Myelofibrosis With Myeloid Metaplasia Research Articles

International Working Group (IWG) consensus criteria for treatment response in myelofibrosis with myeloid metaplasia, for the IWG for Myelofibrosis Research and Treatment (IWG-MRT)

Myelofibrosis with myeloid metaplasia (MMM) is a clinicopathologic entity characterized by stem cell-derived clonal myeloproliferation, ineffective erythropoiesis, extramedullary hematopoiesis, and bone marrow fibrosis and osteosclerosis. Patients with MMM have shortened survival and their quality of life is compromised by progressive anemia, marked hepatosplenomegaly, and severe constitutional symptoms including cachexia. After decades of frustration with ineffective therapy, patients are now being served by promising treatment approaches that include allogeneic hematopoietic stem cell transplantation and immunomodulatory drugs. Recent information regarding disease pathogenesis, including a contribution to the myeloproliferative disorder phenotype by a gain-of-function JAK2 mutation (JAK2(V617F)), has revived the prospect of targeted therapeutics as well as molecular monitoring of treatment response. Such progress calls for standardization of response criteria to accurately assess the value of new treatment modalities, to allow accurate comparison between studies, and to ensure that the definition of response reflects meaningful health outcome. Accordingly, an international panel of experts recently convened and delineated 3 response categories: complete remission (CR), partial remission (PR), and clinical improvement (CI). Bone marrow histologic and hematologic remissions characterize CR and CR/PR, respectively. The panel agreed that the CI response category is applicable only to patients with moderate to severe cytopenia or splenomegaly.

PB2195 ASSESSMENT OF PLATELET MEMBRANE ALTERATION IN PATIENTS WITH MYELOID METAPLASIA WITH MYELOFIBROSIS

Background:Patients with Myeloid Metaplasia with Myelofibrosis (MMM) present at the onset or during evolution thrombotic complications. In the assessment of thrombosis risk are important the presence of JAK2 mutation as well as platelet function. Receptors that define the status of activated platelets (CD62P, CD36) are better expressed in chronic myeloproliferative neoplasms (MPNs) patients with thrombotic complications. Numerous studies have shown a high oxidative status in MPNs patients, a situation that correlates with a higher thrombotic risk.Aims:The aim of our study was to determine if resting membrane potential could be correlated with alterations in expression of platelet receptors and reactive species production (ROS)MethodsThis retrospective study included 35 patients with MMM (16 male and 19 female), median age 61.1 (95% CI of median 60,71‐72) as well as 15 healthy volunteers. The diagnosis of MMM was made according to World Health Organization (WHO) classification of MPNs. We evaluated the flow cytometry markers of platelet adhesion (CD42a, CD42b), aggregation (CD41, CD61) and CD36. Production of reactive species (ROS) was examined using fluorescence method with DCFDA and was assessed by aria under curve (AUC) in serial measurements during 900 sec. The determination of platelet membrane potential was done by fluorescence method using 3,3′‐dipropyl‐2,2′‐thiadicarbocyanine iodide (DiSC3‐5)Results:The ROS production is significantly higher in MMM group: median value of AUC patient group 12780882862,5000 compared with controls 11621365017,5000, p= 0.04. Patients in advanced phase (grade 5 Hackett of splenomegaly) has high level of ROS production compared with patients diagnosed in early stage (grade 1 or 2 Hackett of splenomegaly) median value: 13178014970 vs 12303298585, p = 0.001. There are no differences between groups that was splitted by type of treatment Ruxolitinib/Hydroxiureea or type of mutation diagnosed JAK2V617F/CALR/no mutation. Patients with MMM present higher resting membrane potential (RMP) compared with controls (median value ‐ 63 mV vs–57.5 mV, p = 0.05). The expression of CD36 receptor was higher in MMM group vs controls: median value 27.91 vs 20.91, p = 0.003. Number of microparticle (MP) derivated from platelet, erythrocyte and endothelial cells are no different between patient and control group. We obtain only lower receptor expression on MP surface for CD41/CD61, CD42b and GlyA in patient group compared with control group, p < 0.05. There are significant correlation between resting membrane potential and expression of CD42b (r ‐0.45, p = 0.04) and GlyA receptors (r ‐0.45, p = 0.04).Summary/Conclusion:Patients with MMM especially those with have a higher level of ROS production especially in advanced phase. The hyperpolarisation of cell macrophages membrane could be associated with high ROS production, no reports are regarding platelet membrane. In our study we did not obtain any significant correlation between RMP and ROS production. The expression of CD 36 is higher in MMM patients but was not correlated with ROS production. It was proved that generation of intracellular ROS is associated with CD36 signaling and represent one start point for thrombosis. Low expression of CD42b and GlyA of microparticle surface is associated with lower RMP that correspond to activated status of platelet membrane. We have to verify these results in higher number of patients in order to find significant correlations

Myelofibrosis with myeloid metaplasia (MMM) - Idiopathic myelofibrosis - Agnogenic myeloid metaplasia

Review on Myelofibrosis with myeloid metaplasia (MMM) - Idiopathic myelofibrosis - Agnogenic myeloid metaplasia, with data on clinics, and the genes involved.

Gene Expression Profiling with Principal Component Analysis Depicts the Biological Continuum From Essential Thrombocythemia Over Polycythemia Vera to Myelofibrosis

AbstractAbstract 4115 Introduction:The classical Philadelphia-negative chronic myeloproliferative neoplasms (CMPNs) encompass polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). After several years, a proportion of patients with PV may develop increasing splenomegaly and bone marrow fibrosis to terminate in postpolycythemic myelofibrosis, which then has a very poor prognosis with median survival of only a few years. A high proportion of the ET-population has been shown to have prefibrotic PMF or a “PV-like” phenotype, which after a variable time may terminate in myelofibrosis with myeloid metaplasia (MMM). Although the concept of prefibrotic myelofibrosis as a separate disease entity to be distinguished from ET by distinct histopathological features has been questioned, it seems logical that a continuum exists from “early” myelofibrosis with no or minimal bone marrow fibrosis to the advanced stage of myelofibrosis with myeloid metaplasia. Accordingly, a new concept of these diseases as a biological continuum from ET over PV to PMF has emerged. Indeed, this biological continuum reflects the various clinical stages as also described for chronic myelogenous leukaemia (CML) – a chronic stable phase (ET-PV), an accelerated phase (transitional phase), and a terminal myelofibrosis or blast phase of the disease (PMF-BP).It is evident that the JAK2 V617F mutational load is an important determinant of phenotype, but other genetic and epigenetic events contribute to the phenotypic presentation. Several gene expression studies have identified genes which might be of pathogenetic relevance for the development of CMPNs. However, no study has applied an unsupervised method as Principal Component Analysis (PCA) to discover unknown trends in the data. We have carried out gene expression profiling with PCA to ascertain if this analysis might unravel distinct grouping of disease entities supporting the biological continuum from early ET over PV to the advanced myelofibrosis phase. Patients and Methods:Using HG-U133 Plus 2.0 microarray from Affymetrix, recognizing 54675 probe sets (38500 genes), gene expression microarray studies have been performed on control subjects (n=21) and patients with ET (n =19), PV (n=41), and PMF (n=9). An unsupervised statistical method, PCA, which is an exploratory tool used to uncover unknown trends in the data based on gene expression profiles, was applied to the data. Results:The results from the PCA confirm the hypothesis of a biological continuum from control subjects over ET to PV and finally PMF (figure 1). The figure also reveals that patients with PV in a transitional stage (PVtrans) with pancytosis, huge splenomegaly, and bone marrow fibrosis have a gene profile between PV and PMF. Furthermore, single gene analysis revealed that several genes are highly dysregulated in patients with ET, PV, and PMF compared to control subjects even after correcting for multiple testing. Discussion and Conclusions:Using global gene expression profiling with PCA in patients with different CMPNs (ET, PV, PMF), we have yielded support to the concept of a biological continuum from early ET to the advanced myelofibrosis stage. Studies are in progress to identify single genes or clusters of genes accounting for the biological continuum and accordingly the progression from ET over PV to myelofibrosis. Disclosures:No relevant conflicts of interest to declare.

Myelofibrosis with myeloid metaplasia (MMM)

Review on Myelofibrosis with myeloid metaplasia (MMM), with data on clinics, and the genes involved.

Portal hypertension secondary to myelofibrosis with myeloid metaplasia: A study of 13 cases

To describe the clinical presentation and complications of portal hypertension (PH) secondary to myelofibrosis with myeloid metaplasia (MMM). Medical records for 123 patients with MMM were reviewed. Thirteen patients with PH secondary to MMM were identified. Median ages at time of MMM and PH diagnosis were 61 and 66 years, respectively. The interval from MMM diagnosis to presentation with one of the PH features ranged from 1 to 11 years. Variceal bleeding and ascites were the most common presentations. Of the eight patients who presented with variceal bleeding, six patients underwent endoscopic variceal ligation (EVL) with no variceal recurrence or hematological worsening during a 12-mo follow up period. Patients with MMM might develop PH. Exact mechanisms leading to PH in MMM are still controversial. As in other etiologies, variceal bleeding and ascites are the most common presentations. Anemia may correlate with, and/or predict, the severity of the PH presentation in these patients. EVL can successfully control variceal bleeding in MMM. Further clinical studies are required.

Risk factors of long-term incidences of thrombosis, myelofibrosis and evolution into malignance in polycythemia vera: a single center experience from China

To find out risk factors of incidences of long-term complications of thrombosis, myelofibrosis with myeloid metaplasia (MMM) and evolution into malignance in Chinese PV patients, we evaluated 320 PV patients referred to our center from April 1984 to June 2005 by Kaplan-Meier estimation and Cox proportional hazards models. A total of 250 events of thrombosis were observed in 138 (43.13%) patients. Advanced age, prior thrombosis and hemoglobin out of control were statistically significant risk factors of incidences of thrombotic events. A total of 43 patients progressed into MMM at a median time of 84 (7-240) months, higher white blood cell (WBC) count, splenomegaly, receiving alkylating agent and hydroxycarbamide were associated with the progression into MMM. During the follow-up time, 11 and 2 patients died of fatal complications of thrombosis and acute myeloid leukaemia (AML), respectively. These results suggest that advanced age, prior thrombosis and hemoglobin out of control contributed to relatively high incidence of thromboembolism; higher WBC count, splenomegaly, receiving alkylating agent and hydroxycarbamide were risk factors of evolution to MMM. The main poor factors that influenced the survival of Chinese PV patients were incidences of thromboembolism and evolution into AML.

Myelofibrosis with myeloid metaplasia in a patient with relapsed Hodgkin's lymphoma who underwent autologous hematopoietic stem cell transplantation

Second malignancies after autologous haematopoietic stem-cell transplantation (AHSCT) are well-known long-term complications.We present a case of a 24-year-old male with relapsed Hodgkin lymphoma (HL) with no involvement of his bone marrow who underwent AHSCT. Four years later he developed mild anaemia and a computed tomography showed an enlarged spleen. As his anaemia worsened, a bone marrow was performed. There was no evidence of HL but intense reticular and collagen fibrosis with hypocellularity was detected. Cytogenetic studies could not obtain cells in metaphase in two occasions. PCR for V617F JAK2 mutation was positive. Until now, with 7 years of follow up from his diagnosis of myelofibrosis with myeloid metaplasia (MMM) he did not require specific treatment besides from red cell transfusions when anaemia worsened during a pneumocistis carinii infection.We present this case, because MMM is a infrequent second neoplasm after AHSCT. Revising the literature we could not find any case like this reported previously.

Darbepoetin Alfa for the Treatment of Anemia in Patients with Myelofibrosis with Myeloid Metaplasia (MMM). Results from a Danish Multicenter Study.

Background: Treatment with recombinant human erythropoietin (rHuEPO) may increase the hemoglobin (Hb) concentration in patients with myelofibrosis with myeloid metaplasia (MMM). Only one study in this setting has used darbepoetin alfa (Aranesp®) (DA), an erythropoiesis-stimulating protein with a long half-life allowing less frequent administration.We report the largest series of patients with MMM being treated with DA so far.Methods: Twenty-eight patients were enrolled in a prospective Danish multicenter study. Median age was 71 years (range 50 – 86 years). Inclusion criteria were symptoms of anemia or a Hb concentration ≤ 10 g/dL. Response criteria: A major response (MAR) was defined as either a complete response (CR = no need for blood transfusions and a increase in the Hb-level > 11.5 g/dl), or a partial response (PR = a 50% reduction in the need of blood transfusions, compared to the average monthly need during the 6 months before the start of DA in combination with a stable Hb level > 10 g/dl. A minor response (MIR) was defined as a 50% reduction in the need for blood transfusions compared to the average monthly need the last 6 months preceding start of DA treatment. Non-responders (NRS) were defined as patients with no change or an increased need for blood transfusions.Treatment: All patients were scheduled to receive DA 300 μg sc. once-weekly for at least 12 weeks. In patients who achieved a normal Hb concentration at this dose, the DA dose was decreased to 300 μg every second week or even third week if possible. If the Hb concentration subsequently declined and the patient developed anemia in the subsequent weeks, the dose of DA was increased to a level that maintained a normal Hb concentration. Patients achieving a CR or a PR continued DA beyond 12 weeks. In NRS, the treatment was discontinued after 12 weeks of treatment.Results: The response rate was 65% (17 out of 26 evaluable patients), 6 patients achieving a CR (23%), 3 PR (12%) and 8 MIR (30%). Six of the patients received antibiotic treatment during the study period. Two of these were non-responders. One non-responder developed AML in week 9 and died one week later. Three patients discontinued DA due to possible side-effects (gastrointestinal complaints in 2 patients and in one, bone- and muscle pains, the latter symptoms also being related to disease activity). Four of 17 responders had a serum erythropoietin (s-EPO) > 125 IU/L (median 53 IU/L; range 4,9 – 520 IU/L, while 4 of 9 non-responders had a s-EPO >125 IU/L (median 103 IU/L ; range 11,9 – 730 IU/L. The median serum EPO level was significantly higher in NRS (103 IE/l; range 11, 9 – 730 IU/L) as compared to responding patients (57 IE/l; range 4, 9 – 520 IU/L).Conclusion: Darbepoetin alfa is a well tolerated drug with few side effects and a high response rate in patients with MMM, implying an increase in the Hb concentration and a decrease in the need for blood transfusions in about 50% of the patients. A serum EPO < 125 IU/L is a predictor of a favorable EPO-response, although responses may also be seen in patients with higher serum EPO levels.

Additon of Low-Dose Interferon-alpha (LD-IFN-a) and Lenalidomide after Failure to a Combination of Thalidomide and Prednisone in Myelofibrosis with Myeloid Metaplasia (MMM).

Primary myelofibrosis with myeloid metaplasia (MMM) is an uncommon myeloproliferative disease with limited effective treatment options. Therapy using thalidomide and prednisone (TP) or lenalidomide (L) show variable objective response of improvement of 22% in L to 62% in TP for anemia, 50% in L to 75% in TP for thrombocytopenia, and decrease in splenomegaly in 19% with TP to 33% with L and was well-tolerated. Additional clinical benefits show resolution of leukoerythroblastosis, and a decrease in medullary fibrosis and abnormal angiogenesis. Prolonged therapy with alpha-interferon (IFN-a) can improve hematopoiesis and reverse marrow fibrosis but doses used were poorly tolerated.Methods and Patients: Here we present five patients treated with combination T at 50 mg daily, P at 0.5 mg/kg po for 2 weeks then to 20 mg daily every other day for 3 months with no response. If this was tolerated, low-dose IFN-a (LD-IFN-a) at 1.5 million units sc. three times a week was added. The clinical and hematologic criterion of the European Myelofibrosis Network (EUMNET) were used as response criteria for our study. Three males, 2 females, age ranged from 60 to 85 years who had failed previous treatments from EPO, hydrea and transfusion support. White blood cell counts ranged from 4.3 to 29.7 B/L. Hemoglobin levels ranged from 7.3 to 11.6 g/dL. Platelets ranged from 13,000 to 283,000 B/L. Three patients developed iron overload from rbc transfusions and required iron-chelation therapy.Results: Of the five patients, one had a CR, one had a PR and two had regression that did not meet criteria for response and one unresponsive with no splenomegaly but stable disease. We noted that the addition of LD-IFN-a decreased the elevated WBC counts and Improvement in spleen size was seen about three months after the start of treatment. One patient had a CR in his WBC count approximately a month after starting therapy. The patient with CR had normal hemoglobin but had to discontinue after a year of T due to grade 2 neuropathy and was started on 10 mg/day of L while staying on IFN-a and P. She developed anemia and required transfusions for 3 months and achieved CR with shrinkage of her spleen size from 15 to 4 cm. The patient who was unresponsive to the combination of IFN-a- TP changed from T to L was stopped after the patient developed hemolytic anemia and splenomegaly.Conclusion: Addition of LD-IFN-a to the reported TP or L to replace T show clinical activity in patients with refractory MMM and is well tolerated with minimal toxicity. The use of lenalidomide may alleviate neuropathy but may induce hemolysis as an undesirable side effect. Further studies using low doses of these agents with varying activities to MMM in combination is needed to define their clinical use in the treatment of this disease entity in a much larger number of patients.

Impact of Conditioning on the Outcome of Allografting in Myelofibrosis with Myeloid Metaplasia: Better Survival with Reduced Intensity Approach in Patients ≥50 Years.

We analyzed the impact of intensity of conditioning therapy on the outcomes of allogeneic blood or marrow transplantation (BMT) in patients (pts) with myelofibrosis with myeloid metaplasia (MMM). The study included 46 consecutive patients treated at 7 transplant centers between 1998 and 2005. The indications for BMT were intermediate/high risk disease (n=41) or low risk disease with constitutional symptoms (n=5). Donors were matched sibling/family donor (n=25); mismatched family donor, 2; and unrelated, 19. Twenty-three pts received conventional myeloablative (MY) conditioning: Cy/TBI (n=22); Bu/Cy (n=1), and 23 received non-myeloablative (NMA) conditioning [fludarabine (Flu)/PO or IV Bu (n=16); Flu/TBI 200cGy (n=6); others(n=1)]. Median age at BMT of the MY and NMA group was 47 (31–60) and 54 (38–74) years, respectively. NMA group had a higher proportion of pts ≥50 years (74% vs 30%, p=0.003), a longer interval from diagnosis to BMT (p=0.05) and more transplants using blood stem cells (p=0.0002). At a median follow-up of 31 (1–89) months, 8 and 16 patients were alive in MY and NMA groups, respectively. The transplant related outcomes of the two groups are summarized in the table. Serial pre and post BMT bone marrow biopsy results were available in 24 patients. Median days to resolution of fibrosis were 167 and 363 in the MY and NMA groups (p=0.16). In a multivariate analysis, after adjusting for age the survival was better for pts ≥50 years treated with NMA approach (hazard ratio 2.98, 95% CI 1.09–8.12, p=0.03). In conclusion, both MY and NMA approaches have curative potential for pts with MMM. NMA approach is particularly promising in pts ≥50 years.Table:Comparison of BMT related outcomes for MY and NMA conditioning for MMMOutcomesMY Group (95% C.I.)NMA Group (95% C.I.)P valueNeutrophil engraftment (days)21 (13–46)18 (1–30)0.01Cumulative incidence of graft failure (primary and secondary) at 2-years %30 (16–58)23 (10–50)0.51Median number of hospital days (Day 0 to +100)41 (26–85)27 (8–58)0.0006Cumulative incidence of acute GvHD grade II–IV (%)78 (62–98)18 (7–45)0.0002Cumulative incidence of chronic GVHD at 2-years %94 (79–100)45 (27–74)0.0009Cumulative incidence of TRM at 2-years %43 (27–70)27 (14–55)0.08Progression free survival at 2-years %48 (27–66)64 (40–80)0.11Overall survival at 2-years %57 (34–74)68 (45–83)0.08

A Phase II Trial of Combination Therapy with Thalidomide, Arsenic Trioxide, Dexamethasone, and Ascorbic Acid (TADA) in Patients with Overlap Myelodysplastic/Myeloproliferative Diseases (MDS/MPD) or Chronic Idiopathic Myelofibrosis (CIMF).

Background: Both CIMF and MDS/MPD are clonal hematopoietic disorders characterized by cytogenetic abnormalities and myelofibrosis with resultant organomegally. Arsenic Trioxide (ATO) has demonstrated efficacy in MDS in two multicenter trials, including patients with MDS/MPD. Ascorbic acid (AA) enhances the activity of ATO by depleting intracellular glutathione. Thalidomide (Thal), in combination with ATO or steroids, is efficacious in patients with MDS and in patients with CIMF.Methods: We conducted a multicenter trial of Thal (50mg/d PO x 2 weeks, then 100mg/d), ATO (0.25mg/kg IV d1-5 of week 1, then twice weekly weeks 2–12), Dexamethasone (4mg/d PO x 5d every 4 weeks), and AA (1000mg PO 1–2 hours prior to each ATO infusion) over a 12-week cycle in patients with CIMF or MDS/MPD, from 1/05 to 7/07. Patients continued on Thal for an additional 3 months. Bone marrow was assessed at baseline and after week 12, as was spleen size. The primary endpoint was response as defined by the Modified International Working Group (IWG) treatment response criteria for MDS, and the IWG criteria for myelofibrosis with myeloid metaplasia (MMM).Results: Twenty-eight patients have been enrolled; 27 were evaluable for response. The median age was 66.5 years; 23 patients (82%) had MDS/MPD: 8 with CMML and 15 with MDS/MPD-u, with cytogenetics of: normal (13), +22p (1), +8 (2), −Y (1), +9 (1), −12p (1), complex (2), unknown (2). Five patients (18%) had CIMF with cytogenetics of: normal (3), dup Chr6 (1), unknown (1); Of 14 patients tested, 5 had the JAK2V617F mutation: 1 with CIMF and 4 with MDS/MPD. No patient had the MPL515 mutation. Thirteen patients had splenomegally, and 15 received prior therapies, including erythropoietin agents (9), 5-azacytidine (2), hydroxyurea (1), anagrelide (2), investigational agents (1), and prednisone (2). Median baseline lactate dehydrogenase (LDH), leukocyte count, and platelet count were: 300U/L, 12.1k/L, and 126.5k/L, respectively. Reasons for starting therapy included anemia (8 (29%)), thrombocytopenia (9 (32%)), or disease-related symptoms (11 (39%)). Seven patients (25%) did not complete the entire 12 week course of therapy: 3 withdrew consent, 1 had a low platelet count, 2 due to an adverse event, and 1 due to no response. Responses occurred in 7 patients (26% of total, 35% of those completing 1 cycle of therapy): 6 (21%) by the IWG MMM criteria, 4 (14%) by the IWG MDS criteria, and 3 (11%) by both. Using the IWG MMM criteria, 1 patient with MDS/MPD had a partial remission and 5 had clinical improvement: 2 with MDS/MPD and 1 with CIMF had hemoglobin responses, and 2 had a spleen response. Using the modified IWG MDS criteria, 1 patient with CIMF and 2 with MDS/MPD had erythroid responses; 1 with MDS/MPD had a platelet response. No patient with a JAK2V617F mutation responded. Grade3/4 non-hematologic toxicities included edema (4), fatigue (4), pleural effusion (2), dyspnea (3), motor and sensory neuropathy (1), pericardial effusion (1), zoster (1), and hematoma (1). There were no thrombotic episodes.Conclusion: The TADA regimen is well-tolerated and yields clinical responses in patients with MDS/MPD or CIMF, even in the absence of the JAK2V617F mutation.

Bone morphogenetic protein antagonist gene NOG is involved in myeloproliferative disease associated with myelofibrosis

In a case with secondary myelofibrosis occurring after essential thrombocythemia, cytogenetic analysis revealed an isolated translocation t(X;17)(q27;q22) in all cells. We found that a bacterial artificial chromosome (BAC) encompassing the breakpoint on chromosome 17 long arm contained only one gene, NOG. We therefore investigated the occurrence of this rare breakpoint in myeloproliferative disorders (MPDs). We identified three more patients with a 17q abnormality in MPDs: myelofibrosis with myeloid metaplasia (MMM); chronic myeloid leukemia positive for t(9;22)(q34;q11) with additional t(4;17)(p15;q22) at diagnosis; and myelofibrosis complicating polycythemia vera. All three cases exhibited a split of BACs containing NOG. The protein encoded by NOG, noggin, acts as an antagonist to bone morphogenetic secreted protein 2 and 4 (BMP2 and BMP4). A comparative analysis of gene expression on Agilent 22K oligonucleotide microarrays in purified CD34+ cells from the blood of MMM patients showed significant downregulation of BMPR2, BMPR1B, BMP2, and BMP8; upregulation of BMP3 and BMP10; and a trend to lower expression of NOG. Thus, given that expression and release of BMPs are important in the induction of osteosclerosis and angiogenic activity, the observed BMP deregulations could be triggered by potential NOG genetic alterations in the four cases here described, and may contribute to the myelofibrotic process characterized by bone marrow stromal reaction including collagen fibrosis, osteosclerosis, and angiogenesis.

PTK787/ZK 222584, a small molecule tyrosine kinase receptor inhibitor of vascular endothelial growth factor (VEGF), has modest activity in myelofibrosis with myeloid metaplasia

Angiogenesis is part of the pathophysiology of myelofibrosis with myeloid metaplasia (MMM). PTK787/ZK 222584 (PTK/ZK) is a novel inhibitor of vascular endothelial growth factor receptors. Twenty-nine patients with MMM received a continuous dosing schedule of PTK/ZK doses of 500 or 750 mg twice daily (BID). Transient potentially PTK/ZK related mild nausea, vomiting, dizziness, fatigue, thrombocytopenia, or anorexia occurred in 15% of patients. Dose limiting toxicities of dyspepsia, proteinurea, and/or mucositis were observed in patients treated with 750 mg BID. One (3%) and five (17%) patients achieved complete remission and clinical improvement, respectively. PTK/ZK has modest activity in patients with MMM.

The Effect of Anabolic Steroids on Anemia in Myelofibrosis with Myeloid Metaplasia: Retrospective Analysis of 39 Patients in Japan

Between 1999 and 2005, 285 patients received new diagnoses of myelofibrosis with myeloid metaplasia (MMM) in Japan. Anemic symptoms were present in 162 patients, and hemoglobin (Hb) concentrations were <10 g/dL in 197 patients. Fifty-five MMM patients were treated with anabolic steroids, and their effect on anemia during MMM was evaluated in 39 patients. A "good" response was defined as an Hb increase of >or=1.5 g/dL, cessation of transfusion dependence, and an Hb concentration of >10 g/dL maintained for at least 8 weeks. A "minimum" response was defined as an Hb increase of >or=1.5 g/dL and transfusion independence for at least 8 weeks. Both good and minimum responses were considered "favorable." Favorable responses were achieved in 17 patients (44%, 8 good and 9 minimum responses). None of the pretreatment variables, such as the lack of transfusion dependence, a higher Hb concentration at the start of treatment, or the absence of cytogenetic abnormalities, were associated with a response to anabolic steroid therapy. Adverse events associated with anabolic steroid therapy were moderate and transient. Two patients required definitive withdrawal of treatment. Thus, anabolic steroids are well tolerated and effective for the treatment of anemia in a subset of MMM patients.

The expression of CXCR4 is down-regulated on the CD34+ cells of patients with myelofibrosis with myeloid metaplasia

Purpose: We studied the expression of the chemokine receptor CXCR4 on circulating CD34+ cells of patients with myelofibrosis with myeloid metaplasia (MMM), and examined its relationship to the severity of disease. Patients and methods: Surface and intracellular CXCR4 expression were measured flow cytometrically in 84 consecutive MMM patients, 16 patients with polycythemia vera (PV), and 20 healthy subjects. In 23 MMM patients, CXCR4 gene expression level was also quantitated by real time-RT-PCR in CD34+ cells. Results: The expression of CXCR4 on circulating CD34+ cells was significantly reduced in patients with MMM ( P < 0.001) as compared to normal controls and patients with PV ( P = 0.01). The levels of CXCR4 mRNA in CD34+ cells were lower in patients with MMM as compared with normal subjects, and were directly correlated with the degree of CXCR4 surface expression, demonstrating that transcriptional defects were the major cause for receptor down-regulation. No statistical association was found between JAK2V617F mutational status and the extent of CXCR4 down-regulation. CXCR4 expression on CD34+ cells inversely correlated with the number of circulating CD34+ cells ( R = − 0.55; P < 0.001), and was severely down-regulated in high risk patients and patients with a high “myelodepletion severity index”. CXCR4 down-regulation was associated with advanced patient age, the presence of severe anemia, thrombocytopenia, and degree of bone marrow fibrosis. Conclusions: Reduced expression of CXCR4 by CD34+ cells is a characteristic of MMM which is associated with the constitutive mobilization of CD34+ cells and occurs in patients with advanced forms of the disease.

Bone changes in myelofibrosis with myeloid metaplasia: a histomorphometric and microcomputed tomographic study

Myelofibrosis with myeloid metaplasia (MMM) is a clonal disorder of the haematopoietic stem cell which can be associated with marrow fibrosis and/or osteosclerosis. Because bone progenitors and mature bone cells are influenced by the marrow microenvironment, cellular and tissular changes were assessed by histomorphometry in MMM. Thirteen patients, with a clinical proven MMM, had a bone biopsy of the iliac crest with double tetracycline labelling and osteoclast count. Histomorphometry was done at the 2D level (bone volume, osteoid parameters, bone histodynamic parameters and osteoclast count) and 3D level by microcomputed tomography. All patients had clusters of abnormal megakaryocytes in bone marrow. Newly apposed bone packets were observed in 12 patients and corresponded to an increased thickness of some bone units with new lamellae or focal areas of woven bone anchored on the pre-existing trabeculae. Osteoid parameters were unchanged, only bone formation rate appeared considerably increased in seven patients. There was a net tendency for decrease in osteoclast number and conversion of trabecular pillars into plates. An uncoupling of bone remodelling was evidenced with an increased life-span of osteoblasts associated with a normal/reduced osteoclast activity. A very complex network of factors is candidate to explain bone changes observed in MMM.

Conventional and experimental drug therapy in myelofibrosis with myeloid metaplasia

Myelofibrosis with myeloid metaplasia (MMM) is currently classified as a classic (ie, BCR-ABL-negative) myeloproliferative disorder characterized by anemia, multiorgan extramedullary hematopoiesis, constitutional symptoms, and premature death from either leukemic transformation or other disease complications. Stem cell transplantation can be curative, but many patients either are not appropriate candidates or do not choose to accept the significant risks associated with transplantation. Current pharmacologic therapy has been beneficial mainly in terms of palliating disease-associated cytopenias, constitutional symptoms, splenomegaly, and other organ damage from excess myeloproliferation. Novel treatment strategies are under investigation, including targeted inhibition of JAK2(V617F), the activating tyrosine kinase point mutation present in about half of patients with MMM. In this article, we review both the old and new pharmacologic options for MMM.

Analysis of JAK2V617F mutation in Chinese patients with myeloproliferative disorders

It is now well-recognized that the activating JAK2(V617F) mutation occurs in the majority of patients with polycythemia vera (PV) and approximately half of those with either essential thrombocythemia (ET) or myelofibrosis with myeloid metaplasia (MMM). Here we analyzed JAK2(V617F) mutation in 137 Chinese patients with myeloproliferative disorders by allele-specific polymerase chain reaction (PCR). DNA was extracted from methanol/acetic acid-fixed cells that had been routinely prepared for cytogenetic analysis. A single point mutation (Val617Phe) was identified in JAK2 in 42 (73.7%) of 57 patients with PV, 40 (58.8%) of 68 with ET, and eight (66.7%) of 12 with MMM.

270: Allogeneic hematopietic cell transplantation in myelofibrosis with myeloid metaplasia – lessons from single center results

Objective: Myelofibrosis with myeloid metaplasia (MMM) is a clonal myeloproliferative disorder of later life not generally considered for allogeneic haematopoietic cell transplantation (alloHCT) until recently. The natural course of the disease varies greatly but is eventually fatal in all. We present the results of 35 consecutive transplants for MMM during the last six years in our institution. - Material and Methods: 25 males and 10 females with primary (n=29) and secondary MMM (n=6) were grafted with unmanipulated bone marrow (n=21) or peripheral stem cells (n=14) from a related (n=10) or unrelated (n=25) donor.