Intensified and high-dose chemotherapy with granulocyte colony-stimulating factor and autologous stem-cell transplantation support as first-line therapy in high-risk diffuse large-cell lymphoma.

PURPOSE: In our previous study with MACOPB, we identified a high-risk group of patients with a poor 3-year survival rate of 29%. These patients were defined as having at diagnosis advanced-stage disease with high tumor burden (TB) and elevated lactate dehydrogenase (LDH) level or bone marrow (BM) involvement. A novel therapeutic scheme was investigated to improve the outcome of these patients. PATIENTS AND METHODS: Fifty patients with high-risk diffuse large-cell lymphoma (DLCL) were enrolled. The therapeutic scheme includes three phases: induction with 8 weeks of MACOPB; intensification with a 3-day course of mitoxantrone 8 mg/m2 plus high-dose cytarabine (HDARA-C) 2 g/m2 every 12 hours plus dexamethasone 4 mg/m2 every 12 hours (MAD protocol) and granulocyte colony-stimulating factor (G-CSF) 5 microg/kg on days 4 to 17 to harvest peripheral-blood progenitor cells (PBPC); consolidation with carmustine (BCNU), etoposide, ARA-C, and melphalan (BEAM) regimen; plus autologous stem-cell transplantation (ASCT) with PBPC, marrow, or both. RESULTS: Thirty-six patients (72%) achieved a complete response (CR), 11 (22%) showed no response (NR), and three (6%) died of toxicity. Among the 22 PRs or NRs after the induction phase, 56% of patients achieved a CR with subsequent intensified therapy. With a median follow-up duration of 32 months, the overall survival and failure-free survival rates were 56% and 50%, respectively. The disease-free survival rate is 69% at 32 months. Leukapheresis after MAD and G-CSF yielded a median of 32 x 10(6)/kg CD34+ cells and 80 x 10(4)/kg granulocyte-macrophage colony-forming units (CFU-GM). Thirty-nine patients were autografted and 11 did not undergo ASCT: six because of disease progression, four due to toxicity, and one because of patient refusal. The median times to achieve engrafment were 11 days (range, 7 to 19) to a neutrophil count greater than 0.5 x 10(9)/L and 12 days (range, 8 to 60) to a platelet count greater than 50 x 10(9)/L. CONCLUSION: This sequential scheme with intensified and high-dose chemotherapy with ASCT is feasible with moderate toxicity and may improve the outcome in high-risk DLCL.

Platelet-derived mitogenic activity and bone marrow fibrosis in myeloproliferative disorders.

Mitogenic activity, measured as 3H-thymidine incorporation by NIH 3T3 cells, following stimulation with platelet-rich-plasma-derived serum (PRS), platelet-poor-plasma-derived serum and platelet extract was studied in 14 patients with myeloproliferative disorders (MPD) and 7 normal subjects. Reduced mitogenic activity was found in PRS and platelet extract of patients with MPD, as compared to controls. The average levels of platelet-derived growth factor (PDGF) equivalents were as follows: 16.3 +/- 7.2 pg/10(6) platelets in controls, 6.2 +/- 2.2 pg/10(6) (p less than 0.05) platelets in patients with polycythaemia vera, 1.8 +/- 0.4 pg/10(6) (p less than 0.01) platelets in patients with idiopathic myelofibrosis and 4.0 +/- 0.8 pg/10(6) (p less than 0.05) platelets in patients with essential thrombocythaemia (Dunnett test). A reduction of intraplatelet levels of beta-thromboglobulin, although not statistically significant, was found in the same patients. No apparent relation was found between the amount of PDGF equivalents and the degree of bone marrow fibrosis.

Platelet 5-hydroxytryptamine transport and storage in myeloproliferative disorders.

Platelets of patients with myeloproliferative disorders (MD) such as polycythaemia vera (PV), chronic myelogenous leukaemia (CML), idiopathic myelofibrosis (IM) and essential thrombocythaemia (ET) have been found to have low 5HT levels measured both by a fluorimetric and a liquid chromatographic assay. Km and Vmax for platelet active uptake of 3H-5HT were not significantly different in controls and patients. Inhibition of 5HT reuptake by imipramine or induction of moderate release by fenfluramine were not sufficient to distinguish the group of MD platelets from controls, although some patients had less of a tendency to retain intraplatelet amine. The low platelet 5HT content found in our patients seems not to be the consequence of disturbed active transport of 5HT across platelet membrane. Although defective storage of this amine within the cell is probable, the results of the present study do not rule out the possibility that platelets from MD patients undergo in vivo activation by endogenous stimuli not inhibited by aspirin. 10 d treatment with aspirin did not result in any significant rise in intraplatelet 5HT concentration.

A microplate enzyme-linked immunospecific assay (ELISA) detecting unbound anti-platelet antibodies.

A microplate immune-enzymatic method was developed for detecting serum antiplatelet antibodies. The method involves the use of antigen-coated platelets and alkaline phosphatase-labeled antihuman immunoglobulin. Linear correlation was obtained between the titer of platelet antibodies and substrate conversion. Twenty-four patients with immune thrombocytopenia and 40 normal controls were studied. Eighteen patients and one control were positive. Therefore, sensitivity and specificity were 75% and 97% respectively. ELISA also was found to be more sensitive than the indirect antiglobulin consumption assay (ACA) and appears to be a practical and easy method for routine evaluation of antiplatelet antibodies.

Increased production of mononuclear cell procoagulant activity in Hodgkin's disease.

Procoagulant activity of peripheral blood mononuclear leucocytes was studied in 24 consecutive patients with Hodgkin's disease. Mononuclear cells, tested immediately after isolation, expressed very low activity which was, however, somewhat higher than that of cells from a matched control group (P = 0.063). Procoagulant activity generated by patients' mononuclear cells following stimulation with bacterial endotoxin was significantly higher than that produced by control cells (P less than 0.01). There was no apparent relation between procoagulant activity and pathological staging. The increased capacity of mononuclear phagocytes to produce procoagulant activity might help explain activation of blood coagulation and subsequent fibrin deposition in patients with Hodgkin's disease.

Impaired production of mononuclear cell procoagulant activity in chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) is associated with a low incidence of thrombotic complications, or disseminated intravascular coagulation (DIC), or both, despite the frequent occurrence of severe infections. We have investigated the capacity of blood mononuclear cells to produce procoagulant activity when stimulated with bacterial endotoxin in 16 patients with untreated chronic lymphocytic leukaemia (CLL). Procoagulant activity generated by patients' cells after prolonged incubation with endotoxin was significantly lower than that produced by cells from a matched control group (p less than 0.001). The defect could not be attributed to an inhibitory effect of leukaemic lymphocytes. It is suggested that in CLL the monocyte has an intrinsic functional abnormality of the procoagulant response to endotoxin and possibly to other stimuli. These findings help explain why CLL patients do not develop thrombotic complications despite the high incidence of severe infectious diseases.

Reduced generation of procoagulant activity by endotoxin-stimulated mononuclear cells from patients with chronic myeloid leukaemia.

The capacity of blood mononuclear cells to produce procoagulant activity upon stimulation with bacterial endotoxin in vitro was studied in 21 untreated patients with chronic myeloid leukaemia (CML). Procoagulant activity developed by patients' cells after prolonged incubation with endotoxin was significantly lower than that produced by cells from a matched control group (P less than 0.001). Reduced activity was seen in all patients when each of them was compared to a matched control studied simultaneously. It was below 50% of the control in 19 patients, and in eight of these it was less than 10%. These findings suggest that qualitative abnormalities in mononuclear cell function may exist in CML and might explain why these patients are less prone to thrombotic complications than those with other myeloproliferative diseases.

Reduced platelet factor X-activating activity: a possible contribution to bleeding complications in polycythaemia vera and essential thrombocythaemia.

A recently described platelet coagulant activity, factor X-activating activity (FXAA), was studied in 33 patients with polycythaemia vera and in 5 with essential thrombocythaemia, in order to gain information about possible mechanisms responsible for the haemostatic disorders observed in myeloproliferative diseases. Other parameters of platelet function including bleeding time, spontaneous and ADP-, epinephrine- or collagen-induced platelet aggregation, serotonin content and malondialdehyde (MDA) production in response to thrombin, were investigated simultaneously. Compared to the range obtained from 27 control subjects (60-150%), FXAA was low in all 9 patients with bleeding complications (range: 5-39%), in 1 out of 7 patients with thrombotic manifestations (range: 38-200%) and in 9 out of 22 patients without symptoms (range: 38-500%). Only the bleeding group differed significantly from each of the others. Moreover, of all patients with reduced FXAA, those with bleeding could be clearly distinguished from those without such symptoms on the basis of the degree of the defect. Increased FXAA (above 150%) was found in 2 out of 7 thrombotic patients and in 2 out of 22 asymptomatics. MDA production was significantly lower in the haemorrhagic group and enhanced in the thrombotic one as compared to control subjects or asymptomatic patients. However, a large area of overlap was observed between the four groups. None of the other platelet function parameters studied (bleeding time, platelet aggregation, platelet serotonin content) correlated with the clinical type of haemostatic complication. Our results suggest a significant association between reduced FXAA and bleeding tendency. These findings may be of relevance in understanding the pathogenesis of abnormal bleeding in patients with polycythaemia vera and essential thrombocythaemia.