Increased prevalence of polycythemia vera in parents of patients on polycythemia vera study group protocols

An investigation of relatives of 652 patients entered on studies of the Polycythemia Vera Study Group yielded five documented cases of the disease among the parents of patients. When compared with expected values based on the Connecticut Tumor Registry and other population studies a significant increase was found in the lifetime incidence of polycythemia vera in parents of these patients.     

Incidence of polycythemia vera in a defined population.

Abstract: In this retrospective investigation from Malmö, a city well-suited for epidemiologic studies, 177 patients (88 males and 89 females) with polycythemia vera (PV) were identified between 1950 and 1984. The incidence rate (number of cases/100 000/yr) in both sexes increased significantly, being 1.0 in 1950–1959 and 2.6 in 1980–1984 (adjusted to the European age-standardized population). This is the highest rate reported to date. In 1970–1984 the highest age-specific incidence rates (number of cases/100 000/yr) were found in males ≥ 80 yr and females 70–79 yr of age, being 18.3 and 14.6, respectively. A subgroup of 12 (7%) was identified where the PV diagnosis was not obvious on entry into the study but where it became clear during follow-up. 16 PV patients (9%) had verified or suspected arterial hypoxemia caused by a concomitant condition. We conclude that the increasing PV incidence rates, mainly confined to older age groups, are probably due to better case ascertainment.     

Chronic myelogenous leukemia and acute lymphoblastic leukemia occurring in the course of polycythemia vera

We are reporting an unusual case of a 54-year-old woman with polycythemia vera (PV) who developed Ph chromosome positive chronic myelogenous leukemia (CML) 8 years after the initial diagnosis of PV, and terminating in acute lymphoblastic leukemia (ALL), 11 years after the initial diagnosis. Cytogenetic studies revealed a normal female karyotype at the time of diagnosis of PV and the presence of a Ph chromosome at the time of appearance of CML. Southern blot hybridization revealed a bcr rearrangement in both mononuclear cells and granulocytes. The diagnosis of ALL was established on the basis of morphology, positive TdT staining, and monoclonal antibody studies positive for I2, B4, and J5. This case demonstrates the transition of PV into CML, followed by a blastic transformation into acute lymphocytic leukemia. At termination of her disease there were findings compatible with bi-phenotypic leukemia. These findings would suggest that the disease arose in a primitive multipotential stem cell.     

Myelodysplastic transformation of polycythemia vera: case report and review of the literature

We report a case of refractory anemia with excess blasts (RAEB) developing in a 67-year old man with a history of polycythemia vera; results of cytogenetic and immunophenotyping studies are described. In this report the clinical, cytogenetic and hematologic features of myelodysplasia complicating polycythemia vera are reviewed. Results of immunophenotyping and cytogenetic studies, and the preponderance of cases developing after myelosuppressive therapy suggest that in the majority of cases myelodysplasia is treatment-related.     

红细胞单采在真性红细胞增多症治疗中的应用

目的:观察分析红细胞单采在真性红细胞增多症(PV)治疗中的应用方法及效果。方法:对符合国内PV诊断标准的19例患者,运用血细胞分离机进行异常增生红细胞单采,配合临床药物治疗。比较治疗前后患者血常规中Hb、RBC、Hct、WBC、PLT均值变化,采用SPSS17.0统计学软件统计分析。观察依患者公斤体重和Htc设定红细胞采集量,单次采集后Hct降低情况及首次采集前后Hb均值变化与再次采集前后Hb均值变化的差异。结果:治疗后血液Hb、RBC、Hct均值明显低于治疗前,差异有统计学意义(P0.01)。8例完全缓解,7例临床缓解,4例好转,有效率为100%;单次采集Hct平均降低幅度为16.11%。结论:红细胞单采在PV的治疗中具有显著的疗效,单次采集应考虑PV患者血容量绝对增加的情况,根据患者病情和对红细胞去除的耐受情况适当增加采集量。     

Mixed myeloid—lymphoid colonies in a patient with polycythemia vera

Peripheral blood mononuclear cells from a patient with polycythemia vera were cultured in a methylcellulose system employing human serum. Electron microscopy documented the appearance of mixed colonies containing lymphocytes, granulocytes, megakaryocytes, and erythrocytes. In vitro culture characteristics were similar to those seen for other patients with polycythemia vera, ie, colonies grew in the absence of added erythropoietin or other pathway-specific regulators. Plating efficiency was linearly related to the number of cells plated, which supports the concept that each colony arose from a single cell. The appearance of mixed myeloid—lymphoid colonies points to the existence of a primitive stem cell capable of giving rise to multiple hematopoietic cell lines.     

Role of interferon alpha-2a in the treatment of polycythemia vera

We studied the effects of recombinant interferon alpha-2a (IFN-alpha) in 36 patients with polycythemia vera (PV) previously treated with phlebotomy and/or conventional cytostatic agents. In each patient, after at least 2 months of discontinuation of any cytotoxic therapy, the hematocrit (Hmt) was first brought to normal value by phlebotomy; IFN-alpha treatment was then begun at a starting dose of 3,000,000 IU s. c. three times a week. Response to treatment, which was assessed monthly, was defined as persistent normalization of Hmt without concomitant phlebotomy; in non-responsive patients the initial IFN-alpha weekly dosage was progressively increased. Twenty patients were responsive with a median duration of response of 7 months (range 2-25+ months); out of these, 7 patients are still under treatment and responsive at 13+, 17+, 20+, 22+, 23+, 25+, 25+ months. These findings indicate that a cohort, although small, of patients with PV (19.4%) are persistently sensitive to IFN-alpha; in this subset of patients, this cytokine can therefore provide a useful treatment option, since, contrary to conventional therapeutic approaches such as radioactive phosphorus, cytostatic agents, or phlebotomy, IFN-alpha is devoid of harmful side effects. ©1995 Wiley-Liss, Inc.     

Stimulus-specific defect in oxidative metabolism of polymorphonuclear granulocytes in polycythemia vera

We investigated polymorphonuclear granulocyte (PMN) function in polycythemia vera (PV) in relation to healthy controls. PMN oxidative metabolism, assessed by chemiluminescence (CL), was significantly lower in PV patients after stimulation with leukotriene B4 (LTB4) and f-Met-Leu Phe (fMLP) (60% of control), whereas no difference in CL was seen after stimulation with phorbol myristate acetate (PMA) (120% of controls). Spontaneous and fMLP-induced PMN adherence to an albumin-coated plastic surface, as well as spontaneous migration and LTB4 - and fMLP-induced chemotaxis, were similar to controls. This suggests the presence of a stimulus-specific defect in PMN oxidative metabolism in PV.     

Sialic acid of platelets and granulocytes in polycythemia vera

Previous studies have shown that erythrocytes of polycythemia vera (PV) patients have an increased content of sialic acid on their membrane compared with normal erythrocytes. This has been attributed to the presence of an abnormal clone known to proliferate in this disease. Since granulocytes and platelets originate from the same stem cell that is involved in this disease, it was of interest to see whether these cells also bear increased amounts of sialic acid compared with their normal counterparts. While normal values were found for granulocyte populations, elevated values were found for the platelet populations of PV patients.     

Trends in incidence and clinical presentation of temporal arteritis in olmsted county,minnesota, 1950–1985

Ninety-four Olmsted County, Minnesota residents with temporal arteritis (TA) initially diagnosed between 1950 and 1985 (incidence cohort) were identified. The age- and sex-adjusted incidence of TA per 100,000 population age 50 years or older was 17.0 (95% confidence interval [CI] 13.6–20.5), with a marked increase in incidence with age and a threefold greater incidence in women (23.4, 95% CI 18.2–28.7) than in men (7.4, 95% CI 3.7–11.0). The previously described secular increase in TA incidence in Olmsted County women continued from 1970 through 1985, while TA incidence in men declined in this latter time period. Although the frequency of classic clinical manifestations of TA declined over time, the percentage of patients undergoing biopsy who have positive specimens remained relatively constant (women 41%, men 26%). The incidence rate of temporal artery biopsy also increased for women during this period, but declined for men, suggesting that the differing trends in TA incidence by sex may be partially attributable to a detection bias. Future research in TA etiology and epidemiology should focus on possible causal factors linked to the differential TA incidence by sex.     

Further studies of the defective stimulus-response coupling for the oxidative burst in neutrophils in polycythemia vera

We have previously reported that the chemiluminescence (CL) response of neutrophils (PMN) from patients with polycythemia vera (PV) was abnormally low when induced by surface receptor-dependent stimuli, fMLP and leukotriene B4, but normal when elicited by phorbol myristate acetate (PMA). This study documents that this discrepancy of the CL response to fMLP and PMA remained over a wide range of stimuli concentrations, was not due to iron-deficient PV cells and was also observed with the nitroblue tetrazolium assay. Moreover, another surface receptor-dependent agonist, platelet-activating factor, conferred a significantly lower CL response in PV PMN relative to controls. Treatment with alpha interferon or GM-CSF, to increase fMLP receptors, resulted in a similar enhancement of fMLP-induced CL in PV and controls. CL was normal when induced by a number of non-surface receptor-dependent stimuli. Release of lactoferrin in response to fMLP (and PMA) was normal (as was previously reported fMLP-induced chemotaxis and adherence). Thus, this defect is highly specific for oxidative metabolism, and localized to discrete step(s) of the stimulus-response coupling for fMLP, leukotriene B4 and PAF, but conceivably not due to impairment of the dynamic interaction of fMLP with its receptor.     

Leukemogenic risk of hydroxyurea therapy in polycythemia vera,essential thrombocythemia,and myeloid metaplasia with myelofibrosis

In polycythemia vera (PV), treatment with chlorambucil and radioactive phosphorus (p32) increases the risk of leukemic transformation from 1% to 13–14%. This risk has been estimated to be 1–5.9% with hydroxyurea (HU) therapy. When compared with historical controls, the risk with use of HU does not appear to be statistically significant. The leukemogenic risk of HU therapy in essential thrombocytosis (ET) and in myelofibrosis with myeloid metaplasia (MMM) is unknown. HU remains the main myelotoxic agent in the treatment of PV, ET, and MMM. We studied 64 patients with these three disorders, seen at our institution during 1993–1995. The patients were studied for their clinical characteristics at diagnosis, therapies received, and development of myelodysplasia or acute leukemia (MDS/AL). Forty-two had PV, 15 ET, and 6 MMM, and 1 had an unclassified myeloproliferative disorder. Of the 42 patients with PV, 18 were treated with phlebotomy alone, 16 with HU alone, 2 with p32, 2 with multiple myelotoxic agents, and 2 with interferon-α(IFN-α). Two patients from the phlebotomy-treated group, one from the HU-treated group, and 1 from the multiple myelotoxic agent-treated group developed MDS/AL in the larger group, 11 received no treatment or aspirin alone, 18 were treated with phlebotomy alone, 25 with HU, 5 with multiple myelotoxic agents, 2 with p32, 2 with IFN-α, and 1 with melphalan. Study of the entire group of 64 patients showed that only one additional patient (total of 5 out of 64) developed MDS/AL. This patient had been treated with HU alone. Statistical analysis did not show any association between clinical characteristics at diagnosis, or HU therapy, and development of MDS/AL (P = 0.5). Thus, our data provide no evidence suggestive of increased risk of transformation to MDS/AL with HU therapy in PV, ET, and MMM. Larger, prospective studies are needed to study this issue further. © 1996 Wiley-Liss, Inc.     

Identification of JAK2V617F in patients with polycythemia is highly correlated with conventional criteria for diagnosis of polycythemia vera

One hundred and forty four patients with a clinical indication of suspected polycythemia vera (PV), essential thrombocythemia, or idiopathic myelofibrosis were screened for JAK2(V617F) and the mutation frequency was 47, 51, and 50%, respectively. Previous investigations enabled 42 of 66 patients with suspected PV to be definitively diagnosed either as PV according to WHO criteria or to have this diagnosis excluded. Ninety-six percent of those with PV were JAK2(V617F), whereas all patients without PV did not have the mutation. Early screening of suspected PV patients for JAK2(V617F) rapidly identifies nearly all those with PV without invasive or less specific conventional investigations.     

Endogenous BFU-E in peripheral blood in diagnosis of polycythemia vera

Erythroid progenitors (CFU-E and BFU-E) growth in vitro from bone marrow and peripheral blood of patients with polycythemia vera (PV) was studied using a methylcellulose culture technique. The aim of the study was to find out whether the in vitro colony formation of peripheral blood could be used in the differential diagnosis of PV. In all 25 patients studied, endogenous colonies were found in the bone marrow and peripheral blood. The parallel study of both bone marrow and peripheral blood erythroid progenitors indicates that the presence of endogenous BFU-E in peripheral blood is a dependable test for PV. The results presented here showed that the abnormalities in PV erythroid progenitors are expressed at the level of both CFU-E and BFU-E, suggesting multiple changes in the erythroid progenitors. Our finding indicate that peripheral blood BFU-E differ from bone marrow BFU-E with regard to their dependence for further differentiation on BPA, the activity present in PHA-LCM.     

Changes of the blood lymphocyte population following 32P treatment for polycythemia vera

Orally administrated Na2 32PO4 mainly accumulates in bone marrow where it emits beta-particles which may damage cells. Previously, we showed that 32P treatment for polycythemia vera (PVC) increased the phytohemagglutinin reactivity and proportions of T cells in the blood. Now we have examined the effects of 32P treatment for PCV on natural killer (NK) and B-lymphocyte subsets which are considered to undergo their maturation in bone marrow. A mean isotope dose of 240 MBq given to 14 patients reduced the peripheral lymphocyte counts to 60% at 6 weeks. B cells and NK cells were reduced to the highest relative extent followed by HNK-1 cells and T cells. Although the proportion of NK cells was reduced to 50% there was no concomitant reduction of NK activity against K562 cells. Pokeweed mitogen-triggered secretion of IgM was significantly reduced, but not that of IgG or IgA. It is suggested that lymphocytes which mature in bone marrow may be affected to the highest extent by 32P treatment in PCV.     

The effect of interferon alpha on myeloproliferation and vascular complications in polycythemia vera

Abstract: The effect of interferon alpha (IFN) on myeloproliferation and vascular complications was studied in 32 patients (17 female, 15 male; median age 60.5 yr) with polycythemia vera (PV). IFN therapy was initiated at a median time of 19 months after diagnosis. Ten patients were pretreated with chemotherapy in addition to phlebotomy. IFN dose was 12 megaU/wk during the first year, 9 megaU/wk during the second year and 12 megaU/wk thereafter. During IFN alpha treatment hematocrit level was 45.7% and remained at this level after the second year of treatment, compared to 46.5% before IFN. The frequency of phlebotomy before IFN was 0.49/month and dropped to 0.19/month (p<0.0005) during the first year of IFN treatment. IFN normalized high platelet and leukocyte counts in a majority of patients. The incidence of deep venous thromboses was 3.6%/yr before IFN alpha and 1.8%/yr during the first year of treatment. IFN-induced side-effects were mainly flu-like symptoms, fever, fatigue and arthralgia. In conclusion, IFN allowed the reduction of the dose of chemotherapy and decreased the need of phlebotomy. Despite improvement of hematological parameters, it is still uncertain whether IFN alpha can improve clinical symptoms in PV.