent thromboembolic complications together with hematologic symptoms and progression of the disease and should be further evaluated in prospective studies.

Thrombophihe bei myeloproliferativen Syndromen

Erworbene hämatopoetische Stammzelldefekte sind ein eindrucksvolles Beispiel für Vielfalt und Komplexität des Zustandekommens von Hämo-stasestörungen. Blutungsneigungen erklären sich durch kompliziertes Zusammenspiel von zellulären, thrombozytopenischen Zuständen mit proteolytischen Vorgängen der Hyperkoagula-bilität und Hyperfibrinolyse. Throm-boembolischen Komplikationen aber scheinen noch komplexere Mechanismen zugrunde zu liegen. Neben gesteigerter Megakaryozytenproliferation bei reaktiver Thrombozytose und entarteter Megakaryozytenproliferation bei MPD scheinen auch die anderen Blutzellen erhebliche Einflüsse auf Schweregrad und Lokalisation einer entstehenden Thrombose ausüben zu können. Das sind die Erythrozyten durch den Hämatokritwert, möglicherweise auch durch die größeren Retikulozyten, wie die Komplikationen bei Aderlaßbehandlung der PCV andeuten, und eventuell noch durch Plättchenaktivierung bei Hämolyse. Das sind aber auch die leukämischen Promyelozyten durch größenbedingte Leukostasephänomene bei ATRA-Behandlung der PML. Und da ist schließlich auch das Monozyten-Makrophagen-System, dessen Aktivierung einerseits die intestinale Lokalisation der Thrombosen bei PNH erklären könnte. Andererseits aber macht es durch Expression von Adhäsionsmolekülen und deren besonderer Rea-gibilität mit Endothel der zerebralen Strombahn die bevorzugte zentralnervöse Lokalisation der Thromboseneigung bei PNH verständlich.

Coagulation factor V gene mutation associated with activated protein C resistance leading to recurrent thrombosis, leg ulcers, and lymphedema: successful treatment with intermittent compression

Activated protein C resistance is the most frequent cause of venous thrombosis. We describe a patient with extensive ulcerations and severe lymphedema of the legs after recurrent thrombosis. Laboratory tests revealed a pathologic activated protein C resistance and a reduced functional protein S. The underlying genetic defect was identified as a heterozygous coagulation factor V mutation. A combined therapeutic approach of intermittent compression, repeated debridements and systemic antibiotics resulted in marked improvement of both lymphedema and leg ulcers.

Levels of circulating endothelial adhesion molecules (sE-selectin and sVCAM-1) in adult patients with acute leukemia

The spread of leukemia extends from mobilization of leukemic blast cells from the bone marrow to extramedullary tissue infiltration. Migration of leukemic blasts resembles that of neutrophils and may be regulated by activated endothelial cells via endothelial adhesion molecules such as E-selectin, VCAM-1 and ICAM-1. Plasma levels of soluble adhesion molecules may therefore indicate interaction between leukemic blasts and endothelium, and may be related to leukemic cell mass or subtype of leukemia. In this study, plasma levels of soluble E-selectin, VCAM-1 and ICAM-1 were analyzed in 40 untreated patients with acute leukemia (35 ANLL, five ALL). Plasma concentrations of all three receptors were significantly elevated when compared to healthy controls (P = 0.006, P = 0.0001, and P = 0.0001, respectively) but demonstrated high interindividual variations among leukemic patients. sE-selectin but not sVCAM-1 and sICAM-1 levels correlated with peripheral leukocyte and blast cell counts. Increased levels of either sE-selctin or sVCAM-1 were present in 32 out 40 leukemic patients (80%). FAB subgroups differed in levels of sVCAM-1. The highest levels were measured in acute myelomonocytic and lymphoblastic leukemia, ie in leukemia subtypes with a high incidence of extramedullary blast cell infiltration.

Verträglichkeit und Wirksamkeit einer 5%igen versus einer 10%igen i.v.-lmmunglobulinpräparation bei erwachsenen Patienten mit Immunthrombozytopenie – eine Pilotstudie

Stark erniedrigte Thrombozytenzahlen führen bei autoimmunthrombozy-topenischer Purpura zu einer latenten Blutungsbereitschaft, die bei etwa 2-10% aller erwachsenen Patienten zu schweren intrazerebralen Blutungen führen kann. Durch Gabe von polyvalenten Immunglobulinpräparaten in einer Dosis von 1 g/kg Körpergewicht an 2 aufeinanderfolgenden Tagen kommt es zu einem raschen, jedoch leider nur vorübergehenden Anstieg der Thrombozytenzahlen. Verminderte Volumenbelastung und kürzere Infusionszeiten könnten gerade für ältere Patienten eine Verbesserung dieser Therapieform darstellen. In einer Pilotstudie an 12 Patienten mit Autoimmunthrombozytopenie verglichen wir Effektivität und Verträglichkeit einer neuen 10%igen Immunglobulinpräparation mit dem konventionellen 5 %igen Präparat (Bayer AG, Biologische Präparate, Leverkusen, Deutschland). Patienten mit neu diagnostizierter oder rezidivierter Immunthrombozytopenie wurden zwischen den beiden Präparaten randomisiert, wenn die Thrombozytenzahl unter 20 × 10⁹/1 lag oder eine klinisch manifeste Blutungsneigung bestand. Zwölf Patienten (2 männliche, 10 weibliche) zwischen 25 und 86 Jahren wurden entweder mit dem 5 %igen oder dem 10 %igen IgG-Präparat behandelt. Acht Patienten wiesen Rezidive der Immunthrombozytopenie auf, und 6 Patienten waren mit Kortikosteroiden vorbehandelt. Evaluation von Blutungszeichen und Blutbildkontrollen wurden am 1.-7. sowie am 14. Tag durchgeführt. Während der Infusion erfolgten alle 10 min Messungen der Körpertemperatur und Erfassung potentieller Nebenwirkungen. Bei alien Patienten lag die Thrombozytenzahl 48 h nach Infusionsbeginn über 50 × 10⁹/l, und die Blutungsneigung sistierte. Die beiden Präparate unterschieden sich weder in der Wirkung noch in den potentiellen Nebenwirkungen voneinander. In jeder Behandlungsgruppe trat jeweils am zweiten Behandlungstag eine minderschwere Nebenwirkung auf (Kopfschmerz bzw. Übelkeit). Die Infusionszeit ließ sich durch Verwendung der 10%igen Präparation um durchschnittlich 17% verkürzen, und das Infusionsvolumen wurde halbiert. Aufgrund der Ergebnisse dieser Pilotstudie schließen wir, daß sowohl die 5 %ige als auch die 10%ige Immunglobulinpräparation in der Behandlung der Immunthrombozytopenie im Erwachsenenalter wirksam ist und daß beide Präparate gleich gut vertragen werden.

Neutrophilic dermal infiltrates in granulocytopenic patients with acute leukemia

Acute febrile neutrophilic dermatosis (AFND, Sweet's syndrome) is clinically characterized by fever, neutrophilic leukocytosis, and tender dermal plaques. Histological examination typically reveals infiltration of the dermis by neutrophils. In three patients (2 female, 1 male, 54-59 years) with acute leukemia (2 myelogenous, 1 lymphoblastic) dermal plaques developed during febrile episodes in chemotherapy-induced pancytopenia. The clinical appearance was compatible with AFND. The diagnosis was substantiated by skin biopsies which showed dense neutrophilic dermal infiltrates without leukemic cells. Leukocytoclastic vasculitis was considered as differential diagnosis. Plasma levels of soluble adhesion molecules ICAM-1, VCAM-1, and E-selectin regulating leukocyte transendothelial migration were in the normal range. Systemic glucocorticoids were avoided because of the high risk of infection during prolonged bone marrow aplasia. The lesions were treated with topical steroids and resolved without scarring within 1-5 weeks. AFND has been reported in association with acute leukemia at normal or elevated white blood cell counts. Although implausible from a pathophysiological point of view, similar neutrophilic dermal infiltrates were found in three patients during chemotherapy-induced pancytopenia with white blood cell counts distinctly below 1 x 10(9)/l.

Infusion-related toxicity of three different amphotericin B formulations and its relation to cytokine plasma levels

A prospective study was performed to compare the infusion-associated toxicity of three different amphotericin B preparations and to correlate acute side-effects with plasma levels of tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-1 receptor antagonist (IL-1-RA) during and after the infusions. Six adult neutropenic patients with acute leukaemia suffering from suspected or documented systemic fungal infections were treated on three consecutive days with conventional amphotericin B (AmB), liposomal AmB (AmBisome) and AmB mixed in lipid emulsion (AmB/lipid). Drugs were given over 1-2 h. Drug-induced toxicity was monitored every 30 min for 4 h. Plasma levels of the three cytokines were determined using commercially available enzyme-linked immunosorbent assay (ELISA) techniques. Four of six patients showed toxicity after AmB and AmB/lipid infusions; only one patient reacted to liposomal AmB. Clinical toxicity was associated with increases in TNF-alpha plasma levels during two of four infusions of AmB and three of four infusions of AmB/lipid. Major increases in IL-6 occurred during three of four infusions of AmB and during all four AmB/lipid infusions associated with clinical toxicity. Three of four AmB infusions and all four AmB/lipid infusions accompanied by clinical toxicity were associated with major increases in IL-1-RA plasma concentrations. Liposomal AmB was better tolerated than AmB and AmB/lipid. This formulation also caused the lowest liberation of all three cytokines tested. The severity of clinical symptoms did not correlate closely with absolute cytokine plasma levels. The findings provide further evidence that expression of TNF-alpha, IL-6 and IL-1-RA plays an important role in mediating AmB-related acute toxicity in vivo.

Pulmonary toxicity during infusion of liposomal amphotericin B in two patients with acute leukemia

Pulmonary toxicity with acute dyspnea occurred during infusion of a liposomal amphotericin B preparation (AmBisome) in two adult leukemic patients. The preparation was administered as a one hour infusion at a dose of 3 mg/kg body weight. Within 15 min after starting the infusion, both patients experienced sudden onset of dyspnea and chest tightness. Physical examination showed the patients to be anxious and restless with tachycardia and orthopnea but without other cardiopulmonary findings. No elevation of body temperature, rigors or chills were recorded. Symptoms disappeared within minutes after discontinuing the infusion. At present, the pathophysiologic mechanisms underlying these side effects are unknown.

[Immunoglobulin substitution in malignant lymphoma]

Substitution with intravenously administered immunoglobulin seems to be indicated in lymphoma patients with acquired immunoglobulin deficiency, i.e., primarily patients with chronic lymphocytic leukemia and multiple myeloma. Infectious complications, mainly of the upper airways, are a major cause of morbidity and mortality in these patients. The immunoglobulin levels are correlated with stage of the disease, frequency of infections, and patient survival. Besides immunoglobulin deficiency, there are less well characterized defects of cellular immunity. Three prospective studies evaluating the effectiveness of immunoglobulin substitution in patients with chronic lymphocytic leukemia and myeloma have been published. A dose of 400 mg/kg or 10 g of immunoglobulin was administered intravenously every 3 or 4 weeks. A reduction of bacterial infections, but not of deaths due to infectious complications, was observed. The treatment was usually well tolerated with few side effects. However, to date it has not been established which patient subgroups really benefit from immunoglobulin therapy in terms of improvement of quality of life. Thus a general recommendation of immunoglobulin therapy in chronic lymphocytic leukemia and multiple myeloma can at present not be made.

Immunglobulinsubstitution bei malignen Lymphomen

Die Substitution mit intravenös verabreichtem Immunglobulin erscheint bei malignen Lymphomen vorwiegend dann sinnvoll, wenn, wie häufig bei chronisch-lymphatischer Leukämie und multiplem Myelom, eine Störung der endogenen Immunglobulinproduktion vorliegt. Infektionen, vor allem der oberen Luftwege, stellen bei diesen Krankheiten eine der häufigsten Ursachen von Morbidität und Mortalität dar. Die endogenen Immunglobulinkonzentrationen korrelieren dabei mit Stadium, Infekthäufigkeit und auch dem Überleben der Patienten. Daneben bestehen weitere Störungen der zellulären Immunität, die jedoch teilweise unzureichend charakterisiert sind. Bisher liegen drei prospektive Studien vor, die übereinstimmend eine Abnahme der bakteriellen Infektionen, allerdings nicht der Letalität, unter Immunglobulinsubstitution beschreiben. Es wurden jeweils 400 mg/kg bzw. 10 g i.v. Immunglobulin alle 3 oder 4 Wochen appliziert. Die Behandlung war allgemein nebenwirkungsarm und gut verträglich. Trotzdem kann zurzeit noch keine generelle Therapieempfehlung gegeben werden, da bisher noch unklar ist, welche Patienten hinsichtlich der Verbesserung ihrer Lebensqualität von dieser aufwendigen Behandlungsform profitieren.

Incidence and clinical risk factors for bleeding and thrombotic complications in myeloproliferative disorders. A retrospective analysis of 260 patients

Bleeding and thrombosis are frequent complications in myeloproliferative disorders (MPD) and are associated with severe organ damage and a high mortality. Elevated platelet count, elevated hematocrit, and patient age are regarded as risk factors for bleeding and thromboembolic events in MPD, although the significance of these parameters was not confirmed by clinical studies. We retrospectively analyzed vascular complications in 260 patients with MPD and tried to identify parameters predictive for bleeding and thrombembolic events. Our cohort consisted of 115 patients with chronic myeloid leukemia (CML), 84 patients with polycythemia vera (PV), 26 with essential thrombocythemia (ET), 25 with osteomyelofibrosis (OMF), and 10 patients with unclassifiable MPD. During a median follow-up period of 31 months, 126 patients with chronic MPD suffered bleeding or thrombotic events. Bleeding was observed in 57% of patients with OMF, 23% with PV, 20% with chronic phase CML, and 16% with ET. Thrombotic events were most common in patients with PV (36% of patients), followed by ET, OMF, and chronic phase CML (20%, 17%, and 6% of patients, respectively). Recurrent thrombotic episodes frequently occurred in patients with PV and ET, whereas patients with OMF often had more than one bleeding event. Thirty patients died of thrombohemorrhagic complications during follow-up. Multivariate analysis, including all patients with chronic MPD, revealed that elevated red blood cell count, higher hemoglobin level, and increased percentage of segmented neutrophils at the time of diagnosis were associated with thrombosis, whereas patients with bleeding complications were characterized by low red cell count, lower hemoglobin, and a lower percentage of segmented neutrophils. However, when analyzed by MPD subgroup, none of these parameters retained a predictive value for bleeding or thrombotic events. Moreover, elevated platelet count and patient age were not risk factors for bleeding complications. Thrombotic events were less frequent in patients below the age of 40, and were increased in patients aged 70 and above. However, this was primarily due to the high percentage of elderly patients in subgroups mainly affected by thrombosis (PV and ET). In most MPD subgroups, the rate of bleeding and thrombosis was highest just before and during the first months after diagnosis, and declined thereafter. Thrombohemorrhagic complications were less frequent after phlebotomy in PV and after therapy with alkylating agents in CML. The institution of cytoreductive therapy soon after the diagnosis was made may explain the reduced incidence of complications later in the disease. We conclude that morbidity and mortality from thrombohemorrhagic complications are high in myeloproliferative disorders.(ABSTRACT TRUNCATED AT 400 WORDS)

Circulating activated platelets in myeloproliferative disorders

Platelet activation in patients with myeloproliferative disorders is often suggested by increased platelet alpha-granule secretion and an acquired storage pool defect of dense granules. To determine whether activated platelets circulate in patients with chronic myeloproliferative disorders, we evaluated the binding of monoclonal antibodies against activation-dependent epitopes on resting platelets (P 12, CD 63, and CD 62) in 12 patients with prominent megakaryocytic proliferation (8 patients with essential thrombocythemia, 2 with chronic myeloid leukemia, and 2 patients with polycythemia rubra vera). In addition, platelet aggregation in response to collagen, adenosine diphosphate, platelet activating factor, and agglutination with ristocetin was investigated. In 3 patients there was an increased percentage of platelets binding at least 1 activation marker. In 2 other patients, a trend towards increased antibody binding was observed. Binding of the antibody to thrombospondin (P 12) was related to expression of the GMP 140 protein (CD 62, r = 0.76, p = 0.004). There was no correlation of platelet aggregation defects in vitro to increased expression of platelet activation markers or to thrombohaemorrhagic complications. However, circulating activated platelets were detected in three out of five patients with a history of bleeding or thrombotic complications. The results of this preliminary study suggest that some but not all patients with myeloproliferative disorders showed increased amounts of circulating activated platelets. The relation of bleeding and thrombotic complications to the expression of activation-dependent epitopes on platelets in myeloproliferative disorders requires further investigation.

A prospective study of haemostatic parameters in relation to the clinical course of myeloproliferative disorders

Platelet function and the clinical course of the disease were prospectively investigated in 29 patients with myeloproliferative disorders. Serial determinations (median: 5 investigations per patient within 17 months) of platelet aggregation, plasma and intraplatelet concentrations of beta-thromboglobulin (beta TG) and platelet factor 4 (PF4), and of fibrinopeptide A (FPA) plasma levels were carried out. In the chronic phase of polycythaemia vera, patients with thrombohaemorrhagic complications during the study period had higher platelet count, more severe platelet aggregation defects, and increased plasma levels of beta TG and FPA compared to patients without complications. However, thrombohaemorrhagic complications were not predicted by changes in these parameters in the individual patient during the chronic disease phase. When patients with chronic myelogenous leukaemia entered blast crisis, bleeding complications were related to thrombocytopenia, impaired platelet function and low intraplatelet concentrations of beta TG and PF4. Cytoreduction by chemotherapy in the chronic phase of CML did not alter beta TG and PF4 plasma levels, whereas treatment of polycythaemia rubra vera by venesection favourably influenced platelet alpha-granule secretion and increased intraplatelet concentrations of beta TG and PF4.

Influence of splenectomy on platelet morphometry and function

Functional and morphometric platelet abnormalities may be influenced by splenectomy and thus contribute to postoperative thrombohaemorrhagic complications, especially in patients with splenomegaly and/or platelet defects. We investigated platelet function, platelet secretion, and platelet morphometry before and one week after splenectomy in seven patients with normal platelet production and normal spleen size (Hodgkin's disease) and five patients with splenomegaly and platelet abnormalities (4 with myeloproliferative disorders and 1 with chronic myelomonocytic leukemia). Severe postoperative thrombohaemorrhagic complications occurred only in patients with myeloproliferative disorders, although platelet count and mean platelet volume increased in almost all patients after splenectomy. Four patients with myeloproliferative disorders had impaired platelet aggregation before splenectomy that improved in only one patient after surgery. Platelet buoyant density in this patient group was decreased before splenectomy and normalised thereafter. Concomitantly, intraplatelet concentrations of alpha-granular proteins increased. Before splenectomy, there was a positive correlation between platelet density and platelet volume in patients with Hodgkin's disease (r = 0.59, p less than 0.001), but not in patients with myeloproliferative disorders. There was no correlation between platelet density and platelet volume after splenectomy in either patient group. In conclusion, morphometric platelet abnormalities were found in all patients after splenectomy. In patients with myeloproliferative/myelodysplastic disorders, decreased platelet buoyant density normalised and intraplatelet concentrations of alpha-granule proteins were elevated after splenectomy. However, platelet function defects in this patient group were not corrected and may have been a major cause of thrombohaemorrhagic complications in the postoperative period.

Platelet volume parameters as a diagnostic tool: the influence of anticoagulation and storage conditions on platelet impedance volume

Rapid progress has been made in the design of aperture impedance cell counters, and parameters such as mean platelet volume and platelet distribution width have become routinely available to most physicians. Platelet volume is influenced by both platelet production in the bone marrow and platelet activation or sequestration in the circulation. In thrombocytopenic patients, it is often possible to differentiate between megakaryocytic and amegakaryocytic disease states on the basis of platelet volume analysis. In patients with thrombocytosis, a myeloproliferative disorder may be suspected if the platelet distribution width is high. However, the conditions of sample preparation and storage still give rise to considerable inaccuracy in the determination of platelet volume parameters. In this study, platelet impedance volume was strongly influenced by anticoagulation, storage time, and incubation temperature. Changes in platelet volume were more pronounced in whole blood than in platelet rich plasma. However, mainly large platelets were lost during the preparation of platelet rich plasma. Collecting blood directly into a mixture of citrate and low dose glutaraldehyde stabilized platelet volume for up to 2 h after venipuncture at room temperature. This method reduces platelet volume changes in vitro and is in this respect superior to the usual EDTA blood count or the use of platelet-inhibitory agents.

[Fever of unknown origin and colchicine-sensitive amyloidosis: familial Mediterranean fever?]

A 39-year-old man who had for 20 years suffered from recurrent fever, abdominal pain and joint pains was diagnosed to have generalized amyloidosis type AA. Suspected of having familial mediterranean fever (FMF) he was treated with colchicine, 2 mg daily. Within four years the fever bouts became milder and the amyloidosis no longer progressed. Since the patient was a foundling it was impossible to prove FMF, despite the typical signs and the successful treatment.

Bleeding and thrombosis in chronic myeloproliferative disorders: relation of platelet disorders to clinical aspects of the disease

Bleeding and thrombosis are a major cause of morbidity and mortality in myeloproliferative disorders (MPD). This study evaluates the relation between thrombohemorrhagic complications and platelet abnormalities in different subgroups of MPD. In 57 MPD patients thrombohemorrhagic complications occurred in 71% of patients with polycythemia rubra vera and 50% of patients with osteomyelofibrosis and primary thrombocythemia but in only 29% of patients with chronic myelogenous leukemia. Increased beta-thromboglobulin and platelet factor 4 plasma levels, platelet aggregation defects, and increased dispersion of the platelet volume distribution curve were most frequent in those subgroups where most serious thrombohemorrhagic complications were observed, and multiple platelet-related abnormalities were often found simultaneously. Fibrinopeptide A plasma levels were rarely elevated, however. Our results indicate that platelet abnormalities associated with bleeding and thrombosis are primarily determined by the clinical subgroup of myeloproliferative disease.

Polychemotherapy of acute myelogenous leukemia in a patient with acute intermittent porphyria

The safety of drugs in hepatic porphyrias has largely been established by clinical experience, which is very limited in the case of antineoplastic agents. We administered three cycles of polychemotherapy consisting of daunorubicin, cytarabine and 6-thioguanine, and modified supportive care to a 33-year-old Turkish woman suffering from acute myelogenous leukemia. The urinary excretion of total porphyrins, porphobilinogen, and aminolevulinic acid was continuously monitored. Excretion of these metabolites was permanently elevated, but the values were comparatively low during cytotoxic therapy while peak values were recorded at the onset of fever during bone marrow aplasia; yet there were no clinical signs of porphyritic attacks at that time. A few potentially unsafe drugs were tolerated without an increase in porphyrin excretion. Although the susceptibility to drugs is highly variable in patients with hepatic porphyrias, the treatment of malignancy in these patients seems justified as long as porphyrin excretion under therapy is not grossly elevated over baseline values and appropriately modified supportive care is administered.

Inhibition of platelet thrombus formation by chlorpromazine acting to diminish haemolysis

There is increasing evidence that the sudden, unpredicatable event initiating myocardial infarction is fissuring of an atherosclerotic plaque. The resulting haemorrhage into the arterial wall produces obstructive platelet thrombi, just as arterial haemorrhages elsewhere produce haemostatic platelet plugs. It has been suggested that such platelet aggregation depends on ADP originating in red cells which are subjected to excessive haemodynamic stress at the site of haemorrhage. The release of ADP from red cells has been demonstrated in vitro in equivalent condtions of shear stress; and other mechansims, such as activation by collagen, cannot account for the rapidity with which the platelets react. One of us (G.V.R.B.) has suggested that drugs capable of counteracting haemolysis might diminish the activating effect of erythrocytes on platelets and so inhibit their aggregation as thrombi. Thus, chlorpromazine, added to human blood at concentrations which diminish haemoylsis but do not directly affect platelet aggregation, prolonged the 'bleeding time' from small holes in artificial vessels where extravasation is terminated, as in living arterioles, by aggregated platelets. The bleeding time was also prolonged by apyrase, consistent with the conclusion that the chlorpromazine acted through decreasing plasma ADP. We show here that this occurs through the anti-haemolytic action of chlorpromazine.