Eeva Juvonen

Efficacy and safety of darbepoetin alfa in anaemic patients with lymphoproliferative malignancies: a randomized, double-blind, placebo-controlled study

Summary. This phase 3, randomized, double‐blind, placebo‐controlled study was designed to evaluate the efficacy and safety of darbepoetin alfa in anaemic patients with lymphoproliferative malignancies. Patients (n = 344) with lymphoma or myeloma received darbepoetin alfa 2·25 μg/kg or placebo s.c., once weekly for 12 weeks. The percentage of patients achieving a haemoglobin response was significantly higher in the darbepoetin alfa group (60%) than in the placebo group (18%) (P < 0·001), regardless of baseline endogenous erythropoietin level. However, increased responsiveness was observed in patients with lower baseline erythropoietin levels. Darbepoetin alfa also resulted in higher mean changes in haemoglobin than placebo from baseline to the last value during the treatment phase (1·80 g/dl vs 0·19 g/dl) and after 12 weeks of treatment (2·66 g/dl vs 0·69 g/dl). A significantly lower percentage of patients in the darbepoetin alfa group received red blood cell transfusions than in the placebo group (P < 0·001). The efficacy of darbepoetin alfa was consistent for patients with lymphoma or myeloma. Improvements in quality of life were also observed with darbepoetin alfa. The overall safety profile of darbepoetin alfa was consistent with that expected for this patient population. Darbepoetin alfa significantly increased haemoglobin and reduced red blood cell transfusions in patients with lymphoproliferative malignancies receiving chemotherapy.

Standard-dose anti-CD20 antibody rituximab has efficacy in chronic lymphocytic leukaemia: results from a Nordic multicentre study

Abstract: Objectives: This prospective multicentre study was conducted to assess the efficacy of the monoclonal anti‐CD20 antibody rituximab in patients with chronic lymphocytic leukaemia (CLL). Secondary objectives were defined as the tolerability and feasibility of rituximab in patients with CLL. Methods: Twenty‐four heavily pretreated patients with CLL were treated with a standard dose of 375 mg m−2 of rituximab given once weekly for four doses. Results: The overall response rate was 35% and all the responses were partial as defined by the revised NCI criteria. In 17 (85%) of 20 patients with initially measurable peripheral lymph nodes the size of lymph nodes decreased by at least 50%, while an improvement of the bone marrow infiltration was observed only in two (11%) of 18 evaluable patients. The median duration of the overall response was 12.5 wk. Rituximab was relatively well tolerated. Although side‐effects were common (75%) they were usually mild or moderate. There was only one grade 3 adverse event and no grade 4 events. Conclusions: Standard‐dose rituximab has activity in heavily pretreated patients with CLL, although the response is mainly limited to the lymph nodes and of short duration. Since rituximab has in vitro synergism with chemotherapeutic agents and is well tolerated by CLL patients, it is reasonable to investigate rituximab in combination with other treatments.

Megakaryocyte and erythroid colony formation in essential thrombocythaemia and reactive thrombocytosis: diagnostic value and correlation to complications

Megakaryocyte and erythroid colony formation in vitro by progenitors from the bone marrow and/or blood was studied in 61 patients with essential thrombocythaemia (ET) and 22 patients with reactive thrombocytosis (RT) using the methyl cellulose assay. 47 (77%) of the patients with ET showed megakaryocyte and/or erythroid spontaneous colony formation while 14 (23%) patients did not have any kind of spontaneous colonies. Spontaneous megakaryocyte colony formation was seen in 42 (69%) of the patients and 36 (59%) ET patients showed spontaneous erythroid growth. 31 patients had both types of spontaneous colonies. 11 patients showed only spontaneous megakaryocyte colony formation, and five patients only spontaneous erythroid growth. None of the patients with RT or of the normal controls showed either type of spontaneous growth. Neither the presence of spontaneous megakaryocyte colony formation nor the number of spontaneous colonies correlated with the platelet count. Patients with spontaneous megakaryocyte growth had significantly more often thromboembolic or haemorrhagic problems than those without spontaneous colony formation. In conclusion, it was found that a great majority of patients with ET but none of those with RT grow spontaneous megakaryocyte and/or erythroid colonies. Spontaneous colony formation is strong evidence for a myeloproliferative disorder. The presence of spontaneous colony growth is associated with an increased risk of thromboembolic or haemorrhagic complications regardless of the platelet count, particularly among young patients.

Autologous stem cell transplantation in adult patients with peripheral T-cell lymphoma: a nation-wide survey

Summary:Limited experience is available on the feasibility and efficacy of high-dose therapy (HDT) supported by autologous stem cell transplantation (ASCT) in patients with peripheral T-cell lymphoma (PTCL). Therefore, a nation-wide survey was conducted in adult patients transplanted for PTCL in Finland during 1990–2001. After histopathology review, 37 patients were identified. The median age was 46 years (16–68) at the time of ASCT. Histology included PTCL not otherwise specified in 14 patients, anaplastic large cell lymphoma (ALCL) in 14 patients, and other in nine patients. Disease status at the time of ASCT was CR/PR1 in 18 patients; CR/PR2 in 14 patients, and other in five patients. HDT consisted of either BEAC (N=22) or BEAM (N=15), supported by blood stem cells in 34 patients (92%). Early transplant-related mortality was 11%. With a median follow-up of 24 months from HDT, 16 patients (43%) have relapsed or progressed. The estimated 5-year overall survival (OS) was 54%. Patients with ALCL had superior OS when compared with other subtypes (85 vs 35%, P=0.007). OS at 5 years was 63% in patients transplanted in CR/PR1 vs 45% in those transplanted in other disease status (P=NS). Prospective studies are needed to define the role of ASCT in this lymphoma type.

High incidence of PTLD after non-T-cell-depleted allogeneic haematopoietic stem cell transplantation as a consequence of intensive immunosuppressive treatment

Summary:The occurrence of post-transplant lymphoproliferative disorder (PTLD) in relation to immunosuppressive treatment was determined in 257 patients treated with non-T-cell-depleted allogeneic stem cell transplantation from an HLA-matched sibling (173 patients) or unrelated donor (84 patients). The conditioning consisted of total body irradiation and cyclophosphamide (myeloablative conditioning, 250 patients), or fludarabine combined with cyclophosphamide or a single 2 Gy dose of TBI (nonmyeloablative conditioning, seven patients). In transplantations from an unrelated donor, the patients also received antithymocyte globulin (ATG). The prophylaxis against graft-versus-host disease (GVHD) consisted of cyclosporine A, methotrexate, and methylprednisolone. The autopsy reports of deceased patients were systematically reviewed, and the autopsy materials of cases suggestive of PTLD were re-examined histologically for Epstein–Barr virus (EBV). Nineteen patients with EBV-positive PTLD were identified, of whom six had been transplanted from a sibling donor and 13 from an unrelated donor. All the patients who developed PTLD had been given ATG either for the treatment of steroid-resistant acute GVHD (all PTLD patients with a sibling donor and one with an unrelated donor), or as part of the conditioning (all patients with an unrelated donor). In conclusion, in transplantations from an HLA-identical donor with a non-T-cell-depleted graft, the risk of PTLD correlated strongly with the intensity of the immunosuppressive treatment.

Podocalyxin in Rat Platelets and Megakaryocytes

Podocalyxin is a membrane protein of rat podocytes and endothelial cells. It has not been described in other cell types, and no amino acid or DNA sequence data are available about it. Here we show that podocalyxin antigens are present in rat platelets and megakaryocytes. In resting platelets, the antigens are mainly intracellular but become surface exposed after thrombin stimulation, as shown by immunofluorescence and flow cytometry. By Western blotting, platelet podocalyxin has an apparent Mr of 140,000. Cytocentrifuge slides of rat bone marrow show that anti-podocalyxin antibodies recognize large polyploid cells also expressing CD62P, indicating that the cells are megakaryocytes. From a rat glomerular cDNA library we isolated a clone covering the carboxyl-terminal nucleotides of rat podocalyxin. Its putative transmembrane or intracellular domains are 100% or >93% identical, respectively, with the human and rabbit podocalyxin-like proteins. The truncated extracellular domain extends to include two of the four conserved cysteines shared by podocalyxin-like proteins. By Northern blotting, a 5.5-kb renal cortical transcript is seen. By in situ hybridization, cRNA probes recognize podocytes, endothelial cells, and megakaryocytes, and by reverse transcription polymerase chain reaction, platelets are shown to contain podocalyxin mRNA. Our results show that rat podocalyxin is a homologue of the previously cloned podocalyxin-like proteins and suggest that also in mammals podocalyxin has a role in hematopoiesis, as previously shown in the chicken.

Invasive fungal infections in autologous stem cell transplant recipients: a nation-wide study of 1188 transplanted patients

Abstract:  Based on small single‐centre series, the risk of invasive fungal infections (IFI) has been considered small in autologous stem cell transplant (ASCT) recipients. Purpose: To analyse epidemiological and clinical features of (IFI) among ASCT recipients in Finland 1990–2001. Patients: During the study period, 1188 adult patients received high‐dose therapy supported by ASCT in six centres. Altogether, 1112 patients (94%) received blood progenitor cells. The graft was CD34+ selected in 261 patients (22%). The major diagnostic groups were non‐Hodgkins lymphoma (n = 417), multiple myeloma (n = 395), breast cancer (n = 132) and Hodgkins lymphoma (n = 53). Results: Eighteen patients (1.5%) with IFI were identified. The incidence of proven or probable invasive aspergillosis was 0.8%, followed by candidaemia with an incidence of 0.3%. The median time to the diagnosis of IFI was 35 d (6–162) from the progenitor cell infusion. In fourteen patients (78%) IFI was diagnosed during lifetime and they were treated with antifungal therapy for a median of 50 d. Nine patients (64%) were cured. Conclusions: IFI appears to be a rare event after ASCT and Aspergillus infections seem to be predominant. These epidemiological features have an impact in planning prophylactic and empirical antifungal strategies in ASCT recipients.

The predictive value of vascular risk factors and gender for the development of thrombotic complications in essential thrombocythemia.

Abstract The impact of the cardiovascular risk factors smoking, hypertension, hypercholesterolemia, and diabetes mellitus on the risk of thrombotic complications was evaluated retrospectively in 132 patients with essential thrombocythemia (ET). The median age at diagnosis was 51 years, and the median follow-up time was 65 months. Sixty-three out of 132 patients (48%) had one or more vascular risk factors, whereas 69 patients (52%) had no risk factors. Thirty-two patients were smokers, 27 had hypertension, 21 hypercholesterolemia, and four diabetes mellitus. During the follow-up, 53 patients (40%) had 98 arterial thrombotic events, half of which were disturbances of cerebral circulation. Fifteen patients (11%) experienced 27 venous thrombotic events. The presence of one or more vascular risk factors increased the risk of arterial thrombotic complications. Of the patients, 52% with one or more vascular risk factors and 29% of those without any risk factors had arterial thrombosis (P=0.01). In multivariate analysis the only independent risk factor was smoking (P=0.01). Male gender increased the risk of arterial thrombosis significantly. Thirty-six out of 62 men (58%) but only 17 out of 70 women (24%) had an arterial complication (P<0.001). Smoking had a strong predictive value for the development of arterial complications in women but not in men. Among women 9/15 (60%) of the smokers and 12/82 (15%) of the non-smokers experienced arterial thrombosis (P= 0.002), whereas among men no difference between smokers and non-smokers could be found. According to the present findings, the male gender should be regarded as a risk factor when deciding about the indication for treatment. Smoking should be discouraged especially among women with ET.

Colony formation by megakaryocytic progenitors in essential thrombocythaemia

Colony formation by megakaryocytic progenitors (CFU‐M) from the blood or bone marrow of 12 patients with essential thrombocythaemia was studied in vitro with the methyl cellulose assay. When the cultures were stimulated with plasma from a patient with aplastic anaemia and with phytohaemagglutinin stimulated conditioned medium (PHA‐LCM), the patients showed a significant trend towards higher circulating CFU‐M numbers when compared with the controls; three of the patients exceeded our normal range. In the bone marrow cultures there were no differences in the number or morphology of megakaryocytic colonies between the patients and the controls. When normal human plasma was the only source of colony stimulating activity. 11 out of 12 patients, but none of the controls, showed megakaryocytic colony formation. The same patients also had ‘spontaneous’ erythroid colony growth without the addition of exogeneous erythropoietin into the cultures. Only one of the patients with essential thrombocythaemia (ET) had normal megakaryocytic and erythroid colony formation. The present study shows that, in most patients with ET ‘spontaneous’ CFU‐M colony formation occurs in suboptimal culture conditions, a phenomenon obviously analogous to the spontaneous erythroid colony formation seen in the myeloproliferaative disorders.

Epstein-Barr viral load and disease prediction in a large cohort of allogeneic stem cell transplant recipients.

BACKGROUND We wanted to determine the clinical significance and predictability of Epstein-Barr virus (EBV) infections among a large cohort of recipients of allogeneic, unselected stem cell transplants. METHODS During 1988-1999, a total of 5479 consecutive serum samples obtained during 406 transplantations performed in Helsinki, Finland, were retrospectively analyzed by quantitative polymerase chain reaction for the presence of EBV DNA. RESULTS Overall, EBV DNA was noted in at least 1 serum sample for 57 patients (14.0%), of whom 22 (5.4%) were found to have progressively increasing and ultimately high (>50,000 copies/mL) EBV DNA levels (median level, 179,000 copies/mL). In addition, 16 patients (4.0%) had low EBV DNA levels (median level, 3260 copies/mL) in isolated sera before death. Among the transplant recipients who survived, transient EBV DNAemia (median level, 3110 copies/mL), which apparently corresponded to asymptomatic EBV infection, was noted in 19 patients (4.7%). CONCLUSIONS Low-level EBV DNA positivity in serum occurs relatively frequently after stem cell transplantation and may subside without specific treatment. However, high EBV DNA levels (i.e., >50,000 copies/mL) are strong predictors for the development of posttransplantation lymphoproliferative disease, are not spontaneously reversible, and should be treated immediately. If the EBV DNA level is >or=50,000 copies/mL, the patient can be classified as having life-threatening EBV infection.