A role for tumour necrosis factor-α, Fas and Fas-Ligand in marrow failure associated with myelodysplastic syndrome

Apoptosis of haemopoietic cells in the marrow of patients with myelodysplastic syndrome (MDS) has been suggested as a mechanism for peripheral cytopenias. We determined the expression of Fas (CD95), Fas-Ligand (Fas-L) and TNF-α factors known to be involved in apoptosis, in the marrow of 44 patients with MDS and characterized their functional relevance in in vitro assays of haemopoiesis. Multidimensional flow cytometry revealed phenotypically aberrant blasts as defined by orthogonal light scatter and CD45 expression in the marrow of 24/44 patients. Among those blasts Fas expression was increased on CD34-positive cells and on cells co-expressing HLA-DR. In addition, Fas-L was expressed on some CD34⁺ cells of MDS patients but was never detected on CD34⁺ cells in normal marrow. Fas and Fas-L mRNAs as well as mRNA for TNF-α, known to increase Fas expression in normal marrow, were up-regulated in patients with MDS. TNF-α protein and sTNF-R1 levels in marrow plasma were higher in MDS patients than in controls (P < 0.002 and <0.003, respectively). However, results were dependent upon disease category: TNF-α levels were significantly higher in patients with refractory anaemia (RA) than in patients with RA with excess blasts (RAEB) or RAEB in transformation (RAEB-T) (P = 0.043). Conversely, the proportion of Fas-L-positive cells was lowest in patients with RA (P = 0.037). In marrow cultures, Fas-Ig, rhuTNFR:Fc or anti-TNF-α antibody, by blocking Fas or TNF mediated signals, respectively, significantly increased the numbers of haemopoietic colonies compared to untreated cells (P < 0.001, P < 0.003, P < 0.001, respectively). These results show significant dysregulation in the expression of TNF-α, Fas and Fas-L in the marrow from MDS patients. Altered expression of these molecules appears to be of functional relevance in the dysregulation of haemopoiesis in MDS and may be amenable to therapeutic interventions.     

Oxidative DNA damage in CD34+ myelodysplastic cells is associated with intracellular redox changes and elevated plasma tumour necrosis factor-α concentration

Ineffective haemopoiesis in the myelodysplastic syndromes (MDS) is mediated, at least in part, by apoptosis, though the mechanisms of apoptotic induction are unclear. Tumour necrosis factor-α (TNF-α) promotes apoptosis via intracellular oxygen free radical production, oxidation of DNA and proteins, and is increasingly implicated in the pathogenesis of MDS. Using single-cell gel electrophoresis, we have identified oxidized pyrimidine nucleotides in the progenitor-enriched bone marrow CD34⁺ compartment from MDS patients ( P  = 0.039), which are absent in both CD34⁻ MDS cells ( P  = 0.53) and also CD34⁺ cells from normal subjects ( P  = 0.55). MDS CD34⁺ blood cells also showed oxidized pyrimidine nucleotides compared with CD34⁻ cells ( P  = 0.029). Within normal subjects no differences were seen between CD34⁺ and CD34⁻ bone marrow cell compartments. CD34⁺ bone marrow cell oxidized pyrimidines were strongly associated with elevated plasma TNF-α and low bone marrow mononuclear cell glutathione concentrations (5/6 patients) and the inverse relationship was also found (3/4 patients). This data implies a role for intracellular oxygen free radical production, perhaps mediated by TNF-α, in the pathogenesis of ineffective haemopoiesis in MDS and provides a rationale for the bone marrow stimulatory effects of antioxidants such as Amifostine in MDS.     

Peripheral and bone marrow CD34+ cell levels on chronic myeloproliferative disease

Purpose: The aim of the present study was to examine the relationship between peripheral CD34⁺ and bone marrow CD34⁺ levels and the clinicopathologic characteristics and laboratory parameters of myeloproliferative disease (MPD) patients.

Patients and methods: A total of 103 MPD patients were enrolled in this study. We examined the relationship between bone marrow CD34⁺ and peripheral CD34⁺ levels and the patients’ clinicopathologic and laboratory parameters.

Results: There were no significant correlations between the peripheral CD34⁺ levels and the JAK-2 V617F mutation, thrombosis, white blood cells (WBC), lactate dehydrogenase (LDH), transferrin saturation (TS), ferritin, or bone marrow cellularity. In addition, there were no significant correlations between bone marrow CD34⁺ levels and the JAK-2 V617F mutation, thrombosis, WBC, LDH, TS, ferritin, or bone marrow cellularity (P?>?0.05). We did not identify any significant relationship between peripheral CD34⁺ and bone marrow CD34⁺ levels (P?>?0.05). However, there were significant correlations between peripheral CD34⁺ levels and bone marrow fibrosis (P?+ levels and constitutional symptoms (P?+ levels and bone marrow fibrosis (P?Conclusion: We did not find any significant relationship between the clinicopathologic and laboratory characteristics and peripheral and bone marrow CD34⁺ cells from bone marrow fibrosis patients. There was also no significant relationship between bone marrow CD34⁺ cells and peripheral CD34⁺ cells. Some peripheral CD34⁺ cells may originate from the spleen rather than the bone marrow, which may given us different result of some parameters.     

Patients with high-risk myelodysplastic syndrome can have polyclonal or clonal haemopoiesis in complete haematological remission

The clonality of mature peripheral blood-derived myeloid and lymphoid cells and bone marrow haemopoietic progenitors from 18 females with myelodysplasia (MDS) (five refractory anaemia, RA; one RA with ringed sideroblasts, RARS; three chronic myelomonocytic leukaemia, CMML; four RA with excess of blasts, RAEB; five RAEB in transformation, RAEB-t) was studied by X-chromosome inactivation analysis. Using the human androgen-receptor (HUMARA) assay, we analysed the clonal patterns of highly purified immature CD34⁺38^? and committed CD34⁺38⁺ marrow-derived progenitors, and CD16⁺14^? granulocytes, CD14⁺ monocytes, CD3⁺ T and CD19⁺ B lymphocytes from peripheral blood. In high-risk patients (RAEB, RAEB-t), clonality analysis was performed before and after intensive remission-induction treatment. All patients, except one with RA, had predominance of a single clone in their granulocytes and monocytes. The same clonal pattern was found in CD34⁺ progenitor cells. In contrast, CD3⁺ T lymphocytes were polyclonal or oligoclonal in 14/18 patients. X-chromosome inactivation patterns of CD19⁺B cells were highly concordant with CD3⁺ T cells except for two patients (one RA, one CMML) with monoclonal B and polyclonal T lymphocytes, therefore suggesting a clonal mutation in a progenitor common to the myeloid and B-lymphoid lineages or the coexistence of MDS and a B-cell disorder in these particular patients. After high-dose non-myeloablative chemotherapy, polyclonal haemopoiesis was reinstalled in the mature myeloid cells and immature and committed marrow progenitors in three of four patients achieving complete haematological remission. Therefore we conclude that most haematological remissions in MDS are associated with restoration of polyclonal haemopoiesis.     

Prognostic relevance of cytometric quantitative assessment in patients with myelodysplastic syndromes

Objectives: Morphology and cytogenetics are currently used to define prognosis in myelodysplastic syndromes (MDS). However, these parameters have some limits. Flow cytometry has been recently included in the diagnostic panel for MDS, and its prognostic significance is under evaluation. Methods: Marrow aspirates from 424 MDS patients were analyzed by flow cytometry to evaluate the impact of bone marrow cell immunophenotype on overall survival (OS) and leukemia‐free survival (LFS). The immature compartment of myeloblasts was analyzed by the quantitative expression of CD34 (<3% vs. ≥3%), CD117, and CD11b^?/CD66b^? (<5% vs. ≥5%); myeloid maturation was analyzed by the expression of CD11b⁺/CD66b⁺⁺ (<15% vs. ≥15%) and CD11b⁺/CD66b⁺ (<25% vs. ≥25%). Results:  In univariate analysis, the expression of immaturity markers (CD34⁺, CD117⁺, and CD11b^?/CD66b^?) was associated with shorter LFS and OS (P < 0.0001); higher expression of differentiation markers (CD11b⁺/CD66b⁺⁺ and CD11b⁺/CD66b⁺) was associated with longer LFS (P < 0.0001 and P = 0.0002, respectively) and OS (P < 0.0001). In multivariate analysis, expression of CD34⁺ (P = 0.007), CD117⁺ (P = 0.013), and CD11b⁺/CD66b⁺⁺ (P = 0.023) retained independent prognostic value for OS, while only the expression of CD34⁺ was a prognostic factor for LFS (P = 0.0003). Two different risk groups were defined according to the presence of 0–1 or ≥2 of these factors with significant different LFS and OS (P < 0.0001). This score showed prognostic value in predicting survival even in subanalysis according to IPSS and WHO subgroups. Conclusions: Flow cytometric analysis in MDS may provide meaningful prognostic information. Blast percentage expressed as CD117⁺ or CD34⁺ cells and the quantitative assessment of myeloid maturation showed prognostic value for survival.     

IFN-γ and TNF-α secretion by CD4+ and CD8+ TCRαβ+ T-cell clones derived early after allogeneic bone marrow transplantation

Abstract: Secretion of the potentially antileukaemic cytokines IFN-γ and TNF-α was investigated for CD4 ⁺ and CD8 ⁺ TCRαβ⁺ T-cell clones derived from 4 leukaemia patients 3–6 weeks after allogeneic BMT. We investigated cytokine secretion in response to the activation signal accessory cells + phytohaemagglutinin + Interleukin 2. All clones derived after BMT were capable of IFN-γ and TNF-α secretion, and both for CD4⁺ (n = 96) and CD8⁺ (n = 8) T cells quantities of IFN-γ and TNF-α were significantly correlated with one another. When comparing the overall results for posttransplant and normal T-cell clones derived from 2 bone marrow donors (n = 65), both CD4⁺ and CD8⁺ TCRαβ⁺ T-cell clones showed increased IFN-γ production, and CD4⁺ but not CD8⁺ clones showed a decreased TNF-α secretion. The results suggest that noncytotoxic T cells derived after allogeneic BMT can produce IFN-γ and TNF-α and may thus be capable of mediating antileukaemic effects.     

CD34 immunohistochemistry of bone marrow biopsies: Prognostic significance in primary myelodysplastic syndromes

Bone marrow (BM) biopsies from 58 patients with primary myelodysplastic syndrome (MDS) were studied using QBEND10, a monocional antibody that recognizes the human progenitor CD34 antigen in routine aldehyde-fixed paraffin-embedded samples. FAB subtypes were RA (5 patients), RARS (9 patients), RAEB (20 patients), RAEBt (11 patients), CMML (3 patients). In addition, 10 MDS patients whose BM biopsies revealed heavy reticulum fibrosis were included. Neither the percentage of CD34⁺ cells nor the number of CD34⁺ aggregates (defined as clusters of 3 or more cells) correlated with the presence and morphology of abnormal localizations of immature precursors (ALIP). When all patients were considered, median survival was 69 months in those with less, and 25 months in patients with more than 1% CD34⁺ cells (P < 0.05). Median survival was 15 months in patients with CD34⁺ aggregates and 41 months in those without aggregates (P = 0.0017). When RAEB patients were considered median survival was 41 months in those with less than 1%, and 29 months in those with more than 1% CD34⁺ cells; the 4-year survival chance was 45% in the former and 18.3% in the latter group. Therefore, CD34 positivity of more than 1% identifies a subset of RAEB patients with shorter life expectancy. In addition, leukemic transformation was observed in 11 of 35 patients (31%) with no CD34 aggregates, but in 14 of 23 patients (60%) with aggregates (P < 0.05). CD34 immunostaining, which can be easily performed on routinely prepared BM biopsies, was found to be a powerful prognostic tool for predicting survival and outcome in MDS. © 1994 Wiley-Liss, Inc.     

Composition and function of peripheral blood stem and progenitor cell harvests from patients with severe active rheumatoid arthritis

High-dose chemotherapy with autologous stem cell rescue has been proposed as an intensive therapy for severe rheumatoid arthritis (RA). In view of previous observations of abnormal haemopoiesis in RA patients, the composition and function of peripheral blood stem cell harvests (PBSCH) was investigated. Compared with PBSCH from healthy allogeneic donors mobilized with the same dose of G-CSF (filgrastim; 10 μg/kg/d, n = 14), RA PBSCH (n = 9) contained significantly fewer mononuclear cells (375 v 569 × 10⁶/kg, P = 0.03) and CD34⁺ cells (2.7 v 5.8 × 10⁶/kg, P = 0.003). However, there were increased proportions of CD14⁺ cells (P = 0.006) and CD14⁺CD15⁺ cells (the phenotype of previously described ‘abnormal’ myeloid cells, P = 0.002) in the RA PBSCH which translated into 3.5- and 7-fold increases respectively on a per CD34⁺ cell basis. There were no differences in T-cell activation status as judged by proportions of CD4⁺ and CD8⁺ expressing CD45RA, CD45RO, HLA-DR and CD28 (RA PBSCH, n = 7, donor PBSCH, n = 5, P = 0.2–0.7). Phytohaemagglutinin responses determined fluorocytometrically with induction of CD69 expression were reduced in CD4⁺ and CD8⁺ cells following filgrastim administration in 3/3 RA patients tested. Compared with bone marrow as a potential source of CD34⁺ cells, PBSCH contained 11-fold more T cells (P < 0.0005), 8-fold more B cells (P < 0.0005) and 4-fold more monocytes (P = 0.02). In short-term methylcellulose culture there were no differences in colony counts (CFU-GM, CFU-GEMM, BFU-E) per CD34⁺ cell from PBSCH from RA patients (n = 11) and healthy donors (n = 10). Long-term culture initiator cells were cultured successfully from cryopreserved PBSCH from RA patients (n = 9). In conclusion, PBSCH from RA patients differed significantly in composition from normal individuals, but in vitro studies support normal stem and progenitor cell function. Changes in T-cell function occur during mobilization in RA patients. This work provides reassurance for the use of PBSCH as haematological rescue and baseline data for clinical trials of graft manipulation strategies in patients with RA.     

Thymic stromal cells support differentiation of natural killer cells from CD34+ bone marrow cells in vitro

Abstract: Natural killer (NK) cells are CD3^? CD56⁺ lymphocytes characterized by exhibiting non-MHC restricted cytotoxicity. A developmental relationship between NK cells and T lymphocytes has been proposed, and, moreover, the thymus has been shown to contain NK cell precursors. In this study we utilized an in vitro assay, devised to study T-lymphocyte development from bone marrow progenitors, to investigate the ability of thymic stromal cells to support generation of NK cells from CD34⁺ bone marrow cells. CD34⁺ cells purified from healthy adults were seeded on adherent thymic stromal cells. The cells emerging after culture were phenotypically characterized by flow cytometry. We show that lymphocytes expressing the phenotypical characteristics of NK cells were generated from CD34⁺ bone marrow cells, and that these cells represented 1% of the cells recovered from the cultures. Furthermore, this was accomplished without supplement of exogenous interleukin 2 which is required for NK cell differentiation in bone marrow cultures.     

Comparative quantitative expression of bcl-2 by normal and leukaemic myeloid cells

Summary. Expression of the bcl-2 oncoprotein by AML blasts has previously been demonstrated to be heterogenous with high levels of bcl-2 expression being associated with a low complete remission rate and poor survival. We have quantified bcl-2 expression in AML blasts in relation to expression of the CD34 antigen and in comparison to CD34-positive cells from normal bone marrow. When expressed as molecules of equivalent soluble fluorochrome (MESF) per cell, AML blast cell bcl-2 expression varied from 11.1 to 99.9 × lO³ (median 39.4 × 10³, n=56) with 28.5% of patients expressing high MESF values (>50 × 10³) and 16% of patients expressing low MESF values (<20 × 10³), the remainder expressing intermediate values. There was no significant difference between intensity of bcl-2 expression and FAB classification in the de novo AML cases, and there was no significant differences between de novo and secondary AML cases. Blasts from CD34⁺ AML patients expressed significantly higher levels of bcl-2 (mean MESF 43.6 × 10³, n =36) than CD34^? AML patients (mean MESF 31.7 × 10³, n=19). In five cases of CD34⁺ AML, bcl-2 expression was determined on purified CD34⁺ and CD34^? blast cell populations. In all cases CD34⁺ blasts were found to express significantly higher bcl-2 MESF values compared to the CD34^? fraction. Purified CD34⁺ cells from normal bone marrow consistently expressed high levels of bcl-2 (MESF >75 × 10³ n = 4), which was comparable to that found on CD34⁺ AML cells. Our results suggest that the poor prognosis previously associated with AML blasts expressing the CD34 antigen may in part be related to high expression of bcl-2. Also the ability to measure bcl-2 in AML blasts quantitatively by flow cytometry and to categorize patients into discrete groups may be of value as a prognostic indicator in AML.     

Granulocyte colony-stimulating factor given in addition to interferon-α to mobilize peripheral blood stem cells for autologous transplantation in chronic myeloid leukaemia

In order to potentially mobilize and harvest the Ph^? cells observed in most patients with chronic myeloid leukaemia (CML) during interferon-α (IF-α) therapy, G-CSF (filgrastim), 5 μg/kg/d, was administered subcutaneously together with IF-α to 30 CML patients in haematological remission but with various degrees of cytogenetic remission, after IF-α therapy. Peripheral blood stem cells (PBSC ) were harvested using standard aphereses from day 5 of G-CSF. Patients underwent one to four (median three) aphereses. Median total yields/kg were 7.6 (range 3.8–25) × 10⁸ MNC, 3.4 (0–140) × 10⁶ CD34⁺ cells, and 17 (1.1–107) × 10⁴ CFU-GM. No patient had a significant increase in the percentage of Ph⁺ cells in the bone marrow under G-CSF therapy. The percentage of Ph⁺ cells in apheresis products tended to decrease between the first and the last apheresis (P = 0.05). 14 patients who were not responsive to IF-α were transplanted after conditioning with busulphan 16 mg/kg and melphalan 140 mg/m². Median time to neutrophils > 0.5 × 10⁹/l was 20 d (16–114 d) and to platelets > 50 × 10⁹/l 18 d (12–149 d). Nine patients had a major cytogenetic response post graft, which correlated with the amount of Ph⁺ cells reinfused with the graft (P = 0.02). We conclude that this procedure is feasible, allowing the harvest of enough PBSC, some of them Ph^? in patients who responded to IF-α, to allow autologous transplantation.     

Increased cell apoptosis in bone marrow trephine biopsies and immunomagnetically isolated myeloid progenitor cells in patients with chronic idiopathic neutropenia

The frequency of apoptotic cells in bone marrow trephine biopsies and cytospins of immunomagnetically isolated myeloid progenitor cells was determined in 39 patients with chronic idiopathic neutropenia (CIN) and 12 hematologically normal individuals using the in situ end-labeling (ISEL) apoptosis detection method. We found that 66.7% of the patients but none of the normal controls displayed apoptotic cells equal to or higher than 5% of the total mononuclear cells in bone marrow biopsies (p<0.01). In the double stain, we also found that the proportion of apoptotic CD15⁺ myeloid precursor cells did not differ significantly between patients and control subjects, while the proportion of apoptotic CD34⁺ hemopoietic cells could not be estimated with accuracy because of the presence of CD34⁺ endothelial cells. Significantly increased apoptosis was noted in cytospins of immunomagnetically isolated patient CD34⁺ and CD34⁺/CD33⁺ cells but not CD34^-/CD33⁺ cells, compared to the controls (p<0.001, p<0.02 and p>0.05, respectively). These findings confirm and extend our previous observations in flow-cytometric studies of apoptosis in CIN, indicating that increased apoptosis in CIN bone marrow concerns mainly the CD34⁺ and CD34⁺/CD33⁺ progenitor cell compartments. We conclude that the accelerated apoptosis in these compartments may account for the impaired neutrophil production in CIN patients.     

Haemopoietic defect and decreased expansion potential of bone marrow autografts from patients with acute myeloid leukaemia in first remission

Autologous bone marrow (BM) transplantation for acute myeloid leukaemia (AML) in complete remission (CR) is frequently followed by a slow haemopoietic recovery. We assessed the haemopoietic capacity of purified BM stem cell (CD34⁺DR^?) and progenitor cell (CD34⁺DR⁺) populations from patients with AML in CR, and compared these data with those of normal BM. The feasibility of ex vivo expansion in stroma-conditioned medium supplemented with cytokines was also investigated. The number of CFU-GM produced by initial patient CD34⁺DR^? cells was decreased compared to normal, whereas these values were similar to normal for CD34⁺DR⁺ cells. BFU-E, HPP-CFC and LTC-IC were reduced for both patient CD34⁺DR^? and CD34⁺DR⁺ subpopulations. In contrast to normal, the patient CD34⁺DR^? fraction was not enriched in LTC-IC. CFU-GM expansion from patient CD34⁺DR^? cells was poor and decreased after 14 d of culture. No HPP-CFC expansion could be observed for patient cells. LTC-IC were below the level of detection after 14–21 d of expansion culture of CD34⁺DR^? patient cells, whereas they were variably maintained or expanded for normal cells. After expansion culture, cytogenetic and/or FISH analyses did not reveal the anomalies present at diagnosis, regardless of the cell subpopulation analysed. In conclusion, BM cells of patients with AML in CR show a profound defect at the level of a stem cell enriched population. No meaningful ex vivo expansion could be obtained in culture conditions allowing for a significant expansion from a normal stem cell population.     

Flow cytometric analysis of intracellular CD6 8 molecule expression in normal and malignant haemopoiesis

Summary. CD68 molecules are heavily glycosylated lysosomal membrane constituents of unknown function with strong expression in monocytes and macrophages. Using flow cytometry, we quantified expression levels of CD68 molecules in normal and malignant haemopoietic cells. CD68 molecules are intensely expressed in the cytoplasm and weakly on the surface of mature CD14⁺ monocytes. CD68 expression seems to start very early during granulo-monopoietic differentiation. Virtually all myeloperoxidase (MPO)⁺ bone marrow cells coexpress CD68 and similar proportions of CD34⁺ progenitor cells weakly express CD68 or MPO molecules. During further differentiation, CD68 expression is strongly up-regulated in early MP0⁺ precursor cells which lack lactoferrin (LF) and CD14 molecules. Compared to these, more mature MPO⁺LF⁺ bone marrow and peripheral blood granulocytes express considerable lower levels of CD68. In-line with this broad expression, all investigated acute myeloid leukaemia (AML) cases, classified as FAB M1-M5, were CD68 positive, and compared to normal CD34⁺ bone marrow cells, CD34⁺ AML blast cells expressed increased levels. CD68 expression is, however, not restricted to cells of myeloid origin, because a subset (40 – 15%, n = 6) of CD19⁺ peripheral blood B-lympho-cytes and 50% of B-ALL are also weakly positive. In contrast, normal CD3+ lymphocytes lack (<3%. n = 6) CD68 and only low proportions (6 – 3%, n= 6) of CD56⁺ NK cells are CD68⁺. Also, all investigated T-ALL cases (n = 6) lacked CD68.     

Role of immune dysfunction in pathogenesis of type 1 diabetes mellitus in children

Objective:To investigate the function of cytokines,chemokines,and regulatory T cells(Tregs)in the pathogenesis of Type 1 diabeles mellitus(T1DM)in children.Methods:A total of 35 children with T1DM and 30 healthy controls were enrolled in this study.Levels of serum cytokines(IL-1α,IL-6,IL-10,IL-12,and TNF-α)and chemokines(MIP-1α,MIP-1βand MCP-1)were detected by enzyme-linked immunosorbent assay.Peripheral blood mononuclear cells(PBMCs)were isolated and culture supernatant of phytohaemagglutinin(PHA)-stimulatcd PBMCs was subjecled to ELISA for levels of cytokines(IL-1α,IL-6,IL-10,IL-12 and TNV-α)in T1DM and control group.Furthermore,flow cytometty was used to determine the percentage of Tregs in PBMCs of two groups.Results:Levels of serum cytokines including IL-1α,IL-6,IL-10 andd TNF-αas well as chemokines,such as MIP-1αand MIP-1βin children with T1DM children were significantly higher than those in healthy controls(P0.05,respectively).PBMCs with PHA stimulation in T1DM group secreted more IL-1αand TNF-α(P0.05,respectively),but less IL-10(P0.05),as compared with control group.Furthermore,the proportion of CD4~+,CD25~+,Foxp3.Tregs in PBMCs isolated from children with T1DM was obviously lower than those in heathy controls(P0.05).Conclusions:Immune dysfunction.with uprcgulation of inflanunatory factors such as IL-1α.IL-6.TNF-αand MIP-1α.downregulation of IL-10 and Tregs,plays an important role in the pathogenesis of T1DM in children.     

CD34+ and CFU-GM progenitors are significantly decreased in sivsmm9 infected rhesus macaques with minimal evidence of direct viral infection by polymerase chain reaction

Hematologic abnormalities in the peripheral blood and bone marrow are associated with human immunodeficiency and simian immunodeficiency virus (HIV, SIV) infection. The reasons for these abnormalities remain unclear. Bone marrow specimens collected from uninfected animals (Group A, Controls) and from rhesus macaques experimentally infected with SIVsmm9 during the asymptomatic stage (Group B, SIV⁺ “well”) and during the clinically ill stage (Group C, SIV⁺ “sick”), underwent a variety of in vitro assays of hematopoiesis. Colony forming unit-granulocyte/macrophage (CFU-GM) per plate growth was 46.7 ± 7.7, 31.9 ± 8.4 and 6.5 ± 5.0 (means ± sd, P <.02 each mean compared to the others) in the 3 groups respectively. Burst forming unit-erythroid (BFU-E) growth was similarly decreased in bone marrow samples from the SIV⁺ animals. There was no change in the number of CFU-GM per plate with the removal of plastic adherent or T-cell mononuclear cell fractions. There was no increase in CFU-GM per plate growth with the addition of low dose GM-CSF (1 or 5 ng/mL) though there was a near 67% increase (48 to 80 CFU-GM per plate) with the addition of 100 ng/mL recombinant rhesus IL-3 and 100 ng/mL GM-CSF in SIV⁺ 'sick' animals. Variation in frequency of CD34⁺ progenitor cells in SIV⁺ animals was seen, with 3.0% CD34 cells in SIV^? controls, 4.9% CD34⁺ cells in SIV⁺ 'well' animals and 0.5% CD34⁺ progenitor cells in SIV⁺ 'sick' monkeys (P <.01, each mean compared to the others). Finally, there was minimal evidence of SIV sequences by polymerase chain reaction in pooled cultured CFU-GM, and no evidence in flowcytometrically sorted CD34⁺ progenitor cells from selected animals. Thus, the SIV seropositive rhesus monkey appears to have similar hematopoietic aberrations as are found in HIV infected human subjects and may be an excellent model for studying the interaction of lentiviruses on the kinetics of blood formation.     

Ex vivo expansion and long-term hematopoietic reconstitution ability of sorted CD34<Superscript>+</Superscript>CD59<Superscript>+</Superscript> cells from patients with paroxysmal nocturnal hemoglobinuria

Autologous bone marrow transplantation (ABMT) for paroxysmal nocturnal hemoglobinuria (PNH) remains difficult so far. To expand residual normal CD34⁺CD59⁺ cells isolated from patients with PNH and observe the long-term hematopoietic reconstruction ability of the expanded cells both ex vivo and in vivo, CD34⁺CD59⁺ cells from 13 PNH patients and CD34⁺ cells from 11 normal controls were separated from bone marrow mononuclear cells first by immunomagnetic microbeads and then by flow cytometry autoclone sorting. The cells were then cultivated under different conditions. The long-term hematopoietic supporting ability of expanded CD34⁺CD59⁺ cells was evaluated by long-term culture in semi-solid medium in vitro and long-term engraftment in irradiated severe combined immunodeficiency (SCID) mice in vivo. The best combination of hematopoietic growth factors for ex vivo expansion was SCF + IL-3 + IL-6 + FL + Tpo + Epo. The most suitable time for harvest was on day 7. CD34⁺CD59⁺ PNH cells retained strong colony-forming capacity even after expansion. The survival rate, complete blood cell count recovery on day 90, and human CD45 expression in different organs were similar between the irradiated SCID mice transplanted with expanded CD34⁺CD59⁺ PNH cells and those with normal CD34⁺ cells (P > 0.05) both in primary and secondary transplantation. These data provided a new potential way of managing PNH with ABMT.