Extensive bone marrow necrosis in patients with cancer and tumor necrosis factor activity in plasma

Tumor necrosis factor (TNF), a macrophage secretory protein produced by peripheral blood monocytes from patients with cancer, has been shown to possess cytotoxicity toward tumor cells in vitro. TNF in the blood of individuals with cancer is usually not detectable except with extremely sensitive radioimmunoassay or enzyme-linked immunosorbent assay (ELISA) methods. We have encountered two patients with the rare syndrome of extensive bone marrow necrosis in association with cancer. The first patient presented with marrow failure secondary to necrosis and was found to have adenocarcinoma in thoracic lymph nodes, lung, and marrow lymphatics at autopsy. Plasma tested at two dilutions (1:200 and 1:2,000) contained TNF at a concentration of 8.3 ng/ml, or 80 U/ml by a cytotoxicity assay using LM cells. The presence of TNF was confirmed with immunoblotting. The second patient had a poorly differentiated lymphoid tumor involving bone marrow, pancytopenia, and marrow necrosis. The plasma cytotoxicity assay indicated the presence of 0.7 ng/ml or 7 U/ml TNF. TNF was not detectable in plasma from six other patients with untreated cancer involving bone or bone marrow using either of our methods. The levels of TNF in the two patients with marrow necrosis were greater than those previously measured by others in patients with cancer but were comparable to those noted in patients with lethal sepsis. Since large doses of TNF have been shown to cause organ necrosis in animals, the data presented here are consistent with TNF involvement in mediating the observed marrow necrosis in our patients.     

Effects of tumor necrosis factor-alpha on normal feline hematopoietic progenitor cells.

The effects of tumor necrosis factor-alpha (TNF-alpha) on feline bone marrow hematopoietic progenitors were evaluated by exposing bone marrow mononuclear cells from specific pathogen-free cats to different concentrations of TNF-alpha (ranging from 50 to 800 pg/ml) for 2 h before plating for clonal assays of colony-forming units. TNF-alpha caused a dose-dependent suppression of feline erythroid colony-forming units (CFU-E) and erythroid burst-forming units (BFU-E), whereas granulocyte-macrophage colony-forming units (CFU-GM) were minimally affected. TNF-alpha concentrations as low as 200 pg/ml significantly inhibited growth of erythroid progenitors. Addition of polyclonal rabbit anti-TNF-alpha antibodies completely neutralized the suppressive effect of TNF-alpha on erythroid progenitors. At higher concentrations of TNF-alpha (800 pg/ml), 35% of CFU-E and 21% of BFU-E still survived, indicating that some erythroid progenitors are not sensitive to a single exposure of TNF-alpha in vitro. These results suggest that TNF-alpha may play a role in regulating hematopoiesis in cats and may be involved in the pathogenesis of erythroid aplasia in cats infected with feline leukemia virus.     

Plasma levels of tumour necrosis factor alpha and interleukin-6 predict progression-free survival following thalidomide therapy in patients with previously untreated multiple myeloma

We studied marrow angiogenesis and plasma levels of angiogenic cytokines in 38 patients receiving thalidomide therapy for previously untreated myeloma. The effect of therapy and the relationship of cytokine levels to myeloma cell proliferation, bone marrow microvessel density and progression-free survival (PFS) were studied. High pretreatment tumour necrosis factor-alpha (TNFalpha) levels (> 11 pg/ml) and increased interleukin (IL)-6 of > 2 pg/ml predicted for poorer PFS (TNFalpha, 48% versus 74% at 2 years, P = 0.01; IL-6, 24% versus 70% at 2 years, P = 0.01). None of the other parameters predicted response or PFS, and no significant changes in cytokine levels occurred with therapy.     

前列腺癌树突细胞瘤苗的制备及其应用

目的 构建前列腺癌树突细胞（DC）瘤苗,并探讨其体内外抗前列腺癌的作用。方法 分离C57BL／6小鼠骨髓前体细胞制备DC,光镜下观察DC的形态学特征,混合淋巴细胞试验、辣根过氧化物酶（HRP）吞噬试验观察DC的生物学特性。经RM-1前列腺癌细胞裂解产物致敏构建DC瘤苗,将DC瘤苗皮下注射于18只前列腺癌模型小鼠。结果成熟DC突起多而长,胞内囊泡少,刺激T细胞增殖能力强;DC瘤苗分泌IL-12能力增强;小鼠应用DC瘤苗后,其脾脏T细胞对RM-1细胞具有特异性杀伤作用;荷瘤小鼠肿瘤生长缓慢,坏死明显,瘤体内及肿瘤周围有大量炎细胞浸润。结论小鼠骨髓单核细胞在粒细胞／巨细胞集落刺激因子（GM-CSF）和IL-4诱导下可转化为DC。RM-1前列腺癌细胞裂解物致敏构建的DC瘤苗能诱导T细胞对RM-1细胞产生特异性杀伤作用,且能分泌更多的IL-12,可用于前列腺癌的免疫治疗。     

Plasma thrombopoietin levels in thrombocytopenic states: implication for a regulatory role of bone marrow megakaryocytes

To evaluate the diagnostic value of thrombopoietin (TPO, c-mpl ligand) measurements, and clarify the regulatory mechanisms of TPO in normal and in thrombocytopenic conditions, the plasma TPO concentration was determined in normal individuals (n = 20), umbilical cord blood (n = 40), chronic idiopathic thrombocytopenic purpura (ITP; n = 16), in severe aplastic anaemia (SAA; n = 3), chemotherapy-induced bone marrow hypoplasia (n = 10), myelodysplastic syndrome (MDS; n = 11), and sequentially during peripheral blood progenitor cell transplantation (n = 7). A commercially available ELISA and EDTA-plasma samples were used for the analysis. The plasma TPO concentration in the normals and umbilical cord blood were 52 ± 12 pg/ml and 66 ± 12 pg/ml, respectively. The corresponding values in patients with SAA and chemotherapy-induced bone marrow hypoplasia were 1514 ± 336 pg/ml and 1950 ± 1684 pg/ml, respectively, and the TPO concentration, measured sequentially after myeloablative chemotherapy and peripheral blood progenitor cell transplantation, was inversely related to the platelet count. In contrast, the plasma TPO recorded in patients with ITP (64 ± 20 pg/ml) and MDS (68 ± 23 pg/ml) were only slightly higher than normal levels. In conclusion, TPO levels were significantly elevated in patients in which bone marrow megakaryocytes and platelets in circulation were markedly reduced, whereas TPO levels were normal in ITP patients, and only slightly increased in the MDS patients. These latter patients displayed a preserved number of megakaryocytes in bone marrow biopsies. Our data support the suggestion that megakaryocyte mass affects the plasma TPO concentration. In thrombocytopenic patients a substantially increased plasma TPO implies deficient megakaryocyte numbers. However, TPO measurements do not distinguish between ITP and thrombocytopenia due to dysmegakaryopoiesis, as seen in MDS patients.     

Differentiation of Rabbit Bone Marrow Mesenchymal Stem Cells to Myogenic Cells and Expression of VEGF After Gene Transfection

INTRODUCTIONOriginally identified as a source of osteoprogenitorcells, mesenchymal stem cells (MSCs) coulddifferentiate to adipocytes, chondrocytes, osteoblastsand myoblasts in vitro and undergo differentiation invivo[1], making these stem cells promising candidates formesodermal defect repair and disease management.MSCs have been proposed as an alternative source forthe regeneration of myocardium. There were severalclinical studies of MSCs' effects on ischemic heartdisease[2]. However…     

Endotoxaemia and serum tumour necrosis factor as prognostic markers in severe acute pancreatitis.

Endotoxaemia and circulating tumour necrosis factor are important prognostic factors in severe sepsis and are implicated in the pathogenesis of septic shock. Because clinical and pathological features in acute pancreatitis are similar to septic shock this study sought to determine whether endotoxin and tumour necrosis factor were prognostic factors in 38 patients with prognostically severe acute pancreatitis. Endotoxaemia, present in 19/37 (51%) patients on day 1, was more common in nonsurvivors than survivors (10/11, 91% v 9/26, 35%, p = 0.003). Day 1 serum endotoxin concentrations were higher in patients with a severe outcome (median (interquartile range) 314 (173-563) pg/ml v 0 (0-185) pg/ml, p<0.01) and in non-survivors (266 (173-586) pg/ml v 0 (0-165) pg/ml, p<0.01). Serum tumour necrosis factor was detectable in 47 of 109 samples (43%) from 38 patients (median 35 pg/ml, range 5-943 pg/ml). Day 1 serum tumour necrosis factor correlated with a worse prognostic score and a severe outcome in all patients (n = 38, r = 0.36, p = 0.027; r = 0.33, p<0.05) and with mortality in patients with gall stones (n = 23, r = 0.50, p = 0.02). Our data suggest that endotoxin and tumour necrosis factor could be prognostic factors in severe acute pancreatitis.     

Prognostic value of serum level of interleukin-6 and interleukin-8 in metastatic breast cancer patients

Previous studies indicated that interleukins may stimulate cancer cells growth and contribute to loco regional relapse as well as metastasis. The aim in this study was to investigate the level of interleukin-6 (IL-6) and interleukin-8 (IL-8) in metastatic breast cancer patients and find out the relation between the levels of these cytokines and the clinical out come of patients and to predict the value of these cytokines as independent prognostic factors. The present study was carried out on 40 women divided into two groups; the first group included 30 patients diagnosed as having metastatic breast cancer. The second group included 10 healthy women as controls. An immunoenzymometric assays for the quantitative measurement of human IL-6 and IL-8 were used. The serum level of IL-6 and IL-8 were measured for patients and controls. Serum level of both IL-6 and IL-8 were found to be higher in patients than in healthy volunteers. Serum IL-6 was detected in all patients and controls with a mean value of (25.3 pg/ml) versus (1.5 pg/ml) for patients and controls respectively and this difference was statistically highly significant (P < 0.001). Serum IL-8 was detected in 26 patients (86.7%) and 7 controls (70%) with a mean value of (8.96 pg/ml) versus (3.9 pg/ml) for patients and controls respectively and this difference was also statistically highly significant (P < 0.001). Tumors with size larger than 5 cm at diagnosis were associated with higher level of both IL-6 (32.8 pg/ml) and IL-8 (10.2 pg/ml) in comparison with those with size less than 5cm (IL-6 14 pg/ml) and (IL-8 7.2 pg/ml) and the difference in both cases was statistically significant (P < 0.05). Patients with more than 3 positive lymph nodes had higher level of both IL-6 and IL-8 with a mean value of 32.8 pg/ml and 10.2 pg/ml for IL-6 and IL-8 respectively, than those with less than 3 positive lymph nodes with mean value of 14 pg/ml and 6.9 pg/ml for IL-6 and IL-8 respectively and this difference was statistically significant (P < 0.05). Seventeen of the patients had only one metastatic site (bone or liver or lung metastasis) and 13 had more than one metastatic site and the difference between the two groups was statistically highly significant regarding both IL-6 and IL-8 (P < 0.001). The mean level of IL-6 was 14.6 pg/ml for patients with one metastatic site versus 29.2 pg/ml for patients with more than one metastatic site. The mean level of IL-8 was 6.2 pg/ml versus 11.3 pg/ml for patients with one metastatic site and patients with more than one metastatic site respectively. However, the level of IL-6 and IL-8 did not correlate with hormonal receptors status, tumour grade, menopausal status or site of metastasis. Thus, it could be concluded that serum level of IL-6 and IL-8 are useful prognostic factors in metastatic breast cancer patients.     

Interleukin-2 Levels are Elevated in the Bone Marrow Serum of Patients with Mutilans-Type Rheumatoid Arthritis

In order to investigate the pathogenesis of mutilans-type rheumatoid arthritis (RA), we measured cytokine levels in the bone marrow serum of patients with RA. We studied 35 patients with non-mutilans RA, 19 with mutilans RA, and 20 patients with osteoarthritis (OA) undergoing joint surgery. At the time of surgery, iliac bone marrow and peripheral blood were sampled from all 74 patients and cytokine levels measured. The serum levels of five cytokines (IL-1β, IL-2, IL-3, IL-6 and GM-CSF) were measured by ELISA. Haematologic and inflammatory factors were also measured. Levels of IL-2, IL-6 and GM-CSF in bone marrow serum were significantly higher in all RA patients than in those with OA. Mean (tSD) IL-2 levels were significantly higher in patients with mutilans-type RA (309.8t686.3 pg/ml) than in patients with other types of RA (66.5t173.1 pg/ml; P<0.01). IL-2 was detected significantly more often in patients with mutilans-type RA than in patients with other types of RA (P<0.01). Inflammatory factors were higher in all RA groups than in OA patients. However, the haematologic and immunologic variables were no different between mutilans RA and other types of RA. No correlations were observed between IL-1β, IL-2, IL-3, IL-6 and GM-CSF levels and these laboratory variables. In patients with mutilans-type RA, IL-2 levels in the bone marrow serum were significantly higher than in patients with other types of RA or with OA. This elevation does not appear to be related to systemic inflammation, as there was no correlation with other inflammatory factors. Received: 9 October 2000 / Accepted: 16 July 2001     

Treatment of myelodysplastic syndromes with excess of blasts by bevacizumab is well tolerated and is associated with a decrease of VEGF plasma level

Myelodysplastic syndromes (MDS) are associated with increased bone marrow vascularity and increased levels of various angiogenic factors including Vascular Endothelial Growth Factor (VEGF) which is implicated in the proliferation and survival of leukemic cells. Before the approval of hypomethylating agents in this indication, the GFM conducted a multicenter phase II trial testing the efficacy and tolerance of bevacizumab, a humanized monoclonal antibody against VEGF, in MDS with excess of marrow blasts and its impact on bone marrow angiogenesis. Twenty-one patients were enrolled (16 males and five females) with a median age of 70?years and 19 were evaluable for haematological response after treatment (5?mg/kg IV every 2?weeks for 12?weeks). WHO diagnosis at baseline was RAEB-1 (38%) and RAEB-2 (62%). Treatment was well tolerated and was associated with significant decrease of VEGF plasma level [median (low quartile?Chigh quartile)] from 65.5?pg/ml [LQ (low-quartile)?CHQ (high quartile), 35.3?C87.3 to 30.4?pg/ml (LQ?CHQ, 22.5?C34.0?pg/ml)] (p?<?0.01) and reduction of bone marrow angiogenesis from a median of 20?vessels/mm³ (LQ?CHQ, 16.5?C33?vessels/mm³) to 15.5?vessels/mm³ (LQ?CHQ, 10?C23.2?vessels/mm³) (p?=?0.03). On the other hand, only one patient had a significant haematological response with achievement of RBC transfusion independence. Thus, although bevacizumab had a significant impact on VEGF levels and angiogenesis in our patients, very few responses were seen when this drug was used as single agent. Given its good tolerability profile, however, combination of bevacizumab with other drugs, especially hypomethylating agents, could be considered in MDS.     

Impaired lipopolysaccharide-inducible tumor necrosis factor production in vitro by peripheral blood monocytes of patients with viral hepatitis

We investigated lipopolysaccharide-induced tumor necrosis factor production in vitro by peripheral blood monocytes from patients with various liver diseases. Tumor necrosis factor production was found to be significantly reduced in patients with chronic hepatitis B (n = 17; 135 +/- 30 pg tumor necrosis factor/ml; mean +/- S.E.M.) and patients with chronic non-A, non-B hepatitis (n = 15; 212 +/- 22 pg tumor necrosis factor/ml) compared with healthy control individuals (n = 47; 411 +/- 40 pg tumor necrosis factor/ml; p less than 0.0005 and p less than 0.01, respectively). This reduced tumor necrosis factor production was not only seen with an optimal stimulating concentration of lipopolysaccharide (100 ng/ml) but also with suboptimal concentrations (0.1 ng/ml). In contrast to patients with chronic viral hepatitis, monocytes from patients with alcohol-induced cirrhosis (n = 26; 444 +/- 49 pg tumor necrosis factor/ml), primary biliary cirrhosis (n = 7; 412 +/- 81 pg tumor necrosis factor/ml) and alcohol-induced fatty liver changes (n = 5; 401 +/- 62 pg tumor necrosis factor/ml) produced normal amounts of tumor necrosis factor when stimulated with an optimal concentration of lipopolysaccharide. Lipopolysaccharide (0.1 ng lipopolysaccharide/ml)-stimulated peripheral blood monocytes of patients with chronic hepatitis B (n = 15; 102 +/- 32 pg/ml) or non-A, non-B hepatitis (n = 13; 97+/- 16 pg/ml) could not be induced to produce more tumor necrosis factor either when prestimulated with gamma-interferon (170 +/- 45 pg/ml and 149 +/- 32 pg/ml, respectively), a lymphokine known to activate monocytes, or with the cyclooxygenase inhibitor indomethacin to reduce the suppressive effect of prostaglandin E2 (148 +/- 40 pg/ml and 153 +/- 45 pg/ml, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cytokine production by primary bone marrow megakaryocytes

Primary human bone marrow megakaryocytes were studied for their ability to express and release cytokines potentially relevant to their proliferation and/or differentiation. The purity of the bone marrow megakaryocytes was assessed by morphologic and immunocytochemical criteria. Unstimulated marrow megakaryocytes constitutively expressed genes for interleukin-1 beta (IL-1 beta), IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha), by the polymerase chain reaction (PCR) and Northern blot analysis. At the protein level, megakaryocytes secreted significant amounts of IL-1 beta (53.6 +/- 3.6 pg/mL), IL-6 (57.6 +/- 15.6 pg/mL), and GM-CSF (24 +/- 4 pg/mL) but not TNF-alpha. Exposure of human marrow megakaryocytes to IL-1 beta increased the levels of IL-6 (87.3 +/- 2.3 pg/mL) detected in the culture supernatants. Transforming growth factor- beta was also able to stimulate IL-6, IL-1 beta, and GM-CSF secretion, but was less potent than stimulation with phorbol-12-myristate-13- acetate (PMA). The secreted cytokines acted additively to maintain and increase the number of colony-forming unit-megakaryocytes colonies (approximately 35%). These studies demonstrate the production of multiple cytokines by isolated human bone marrow megakaryocytes constitutively or stimulated in vitro. The capacity of human megakaryocytes to synthesize several cytokines known to modulate hematopoietic cells supports the concept that there may be an autocrine mechanism operative in the regulation of megakaryocytopoiesis.     

Atypical leukemia accompanied by vitamin B12 deficiency]

A 76 year old female with atypical leukemia complicated by vitamin B12 deficiency demonstrated marked fluctuation in blast percentage and hemopoiesis over 8 month period. She underwent surgical removal of pancreas head cancer 5.5 years ago. In January 1989 severe pancytopenia and mild increase of bone marrow blast were found. Blood transfusions and inadvertent administration of Vitamin B12 resulted in alleviation of pancytopenia and decrease in blast percentage. Several months later her bone marrow blast exceeded 30%, when serum B12 concentration was below 90 pg/ml. B12 injection and blood transfusion resulted in significant improvement in her hematological condition, but shortly thereafter she died of fulminant hepatitis. Her bone marrow cells showed a polyclonal constitution, as assessed by the RFLP-methylation technique using the PGK gene as a probe. The coexistence of leukemic- and normal clones under Vitamin B12 deficiency conditions and the differing behavior of such clones to B12 supplementation may explain the unusual clinical course observed in this patient.     

Plasma thrombopoietin concentrations in thrombocytopenic and non-thrombocytopenic patients in a neonatal intensive care unit

Thrombocytopenia is a frequent occurrence in the neonatal intensive care unit (NICU), but the role of thrombopoietin (Tpo) in the pathophysiology is unknown. We obtained serial plasma Tpo concentrations in 20 thrombocytopenic neonates in our NICU, and performed bone marrow studies in 15. The initial Tpo levels ranged from undetectable (<41 pg/ml) to 1112 pg/ml and did not correlate with gestational age or platelet count. Neonates with decreased marrow megakaryocytes did not have plasma Tpo levels as high as those reported in adults, particularly in small for gestational age infants (Tpo < 300 pg/ml). In 14/15 neonates followed until resolution, the Tpo concentration decreased as the platelet count increased.     

Serum leptin,prolactin and vascular endothelial growth factor (VEGF) levels in patients with breast cancer

Angiogenesis plays an important role in tumor growth and metastasis in solid tumors. VEGF is an important regulator of tumor angiogenesis. Both leptin and prolactin have also been suggested to have roles in the regulation of angiogenic process. In our study, we measured serum leptin, prolactin and VEGF levels in 30 metastatic, 55 non-metastatic breast cancer patients and 25 control subjects. Serum leptin levels were found to be similar in non-metastatic (38.1+/-19.5 ng/ml), metastatic patients (39.6+/-16.3 ng/ml) and control subjects (35.6+/-13.9 ng/ml) (p>0.05). There was no statistically significant difference between patients with visceral metastasis (44.0+/-16.8 ng/ml) and patients with bone metastasis (35.2+/-15.0 ng/ml) (p>0.05). Serum prolactin levels were found to be similar in non-metastatic (12.2+/-10.7 ng/ml), metastatic patients (11.6+/-8.2 ng/ml) and control subjects (12.3+/-8.1 ng/ml), (p>0.05). Moreover, serum prolactin levels were not different in patients with visceral (11.4+/-8.8 ng/ml) and bone metastasis (11.8+/-8.0 ng/ml), (p>0.05). Metastatic patients had higher serum VEGF levels (249.8+/-154.9 pg/ml), when compared to the non-metastatic patients (138.7+/-59.3 pg/ml) and control subjects (108.4+/-47.7 pg/ml), (p<0.05). There was no difference in serum VEGF levels in non-metastatic patients and control subjects (p>0.05). Patients with visceral metastasis (337.0+/-168.0 pg/ml) had higher serum VEGF levels, when compared to patients with bone metastasis (162.6+71.8 pg/ml), (p<0.05). Serum VEGF activity may be used to evaluate angiogenic and metastatic activity in breast cancer patients. However, serum leptin and prolactin levels does not seem to be related with angiogenic activity and metastasis in breast cancer patients.     

Anorexia nervosa with neutropenia--response of neutrophils to G-CSF]

A 50-year-old woman with anorexia nervosa was admitted for evaluation of neutropenia (WBC 1,600/microliters). Her bone marrow was gelatinous, and myeloid cells had decreased. Homogeneous substance deposited in the marrow, stained by alcian blue (pH 2.5), indicative of acid mucopolysaccharides. CFU-G and CFU-GM were decreased in number and myeloid pool in the bone marrow also decreased. Anti-neutrophilic antibody was negative. Neutropenia may be related to myeloid hypoplasia, due to increase of acid mucopolysaccharides replacing adipose cells in the bone marrow under long-term mal-nutritional state. Neutrophils markedly increased by administration of rhG-CSF 5.0 micrograms/kg/day for 14 days without the first peak. Serum G-CSF level did not increase (less than 60 pg/ml). It is effective to administer G-CSF to anorexia nervosa with neutropenia.     

Effects of radiation and 4-hydroperoxycyclophosphamide on production of G- and GM-CSF by stromal cells.

The effects of in vitro radiation and exposure to 4-hydroperoxycyclophosphamide (4-HC) on the production of G- and GM-CSF by different components of the human hematopoietic microenvironment are described. The marrow microenvironment is composed of fibroblasts, endothelial cells, macrophages, and adipocytes. To study the effects of radiation/4-HC on colony-stimulating factor (CSF) production by stromal cells, confluent layers of umbilical cord endothelial cells (EC), marrow fibroblasts (MF), and heterogeneous adherent layers (HAL) derived from long-term marrow cultures were established. These layers were exposed to radiation up to 3000 cGy and/or 100 mumol/ml of 4-HC and subsequently stimulated with IL-1 beta on day 0, 7, or 14 after radiation/4-HC. Following IL-1 exposure conditioned medium (CM) was collected and G- and GM-CSF levels were measured by ELISA and their ability to support colony formation was assessed. G- and GM-CSF levels after exposure to 4-HC and radiation were 12,460 +/- 172 pg/ml and 2268 +/- 160 pg/ml for EC, 2214 +/- 94 pg/ml and 263 +/- pg/ml for MF, and 3168 +/- 316 pg/ml and 356 +/- 34 pg/ml for HALs, respectively. For each cell group there was no significant difference between levels obtained without exposure and levels after exposure to 4-HC and/or radiation (p > 0.6). Comparison of levels obtained from different cell groups showed significant differences with EC media being the highest (p < 0.0001). To test the activity of these measured factors, CM of different sources was used in colony assays of CD 34+ cord blood progenitors.(ABSTRACT TRUNCATED AT 250 WORDS)     

Flt3 ligand level reflects hematopoietic progenitor cell function in aplastic anemia and chemotherapy-induced bone marrow aplasia

Flt3 ligand (flt3L) is a member of a small family of cytokines acting as tyrosine kinase receptor ligands that stimulate the proliferation of primitive hematopoietic progenitors in vitro. To gain insight into the physiological role of flt3L in early hematopoiesis, levels of flt3L were determined in serum of patients with multilineage bone marrow failure and related to the severity of stem cell depletion. In patients with aplastic anemia (AA) and in cancer patients with chemotherapy- induced transient suppression of hematopoiesis, flt3L fluctuated in an inverse relationship to the degree of bone marrow failure. In severe AA at diagnosis, levels of circulating soluble flt3L were highly elevated (2,653 +/- 353 pg/mL) as compared with normal blood serum values of 14 +/- 39 pg/mL. Flt3L returned to near normal levels within the first 3 months following successful bone marrow transplantation and in autologous remission induced by immunosuppressive therapy with antilymphocyte globulin (ALG; 100 +/- 31 and 183 +/- 14 pg/mL, respectively). In contrast, rejection of the graft or relapse of the disease after ALG was accompanied by an increase to high pretreatment concentrations of the circulating cytokine (3,770 +/- 2,485 and 1,788 +/- 233 pg/mL, respectively). Flt3L in serum inversely correlated with the colony-forming ability of AA bone marrow precursors in vitro (R = - .86), indicating that the concentration of the ligand reflects hematopoiesis at the progenitor cell level. Flt3L increased to 2,500 pg/mL in the serum of leukemia patients during chemoradiotherapy- induced bone marrow suppression and returned to normal values along with hematopoietic recovery. Expression of the membrane-bound form of flt3L was significantly elevated in mononuclear bone marrow and peripheral blood cells from patients with severe pancytopenia, suggesting de novo synthesis of the factor in response to bone marrow failure. The data provide a strong argument for the involvement of flt3L in the regulation of early hematopoiesis in vivo.     

Plasma levels and production of soluble stem cell factor by marrow stromal cells in patients with aplastic anaemia

Defective marrow stroma or microenvironment have been proposed as one of several mechanisms to account for bone marrow failure in aplastic anaemia (AA). Stem cell factor (SCF), the ligand for the c-kit receptor, is produced mainly by marrow stromal cells and seems to reflect the haemopoietic function of bone marrow stroma. We measured the plasma levels of soluble SCF in 87 patients with AA and investigated the production of soluble SCF by the marrow stromal cells of 46 patients with acquired AA. The mean plasma SCF concentrations in the AA patients and normal controls were not significantly different (1098 ± 398 pg/ml versus 1160 ± 316 pg/ml, respectively), and there was no significant correlation between the peripheral blood counts and the SCF concentrations. However, the mean SCF concentration in patients who received prednisolone ± anabolic steroids at the time of sampling was significantly lower than that in the patients who did not receive both agents. We did not find any correlation between the changes in SCF concentrations and the response to immunosuppressive therapy, although it did increase significantly after bone marrow transplantation. The ability of marrow stromal cells to release soluble SCF did not differ significantly between the patients with AA and normal controls. We conclude that soluble SCF production does not appear to be altered in patients with AA and that defective production of soluble SCF is unlikely to be the cause of AA in most patients.     

经静脉移植骨髓单个核细胞治疗慢性心衰前后BNP水平的变化

目的观察经静脉移植骨髓单个核细胞治疗慢性心衰前后脑钠肽（BNP）水平的变化。方法慢性心衰患者25例,移植前1d经髂后上脊抽取骨髓约60ml,经分离提取骨髓单个核细胞过夜,次日经静脉直接注入患者静脉内。移植前、移植后3d和7d抽血分离血浆-70℃保存。经酶联免疫法测定血浆BNP水平。结果移植前、移植后3d、移植后7d血浆BNP水平分别为（87．79±19．27）、（64．21±10．89）、（50．97±8．44）pg/ml,移植前与移植后7d比较有显著性差异。结论经静脉移植骨髓单个核细胞能使慢性心衰患者7d后的BNP明显下降。