Tefferi, Ayalew

Abstract All-trans retinoic acid (ATRA) syndrome is a complex constellation of symptoms that arise in about 15% of patients who receive retinoic acid as therapy for acute promyelocytic leukemia (PML). This syndrome typically consists of fever, dyspnea, weight gain, pulmonary infiltrates, pleural or pericardial effusions, episodic hypotension, renal dysfunction, and leukocytosis. Rarely does this entity present as typical chest pain suggestive of an acute myocardial infarction. A 39-year-old man diagnosed with acute PML treated with idarubicin and ATRA was admitted for febrile neutropenia, nausea, vomiting, cough, and epigastric pain despite being on ciprofloxacin and metronidazole at home. He continued to have low-grade fevers despite being on antibiotics and antifungals. On hospital day three, he was transferred to the CCU for worsening non-radiating left substernal chest pain associated with nausea and vomiting, new inferior lead 2 mm ST segment elevation, lateral lead T wave inversion, troponin and CKMB elevation, and hypotension not responding to frequent fluid boluses. A Swan-Ganz catheter was placed and pressors were started. The patient was found to have a dramatic neutrophil-predominant leukocytosis only hours after a CBC showed neutropenia. He also developed anuric acute renal failure. A cardiac catheterization was considered but could not be performed because of thrombocytopenia and the patient’s renal status. Subsequent EKG’s revealed more impressive changes. New 3 mm ST segment elevations and T wave inversions were noted in the lateral leads, the inferior lead ST segment elevations persisted and new inferior lead T wave inversions were present. An emergent echocardiogram was obtained which showed a significantly decreased LVEF at 36% and global LV hypokinesis without pericardial effusion. The constellation of symptoms was more suggestive of ATRA syndrome versus acute coronary syndrome and intravenous dexamethasone was started. The patient’s chest pain resolved spontaneously over the next three hours, the dramatic EKG findings and elevated cardiac enzymes resolved over the next few days, and the patient was transferred back to the admitting hematology service. A follow-up echocardiogram before discharge revealed a normal LVEF at 74% and no residual wall motion abnormalities. He eventually required hemodialysis for continued renal failure, which was continued as an outpatient after discharge. Of note, the patient’s fever resolved after beginning dexamethasone and multiple blood, urine, stool, and sputum cultures obtained remained negative throughout the hospital stay. This clinical situation presents a very distinct dilemma in how to proceed with clinical care. The presenting symptoms, signs, diagnostics, and imaging alone were all suggestive of a worsening ischemic cardiac process. But in considering the clinical presentation as a whole, especially the concomitant renal failure, fever in the setting of broad-spectrum coverage, and dramatic leukocytosis, we were more convinced of a systemic reaction to recent ATRA use. We maintained a low threshold for beginning an acute coronary syndrome protocol involving antiplatelet agents but were supported in our diagnosis by the patient’s remarkable recovery shortly after beginning intravenous steroids.

Abstract Idiopathic HES is a myeloproliferative disorder (MPD) characterized by persistent overproduction of eosinophils resulting in organ damage. In a small subset of patients (pts), the disease is caused by the FIP1L1-PDGFR-α fusion tyrosine kinase. Its expression has been associated with complete clinical responses to therapy with tyrosine kinase inhibitor (TKI) imatinib mesylate. In contrast, there is no specific therapy for pts with HES lacking FIP1L1-PDGFR-α expression and corticosteroids are used for palliation. Alemtuzumab (Campath-1H™) is a humanized rat monoclonal antibody directed against the CD52 antigen. Since CD52 is expressed on eosinophils, we evaluated its efficacy in pts with FIP1L1-PDGFR-α-negative symptomatic HES. A total of 9 pts (5 male, 4 female) received alemtuzumab in weekly cycles at the dose of 30 (8 pts) or 10 (1 pt) mg 3 times a week intravenously or subcutaneously. During the first week alemtuzumab was given in escalating doses (3→10→30mg) to assure tolerance. Median age was 53 years (range 24–70), time from HES diagnosis to alemtuzumab therapy 34 months (range 4–195), median WBC 17×109/L (range 6.9–82.4), absolute eosinophil count (AEC) 9×109/L (range 0.7–30), and bone marrow eosinophils 23% (range 10–68). Three pts had abnormal cytogenetics: del11(q23), +8, and t(5;6). Pts had received a median of 3 prior therapies (range 2–6), including corticosteroids (prednisone; n=9), imatinib (n=7), dasatinib (n=3), interferon-alpha (n=3), hydroxyurea (n=3), nilotinib (n=2), and cladribine (n=2). A total of 121 weekly cycles have been administered (median 13 cycles) thus far. A complete hematologic response (CHR; i.e. AEC normalization) was observed in 8 pts (89%) within 4 weeks of therapy; peripheral blood eosinophils were undetectable in 6 of 8 CHR pts. Follow-up bone marrow specimens were available in 3 pts while in CHR (after a median of 5.5 weekly alemtuzumab cycles) showing complete response in 2 and partial response in 1 pt. In addition, 3 pts that were on prednisone and 2 on hydroxyurea at the start of alemtuzumab discontinued them within 2 weeks into therapy. One pt had a remarkable partial response with reduction of AEC from 47.5 to 1×109/L after 8 weekly cycles of alemtuzumab; this patient was on 3g of hydroxyurea and 80mg of prednisone at the start of alemtuzumab and was able to discontinue hydroxyurea and decrease prednisone to 10mg while on alemtuzumab. Five pts who stopped alemtuzumab experienced relapse after a median time of 3.5 weeks (range, 1 to 10) and 1 relapsed while receiving alemtuzumab after 14 weekly cycles. Three pts are currently on alemtuzumab: 2 receiving 30 mg weekly as maintenance while in CHR after 8+ and 19+ weeks, respectively, and 1 with partial response is receiving 30mg 3 times a week. One relapsed pt was rechallenged with alemtuzumab and normalized AEC again. Alemtuzumab was generally well tolerated. Grade 3–4 drug-related toxicities occurred in 2 pts, 1 with neutropenia and 1 with infusion-related fever, which led to transient and complete alemtuzumab discontinuation, respectively. Two pts experienced CMV reactivation that required therapy. In summary, alemtuzumab was well tolerated and has remarkable activity in pts with FIP1L1-PDGFR-α-negative HES. Different dose schedules of alemtuzumab that include prolonged maintenance therapy are warranted to improve the response duration. Updated clinical results will be presented.

Abstract Background: Scant data exists regarding the burden of fatigue and constitutional symptoms in patients with myeloproliferative disorders (MPDs) (essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis with myeloid metaplasia (MMM)). Methods: An Internet based survey of MPD patients regarding clinical course, blood counts, constitutional symptoms, and fatigue (FACT-AN and Brief Fatigue Inventory (BFI)). Results: Patient Demographics: A total of 1179 MPD patients (median age 56; 41.4% male) internationally (76% USA: 50 states, 30 countries, 6 continents) responded to the survey. Self reported diagnoses were PV (35%), ET (26%), or MMM (39%). Clinical History: 1025 patients (87%) had undergone MPD therapy (drugs 70.5%, phlebotomy 44.1%, other 16%). Thrombosis (n=261, 22%), hemorrhage (N=272; 23%), and splenomegaly (N=478 (43%) were frequently reported. Blood tests (available in 917) showed 39% were anemic, 7% transfusion dependent. Symptoms: Fatigue, pruritus, night sweats and bone pain were present across the majority of MPD patients (see table). Additionally it was observed that these symptoms appeared with nearly equal frequency in PV as in MMM patients. However MMM patients displayed more advanced features (fevers, night sweats and weight loss). MPD Associated Constitutional Symptoms in 1179 Patients SYMPTOM PV (N=405) ET (N=304) MMM (N=456) MISSING (N=14) TOTAL (N=1179) P VALUE Fatigue 344 (84.9%) 220 (72.4%) 381 (83.6%) 7 945 (81.1%) <0.0001 Pruritus 265 (65.4%) 120 (39.5%) 228 (50.0%) 3 613 (52.6%) <0.0001 Night Sweats 199 (49.1%) 123 (40.5%) 254 (55.7%) 4 576 (49.4%) 0.0002 Bone Pain 174 (43.0%) 125 (41.1%) 214 (46.9%) 4 513 (44%) 0.2480 Fevers 53 (13.1%) 26 (8.6%) 81 (17.8%) 2 160 (13.7%) 0.0013 Weight Loss 39 (9.6%) 22 (7.2%) 93 (20.4%) 0 154 (13.2%) <0.0001 Spleen Pain 17 (4.2%) 27 (8.9%) 30 (6.6%) 4 74 (6.3%) <0.0001 Fatigue (82% MPD linked) was significantly increased across all MPD subtypes compared to published controls for both the BFI (P<0.0001) and Fact-An (P<0.0001). Additionally 69% curtail social activity because of fatigue, 35% need assistance with activities of daily living, and 11% reported MPD associated medical disability. Fatigue strongly correlated with multiple MPD disease features including: anemia, bone pain, constitutional symptoms, pruritus, splenic pain, smoking, thrombosis, and hemorrhagic events (all p<0.0001). Interestingly, even in “asymptomatic” MPD patients (those without anemia, splenomegaly, or thrombohemorrhagic complications) (n=279)) 24% (41% PV, 31% ET, 28% MMM) described significant fatigue worse than published controls. Conclusions: Fatigue and other constitutional symptoms are a significant burden to MPD patients, despite current therapies employed. Additionally fatigue is also a significant problem even in MPD patients lacking other advanced disease features. Clearly, direct attempts to improve fatigue (through pharmacologic and non-pharmacologic interventions) are necessary.

Abstract Background: Constitutive activation of the JAK-STAT signaling pathway through acquisition of the JAK2V617F mutation plays a key role in the pathogenesis of related myeloproliferative disorders (MPD) including polycythemia vera (PV), agnogenic myeloid metaplasia (AMM), and essential thrombocythemia (ET). Hypothesis: Genetic variation in JAK2 and/or the cytokine receptor genes for erythropoietin (EPOR), thrombopoietin (MPL), and granulocyte colony stimulating factor (GCSFR), influences the expression of a specific disease phenotype (PV, AMM, or ET). Methods: We studied 179 Caucasian MPD patients (PV=84, AMM=58, ET=37) for genetic variation in 4 candidate genes (i.e. JAK2, EPOR, MPL, GCSFR) through single nucleotide polymorphism (SNP) and haplotype analyses. A total of 32 LD (linkage disequilibrium) tag-SNPs with a minimum allele frequency of at least 5% were selected from the HapMap CEU database (JAK2=13, EPOR=4, MPL=5, GCSFR=10). Genotyping was performed using archived DNA from enriched neutrophils. Results: Seventy six (94%), 26 (45%), and 14 (38%) patients with PV, AMM, and ET, respectively, carried the JAK2V617F mutation. Significant differences in allele frequencies was observed at 6 SNP loci (rs10758669, rs3808850, rs7849191, rs7046736, rs10815148, and rs12342421, p-values < 0.0005), all within the JAK2 gene, in comparing our overall study population with the founder Caucasian population in the HapMap database. In the additive genotype-phenotype association analysis adjusted for gender and age at diagnosis, 3 SNP loci in JAK2 (rs7046736, rs10815148, and rs12342421) were found to be significantly, but reciprocally associated with PV (p-values < 0.00006, odds ratio=0.37, 2.82, and 2.39, respectively) and ET (p-values < 0.002, odds ratio=2.50, 0.36, and 0.41, respectively), but not AMM, in terms of the minor allele being ’protective’. These three SNPs were all in high LD, with the ’r2’ measures of LD between 0.59 and 0.71. Furthermore, 2 additional JAK2 SNP loci (rs10758669, p-value = 0.0024 and rs10974947, p-value = 0.0046) were significantly associated with PV (odds ratio=1.88 and 0.47, respectively), but not ET or AMM. Similarly, presence of the minor allele at a single SNP locus in EPOR (rs318699, p-value = 0.0012) was significantly associated with PV only (odds ratio=2.16). For the phenotype-genotype intragene haplotype analyses, the EPOR intragene haplotypes GAAA and GGAA were significantly associated with PV (simulated global p-value = 0.058, simulated individual p-values 0.0013 and 0.0068, haplotype frequency of 35% and 56%, respectively). In addition to EPOR, 6 intragene haplotypes within JAK2 where significantly associated with PV (simulated global p-value < 0.0001, individual simulated p-values < 0.03). Conclusion: The current study demonstrates a genotype-phenotype association that involves JAK2 and EPOR in the setting of PV, but not that of AMM. Some JAK2 SNPs were found to be associated with both PV and ET but in opposite direction. Therefore, genetic variation among MPDs might contribute to phenotypic diversity in the presence of specific mutations.

Abstract The FIP1L1-PDGFR-α fusion kinase induces hypereosinophilic syndrome (HES) in a subset of patients (pts). Imatinib is a potent inhibitor of PDGFR-α and has been associated with durable hematologic responses in pts with HES. However, development of kinase domain mutations may hamper TKI activity, underscoring the need for novel agents to prevent or overcome resistance. We evaluated the efficacy of the novel TKI EXEL-0862 in FIP1L1-PDGFR-α-expressing cells. In 72-hour MTS assay, EXEL-0862 inhibited EOL-1 cell proliferation with an IC50 of 1.0 nM and markedly decreased phosphorylation of STAT3 and Erk1/2, suggesting inhibition of downstream targets of PDGFR-α. More important, EXEL-0862 induced dose-dependent inhibition of PDGFR-α phosphorylation in peripheral blood mononuclear cells from a pt with HES. Exposure of EOL-1 cells to EXEL-0862 10 nM for 24 hours caused apoptosis as evidenced by flow cytometry (annexin-V/PI staining) and transmission electron microscopy. This was coupled with time-dependent cleavage of caspases-3, caspase-9, and PARP and with mitochondrial damage as reflected by cytochrome c translocation into the cytosol, and a diminished mitochondrial transmembrane potential. Of note, apoptotic features were not evident after 16 hours of EXEL-0862 exposure. Immunoblots showed marked downregulation of Mcl-1, but not of Bcl-2, Bcl-XL, or Bax. To elucidate the mechanism of Mcl-1 cleavage, EOL-1 cells were exposed to 10 nM EXEL-0862 for 6 hours followed by cycloheximide (5 μg/ml), a potent translation inhibitor, which resulted in marked Mcl-1 turnover. Treatment with the proteasome inhibitor MG-132 failed to abrogate EXEL-0862-induced Mcl-1 cleavage, suggesting proteasome-independent degradation. Rather, a decrease of pro-form Mcl-1 (p42) and increase of the cleaved Mcl-1 peptide form of Mcl-1 (p28) coincided with caspase-3 activation. Pretreatment with 20 μM pan-caspase inhibitor Z-VAD abolished EXEL-0862-induced Mcl-1 cleavage, pointing to a caspase--dependent mechanism. Collectively, our results establish EXEL-0862 as a solid candidate for the targeted treatment of pts with FIP1L1-PDGFR-α-positive HES.

Abstract Background: Lenalidomide (Revlimid; Celgene Co. New Jersey, USA) has ameliorated cytopenias and induced cytogenetic responses in patients with MDS, especially those with del(5)(q13q33)) (List et. al. NEJM2005;352:549–57)., and myelofibrosis with myeloid metaplasia with del(5)(q13q33) (Tefferi et. al. Blood 2006 epub). However, no data exist regarding lenalidomide efficacy in patients with del(5)(q13q33) who have progressed to AML. Case: An 82 year old woman presented to our institution with a several year history of MDS associated with mild anemia, thrombocytosis, and isolated del(5)(q13q33). She had required no prior MDS-specific therapy, and had suffered no thrombohemorrhagic complications. Subsequently, in response to worsening anemia (hemoglobin 9.9 g/dL), leukopenia (1.5 × 109/L), and neutropenia (0.45 × 109/L), with the appearance of peripheral circulating blasts (2%), a bone marrow was obtained. The marrow demonstrated minimally differentiated AML (AML-M0) with 34% blasts and trilineage dysplasia. Karyotypic analysis showed 11 of 20 metaphases containing the del(5)(q13q33), while allele specific PCR demonstrated the presence of JAK2V617F. Therapy: After discussion of the therapeutic alternatives with the patient (including the high risk and likelihood of failure with conventional induction chemotherapy with AML that arises in the context of MDS in an elderly patient (median survival 3–4 weeks - DeLima et. al. Br J Haem1996;93:89), and the responses reported with lenalidomide for patients with interstitial chromosome 5q deletions and MDS, she elected to begin lenalidomide at a dose of 10mg/day. She tolerated the agent well, without any adverse effects. After three months of treatment, she had normal peripheral blood counts, and no evidence of circulating blasts. A repeat marrow exam showed a slightly hypercellular marrow with 5% blasts, improved granulocyte maturation, and a completely normal female karyotype (>20 metaphases counted). This would be considered a partial response by the International Working Group for Acute Myeloid Leukemia (Cheson et. al. JCO2003;21:4642–49). After two additional months of lenalidomide the patient had evidence of disease progression, with recurrent leukopenia, thrombocytopenia, and 10% blasts in the marrow. Additionally, karyotype showed clonal progression, with 10/30 metaphases having the del (5) (q13q33), and 7 of them with multiple other structural abnormalities including loss of 17p. Alternative therapy was initiated. Discussion: To our knowledge, this is the first report of lenalidomide monotherapy resulting in achievement a solid 5 month partial remission in an elderly patient with high risk AML . The patient reported a high quality of life during this time, and was free of transfusions, hospitalization, and infection. The co-existence of the JAK2V617F mutation, a finding more commonly associated with myeloproliferative disorders, is an additional intriguing aspect to this case. JAK2V167F has been described in 6.2% MDS patients with del(5)(q13q33) (Ingram et. al. Leukemia 2006 April 16), and the clinical significance is unknown. Conclusions: Few agents offer legitimate therapeutic benefit to elderly patients with secondary AML. Lenalidomide may have activity as monotherapy against AML arising from del(5q)-associated chronic myeloid disorders. However, the apparent ability of the disorders to undergo clonal evolution suggests that combination or sequential therapy of lenalidomide with other novel or traditional agents should be explored.

Abstract Background: Overall prognosis in CMML is unfavorable. The only curative option is ASCT, yet the limited data available from the largest reported series, reports 2 year overall (OS) and disease free (DFS) survival of only 21% and 18%, respectively [Kroger et al, BJH 2002, 118: 67]. Data on DLI for CMML are generally restricted to case reports. We retrospectively reviewed our experience of ASCT and DLI for adults with CMML. Patients: Seventeen consecutive patients (11 males) with CMML underwent ASCT from 1992 to 2004. At transplant, median (range) age was 50 years (26–60), duration of disease 7 months (2.5–44), and bone marrow (BM) blast count 6% (1–58%). Prior to transplant, 11 had evolved into acute myeloid leukemia (AML). Of these, 10 received standard induction chemotherapy but only one achieved complete remission (CR); 5 had persistent CMML and 4 refractory AML. Karyotype at transplant was either normal (n=9) or revealed isolated monosomy 7 (n=4), complex (n=1), or single, nonrecurrent abnormalities. ASCT: Conditioning was Cytoxan/Total Body Irradiation in all but one who received a non-myeloablative (NMA) regimen (cladrabine/ATG/thiotepa). Stem cell source was HLA-identical sibling in 14 patients and unrelated in 3 peripheral blood (PB) in 7, BM in 8, or both in 2. Median BM mononuclear cell/kg dose was 2.3 (1.7–4.15) x 108 and PB CD34 cell/kg was 5.12 (0.94–7.29) x 106. Graft versus host disease (GVHD) prophylaxis was cyclosporin alone (n=3), with methotrexate (n=12), or prednisone (n=1) or was tacrolimus/methotrexate (n=1). Post-transplant course: All but one patient who died on day 11 of sepsis engrafted (sustained ANC > 500) at a median of 19.5 days (13–31). CR was documented in 13 (76%) post-ASCT. Acute GVHD was grade II-IV (75%) and III-IV (37.5%) and chronic GVHD was extensive (n=37.5%). Seven (41%) demonstrated relapse or persistent disease at a median of 6 months (3–55.5) and 13 (76%) have died due to disease (n=6) or transplant related mortality (n=7). DLI: Six patients underwent DLI for morphologic (4 recurrent/persistent CMML, 1 early AML with extramedullary disease) or cytogenetic relapse (n=1), at a median of 19.5 days (6–52) post-relapse. Median BM blast count at DLI was 3% (1–22%). The median CD3+ cell dose infused was 30.45 x 107 cells/kg (11.2–45.5), given in a median of 3 infusions (range: 1–3). Four did not respond, but two (one with cytogenetic and one with morphologic relapse) achieved a durable CR of 15 months each, both had extensive CGVHD, from which one died of complications. The other relapsed but failed to respond to a second DLI and died of disease. Survival: For the entire cohort, median DFS and OS were 6 months and 7 months, respectively. At last follow up, 4 remain alive, 3 in continuous CR (18%), at 12, 29 (treated with the NMA regimen) and 116 months, respectively. Of the 3 patients surviving in remission, all had transformed to AML prior to ASCT and only one had achieved CR following induction chemotherapy. Multivariate analysis failed to demonstrate any significant effect of age, duration of disease, BM blast %, karyotype or induction chemotherapy on RFS or OS, likely reflecting the small numbers available for analysis. Conclusion: The current study demonstrates anti-CMML activity of both ASCT and DLI although overall outcome is less than encouraging and unpredictable. Novel approaches are needed.

Abstract BACKGROUND. Several studies have recently reported on the occurrence of a JAK2 V617F mutation in myeloid cells from the majority of patients with polycythemia vera (PV). The clinical relevance of this novel observation is currently under study. Similarly, there is limited information regarding the correlation of JAK2 V617F mutational status and neutrophil PRV-1 transcript level in PV, secondary polycythemia (SP) and other myeloproliferative disorders (MPD). METHODS. In a single institutional study, mutation screening for JAK2 V617F was performed in DNA derived from archived blood granulocytes from 63 consecutive patients with PV in whom current diagnostic criteria were strictly applied and diagnosis confirmed by bone marrow histology. Concomitant quantitative analysis of neutrophil PRV-1 expression was performed in 28 of the 63 patients and the results of both JAK2 V617F and PRV-1 analysis in these 28 patients were compared with those from another 22 patients with essential thrombocythemia (ET), 10 with myelofibrosis with myeloid metaplasia (MMM), 19 with SP, and 11 healthy volunteers. RESULTS. The 63 patients with PV were followed for a median of 33 months (range 3–324) from the time of initial diagnosis. During this period, 3 patients have died including 2 from acute myeloid leukemia (AML). Disease transformation into either AML or MMM has occurred in 2 and 4 patients, respectively. The median time from diagnosis to the time of mutation analysis was 12 months (range 0–306). JAK2 V617F was detected in 58 of the 63 patients with PV (92%; homozygous in 21%). The clinical phenotype of the 5 patients with wild-type allele was otherwise typical for the disease. A statistical comparison between JAK2 V617F heterozygotes (n=45) and homozygotes (n=13) in PV did not reveal significant associations in regards to age, gender, leukocyte or platelet count at diagnosis, disease duration, or the incidences of thrombosis or bleeding. However, JAK2 V617F homozygotes, compared to their heterozygote counterparts, displayed significantly higher hemoglobin level at diagnosis (p=0.001), increased incidence of pruritus (69% vs. 38%; p=0.04), and a higher rate of fibrotic transformation (23% vs. 2%; p=0.009). The overall (homozygous) JAK2 V617F mutational frequencies in the other study patients with ET, MMM, SP, and healthy controls were 55% (0%), 30% (0%), 0%, and 0%, respectively. The corresponding figures for increased PRV-1 expression in these patients were 18%, 20%, 21%, and 9% as compared to 89% in PV. In patients with either ET or MMM, the likelihood of detecting JAK2 V617F was significantly higher in the presence of an increased PRV-1 expression (83% vs. 38%; p=0.05). Similarly, in patients with PV, homozygous as compared to heterozygous JAK2 V617F correlated with higher levels of PRV-1 expression (p=0.07). CONCLUSIONS. The current clinical study demonstrates a mutant allele dose effect on erythrocytosis, PV-characteristic clinical features, and granulocyte PRV-1 expression in PV. Furthermore, compared to the PRV-1 assay, mutation screening for JAK2 V617F displayed greater specificity in distinguishing PV from SP.

Abstract Background: Allogeneic hematopoietic stem cell transplantation is potentially curative in agnogenic myeloid metaplasia (AMM) but is associated with substantial mortality and morbidity that necessitates accurate identification of patients in whom benefit outweighs risk. The current single institutional study investigates prognostic variables in transplant-eligible patients with AMM with the main objective of improved discrimination between intermediate- and high-risk patient categories. Methods: Patients diagnosed with AMM before the age of 60 years and seen at Mayo Clinic were identified and the diagnosis confirmed. Relevant demographic, clinical and laboratory characteristics were abstracted and the impact of various parameters on overall survival was evaluated with univariate and multivariate analysis. Results: A cohort of 159 patients (median age 52 years, range 18–60; 89 males) with AMM is described. Median follow-up from initial diagnosis was 63 months (range 0–300). During this period, 102 patients have died; overall median survival 79 months. Multivariate analysis of parameters measured in all study patients at diagnosis identified thrombocytopenia (platelet count < 100 x 109/L) as the strongest predictor of inferior survival (p=0.002). In addition, a hemoglobin level of <10 g/dL (p=0.003), white blood cell count of either <4 or >30 x 109/L (p=0.03), and older age (p=0.02) were also found to be independent indicators of poor prognosis. However, when the analysis included parameters that were measured in variable proportion of the study population, the independent prognostic factors for poor survival were thrombocytopenia (p=0.0001), anemia (p=0.01), and the presence of unfavorable cytogenetic abnormalities (0.001). Based on the above findings, we constructed a new complete blood count (CBC)-based prognostic scoring system (Figure 1) that performed better than the Dupriez scoring system in discriminating intermediate- from high-risk patient categories(Figure 2). Figure Figure Conclusions: Thrombocytopenia is a strong predictor of poor survival in transplant-eligible patients with AMM. The incorporation of platelet count into the Dupriez prognostic scoring system might allow the construction of an improved, CBC-based scoring system that can accurately identify high-risk as well as intermediate-risk patients with AMM.

Abstract Background: In essential thrombocythemia (ET), homozygosity for the JAK2 V617F mutant allele is rare despite the frequent (23–57%) occurrence of the heterozygous state. This is in direct contrast with the situation in polycythemia vera (PV) where homozygosity for the mutation is seen in 25–33% of the cases. The particular observation is consistent with what has been observed in vitro as well as in animal studies where JAK2 V617F has been associated with induction of erythropoietin hypersensitivity in cell lines and erythrocytosis in mice (James et al. Nature2005;434:1144). Therefore, regardless of whether or not JAK2 V617F represents a primary event in myeloproliferative disorders, it is probable that it promotes a PV phenotype. In the current study, we explore this hypothesis as well as investigate the long-term prognostic relevance of the mutation in a well defined cohort of patients with ET seen at a single institution. Methods: The diagnosis of ET was according to the WHO classification of tumors (Jaffe ES et al. Lyon, IARC press, 2001). All patients were seen at the Mayo Clinic and patient characteristics and subsequent clinical events were determined both retrospectively (chart review) and prospectively (by means of a questionnaire sent both to patients and their primary doctors). In addition date and cause of death were confirmed by probing both the social security index and the national death index. DNA for mutation screening was derived and sequenced from either archived unsorted cells from the bone marrow or prospectively collected peripheral blood granulocytes according to previously published methods (Levine et al. Cancer Cell, 2005;7:387). Results: The study cohort consisted of 150 consecutive patients with ET including 99 females and 51 males (median age 49.8 years; range 16.8–98). Overall, JAK2 V617F was detected in 73 patients (48.7%) but none were homozygous for the mutant allele. At diagnosis, ET patients with JAK2 V617F were significantly older (median age of 53.5 vs. 42.3; p=0.02) and also displayed higher readings of both hemoglobin level (p=0.0002) and leukocyte count (p=0.005). All study patients have now been followed for a median of 11.4 years from diagnosis (range 0–32.7) and follow-up period was similar between the two mutational categories (p=0.53). During this period, 32 patients have died and the median survival for the entire group was 19.3 years; 21.9 and 17.7 years in the absence and presence of the mutation, respectively (p=0.09). Disease transformation into acute leukemia, myelofibrosis, and PV occurred in 6 (4%), 15 (10%), and 8 (5.3%) patients, respectively, and the only significant difference between the two mutational categories in this regard was the higher incidence of transformation into PV in patients with the mutation (p=0.02). Multivariate analysis identified age, hemoglobin level, and thrombosis history at diagnosis but not JAK2 V617F mutational status as independent risk factors for survival. Conclusion: Although the presence of JAK2 V617F in ET appears to promote a PV phenotype, it might not carry treatment-relevant information.