The most important prognostic factor in current clinical management of acute myeloid leukemia (AML) is the leukemic karyotype, identifying patients with relatively favorable, intermediate and adverse prognosis. Unfortunately, the majority of patients are assigned to the intermediate risk group although they represent a broad spectrum regarding prognosis. While molecular mapping may diminish this problem in the future, an approach to prognostic stratification of patients within the intermediate risk group is urgently needed in order to develop risk-adapted treatment strategies and evaluate the efficacy of new treatments. The aim of this retrospective study was to evaluate the prognostic impact of diagnostic multiparametric flow cytometry (MFC) in the cytogenetic intermediate risk group of AML patients. Diagnostic samples were obtained from 162 AML patients (median age 66 years, range 0–88; cytogenetic risk group favorable/intermediate/adverse/unknown 11/91/17/43; bone marrrow/blood 141/21). Four-color flow cytometry and a panel of 35 monoclonal antibodies was used to characterize the immunophenotype of AML blast cells, defined by side scatter and CD45 expression. For each antigen in the panel, mean fluorescence intensity (MFI) of the blast cell population was recorded. For each antigen, the expression pattern was characterized as homogeneous or heterogeneous. Heterogeneous antigen expression was defined as the presence of two or more subpopulations, within the blast cell gate, expressing the antigen in question with distinctly different intensities. Flow cytometry data, biological and clinical variables for the cytogenetic intermediate risk group and for patients with unknown cytogenetic risk were analysed by univariate Cox regression analysis and selected variables were analysed by multivariate Cox regression analysis (backward likelihood-ratio statistics, p<0.05 considered significant) with overall survival as outcome variable. Four conventional variables and four blast cell phenotype variables significantly predicting inferior survival were identified: FAB type other than 0/1 (p<0.03), presence of extramedullary disease (p<0.007), high white blood count (p<0.0005) and high age (p<0.0005); a heterogeneous CD117 expression (p<0.009), heterogeneous CD90 expression (p<0.03) as well as high MFI of CD56 expression (p<0.0005) and low MFI of CD58 expression (p<0.001) for CD45/SSC gated blast cells. The prognostic model identified two subsets of cytogenetic intermediate risk patients with a median overall survival of 0.1 and 1.5 years respectively. The subset of cytogenetic intermediate risk patients with high risk according to the prognostic model had an outcome inferior to that of the cytogenetically defined adverse risk group. This prognostic model was also valid for patients with unknown cytogenetic risk and for patients assigned to the favorable and adverse risk groups by cytogenetics. Informative MFC was applicable in 96% of the cases analysed. The prognostic model should be evaluated in a prospective clinical multicentre trial.

Abstract: Purpose: To estimate the clinical significance of low serum concentrations of mannose‐binding lectin (MBL) in patients with acute myeloid leukaemia (AML) during initial cancer chemotherapy. Patients and methods: 80 consecutive, newly diagnosed, and unselected AML patients (age 18–77 yr) undergoing remission induction chemotherapy. The patients were examined for 28 d. Main findings: Low levels of serum MBL (<1000 μg/L) were found in 16/80 patients at diagnosis. This frequency is similar to what is found in the general population. In the remaining 64 patients, MBL concentrations were significantly higher than in controls and showed only a slight rise during the period of antineoplastic chemotherapy with its associated infectious complications. Low levels of MBL did not affect overall survival or morbidity in terms of incidence or duration of fever, or occurrence of septicaemia or pneumonia. Long‐term survival was likewise independent of MBL concentration. Conclusion: MBL levels have no discernible influence on the occurrence or course of infections in AML patients during the initial hospitalisation. The predominant immunodeficiency during this phase is the profound granulocytopenia, which also compromises important effector functions of MBL. The finding in most AML patients of elevated MBL concentrations on admission is most likely because of the role of MBL as an acute phase reactant.

The clinical, histological, phenotypic and genotypic features of a lymphoblastoid natural killer (NK)-cell lymphoma presenting in the skin in a young caucasian woman are described. The disease behaved aggressively, but long-lasting remission was obtained by combination chemotherapy followed by autologous bone marrow transplantation. The blastoid cells were positive for terminal deoxynucleotidyl transferase, CD34, CD56 and CD4. Furthermore, the NK-cell receptor complex CD94/NKG2 was strongly expressed, as shown by examination with reverse transcription-polymerase chain reaction. The T-cell receptor (TCR)-gamma genes were in germline, and with the exception of CD4 all T-cell antigens were negative, including CD3, TCR-beta, TCR-delta, TIA-1, granzyme B and perforin. Epstein-Barr virus was negative, and no expression was seen of myeloid cell-associated markers. Molecular analysis showed no abnormalities of the CDKN2A (p16), CDKN2B (p15) or TNFRSF6 (Fas) genes. By contrast, a 34-bp deletion in exon 7 of the TP53 (p53) gene was detected. It is suggested that lymphoblastoid NK-cell lymphoma, which is a rare but distinctive disease, originates from NK cell precursors and may be associated with and possibly caused by alterations in the TP53 gene. Experience is too limited to warrant therapeutic suggestions. However, stem cell transplantation may be a useful option in younger patients.

A high-affinity receptor for urokinase-type plasminogen activator (uPAR) has been identified on the plasmamembrane of a number of different cell types, and has been shown to be important for plasminogen activation, cell adhesion, and possibly signal transduction. uPAR and uPA cosediment with secretory vesicles and specific granules by subcellular fractionation and translocate to the plasma membrane upon activation of neutrophils. Here the subcellular distribution of uPAR and uPA is studied by electron microscopy of neutrophils using immunogold double labeling for uPAR and uPA and a set of markers for well-defined subtypes of granules: matrix metalloproteinase type-9 (MMP-9) for gelatinase granules, lactoferrin (LF) for specific granules, and myeloperoxidase (MPO) and neutrophil elastase (NE) for primary granules. With this technique uPAR colocalizes with uPA in 71% of labeled granules. In granules containing uPAR the degree of coexpression with MMP-9, MPO and NE was 19, 66, and 74%, respectively. In granules labeled for uPA the corresponding overlap with MMP-9, MPO and NE was 24, 64, and 51%, respectively. Low levels of co-localization were found for uPAR and LF (7%) and for uPA and lactoferrin (5%). The results indicate that uPAR and uPA arepresent in gelatinase granules and primary granules, but rarely in specific granules. The demonstration of uPAR and uPA in primary granules is of particular interest, and may indicate that uPAR and uPA participate in the activation of latent hepatocyte growth factor of neutrophils.

In this preclinical evaluation we have compared the efficacy of three clinical CD34 + enrichment procedures with respect to purity, yield and recovery, as well as risk of selective loss of CD34 + lineage-specific subsets. The three devices work by different principles and have several different manipulation steps: The magnetic field separator uses paramagnetic iron-dextran particles; the magnetic microbead selection is based on the advantage of a large surface area for immobilisation of the monoclonal antibody within a very small volume; the original immunoabsorption technique is based on the use of biotinylated antibody applied to a column of avidin-coated sephadex beads. The results of this evaluation gave a median purity 96% (88–98%), 86% (62–97%), and 49% (18–85%), and median yield of 65% (54–100%), 40% (21–74%), and 30% (8–55%), respectively. Subset analysis recognised a selective loss of CD34 + /61 + after enrichment, most likely due to class I–II antibodies used for the enrichment step or, alternatively, nonspecific binding of megakaryocytic progenitors. Tumour cell spiking experiments on a clinical scale documented an expected 2–4 log reduction resulting in a number of potentially malignant cells in the CD34 enriched product. Our data support four major conclusions: First, that magnetic field separation is superior to magnetic beads and chromatography selection, mainly due to the risk of cell loss and insufficient recovery with the two latter methods. Second, that late differentiated progenitors with CD34 class III epitopes present are lost during the enrichment procedures. The third major conclusion is that chromatography selection results in a selective loss of CD34 bright cells, which are most likely uncommitted early progenitors. This was an unexpected finding which may be a consequence of an imbalance between the strong forces between biotin–avidin and insufficient physical manipulation for CD34 + cell release. Finally, the data document that CD34 selection alone is an inappropriate way to eliminate tumour cells due to the uncontrolled variables and the inconsistent outcome. The only products which can be expected to be purged free of tumour cells are the ones with very minimal (<10 −5 ) contamination in the starting products, ie products documented tumour free with the most sensitive techniques for quantitation. If this is not the case, the optimal purging strategy may be a two-step procedure including CD34 selection and subsequent depletion of the tumour cells in question.

Migration of neutrophils in patients with paroxysmal nocturnal haemoglobinuria (PNH) was studied using two different complement-free in vitro model systems, subagarose and transendothelial migration. In the subagarose migration assay the mean migration distance of PNH neutrophils was slightly, but significantly, reduced to 1236 microns (range 753-1586, n = 6) compared to a normal mean of 1476 microns (range 1076-1768, n = 6, P = 0.016). By immunocytochemical staining for the urokinase type plasminogen activator receptor (uPAR) which is a glycosyl-phosphatidyl-inositol (GPI) anchored protein expressed by normal, but not by PNH-affected, neutrophils, it was shown that the uPAR-positive subpopulation of normal neutrophils predominated among the faster migrating cells (60-80% normal cells at the front of migration) while uPAR-negative (i.e. PNH-affected neutrophils) were more numerous close to the application well (5-30% normal cells). When migration of neutrophils was tested across a monolayer of human umbilical vein endothelial cells (HUVEC) cultured on polycarbonate filters, there was a 3-4-fold impairment of the migration of the PNH-affected neutrophils both in the absence of stimulation and after stimulation with fMLP (P < 0.001 in both cases). After IL-1 stimulation of the endothelium the impairment was even more pronounced (8-fold difference, P < 0.001). When the endothelial cells were grown on collagen-coated filters the impairment of the migration of PNH neutrophils was less pronounced, but still significant after stimulation with fMLP and IL-1 (2-fold, P < 0.05 in both cases). These results demonstrate that there is a complement-independent impairment of migration of neutrophils from patients with PNH which may be related to their failure to express GPI-linked proteins involved in cell migration and/or adhesion such as the uPA receptor and the CD66b antigen.

In a multicentre study of 635 consecutive newly diagnosed patients with B-CLL, the histological bone marrow (BM) specimens were reviewed independently by each of 3 pathologists and found evaluable for BM infiltration pattern in 575 patients, 404 of whom had a CD5(+), mainly FMC7(-), faint surface-membrane immunoglobulin (SIg) fluorescence-intensity phenotype. In these 404 patients the following BM infiltration patterns were found: mixed nodular-interstitial (30%), moderate interstitial (44%), heavy interstitial (20%) and diffuse packed (6%). In univariate survival analysis, significant differences were found according to BM pattern (p<0.05), the presence of nodules being a favorable prognostic sign. In multivariate survival analysis in a model including age, clinical stage, BM pattern, BM lymphocytosis, WBC and sex, only age and stage but not BM pattern or BM lymphocytosis had independent prognostic significance. In stage A, progression-free survival was significantly longer in patients with nodular than in patients with non-nodular bone-marrow pattern. The overall survival of these patients, however, did not differ, possibly owing to the prompt and prolonged treatment given to most patients at the time of progression to stage B or C. We conclude that in CD5(+), SIg(faint), mainly FMC7(-) B-CLL, bone-marrow histology may predict unstable disease in early clinical stage but is not important for treatment decisions, when these are based on clinical stage.

It has been known for decades that blood neutrophilia occurs after the administration of etiocholanolone, adrenocortical steroids, and endotoxins. Neutrophil leukocytosis in general may be due to several mechanisms such as increased stimulation of the myelopoiesis, increased release from the marrow, a shift from the marginated to the circulating pool (demargination), prolongation in the peripheral half-life, and decreased migration of neutrophils from the blood to the tissue. However, the principal cause of the neutrocytosis for each of the above mentioned agents is increased release of neutrophils from the bone marrow reserves. Since a sufficient reserve capacity is a prerequisite for optimal defenses against infections, the marrow response has been used to estimate the dose of chemotherapy expected to be tolerated without life-threatening neutropenia. However, none of the above "test substances" have gained widespread use due to adverse reactions or undesirable effects on neutrophil function. Recent progress in biotechnology has developed recombinant human (rh) hematopoietic growth factors ready for clinical use. Marrow myelopoiesis is stimulated by granulocyte colony-stimulating factor (rhG-CSF) and granulocyte-macrophage CSF (rhGM-CSF). The immediate effect, however, is mobilization of mature neutrophil granulocytes to the blood. Bone marrow cellularity seems to influence the neutrophil number mobilized during 24 hours by one subcutaneous injection of either rhG-CSF or rhGM-CSF. A recent pilot study has suggested such a "24 hour stimulation test" to predict severe neutropenia following cyclic chemotherapy. This concept is illustrated by two case reports. The "stimulation test" suggests that we may devise strategies to define patient subsets which may benefit from prophylactic growth factor administration during cyclic chemotherapy.

The urokinase plasminogen activator (uPA) is a proteolytic enzyme which converts the proenzyme plasminogen to the active serine protease plasmin. A cell surface receptor for uPA (uPAR) is attached to the cell membrane by a glycosyl‐phosphatidylinositol anchor. Binding of uPA to uPAR leads to an enhanced plasmin formation and thereby an amplification of pericellular proteolysis. We have shown previously that uPAR is expressed on normal blood monocytes and granulocytes, but is deficient on affected blood monocytes and granulocytes in patients with paroxysmal nocturnal haemoglobinuria (PNH), and that uPAR is present in plasma from these patients. In this study a newly established sensitive enzyme‐linked immunosorbent assay (ELISA) has been applied for quantttation of uPAR in plasma. Unexpectedly, we found that uPAR is not only present in PNH plasma but also in plasma from healthy individuals. In 39 healthy individuals the mean plasma‐uPAR value ±SD was 31 ± 15 pm, median 28 (range 11‐108), and the corresponding value for six PNH patients was 116±67 pm, median 90 (range 61‐228). The elevated uPAR‐level in PNH patients was highly significant (Mann‐Whitney test; P < 0.0001), and may possibly contribute to the propensity for thrombosis in PNH by inhibition of the fibrinolytic system. Binding of pro‐uPA by uPAR in plasma may interfere with the appropriate binding of pro‐uPA to cell‐bound uPAR and therefore inhibit cell‐associated plasmin generation and fibrinolysis. It is likely that the uPAR in normal plasma reflects the overall level of activity of the uPAR‐mediated cell surface proteolysis. The present ELISA may be used for studies of uPAR levels in plasma from patients with conditions in which this activity might be increased, such as cancer and inflammatory disorders. Future studies will determine if uPAR in plasma is a parameter of clinical importance in these diseases.

The value of s-Transferrin Receptor (s-TfR) measurements in recognizing simultaneous iron deficiency in anaemia of chronic disease was examined in 35 anaemic patients with active rheumatoid arthritis. Based on a quantification of stainable bone marrow (marrow iron grade 0-4) and serum ferritin concentrations (levels < 60 micrograms l-1) compatible with iron deficiency) the anaemia was found to be aggravated by iron deficiency in 19/35 or 54% of the patients. There was no significant difference between the mean s-TfR concentrations in patients with adequate iron in comparison to patients with iron depletion [2.9 (1.6) mg l-1 v. 2.7 (1.4) mg l-1; t = 0.273; p = 0.786; Student's t-test]. Mean s-TfR levels in both patients with adequate iron and depleted iron stores were within the normal range, but tended to be higher than in normal individuals [mean (SD): 1.54 (0.43) mg l-1]. In patients with no stainable marrow iron (MIG 0; N = 15) a significant inverse correlation was found between s-TfR concentrations and s-ferritin levels (r = 0.57; p < 0.05). 5/15 patients with MIG = 0 exhibited significantly raised concentrations of s-TfR values > 3.05 mg l-1 (the highest normal value of the normal range). Increases of s-TfR levels were consistently moderate, and never exceeded a level of 7 mg l-1, which is markedly lower than concentrations measured in patients with iron deficiency anaemia.(ABSTRACT TRUNCATED AT 250 WORDS)