We demonstrate that HEL, a human erythroleukemic cell line, has numerous megakaryocytic markers which were markedly enhanced following the addition of the inducers dimethyl sulfoxide or 12‐O‐tetradecanoylphorbol‐13‐acetate to the culture medium. Ultrastructural and cytochemical studies showed: (i) the presence of organelles morphologically resembling the platelet alpha‐granules; and (ii) a peroxidase activity with the same characteristics as that specifically found in platelets. The platelet alpha‐granule proteins (von Willebrand factor, platelet factor‐4 and beta‐thromboglobulin) were immunologically detected in the HEL cell cytoplasm and their amounts increased after induction. Of particular interest was the presence of platelet membrane proteins. A monoclonal antibody specific for glycoprotein Ib bound to HEL cells. Platelet membrane glycoproteins IIb and IIIa were identified on intact cells using specific antibodies in a binding assay or in cell lysates using either crossed immunoelectrophoresis or an immunoblotting procedure following SDS‐polyacrylamide gel electrophoresis. Most HEL cells also expressed the platelet alloantigen PIA1. All of the platelet membrane proteins were present in higher amounts after induction. Glycophorin A, specific for the erythroid lineage, was also detected on HEL cells. Thus, while confirming the presence of erythroid markers, our studies provide evidence that the HEL cell line also expresses platelet antigens. As such, HEL cells represent a unique system with which to study the biosynthesis of platelet‐specific proteins and glycoproteins.

Therapy planning in patients with myelodysplastic syndromes (MDSs) is complicated by its high prognostic heterogeneity. Forty-one patient and disease characteristics at onset of 370 patients with MDS were analyzed to identify significant prognostic factors for survival and transformation to acute myeloblastic leukemia (AML), and to develop and validate a regression model for predicting survival. Multivariate regression analysis showed that the total bone marrow percentage of blast cells, age, platelet count, WBC count, and hemoglobin level were the characteristics more significantly associated with survival in the overall series. The bone marrow percentage of type I blast cells was the most important factor predicting transformation into AML. Proportional hazards regression analysis in a randomly selected training sample of 240 patients demonstrated that the combination of total bone marrow percentage of blast cells, platelet count, and age had the strongest predictive relation to survival length. The resulting regression models, continuous and categorized, were validated in the remaining test sample of 130 patients by demonstrating its capability of segregating patients into low-, intermediate-, and high-risk groups, with distinctively different survival curves (P less than .0001). A scoring system derived from the categorized model also had a great prognostic value (P less than .0001). These regression models and the simpler scoring system may be accurately used for decision-making regarding therapy in MDS patients.

Summary:The number of CD34 ؉ cells has been described as the best parameter for predicting the quality of engraftment in peripheral blood progenitor cell (PBPC) transplantation in the early post-transplant period. In this study we have determined the optimal number of CD34 ؉ cells in order to maintain engraftment in the long term in a series of 100 patients receiving autologous PBPC transplantation. Based on our previous experience on the speed of early hematopoietic recovery, four subgroups of patients were established: patients infused less than 0.75 ؋ 10 6 /kg CD34 ؉ (n = 9), 0.75 to 1.25 (n = 24), 1.25 to 2.0 (n = 37) and more than 2.0 (n = 30). These groups were designated as low, intermediate-low, intermediate-high and high CD34 groups, respectively. Transitory loss of neutrophil engraftment was observed in 67%, 30%, 16% and 6% of patients in the four mentioned CD34 groups respectively, with statistically significant differences between the different groups. Significant differences were also observed between the low CD34 group and the rest of the groups as regards platelet and red blood cell transfusion requirements, fever episodes, days of hospitalization and antibiotic requirements throughout the first year. Our results show that the dose of CD34 ؉ cells influences engraftment also in the late post-transplant period, and correlates with transfusion and antibiotic requirements, fever episodes and days of hospitalization during the first year posttransplant.

Summary:The aim was to analyze quality-of-life (QOL) during the first year post transplant in 47 patients undergoing reduced-intensity conditioning (RIC) allotransplantation, and to compare these with a similar subgroup of patients receiving autologous stem cell transplantation (ASCT). We used self-reported questionnaires. Each answer scored from 0 (not at all) to 4 (very much), with higher scores indicating worse functioning. Mean value of physical categories among RIC transplants ranged between 1.23 and 0.77 indicating that patients scored very low for physical symptoms. Patients undergoing ASCT had higher scores in questionnaires performed early after transplant and then gradually improved (Po0.001). Overall, when we compared physical functioning scores, allo-RIC did significantly better (P ¼ 0.049). Nevertheless, while allo-RIC scores were significantly better for the first three questionnaires, ASCT patients did better in the last two questionnaires. These findings are in accordance with the toxicities observed in both subgroups which are lower in the RIC group early after transplant. No significant differences were observed between either subgroup for any of the functional, social/ family, psychological distress and satisfaction with doctor/nurse relationship items. We have observed similar QOL among patients undergoing RIC-allo as compared to ASCT although GVHD remains an important 'event' in QOL.

Ten characteristics of bone marrow (BM) biopsies in paraffin sections, obtained at diagnosis from patients with myelodysplastic syndromes (MDS) classified according to the FAB criteria, were analysed to identify both the most relevant morphologic data and any possible influence on survival. Agreement between two observers was obtained for 94% of the data. BM cellularity was increased in 63% of the cases and was higher in refractory anaemia with excess of blasts (RAEB). RAEB in transformation (RAEB-t) and chronic myelomonocytic leukaemia (CMML) (P = 0.001). Dysmegakaryopoiesis and dyserythropoiesis were present respectively in 83% and 72% of the cases, with slight differences among the FAB subtypes. Abnormal localization of immature precursors (ALIP) was found in more than half of the cases and somewhat more frequently seen in the RAEB + RAEB-t + CMML group (P = 0.07). Eosinophilia, plasmacytosis and reticulin fibrosis were evident in 26%, 18% and 47% of the cases respectively. Cellularity (P = 0.006), eosinophilia (P = 0.009) and, to some extent, dysmegakaryopoiesis (P = 0.07) bore a certain relationship with survival on univariate analysis. The presence of ALIP was not seen to affect the outcome. Multivariate analysis showed that the cellularity and presence of dysmegakaryopoiesis, in BM biopsy, added significant independent prognostic information to that achieved with age, platelet count and proportion of blast cells in BM aspirate, three variables with proven prognostic value in MDS patients. Using a regression model including these five characteristics we have stratified the patients into low, intermediate and high-risk groups with different survivals (P = 0.00001). The present findings show that BM biopsy is able to provide both morphological characteristics and information about the prognosis of survival, and should thus be included in the initial evaluation of MDS.