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Histo- and immunomorphometry of megakaryopoiesis in chronic myeloid leukemia with myelofibrosis and so-called primary (idiopathic) osteo-myelofibrosis/-sclerosis.

A morphometric study was performed on trephine biopsies of bone marrow in patients with chronic myeloid leukemia (CML) accompanied by myelofibrosis and in so-called primary (idiopathic) osteomyelofibrosis/-sclerosis (OMF) to evaluate distinctive features of megakaryopoiesis. The periodic acid Schiff reaction (PAS) and a monoclonal antibody against glycoprotein IIIa were employed for the identification of megakaryocytes including precursor cells and Gomori's silver impregnation to determine the density of argyrophilic fibers. All patients with CML revealed a slight to moderate degree of medullary fibrosis and were compared with early hyperplastic stages of OMF showing an identical fiber count. Statistical analysis disclosed that distinctive features existed between these two subgroups. Amongst these variables were sizes of megakaryocytes and corresponding nuclei, frequency of bare nuclei, emperipolesis and numbers of isolated nuclear fragments as well as the circular deviation of cell and nuclear perimeters. Immunomorphometry also included immature elements (pro- and megakaryoblasts) of the megakaryocyte series. Consequently higher cell counts were calculable in both groups combined with smaller sizes and a more rounded aspect of nuclei. However, following immunostaining, significant differences in several megakaryocytic parameters (frequency, size, shape of nuclei) were still demonstrable between CML and OMF cases.

Adult↗

Clinical and cytogenetic characteristics of myelodysplastic syndromes developing myelofibrosis.

Myelofibrosis occurs in various hematologic neoplasias, including myelodysplastic syndrome (MDS), with a relatively low incidence. To gain insight into the clinical and cytogenetic implications of MDS patients in whom myelofibrosis develops, statistical analysis was done on 82 primary MDS patients with successful cytogenetic results. Seven patients had myelofibrosis during the course of the disease (8.5%, Group I), 34 had abnormal karyotypes without myelofibrosis (41.5%, Group II), and the other 41 had abnormal karyotypes without myelofibrosis (50%, Group III). All of the MDS patients except one with myelofibrosis had cytogenetic abnormalities, and four of them had multiple chromosome abnormalities. In univariant analysis, MDS patients with myelofibrosis showed no significant differences in age, sex, or peripheral blood data. In contrast, patients with chromosome abnormalities evolved into myelofibrosis with a high incidence compared with those with normal karyotypes (14.6% versus 2.4%, P = 0.054). The occurrence of myelofibrosis was higher during the first 6 months after the diagnosis of MDS than in the next 6 months (6.1% versus 0%, P = 0.045). Most of the MDS patients survived for less than 10 months after myelofibrosis was evident. Furthermore, survival was significantly shorter in Group I compared with Groups II (P less than 0.05) and III (P less than 0.01). Among the MDS patients in whom myelofibrosis developed, some were associated with acute megakaryoblastic leukemia, indicating a heterogeneity of clinical features in MDS with myelofibrosis.

Adult↗

A review of myelofibrosis in dogs.

Myelofibrosis is a proliferative response of the bone marrow fibroblasts. Myelofibrosis can be classified as primary or secondary depending on the underlying etiology. Primary myelofibrosis is a myeloproliferative disorder in humans in which there is a clonal proliferation of a pluripotent stem cell. Hemopathology includes finding nucleated red blood cells and immature granulocytes in the circulation, extramedullary hematopoiesis, and myelofibrosis. The proliferation of the bone marrow fibroblasts is not clonal in origin. To the best of this author's knowledge, this type of myelofibrosis has not been reported to occur naturally in the dog. Secondary myelofibrosis has been reported in the dog associated with neoplastic conditions, irradiation, congenital hemolytic anemias, and a variety of unknown etiologies. It has been shown in some cases of myelofibrosis that there is often concurrent bone marrow necrosis. Bone marrow necrosis has been documented in dogs with Ehrlichiosis and septicemia, and associated with drug treatment, including estrogens and cephalosporins. It is though that this necrosis is due to the destruction of the bone marrow microvasculature and/or hematopoietic elements. Release of growth factors by inflammatory cells may lead to the subsequent fibroblast proliferation. Several cases of secondary myelofibrosis in female laboratory beagles have been recently observed. These dogs present with a severe nonregenerative anemia and often a mild neutropenia with varying degrees of myelofibrosis in the bone marrow. Some animals have had concurrent bone marrow necrosis. At this time, the exact etiology is unknown.

Animals↗

Peripheral monocytes and CD4+ cells are potential sources for increased circulating levels of TGF-beta and substance P in autoimmune myelofibrosis.

Myelofibrosis is an uncommon phenomenon associated with a variety of neoplastic and inflammatory processes. Although there is evidence that cytokines elaborated by clonal malignant hematopoietic cells are implicated in myelofibrosis in primary hematologic disorders, there has been little data to date on the pathophysiology of myelofibrosis in autoimmune disorders. Here we report a case of autoimmune myelofibrosis with pancytopenia. Peripheral blood monocytes and CD4-positive lymphocytes produced significantly elevated levels of transforming growth factor beta (TGF-beta) compared to similar cells from healthy volunteer controls. TGF-beta has been implicated in the pathogenesis of myelofibrosis associated with primary hematological malignancies. Furthermore, substance P, previously linked to myelofibrosis, was also detected in elevated levels in the patient's serum and correlated negatively with the levels of the patient's blood counts. These findings suggest a role for both TGF-beta and substance P in the pathophysiology of autoimmune myelofibrosis. This is the first report of deregulated production of TGF-beta by monocytes in the pathobiology of autoimmune myelofibrosis.

Adult↗

Idiopathic myelofibrosis: a clinical study of 80 patients.

A series of 122 consecutive patients with bone marrow fibrosis initially referred or categorized as idiopathic myelofibrosis is described. After a clinical and pathological review 14 patients were classified as postpolycythaemic myelofibrosis and 7 patients as a transitional myeloproliferative disorder. In 13 patients a diagnosis of hairy cell leukaemia was made, 3 patients had malignant lymphoma, 2 had malignant histiocytosis, and 1 patient had systemic lupus erythematosus with myelofibrosis. Two patients were excluded for further analysis owing to insufficient data. In the remaining 80 patients a diagnosis of idiopathic myelofibrosis was made. The clinical and laboratory findings in this series of patients are presented and compared to those in previous series. Infectious, cardiovascular, thromboembolic, and haemorrhagic complications were frequent, being recorded in 63%, 50%, 40%, and 33% of the patients, respectively. Various autoimmune phenomena were found in a proportion of the patients, but none had clinical evidence of connective tissue disease. Fifteen patients (19%) had a syndrome of acute myelofibrosis. The diagnostic criteria for this disease entity and its place within the spectrum of myeloproliferative disorders are discussed. In the present series acute myelofibrosis was found to encompass various transitional stages toward the evolution of acute leukaemia. It is proposed that acute or malignant myelofibrosis is considered as an acute variant of idiopathic myelofibrosis. Within this syndrome the acute variant seems to be far more common than previously recognized, which may also explain the marked clinical heterogeneity of the myelofibrosis/osteomyelosclerosis syndrome in this and most previous series.

Adult↗

Autoimmune myelofibrosis: report of three cases and review of the literature.

Autoimmune myelofibrosis is a distinct clinicopathological entity, recognizing immunopathogenetic mechanisms and occurring isolately or in association with systemic and/or organ-specific autoimmune diseases. It results in chronic cytopenias, and is defined by a pattern including bone marrow, peripheral blood, serological and clinical features. It has to be distinguished from other disorders having myelofibrosis. Among these, the most relevant differential diagnosis is with chronic idiopathic myelofibrosis, particularly when disclosing autoimmune clinical and/or laboratory features as epiphenomenon related to a secondary immune-dysregulation. Here we report on 3 patients admitted because of chronic cytopenias. In all of them, the clinicopathological evaluation essentially demonstrated myelofibrosis, not clustered megakaryocytes, reactive lymphoid infiltration in marrow biopsies, absence of significant tear-drop poikilocytosis and leukoerythroblastosis on peripheral blood smears, normal-sized spleen, positive autoimmune serology. The resulting patterns met the diagnosis of autoimmune myelofibrosis occurring isolately in a patient and associated with Sjögren's syndrome or concomitant Sjögren's syndrome and Hashimoto's thyroiditis in the other two, respectively. Transient improvements in cytopenias and unmodified myelofibrosis were observed following corticosteroid treatment. It is noteworthy the lack of a specific therapy, being the underlying pathophisiology of myelofibrosis still unclear. In conclusion, increased awareness of the clinicopathological pattern identifying autoimmune myelofibrosis is recommended in order to improve basic and clinical knowledge of this emerging entity.

Adult↗

Myelofibrosis in primary myelodysplastic syndromes: a retrospective study of 352 patients.

In a retrospective study of 352 patients with primary myelodysplastic syndromes, 61 (17.3%) revealed myelofibrosis in bone marrow biopsies. The fibrosis was observed to occur mostly focally (41/61 cases), and collagen deposits were found very rarely (4/61). The histopathology of bone marrow biopsies revealed hyperplasia and disturbed differentiation in megakaryopoiesis; the frequency and grade of dysplasia in megakaryopoiesis increased with advancing myelofibrosis. Reticulin fibrosis occurred in all subtypes of MDS; however, there was a higher incidence in chronic myelo-monocytic leukaemia (CMMoL). The frequency of cytogenetic aberrations was significantly higher in the MDS cases with myelofibrosis, compared to the cases without fibrosis. Clinical data showed significantly lower values of haemoglobin and lower platelet counts in MDS with myelofibrosis. Life expectancy was reduced to 9.6 months, compared with 17.4 months in MDS without fibrosis. In refractory anaemia, the survival times were 10.0 months in MDS with myelofibrosis, compared to 28.9 months in MDS without myelofibrosis. 36.6% of the patients with MDS and myelofibrosis developed a transformation into ANLL during the course of the disease. Myelofibrosis therefore seems to herald a poor prognosis.

Adult↗

[Coexistence of myelofibrosis and collagen diseases].

Hematologic abnormalities are common in association with collagen diseases, specially Systemic Lupus Erythematosus and include anemia, neutropenia, thrombocytopenia with alterations in lymphocyte subpopulations. On the other hand, patients with unexplained fibrosis of the bone marrow (the syndrome of idiopathic myelofibrosis or primary myelofibrosis) have clinical and laboratory evidence of immunologic dysfunction. Clinical findings include the presence of arthritis, vasculitis and erythema nodosum. Laboratory abnormalities include the presence of circulating immune complexes, antinuclear antibodies, positive direct Coombs test, elevated latex fixation and a circulating lupus type anticoagulant. Total hemolytic complement markedly depressed has also been reported. These data suggest that immunologic mechanisms associated with activation of the complement system play an important role in the disease process of some patients with agnogenic myeloid metaplasia with myelofibrosis. A review of the literature revealed that myelofibrosis occurring in the setting of collagen diseases is rare. However, a role for immunologic factors in the pathogenesis of myelofibrosis is also supported by the patients with coincident well defined collagen disease and myelofibrosis. In this report, we present two patients with such an association. Case 1 was a 58-year-old male with a two year duration history of rheumatic arthritis. He had bone erosions on hands, splenomegaly and myelofibrosis. Rheumatoid factor (latex) was positive: 1:2560. He had positive LE cells and hypocomplementemia: 37 CH50/ml (NV 70-150). The patient did not meet criteria for SLE. Case 2 was a 36-year-old female admitted because of dyspnea and fever. Diagnosis of myeloid metaplasia with myelofibrosis and progressive systemic sclerosis had been made four years before hand.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Regression of myelofibrosis and osteosclerosis following hematopoietic cell transplantation assessed by magnetic resonance imaging and histologic grading.

Myelofibrosis is a reactive, often inhomogeneous process in the marrow cavity, and sampling errors on biopsies obtained to diagnose and monitor the course of myelofibrosis have been a constant problem in hematopathology. We investigated the potential utility of magnetic resonance imaging (MRI) of the lumbar spine, pelvis, and femora as a diagnostic and monitoring technique for assessment of myelofibrosis. Findings on serial marrow biopsies were correlated with T1-weighted spin-echo and short inversion time inversion recovery (STIR) images in patients with chronic idiopathic myelofibrosis or myelofibrosis developing from polycythemia vera or essential thrombocythemia who underwent hematopoietic cell transplantation (HCT). Thirty-five patients were studied before HCT; 11 were followed for 3 months and 10 patients for >/=1 year after HCT with sequential marrow biopsies and MRI studies. MRI allowed direct visualization of the biopsy sites and correlation of histologic and MRI findings. MRI also provided assessment of the extent and degree of myelofibrosis in a large volume of the skeletal marrow. There was good correlation between biopsy results and MRI findings at specific biopsy sites and between successful HCT and resolution of fibrosis and osteosclerosis as determined by MRI. We conclude that in patients with myelofibrosis, MRI of the skeleton provides a comprehensive assessment of the pattern and extent of fibrosis and allows for correlation with biopsy findings. In patients undergoing HCT, MRI accurately reflects response or progression of marrow disease.

Adult↗

Fatal familial infantile myelofibrosis.

Malignant megakaryopoiesis can cause chronic or acute myelofibrosis through production of fibrogenic cytokines. Chronic myelofibrosis is a clonal disorder with marrow fibrosis, myeloid metaplasia, gross splenomegaly, and teardrop cells. Acute myelofibrosis differs by its aggressiveness, by the fact that it is more common in children, and by lack of organomegaly or anisopoikilocytosis. Surprisingly, in early childhood and infancy, splenomegaly and teardrop red cells become an important feature. Infantile myelofibrosis is a rare disease, except in Down syndrome. Familial occurrence of infantile myelofibrosis is exceedingly rare. The author describes an unfortunate family whose four consecutive children died of a very fulminant form of acute myelofibrosis during their first year of life. The fulminant nature of the disease, the degree of splenomegaly, and the prominence of anisopoikilocytosis were even more marked than in currently reported cases of infantile myelofibrosis. The mode of inheritance remained illusive. With two female children, sex-linked inheritance was not possible. It could not have been inherited in an autosomal dominant fashion with normal parents and with two normal children from the father's second marriage. A new autosomal dominant mutation in the germ cell of either parent is another possibility. Autosomal recessive inheritance remained a logical explanation, although such a high degree of disease presentation in a non-consanguineous marriage seems to put that possibility in question.

Adult↗

[Development of polycythemia to myelofibrosis. Monitoring by the assay of the procollagen III amino-propeptide].

The conventional methods used in the follow-up of myelofibrosis being both invasive and expensive, we propose an easy and sensitive immunoassay of the procollagen III aminoterminal peptide (propeptide) which is separated and released in serum during synthesis of collagen III by bone marrow fibroblasts. This propeptide was assayed in the sera of 25 healthy adults (controls), 48 patients with polycythaemia vera and 20 patients with myelofibrosis (secondary to polycythaemia in 14). Significant differences in mean values were found between controls (7.6 +/- 2.1 ng/ml), patients with polycythaemia (9.9 +/- 4.3 ng/ml) and patients with myelofibrosis (38.1 ng/ml). There was some overlapping between values in controls and in patients with polycythaemia, partly due to the fact that 12 of these 48 patients without reticulin bone marrow fibrosis had normal serum propeptide levels. Propeptide values in patients with myelofibrosis were much scattered (range: 13-103 ng/ml). Moreover, values above 25 ng/ml were associated with myelofibrosis of recent onset (less than or equal to 2 years) and values below 25 ng/ml with myelofibrosis of more than 4 years' duration. The procollagen III aminoterminal peptide immunoassay therefore is a non-invasive and sensitive method for accurate assessment of bone marrow progressive involvement in myeloproliferative diseases associated with myelofibrosis. It could also be used to evaluate the effectiveness of antifibrosing agents.

Adult↗

Quantitative and functional studies of impaired natural killer (NK) cells in patients with myelofibrosis, essential thrombocythemia, and polycythemia vera. I. A potential role for platelet-derived growth factor in defective NK cytotoxicity.

In view of the possibility that immunological dysfunctions may be involved in initiating or contributing to the pathogenesis of myeloproliferative disease, we investigated quantitative and functional activity of natural killer (NK) cells in patients with polycythemia vera, essential thrombocythemia and myelofibrosis, and have demonstrated, especially in myelofibrosis, a measurable cytotoxic defect in the ability of their peripheral blood mononuclear cells to efficiently kill the standard NK target, K-562. Furthermore, highly purified, FACS-sorted CD16+ lymphoid cells from patients with myelofibrosis were consistently defective in their ability to lyse K-562 targets, and could not be augmented substantially with recombinant interleukin (IL)-2. Only patients with myelofibrosis had significantly lower percentages and absolute numbers of CD16+ cells as compared to patients with essential thrombocythemia and polycythemia vera. Further experiments demonstrated that patients with myelofibrosis, although having fewer CD16+ NK cells, had a significantly increased proportion of CD16+ cells with detectable platelet-derived growth factor (PDGF) on their surface. In contrast, surface PDGF was barely detectable on CD16+ cells from patients with polycythemia vera and essential thrombocythemia, as well as from normal controls. Having previously reported that physiologic quantities of PDGF significantly inhibit human NK cell cytotoxicity, and that patients with myelofibrosis and essential thrombocythemia have significantly elevated circulating levels of plasma PDGF, we now have demonstrated that pretreatment of normal NK cells with concentrated, PDGF-containing, platelet-poor plasma from patients with these diseases significantly inhibits NK cytotoxicity. This inhibitory effect was reversed by neutralization of plasma PDGF with anti-PDGF (coupled to Sepharose resin). Both the NK defects demonstrated in this study, and the abnormal plasma PDGF results reported earlier, are most striking in myelofibrosis and least abnormal in polycythemia vera, with an intermediate degree of abnormality in essential thrombocythemia. Our new findings suggest a causal correlation between abnormal platelet release, plasma accumulation of PDGF, and the observed NK immunodeficiency in these myeloproliferative patients.

Adult↗

[Acute or subacute myelofibrosis].

Nine patients were selected according to the following criteria: 1. Hematological findings consistent with the diagnosis of myelofibrosis with myeloid metaplasia (MMM), except for an excess of blasts in the blood and bone marrow; 2. No previous (silent) phase of MMM. 3. No PH1 chromosome, and 4. No identifiable cause of secondary myelofibrosis. These patients had either an acute or subacute myelofibrosis. The onset of such symptoms as fever, bone pain, hemorrhage and mild splenomegaly was rapid. Terminal acute leukemia or more often progressive bone marrow biopsy showing myelofibrosis with persistence of differentiated myeloid tissue, particularly megacaryocytes. Isotopic studies (59Fe and 51Cr) showed splenic erythroid metaplasia, poor bone marrow 59Fe uptake and increased peripheral red blood cell destruction. This study confirms that malignant myelosclerosis is a well-defined syndrome which must be distinguished from: a) Acute transformation of typical agnogenic myeloid metaplasia even though it was previously undiagnosed (4 cases of MMM illustrating this possibility have been reported); b) Acute myeloblastic leukemia with myelofibrosis; and c) Myelofibrosis secondary to lymphomatous or carcinomatous bone-marrow invasion (2 cases with acute myelofibrosis appearing long after appropriate treatment have been reported).

Acute Disease↗