Incidence of chronic myeloproliferative disorders in the city of Göteborg, Sweden 1983-1992.

An estimation of the incidence of polycythaemia vera (PV), essential thrombocythaemia (ET) and chronic idiopathic myelofibrosis (CIM) in the city of Göteborg, Sweden during the period 1983-1992 was made from a retrospective case analysis of patients registered as chronic myeloproliferative disorders (CMPD) at the Departments of Medicine and the Department of Pathology of the two major hospitals in the city. A total of 125 cases of PV, 56 males and 69 females were identified. The number of cases as well as the age-specific incidence increased with age. The over all annual gender-specific incidence was 2.69 cases per 10(5) male inhabitants and 3.12 cases per 10(5) female inhabitants. The incidence of PV in relation to the European Standard Population was 2.02 cases per 10(5) inhabitants and year. There were 72 cases, 20 males and 52 females, with ET. The age-specific incidence was in all ages higher for females than for males and increased with age. The annual gender-specific incidence was 0.96 per 10(5) male inhabitants and 2.35 per 10(5) female inhabitants. The incidence of ET in relation to the European Standard Population was 1.28 per 10(5) persons and year. There were 20 cases of CIM, 11 males and 9 females. The annual gender-specific incidence of CIM was 0.53/10(5) male inhabitants and 0.41/10(5) female inhabitants. The incidence of CIM in relation to the European Standard Population was 0.31 per 10(5) persons and year. Seven persons, 2 males and 5 females, had a CMPD that could not be included in any of the above-mentioned groups, but were registered as CMPD, unclassified.

Plasma erythropoietin concentrations in polycythaemia vera with special reference to myelosuppressive therapy.

In 80 patients with polycythaemia vera (PV) a total of 108 venous blood samples were obtained and analysed for EDTA-plasma erythropoietin (EPO) concentration. At the time of study 21 of the PV patients were newly diagnosed and had prior to blood sampling neither received phlebotomy treatment nor therapy with myelosuppressive agents; these subjects had a mean plasma EPO concentration of 0.5+/-0.9 IU/L. Thirty-seven patients treated with phlebotomy only had a mean plasma EPO concentration of 2.5+/-2.9 IU/L. The mean plasma EPO concentrations for 26 patients treated with hydroxyurea, 13 patients treated with radiophosphorous and 11 patients given a combination of myelosuppressive agents were 8.9+/-8.0, 10.9+/-12.6 and 7.2+/-7.4 IU/L, respectively. Untreated patients and patients on phlebotomy only had significantly lower values for plasma EPO than patients on therapy with myelosuppressive drugs. This finding persisted also after a correction for differences in haemoglobin levels had been introduced. Thereby, the present results would suggest a difference in the EPO feedback system in untreated and phlebotomised PV patients compared to PV patients treated with myelosuppressive agents.

Granulocyte-macrophage colony-stimulating factor as immunomodulating factor together with influenza vaccination in stem cell transplant patients.

The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the serological response at influenza vaccination was studied in 117 patients who had undergone stem cell transplantation (SCT). The vaccine response was evaluated as significant increases in levels of influenza hemagglutination-inhibition (HAI) antibodies and of IgG antibodies measured by enzyme-linked immunosorbent assay (ELISA). There was no difference in antibody response to either influenza A or B in 64 patients who received GM-CSF at vaccination, compared with the 53 who did not. In the subgroup of allogeneic SCT patients, HAI showed that the response rate to the influenza B vaccine was significantly higher in the treatment group (P<.05). ELISA showed that autologous SCT patients with breast cancer who received GM-CSF had a better response to influenza A (P<.05) and B (P<.01). At early vaccination, 4-12 months after stem cell transplantation, these responses were more pronounced. GM-CSF appears to improve the response to influenza vaccination in some groups of SCT patients, but only to a limited extent.

The red cell mass, plasma erythropoietin and spleen size in apparent polycythaemia.

It has been shown previously that measurement of the spleen size and plasma erythropoietin (EPO) concentration are valuable adjuncts in the diagnostic work-up of patients with polycythaemia vera. The aim of the present work was to evaluate their value in the assessment of apparent polycythaemia (AP). Therefore, over a 24-month period we routinely performed bone marrow biopsies, measurement of red cell mass (RCM) and plasma volume (PV), spleen size determination by gamma camera scintigraphy and determination of the plasma EPO concentration in consecutive patients referred to us because of elevated values for packed cell volume (>0.48 in females and >0.51 in males). After having excluded patients with clonal and secondary polycythaemias we were left with 38 patients (27 males and 11 females) with AP. In all of them the measured RCM was within normal range, i.e. <36 ml/kg for males and <32 ml/kg for females. The subjects were characterized by moderate increase in RCM and a concomitant moderate decrease in PV. Thus, as an average the measured RCM exceeded the predicted values by 14% in males and by 12% in females; conversely, as compared to the predicted values the average measured value for PV was reduced by 17% in males and by 8% in females. The average RCM for males was 29+/-3 ml/kg; the corresponding figure for females was 23+/-4 ml/kg. It was shown that 86% of the subjects had plasma EPO concentrations within the control range; the remaining had values slightly above or below the control range. The mean posterior spleen scan area was 57+/-16 cm2 and mean left lateral area 57+/-17 cm2; the reference value for spleen scan area (for both projections) is 57+/-12 cm2. Of the patients 35/38 (92%) had a spleen scan area within the mean+2SD for controls and 38 subjects (100%) had values within the mean+3SD. It is concluded that measurement of plasma EPO and a careful assessment of the spleen size should always be considered in the evaluation of patients with elevated values for venous packed cell volume.

Impact of endogenous thrombopoietin levels on the differential diagnosis of essential thrombocythaemia and reactive thrombocytosis.

By using the newly commercialized Quantikine human TPO immunoassay, plasma thrombopoietin (TPO) concentrations were measured in 12 patients with essential thrombocythaemia (ET), 13 patients with reactive thrombocytosis (RT) and 11 healthy volunteers. For the healthy volunteers the mean plasma TPO concentration was 21.1+/-11.0 pg/ml. The mean plasma TPO concentration in the group of RT was slightly lower (16.4+/-8.6 pg/ml) but did not differ significantly from the control group. The mean plasma TPO concentration in ET patients (44.1+/-45.2 pg/ml) was significantly (p<0.05) higher than the mean for RT patients, but did not differ statistically from the mean of healthy volunteers. These data suggest a defective clearance of plasma TPO in patients with ET.

Plasma erythropoietin by high-detectability immunoradiometric assay in untreated and treated patients with polycythaemia vera and essential thrombocythaemia.

By using an immunoradiometric method with a stated detection limit of < or =1 IU/l (stated normal reference limit in adults 3.7-16 IU/l) we determined EDTA-plasma erythropoietin (EPO) in 58 patients with polycythaemia vera (PV) and 49 patients with essential thrombocythaemia (ET). At the time of blood sampling, 20 of the PV patients were newly diagnosed and untreated, 23 were treated by phlebotomy only, and 30 also received myelosuppressive treatment (with 32P, hydroxyurea or alpha-interferon). Of the ET patients 24 were untreated and 28 received myelosuppressive therapy. For comparison plasma EPO was also determined in 10 patients with pseudopolycythaemia (PP). In this latter group the results for plasma EPO agreed well with the cited normal reference limits. The majority of untreated PV patients (12/20) had undetectable plasma EPO concentration, and the remainder all had values below the lower normal reference limit. Plasma EPO in PV was not significantly influenced by phlebotomy therapy. Twelve of the 24 untreated ET patients (50%) had plasma EPO values below the reference interval (undetectable in 2 patients). The mean EPO concentration was significantly lower in PV patients receiving phlebotomy therapy than in patients with untreated ET. In the total material of PV and ET treated with myelosuppressive agents the PV patients showed significantly lower values for EPO concentration than did patients with ET. The present results support the view that EPO measurements by high-detectability methods are diagnostically useful and should be included in the panel of new criteria for the diagnosis of PV.

Treatment of anemia in myelodysplastic syndromes with granulocyte colony-stimulating factor plus erythropoietin: results from a randomized phase II study and long-term follow-up of 71 patients.

Treatment with erythropoietin (epo) may improve the anemia of myelodysplastic syndromes (MDS) in approximately 20% of patients. Previous studies have suggested that treatment with the combination of granulocyte colony-stimulating factor (G-CSF) and epo may increase this response rate. In the present phase II study, patients with MDS and anemia were randomized to treatment with G-CSF + epo according to one of two alternatives; arm A starting with G-CSF for 4 weeks followed by the combination for 12 weeks, and arm B starting with epo for 8 weeks followed by the combination for 10 weeks. Fifty evaluable patients (10 refractory anemia [RA], 13 refractory anemia with ring sideroblasts [RARS], and 27 refractory anemia with excess blasts [RAEB]) were included in the study, three were evaluable only for epo as monotherapy and 47 for the combined treatment. The overall response rate to G-CSF + epo was 38%, which is identical to that in our previous study. The response rates for patients with RA, RARS, and RAEB were 20%, 46%, and 37%, respectively. Response rates were identical in the two treatment groups indicating that an initial treatment with G-CSF was not neccessary for a response to the combination. Nine patients in arm B showed a response to the combined treatment, but only three of these responded to epo alone. This suggests a synergistic effect in vivo by G-CSF + epo. A long-term follow-up was made on 71 evaluable patients from both the present and the preceding Scandinavian study on G-CSF + epo. Median survival was 26 months, and the overall risk of leukemic transformation during a median follow-up of 43 months was 28%. Twenty patients entered long-term maintenance treatment and showed a median duration of response of 24 months. The international prognostic scoring system (IPSS) was effective to predict survival, leukemic transformation, and to a lesser extent, duration of response, but had no impact on primary response rates.

Histamine in cancer immunotherapy.

A novel strategy for enhancing the efficacy of immunotherapy with interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) in human neoplasia is presented. IL-2 and IFN-alpha are potent activators of the antitumour activity of natural killer (NK) cells but only rarely reduce the tumour burden in treated patients. Recent studies suggest that a reason why these cytokines are insufficiently effective in human cancer is that phagocytes inhibit the tumour-killing activity of NK cells at the site of the tumour. Histamine prevents the phagocyte-induced, NK cell-inhibiting signal; thus, histamine and IL-2 or histamine and IFN-alpha synergize to induce NK cell-mediated killing of human tumour cells in vitro. Further, treatment of tumour-bearing mice with histamine enhances IL-2- and IFN-alpha-induced destruction of NK cell-sensitive tumour cells in vivo. More than 50 patients with neoplastic disease have been treated with histamine, given in subcutaneous injections, together with IL-2 or IFN-alpha. The results of two pilot trials in metastatic melanoma suggest that the addition of histamine to IL-2 and IFN-alpha prolongs survival time and induces regression of tumours, such as liver melanoma, which are otherwise considered refractory to immunotherapy. The results of a trial in acute myelogenous leukaemia (AML) suggest that histamine and IL-2 protects AML patients against relapse of leukaemic disease. Histamine is well tolerated: for example, AML patients in remission have treated themselves with histamine at home without supervision for a total of > 300 weeks with only a handful of therapy-related hospital contacts. Controlled trials in melanoma and AML are under way to further investigate the putative benefit of histamine in neoplastic disease.

Histamine and interleukin-2 in acute myelogenous leukemia.

Interleukin-2 (IL-2) activates natural killer (NK)-cells to destroy leukemic blasts from patients with acute myelogenous leukemia (AML), but even aggressive regimens of IL-2 fail to prevent relapse or prolong remission time in AML. Results obtained in studies of NK-cell-mediated killing of AML blasts show that monocytes inhibit IL-2-induced lysis of AML blasts in vitro. Histamine, a biogenic amine, prevents the monocyte-derived, inhibitory signal; thereby, histamine and IL-2 synergize to induce killing of AML blasts. Here we present updated results of a post-consolidation trial in which histamine (0.5-0.7 mg s.c. bid) has been administered together with IL-2 (1 micro/kg s.c. bid) to 22 AML patients (aged 29-79, mean 59) in repeated courses of three weeks, continued until relapse or until a disease-free remission of 24 months. Low-dose therapy with cytarabine and thioguanine was given between the initial courses of histamine/IL-2. In 13 patients, treatment according to this protocol was started in first complete remission (CR1). The mean remission time in CR1 patients is 19 (median 14) months, and 9/13 remain in CR. Nine patients have entered the protocol in CR2 (n=6), CR3 (n=2), or CR4 (n=1). The mean remission time in CR2-4 is 19 (median 21) months, and 6/9 patients remain in CR. Seven out of seven evaluable patients have achieved a duration of CR which exceeds that of the foregoing remission. Histamine has been well tolerated, and 21/22 CR patients have treated themselves at home throughout the trial. We conclude that the putative benefit of histamine treatment in AML should be the focus of a randomized trial.

Outcome for patients with leukemia, multiple myeloma and lymphoma who relapse after high dose therapy and autologous stem cell support.

Relapses after autologous transplantation are a serious clinical problem in patients with haematological diseases. The decision making for handling of such patients is difficult and the aim of this retrospective analysis of posttransplant relapses was 1) to obtain information of practical importance for the management of future relapses and 2) to evaluate the basis for clinical phase I-II trials of salvage therapy combined with biological modifiers. Included in the study were 283 patients with acute leukemia, multiple myeloma and malignant lymphoma who relapsed after autologous transplantations during a five year period from 1989 to 1994. Chemo- and radiotherapy was given to 229 patients after relapse or due to progressive disease and the response evaluated after 90 days. Fifty four patients (24%) obtained a complete remission and 44 patients (19%) partial responses. The overall median survival from relapse was 5 months. In the group given salvage treatment the median survival was 7 months and in the 54 patients who obtained remission the median survival was 15 months. So far 6 of 14 patients in continuous complete remission have a remission time after relapse longer than the time in remission after transplantation. Survival after relapse depended upon the time from transplantation to relapse, primary disease and if salvage therapy was given. In conclusion posttransplant relapses can be treated but the strategy has to be evaluated in future clinical trials.

Intensive treatment in order to minimize the Ph-positive clone in CML. Danish-Swedish CML Group.

With the rationale that a significant reduction of the malignant clone in CML might prolong time to metamorphosis, intensive treatment was given to patients < or = 55 years. Six months of hydroxyurea and high dose interferon-alpha (IFN-alpha) was followed by one to three courses of intensive chemotherapy. Patients who had a donor were allotransplanted and patients who became Ph-negative in bone marrow were autotransplanted. On 1 May 1995, 160 patients were registered in the study. Fifty-one percent of the patients who received six months IFN-alpha and hydroxyurea had a significant Ph-reduction and 5% became Ph-negative. The corresponding figures after two intensive chemotherapy courses were 47 and 28%, respectively. Twenty-seven of 30 autotransplanted patients have been analysed for Ph. Seventeen have relapsed cytogenetically, while ten are Ph-negative 1-64 + months after ABMT. BMT was performed in 59 patients. The actuarial 6-year survival from diagnosis of all 160 registered patients is 68%, which seems to be better than for age-matched historical controls.

Flow cytometric analysis of megakaryocyte ploidy in chronic myeloproliferative disorders and reactive thrombocytosis.

Megakaryocyte (MK) ploidy patterns were analysed by flow cytometry in 29 newly diagnosed and previously untreated patients with chronic myeloproliferative disorders (MPD) and concomitant thrombocytosis, in 9 patients with reactive thrombocytosis (RT) and in 12 healthy individuals. Unfractionated bone marrow from routine aspirates was used. MKs were identified with a fluorescein labelled monoclonal antibody specific for glycoprotein IIIa (GPIIIa) and DNA was stained with propidium iodide. For the 12 healthy volunteers the mean modal ploidy number was 16 N; the 9 patients with RT displayed an identical MK ploidy pattern. The frequency of MKs with a ploidy > or = 32 N was 45% among the patients with essential thrombocythaemia (ET) compared to 32% among the healthy volunteers (p < 0.001). MKs with ploidy number > or = 64 N, comprising approximately 13% of the total number of MKs, was a characteristic finding in the patients with ET. Similar findings were present in 8 patients with polycythaemia vera (PV). In patients with PV 34% and 6% of the MKs displayed ploidies > or = 32 N and > or = 64 N, respectively. In contrast, a distinct shift towards lower ploidy number, with 63% of MKs < or = 8 N, was found among the 4 patients with chronic myeloid leukaemia (CML). The present results indicate that by using flow cytometric analysis of MK ploidy distribution in patients with thrombocytosis, those with a reactive cause are likely to be discriminated from patients with myeloproliferative thrombocytosis, i.e. PV and ET on one hand and CML on the other hand. The distinction between ET and PV, however, has to be made on other grounds.

Assessment of spleen size using gamma camera scintigraphy in newly diagnosed patients with essential thrombocythaemia and polycythaemia vera.

By using gamma camera imaging the spleen size was assessed in 18 consecutive patients with essential thrombocythaemia (ET) and in 18 consecutive patients with polycythaemia vera (PV). All ET and PV patients were newly diagnosed and had not received any myelosuppressive therapy prior to study. The spleen areas in both posterior and left lateral projections were determined. Eighteen consecutive patients with idiopathic thrombocytopenic purpura (ITP) served as a control group since by definition they do not present with splenic enlargement; in these latter subjects the mean posterior and left lateral splenic areas were almost identical (48 +/- 15 and 47 +/- 17 cm2, respectively). In comparison with this control group patients with ET and PC had significantly larger spleens. In both ET and in PV patients the left lateral spleen scan area exceeded the posterior one. Patients with PV had larger splenic areas in both projections than did patients with ET, but the differences were not statistically significant. Compared to the ITP patients it was found that at least 50% of the ET patients and at least 61% of the PV patients at diagnosis presented with splenomegaly.

Effects of Erwinia-asparaginase on the coagulation system.

L-Asparaginase treatment during induction therapy in acute lymphoblastic leukaemia (ALL) is known to be frequently complicated by thromboembolic events. It was recently suggested that L-asparaginase derived from Erwinia chrysanthemi alters the coagulation system less severely than does Escherichia coli asparaginase. In a series of 11 adult patients with ALL, we investigated some parameters of the coagulation system during treatment with Erwinia asparaginase. The doses employed were rather high; all patients below the age of 60 years received 15,000 U/m2 daily over 14 days. In accordance with what is known from treatment with E. coli asparaginase, we observed significant lowering of antithrombin as well as of fibrinogen. However, as to fibrinogen indeed a significant decrease had occurred prior to the institution of Erwinia asparaginase treatment. The most striking observation in the present study was that the levels of prothrombin complex, reflecting the function of K-vitamin dependent coagulation factors II, VII and X, remained within normal ranges during treatment. This indicates that these coagulation factors were not affected by Erwinia asparaginase, an observation at variance with several reports where E. coli asparaginase was investigated. This latter observation was the only finding which could lend support to the view that Erwinia asparaginase affects the coagulation system less than E. coli asparaginase. Finally, one of our patients developed a sinus thrombosis, a severe thrombotic complication.

A combination of granulocyte colony-stimulating factor and erythropoietin may synergistically improve the anaemia in patients with myelodysplastic syndromes.

In an attempt to obtain a synergistic effect on the hemoglobin levels in anaemic patients with myelodysplastic syndromes (MDS), granulocyte colony-stimulating factor (G-CSF) and erythropoietin (epo) were combined in a clinical phase II trial. Twenty-two patients with MDS were included in the study. G-CSF was given alone for six weeks and then in combination with epo for the following twelve weeks. Eight (38%) of 21 evaluable patients showed a significant increase in hemoglobin. One patient with a previous response and subsequent failure to epo alone improved after the addition of G-CSF. Responses were more frequent in patients with less advanced pancytopenia, lower endogenous levels of serum-epo and in those with ring sideroblasts in the bone marrow. The response frequency of 38% is higher than in any study of epo as monotherapy. Moreover, patients with ring sideroblasts, who respond poorly to epo alone, showed a response rate of 60%. Our findings suggest a synergistic in vivo effect of granulocyte-CSF and erythropoietin in patients with myelodysplastic syndromes.

Measurement of spleen size using gamma camera scintigraphy in essential thrombocythaemia.

By using gamma camera imaging the spleen size was determined in 33 consecutive patients with essential thrombocythaemia (ET) and in 33 consecutive patients with reactive thrombocytosis (RT). All ET patients were newly diagnosed and had not received myelosuppressive treatment prior to study; they all fulfilled the criteria for ET as established by the Polycythemia Vera Study Group. In both posterior and lateral projections, the spleen area in the group of ET patients was significantly larger than in the RT patients. The present study has shown that 39% of ET patients at diagnosis have splenic enlargement. Evaluation of spleen size is therefore a useful diagnostic test in patients presenting with unexplained thrombocytosis.

Treatment of myelodysplastic syndromes with retinoic acid and 1 alpha-hydroxy-vitamin D3 in combination with low-dose ara-C is not superior to ara-C alone. Results from a randomized study. The Scandinavian Myelodysplasia Group (SMG).

63 evaluable patients with myelodysplastic syndromes (MDS) and 15 with acute myelogenous leukemia (AML) were randomized between low-dose ara-C (arm A) and low dose ara-C in combination with 13-cis-retinoic acid (13-CRA) and 1 alpha-hydroxy-vitamin D3 (1 alpha D3) (arm B). 69 patients were evaluable and 18 (26.1%) responded to therapy. The addition of 13-CRA and 1 alpha D3 had no positive influence on survival of the patients, remission rates or duration of remissions. 12/27 patients in arm A and 6/29 patients in arm B progressed from MDS to AML during the course of the study (p = 0.0527). Arm B gave significantly more side-effects than arm A (p = 0.005). Therapeutic effects of 13-CRA and 1 alpha D3 on MDS is not supported by this study. However, an inhibiting effect on AML development in some MDS subgroups cannot be excluded.

Recombinant interferon-alpha-2b treatment of hairy-cell leukaemia: experience with a low-dose schedule.

50 patients with hairy cell leukaemia (HCL) were treated with recombinant interferon (IFN) alpha-2b 2.0 x 10(6) IU/m2 subcutaneously three times weekly to evaluate the efficacy of low-dose IFN therapy in inducing and maintaining remission of the disease. At the time of this report 48 patients, of whom 22 were splenectomized, had been treated for at least 3 months and were considered evaluable for response. The median observation time on IFN-alpha-2b was 11 months (range 3 to 20). 4 cases with atypical disease (spongy lymphoid myelofibrosis) were also included. All patients responded to IFN. After 3 months 11/48 patients (23%) had achieved a partial remission (PR) with normalization of peripheral blood values. After 6 months 27/43 patients (63%) had achieved a favourable response; complete remission (CR) was recorded in 4 and PR in 23 patients. The proportion of patients with favourable responses (CR + PR) increased with the duration of therapy and after 12 months of therapy 23/28 (82%) patients showed CR or PR, 9 patients (32%) being in CR. Splenectomized patients disclosed a trend towards a more rapid response. It is concluded that IFN-alpha-2b is a highly effective first-line therapy for HCL.

Acute nonlymphatic leukemia among deck officers on coastal tankers: a report of two cases.

Deck officers on coastal tankers may be exposed to high concentrations of cargo vapors during loading and tank-cleaning operations. Two cases of acute nonlymphatic leukemia are described. Both men had worked as chief officers on coastal tankers transporting benzene and other petroleum products.