Primary autoimmune myelofibrosis: definition of a distinct clinicopathologic syndrome

Myelofibrosis is characterized by reticulin fibrosis of the bone marrow with resulting features of myelophthisis. Besides hematopoietic malignancies and other neoplasms involving the bone marrow, myelofibrosis has been described in association with autoimmune disorders, especially systemic lupus erythematosus. We describe the clinicopathologic features of a primary form of autoimmune myelofibrosis (AIMF) in patients who do not have systemic lupus erythematosus or another well-defined autoimmune syndrome. Absence of marked splenomegaly, peripheral blood cytopenias with mild teardrop poikilocytosis and leukoerythroblastosis, bone marrow lymphoid aggregates, and presence of autoantibodies are some of the salient features of primary AIMF. AIMF should especially be differentiated from chronic idiopathic myelofibrosis, a neoplastic myeloproliferative disease. Primary AIMF appears to have an excellent prognosis, with all patients reported in this series responding to a short course of corticosteroid therapy.     

Peritonitis in myelofibrosis: a cautionary tale

BACKGROUND:Primary myelofibrosis(PMF)is a myelopro-liferative disorder characterized by bone marrow fibrosis. Extra-medullary hematopoiesis sometimes occurs even in the peritoneal cavity,apart from organs such as the liver,spleen, and lymph nodes.This may sometimes be complicated by spontaneous infection and complications.We report a rather unusual case of PMF,who presented as an emergency with spontaneous peritonitis to general surgery department and had a fulminant clinical course. METHOD:A clinical case note review was done and a literature search was undertaken. RESULTS:A rather unusual case of PMF,who presented as an emergency with spontaneous peritonitis to general surgery department.The patient underwent a laparotomy and had a fulminant clinical course. CONCLUSIONS:Peritonitis in myelofibrosis may have a number of causes.Clinicians need to be aware of them and provide conservative management prior to surgical treatment.     

Bone marrow fibrosis in 66 patients with immune thrombocytopenia treated with thrombopoietin-receptor agonists: a single-center,long-term follow-up

Thrombopoietin-receptor agonists increase platelet counts by stimulating the thrombopoietin receptor. Bone marrow fibrosis has been reported in patients receiving thrombopoietin-receptor agonists. This study determined the extent of myelofibrosis, its clinical relevance, and incidence of phenotypic or karyotypic abnormalities in patients with immune thrombocytopenia treated with thrombopoietin-receptor agonists. The grade of myelofibrosis was assessed before (n=15), during (n=117) and after (n=9) treatment in bone marrow biopsies from 66 patients. The proportion of bone marrow biopsies showing no fibrosis (myelofibrosis grade 0) decreased from 67% pre-treatment to 22% at last biopsy, of which 59% had grade 1 myelofibrosis and 18% had grade 2 myelofibrosis. The median duration of treatment with thrombopoietin-receptor agonists to last bone marrow biopsies was 29 months; patients who had two or more biopsies significantly more frequently had myelofibrosis grades 2/3 in the last bone marrow biopsies as compared to the first. Older age was associated with higher grades of fibrosis. No differences in blood counts or lactate dehydrogenase levels were found between patients with myelofibrosis grades 0/1 and those with grade 2. No clonal karyotypic or immunophenotypic abnormalities emerged. This study found that thrombopoietin-receptor agonists induce myelofibrosis grades 2/3 in approximately one-fifth of patients with immume thrombocytopenia, increasingly with >2 years of treatment with thrombopoietin-receptor agonists. Annual/biannual follow-up with bone marrow biopsies is, therefore, recommended in patients being treated with thrombopoietin-receptor agonists in order to enable prompt discontinuation of these drugs should grades 2/3 myelofibrosis develop. Discontinuation of thrombopoietin-receptor agonists may prevent development of clinical manifestations by stopping progression of fibrosis in grade 2/3.     

Tetraspanin CD9 participates in dysmegakaryopoiesis and stromal interactions in primary myelofibrosis

Primary myelofibrosis is characterized by clonal myeloproliferation, dysmegakaryopoiesis, extramedullary hematopoiesis associated with myelofibrosis and altered stroma in the bone marrow and spleen. The expression of CD9, a tetraspanin known to participate in megakaryopoiesis, platelet formation, cell migration and interaction with stroma, is deregulated in patients with primary myelofibrosis and is correlated with stage of myelofibrosis. We investigated whether CD9 participates in the dysmegakaryopoiesis observed in patients and whether it is involved in the altered interplay between megakaryocytes and stromal cells. We found that CD9 expression was modulated during megakaryocyte differentiation in primary myelofibrosis and that cell surface CD9 engagement by antibody ligation improved the dysmegakaryopoiesis by restoring the balance of MAPK and PI3K signaling. When co-cultured on bone marrow mesenchymal stromal cells from patients, megakaryocytes from patients with primary myelofibrosis displayed modified behaviors in terms of adhesion, cell survival and proliferation as compared to megakaryocytes from healthy donors. These modifications were reversed after antibody ligation of cell surface CD9, suggesting the participation of CD9 in the abnormal interplay between primary myelofibrosis megakaryocytes and stroma. Furthermore, silencing of CD9 reduced CXCL12 and CXCR4 expression in primary myelofibrosis megakaryocytes as well as their CXCL12-dependent migration. Collectively, our results indicate that CD9 plays a role in the dysmegakaryopoiesis that occurs in primary myelofibrosis and affects interactions between megakaryocytes and bone marrow stromal cells. These results strengthen the “bad seed in bad soil” hypothesis that we have previously proposed, in which alterations of reciprocal interactions between hematopoietic and stromal cells participate in the pathogenesis of primary myelofibrosis.     

Myelofibrosis secondary to hyperparathyroidism.

We report on a young female who had presented with fatigue, bilateral knee pain and gait disturbance. Primary hyperparathyroidism was diagnosed together with splenomegaly and anemia. Bone marrow biopsy revealed myelofibrosis. A parathyroid adenoma was excised during surgical intervention. As early as three months after the operation, hematologic parameters improved along with bone markers without any other intervention. The control bone marrow biopsy demonstrated well marked regression in marrow fibrosis. Her spleen has also gradually decreased in size. These findings indicate that her myelofibrosis was the result of primary hyperparathyroidism. Anemia associated with primary hyperparathyroidism may be due to bone marrow fibrosis.     

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.     

Bone marrow hypervascularity in patients with myelofibrosis identified by infra-red thermography

Summary Infra-red thermography was used to assess bone marrow vascularity in six patients with myelofibrosis secondary to myeloproliferative disorders (four primary myelofibrosis and two primary proliferative polycythaemia). The technique was evaluated with conventional static and dynamic radio-isotopic imaging and with immunohistochemical staining of bone marrow biopsies. Infra-red thermography identified increased bone marrow blood flow in patients with established myelofibrosis and correlated with dynamic radio-isotopic studies of blood flow and hypervascularity identified by immunohistochemistry. Increased bone marrow blood flow and vascular proliferation was not confined to the central bone marrow but also extended into the peripheral marrow of the long bones. Endothelial cell proliferation may be an initiating event in the pathogenesis of myelofibrosis but evaluation of bone marrow vascularity and blood flow has hitherto relied on invasive and complicated techniques. This study has identified bone marrow hypervascularity in patients with myelofibrosis and shown infra-red thermography to be a simple non-invasive method of assessing vascularity. This non-invasive technique may be used to study disease progression and response to therapeutic regimens in patients with myelofibrosis and to study bone marrow blood flow in other bone marrow disorders.     

Bone marrow hypervascularity in patients with myelofibrosis identified by infra-red thermography.

Infra-red thermography was used to assess bone marrow vascularity in six patients with myelofibrosis secondary to myeloproliferative disorders (four primary myelofibrosis and two primary proliferative polycythaemia). The technique was evaluated with conventional static and dynamic radio-isotopic imaging and with immunohistochemical staining of bone marrow biopsies. Infra-red thermography identified increased bone marrow blood flow in patients with established myelofibrosis and correlated with dynamic radio-isotopic studies of blood flow and hypervascularity identified by immunohistochemistry. Increased bone marrow blood flow and vascular proliferation was not confined to the central bone marrow but also extended into the peripheral marrow of the long bones. Endothelial cell proliferation may be an initiating event in the pathogenesis of myelofibrosis but evaluation of bone marrow vascularity and blood flow has hitherto relied on invasive and complicated techniques. This study has identified bone marrow hypervascularity in patients with myelofibrosis and shown infra-red thermography to be a simple non-invasive method of assessing vascularity. This non-invasive technique may be used to study disease progression and response to therapeutic regimens in patients with myelofibrosis and to study bone marrow blood flow in other bone marrow disorders.     

Autoimmune Myelofibrosis and Systemic Lupus Erythematosus in a Middle-Aged Male Presenting Only with Severe Anemia: A case report

Autoimmune myelofibrosis is a distinct clinicopathologic entity that occasionally occurs with autoimmune disorders such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. Most cases of autoimmune myelofibrosis have been reported in female patients with a known history of SLE. We report a case of a middle-aged male patient with an unusual presentation of SLE and autoimmune myelofibrosis who presented only with severe anemia initially and was later diagnosed with SLE and autoimmune myelofibrosis. The patient''s condition improved dramatically after treatment with corticosteroids.SLE and autoimmune myelofibrosis is a rare but potentially devastating condition. Anemia maybe the only presenting symptom in addition to bone marrow fibrosis and careful clinical and laboratory assessment is imperative. Corticosteroids maybe useful and spare patients from bone marrow transplantation.     

Pancytopenia and secondary myelofibrosis could be induced by primary hyperparathyroidism

Hyperparathyroidism may be a precipitating factor important to the development of myelofibrosis: however, there has been only a few reports regarding myelofibrosis secondary to primary hyperparathyroidism. Recently, a rare case of pancytopenia caused by myelofibrosis in a 41-year-old woman who complained of general weakness and arthralgia presented to our clinical service. The patient was diagnosed with primary hyperparathyroidism with pancytopenia. Bone marrow biopsy revealed myelofibrosis. Right parathyroidectomy was performed and a parathyroid adenoma was totally excised. After surgery, the CBC counts and other clinical abnormalities gradually improved without further intervention. We concluded that the pancytopenia was because of bone marrow fibrosis resulting from primary hyperparathyroidism. Therefore, physicians should consider myelofibrosis secondary to primary hyperparathyroidism as a cause of pancytopenia in hypercalcemic patients, even though it is rare.     

Cytogenetic studies of bone marrow fibroblasts cultured from patients with myelofibrosis and myeloid metaplasia.

Cytogenetic studies of bone marrow fibroblasts and blood cells from peripheral blood or bone marrow were performed in 19 patients with myelofibrosis with myeloid metaplasia (group 1), nine patients with other myeloproliferative syndromes without myelofibrosis (group 2), and 12 patients with anaemia secondary to iron deficiency or chronic inflammatory disease (group 3). Clonal cell populations with abnormal karyotypes were seen in the bone marrow or blood in five of 14 (36%) group 1 patients, one of nine (11%) group 2 patients and none (0%) of the group 3 patients. Abnormal karyotypes of bone marrow fibroblasts were found in three of 16 (19%) of patients of group 1, and in two of nine (22%) and two of 12 (17%) patients each of groups 2 and 3, respectively. Since abnormal karyotypes can be found in bone marrow fibroblasts cultured from normal subjects, and since the abnormalities seen in the bone marrow fibroblasts differed from those found in bone marrow or blood cells, it is suggested that abnormal karyotypes found in bone marrow fibroblasts cultured from patients with primary myelofibrosis do not necessarily reflect neoplasia. The results of this study are compatible with the widely accepted hypothesis that in patients presenting with 'primary' myelofibrosis, the fibrosis is a secondary reactive process.     

Primary myelofibrosis and its targeted therapy

Primary myelofibrosis is a unique entity among BCR-ABL-negative myeloproliferative diseases, manifesting as bone marrow fibrosis and pancytopenia. Considerable evidence indicates that genetic and epigenetic abnormalities can result in defective clonal hematopoietic stem cell proliferation in addition to bone marrow microenvironment alteration. The “bad seeds in bad soil” theory illustrates the orchestrating efforts of hematopoietic stem cells, stromal cells, and their surrounding signaling molecules in myelofibrosis progression and malignancy transformation, though the exact mechanism of myelofibrosis is still not clear. This study reviews current concepts and questions regarding the pathogenesis of primary myelofibrosis and discusses the emerging targeted therapy aimed at restoring normal bone marrow environment and halting bone marrow fibrotic deterioration.     

Advances in myelofibrosis: a clinical case approach

Primary myelofibrosis is a member of the myeloproliferative neoplasms, a diverse group of bone marrow malignancies. Symptoms of myelofibrosis, particularly those associated with splenomegaly (abdominal distention and pain, early satiety, dyspnea, and diarrhea) and constitutional symptoms, represent a substantial burden to patients. Most patients eventually die from the disease, with a median survival ranging from approximately 5–7 years. Mutations in Janus kinase 2 (JAK2), a kinase that is essential for the normal development of erythrocytes, granulocytes, and platelets, notably the V617F mutation, have been identified in approximately 50% of patients with myelofibrosis. The approval of a JAK2 inhibitor in 2011 has improved the outlook of many patients with myelofibrosis and has changed the treatment landscape. This article focuses on some of the important issues in current myelofibrosis treatment management, including differentiation of myelofibrosis from essential thrombocythemia and polycythemia vera, up-dated data on the results of JAK2 inhibitor therapy, the role of epigenetic mechanisms in myelofibrosis pathogenesis, investigational therapies for myelofibrosis, and advances in hematopoietic stem cell transplant. Three myelofibrosis cases are included to underscore the issues in diagnosing and treating this complex disease.     

Abnormalities of chromosome 13 in myelofibrosis

19 patients with myelofibrosis, primary or following polycythaemia vera were studied cytogenetically. Bone marrow cells, unstimulated and stimulated cells from peripheral blood were investigated. 7 patients were found to have clonal aberrations, 3 of whom had a structural rearrangement of chromosome 13. In 2 additional cases single mitoses with 13q- were found. Reviewing the files on patients previously studied in our laboratory, 2 more patients with 13q- markers were noted. Both had had haematologic disorders in which fibrosis of the bone marrow can be found, but this feature could not be evaluated retrospectively, because no biopsies had been taken. Our data and those found in the literature suggest that rearrangements of 13q12 → q22 are often associated with myelofibrosis, both in its primary form or following polycythaemia vera.     

Reversal of bone marrow fibrosis and subsequent development of polycythemia in patients with myeloproliferative disorders

Bone marrow fibrosis is a characteristic finding in agnogenic myeloid metaplasia and in the spent phase of polycythemia vera. It is commonly believed that the reticulin deposition is irreversible. However, we report four patients who demonstrated clinical and laboratory evidence of transition from myelofibrosis to polycythemia. The transition was documented by improvement in the hemoglobin concentration and by determination of the Cr51 red blood cell mass, accompanied by a resolution of the fibrosis on serial bone marrow biopsies. Two of the patients had been treated with alkylating agents and splenectomy, one with myelosuppressive therapy without splenectomy, and one with splenectomy alone. These findings indicate that bone marrow fibrosis in the chronic myeloproliferative disorders is not always an irreversible phenomenon. Pathogenetic implications will be discussed.     

Hematological Evaluation of Primary Extra Nodal Versus Nodal NHL: A Study from North India

Primary extra nodal lymphomas (EN-NHL) are different from primary nodal non-Hodgkin’s lymphoma (N-NHL) and are comparatively less common. Hemogram findings and bone marrow involvement is less studied and very few reports are available in the literature. The present study is a retrospective analysis of bone marrow samples evaluated for staging of non-Hodgkin’s lymphoma. The age, sex distribution, clinical features, and site of presentation, hemogram findings, pattern of bone marrow involvement and grade of reticulin fibrosis was noted. These findings were compared with the type of non-Hodgkin’s lymphoma and prognostic information was determined. A total of 647 cases of NHL, which underwent bone marrow examination for staging, over a seven year period, were retrieved and analyzed for all hematological parameters. Prevalence of EN-NHL was 23.5% (152/647), while nodal NHL comprised 76.5% (495/647) of all NHL cases. 90.1% (137/152) cases of EN-NHL were adult patients, out of which 15.3% (21/137) cases showed bone marrow infiltration as compared to 89% (441/495) adult primary nodal NHL cases, of which 39% (175/441) showed bone marrow infiltration. 9.9% (15/152) cases of EN-NHL were pediatric patients, out of which 40% (6/15) showed bone marrow infiltration, while 10.9% (54/495) of nodal NHL cases were pediatric, of which 20.3% (11/54) showed bone marrow infiltration. Hemogram findings were not found useful in predicting bone marrow infiltration in both nodal as well as EN-NHL. 100% (6/6) of pediatric patients had high grade lymphoma as compared to 48% (9/21) of adult patients, showing bone marrow infiltration in EN-NHL group. Reticulin fibrosis also did not reveal relation with grading of NHL. Prognostically EN-NHL of stomach and central nervous system were found to be better than EN-NHL of other sites, as none of these cases showed bone marrow infiltration. EN-NHL can involve various sites and the prognosis depends upon the sites of disease as well as the type of NHL. Moreover, pediatric EN-NHL cases are likely to have poorer prognosis, due to increased risk of bone marrow involvement as compared to their counterparts having primary nodal NHL. Bone marrow infiltration at times cannot be assessed reliably from hemogram findings only and a bone marrow biopsy for staging is mandatory.     

Rapid regression of bone marrow fibrosis after dose-reduced allogeneic stem cell transplantation in patients with primary myelofibrosis

OBJECTIVE: To investigate the effect of a busulfan/fludarabine-based reduced intensity conditioning followed by allogeneic stem cell transplantation on regression of bone marrow fibrosis in patients with myelofibrosis. METHODS: Twenty-four patients (male, n = 16; female, n = 8) with a median age of 52 years (range, 32-63 years) were included. Six patients were transplanted from human leukocyte antigen-identical siblings and 18 patients from matched unrelated donors. Diagnosis was primary myelofibrosis in 18 patients and secondary myelofibrosis in 6 patients; in 4 of them, primary myelofibrosis evolved from polycythemia vera, and in 2 of them from essential thrombocythemia. Using the European Consensus on grading bone marrow fibrosis, all patients had advanced marrow fibrosis MF-2 (n = 13) or MF-3 (n = 11) before allografting According to the Lille Risk Factor Scoring System, patients were classified as low risk (n = 5), intermediate risk (n = 16), or high risk (n = 3). RESULTS: After stem cell transplantation, a complete (MF-0) or nearly complete (MF-1) regression of bone marrow fibrosis was seen in 59% at day +100, in 90% at day +180, and in 100% at day +360. No correlation between occurrence of acute graft-vs-host disease and fibrosis regression on day +180 was observed. CONCLUSION: This study shows that allogeneic stem cell transplantation after reduced-intensity conditioning resulted in rapid regression of bone-marrow fibrosis.     

A sequential histological study of bone marrow fibrosis in idiopathic myelofibrosis

A sequential histological study of bone marrow biopsies from 36 patients with idiopathic myelofibrosis was performed to investigate the accumulation of connective tissue in the bone marrow during the course of the disease and the influence of therapy on this process. The degree of bone marrow fibrosis was graded semiquantitatively from 0 (normal) to +5 (extensive collagen fibrosis and ostemyelosclerosis). The median interval between the first and final biopsy was 25 months (range 3 to 103) in patients with chronic idiopathic myelofibrosis and 2 months (range 1 to 14) in patients with a syndrome of acute myelofibrosis. In most patients with chronic IMF the bone marrow fibrosis remained unchanged. Regression of bone marrow fibrosis in 9 patients with chronic IMF was associated with immunosuppressive/-cytotoxic treatment or splenectomy. Severe bone marrow fibrosis completely resolved during intensive chemotherapy of a patient with acute myelofibrosis. No relationship existed between spleen size and the degree of bone marrow fibrosis.     

Myelodysplastic syndrome with increased marrow fibrosis: a distinct clinico-pathological entity

Seventeen cases of myelodysplastic syndrome (10 primary and seven secondary to previous radio-chemotherapy), characterized by trilineage dysplasia, severe bone marrow fibrosis and a high number of megakaryocytes, are described. All of these patients had similar clinical and prognostic features consisting of pancytopenia, modest or absent visceral enlargement and poor survival. The use of CD61 antibodies, which recognize megakaryocytic cells at all stages of maturation, confirmed that these patients had a higher number of these cells than either normal subjects or patients affected by myelodysplastic syndrome (MDS) without fibrosis. Furthermore, primary and secondary MDS with fibrosis, although clinically and histopathologically similar, differed in terms of the number of megakaryoblasts which were significantly higher in primary forms (P less than 0.02). We conclude that MDS with fibrosis may represent a clinicopathological entity which needs to be distinguished from other MDS subtypes as well as from idiopathic myelofibrosis or malignant myelosclerosis.     

Identification of new target molecules PTK2, TGFBR2 and CD9 overexpressed during advanced bone marrow remodelling in primary myelofibrosis

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by remodelling of the bone marrow, including progressive myelofibrosis and exaggerated angiogenesis. Advanced PMF frequently shows a full-blown fibre meshwork, which avoids aspiration of cells, and the expression profile of genes related to stroma pathology at this stage remains largely undetermined. We investigated bone marrow core biopsies in PMF showing various degrees of myelofibrosis by custom-made low density arrays (LDA) representing target genes with designated roles in synthesis of extracellular matrix, matrix remodelling, cellular adhesion and motility. Among a set of 11 genes up-regulated in advanced stages of PMF ( P  ≤ 0·01) three candidates, PTK2 protein tyrosine kinase 2 ( PTK2 ), transforming growth factor β type II receptor ( TGFBR2 ) and motility-related protein-1 (CD9 molecule, CD9 ), were investigated in more detail. PTK2 , TGFBR2 and CD9 were significantly overexpressed in larger series of advanced PMF stages ( P  ≤ 0·01 respectively). Endothelial cells of the increased microvessel network in PMF could be identified as a predominant source for PTK2 , TGFBR2 and CD9 . CD9 also strongly identified activated fibroblasts in advanced myelofibrosis. We conclude that PTK2 , TGFBR2 and CD9 represent new target molecules involved in bone marrow remodelling of PMF and warrant further investigation for potential targeted therapy.