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Background aims. Aplastic anemia (AA) is a rare but potentially life-threatening disease. There is a need for the development of new, more effective and less toxic therapies for treating AA. The safety and efficacy of an immune cell-based therapy for AA was examined. Methods. Thirty-one patients with idiopathic AA received intravenous infusions of ex vivo-activated autologous and allogeneic immune cells at least once a week. Response to therapy was assessed by symptoms, transfusion dependency, blood counts, bone marrow biopsy and survival. Results. Of the 31 patients, 25 (81%) had either complete (11, 35%) or partial (14, 45%) responses, while six (19%) showed no response to the therapy. The overall survival rates at 3 years were 90%. Conclusions. The therapy described appears to be safe and effective. The data from this pilot study suggest that a larger, controlled study is warranted.

This study was aimed to investigate the effect of human bone marrow mesenchymal stem cells (hBMMSC) on the hematopoietic recovery of sublethally irradiated mice. Female BALb/c mice irradiated with (60)Co γ-ray at a single dose of 6 Gy received graded doses of hBMMSC (1×10(5), 1×10(6) and 5×10(6)) by intravenous infusion. The counts of leukocytes, platelets, erythrocytes and hemoglobin level in peripheral blood, the amount of bone marrow hematopoietic progenitors, and the serum levels of human TPO, SCF and G-CSF as well were evaluated at different time points after transplantation. The results showed that hBMMSC infusion had little protective effect on the survival of irradiated mice. Compared with the control mice, the peripheral blood cell counts of hBMMSC-treated mice were not obviously elevated during 3 weeks after infusion, however, blood cell counts were significantly greater at 4 weeks after cell treatment (P0.05). The amount of colony-forming unit of mononuclear cells and granulocyte/monocytes in bone marrow of mice that received middle and high doses of hBMMSC were dramatically greater than that in control mice (P0.05). Two days after hBMMSC administration, human G-CSF and SCF could be detected in the sera from hBMMSC-treated mice, and the G-CSF concentration of mice that received high-dose hBMMSC was significantly higher than that in other groups (P0.01). Nevertheless, human TPO was undetectable in the sera of all mice tested and serum human G-CSF and SCF could not be detected on days 9 and 16 in all groups. It is concluded that hBMMSC may promote the hematopoietic recovery of irradiated mice, probably by transient secretion of hematopoiesis-associated factors by the implanted cells.

The objective of this study was to explore the protective effects of human bone marrow mesenchymal stem cells (MSC) on hematopoietic organs of irradiated mice. Human bone marrow MSC were isolated, ex vivo expanded, and identified by cell biological tests. Female BALB/c mice were irradiated with (60)Co γ-ray at a single dose of 6 Gy, and received different doses of human MSC and MSC lysates or saline via tail veins. The survival of mice was record daily, and the femurs and spleens were harvested on day 9 and 16 for pathologic examination. The histological changes were observed and the cellularity was scored. The results showed that the estimated survival time of MSC- and MSC lysate-treated mice was comparable to that of controls. The hematopoiesis in the bone marrow of mice that received high-dose (5×10(6)) of MSC or MSC lysates was partially restored on day 9 and the capacity of hemopoietic tissue and cellularity scorings were significantly elevated as compared with that of controls (P0.05). Proliferative nudes were also obviously observed in the spleens of mice that received high-dose of MSC or MSC lysates on d 9 after irradiation. The histological structures of the spleen and bone marrow of the mice that received high-doses (5×10(6)) of MSC or MSC lysates were restored to normal, the cell proliferation displayed extraordinarily active. Further, the cellularity scores of the bone marrow were not significantly different between the high-dose MSC and MSC lysate-treated mice. It is concluded that the bone marrow MSC can promote the hematopoietic recovery of the irradiated mice, which probably is associated with the bioactive materials inherently existed in bone marrow cells.

To explore the safety and curative effects of autologous bone marrow-derived mesenchymal stem cells (BMSCs) in the treatment of silicosis.The protocol was approved by the Ethics Committee of the hospital, and ten patients with silicosis who had given written consent were enrolled in this study. BMSCs isolated from 100 ml of bone marrow for each case were purified and cultured. In each case the 3rd generation of qualified BMSCs (5 × 10(7)) were intravenously administered weekly for 3 weeks. Three cases among 10 patients were treated with BMSCs modified by hepatocyte growth factor (HGF) gene. The clinical symptoms, chest films, chest CT, pulmonary functions, T cells, serum IgG and ceruloplasmin (CP) were observed in 6 or 9 months after treatment.No obvious sub-effect was observed in cases treated with BMSCs, the clinical symptoms (such as cough, sputum and chest tightness) basically disappeared in 9 months after treatment. Pulmonary function tests showed that FVC increased from 71.2% ± 17.0% to 84.0% ± 10.9% (P0.01) and FEV1.0 increased from 67.5% ± 17.7% to 80.6% ± 14.9% (P0.01). The levels of serum CP and IgG significantly decreased (P0.01). Further, the chest films and CT in cases treated with autologous BMSCs modified by HGF gene were improved to different extent.Treatment with autologous BMSCs modified by HGF gene exhibit a beneficial effect on silicosis.

To compare the difference of effects on SiO(2)-induced alveolitis and early fibrosis between bone marrow-derived mesenchymal-like stem cells (BM-MSCs) and BM-MSCs transfected by pcDNA3.1-HGF and to explore the mechanism of this effects.The Primary BM-MSCs from Wistar male young rats were cultured and labeled by 4, 6-diamidino-2-phenylindole (DAPI). Fifty Wistar rats were randomly divided into 3 groups:model group (10 rats),which was administered with SiO(2) by the trache, the next day,injected PBS via the tail vein; BM-MSCs group (20 rats),which was administered with SiO(2) by the trache, the next day,injected with 1 ml suspension of BM-MSCs via the tail vein; pcDNA3.1-HGF plus BM-MSC group (20 rats),which was administered with SiO(2) by the trache, the next day,injected with 1 ml suspension of BM-MSCs transfected by pcDNA3.1-HGF via the tail vein. On the 14th and 28th days after treatment, half of the animals were sacrificed, respectively, and the lungs were harvested for frozen section to observe the cell marked by DAPI. HE staining under a fluorescent microscope, and to observe the pulmonary alveolitis and fibrosis by HE and Masson staining under a light microscope. Western blot assay was used to detect the expression of HGF in rat lungs. The expression levels of tumor necrosis factor-α (TNF-α) in pulmonary tissues were analyzed quantitatively by ELISA. The contents of HYP in pulmonary tissues were analyzed quantitatively by sample hydrolysis method.On the 14th and 28th days after treatment, the scores of pulmonary alveolitis and early fibrosis in pcDNA3.1-HGF plus BM-MSCs group were 2.36 ± 0.17, 2.8 ± 0.14 and 0.1 ± 0.11, 1.16 ± 0.13, which were significantly lower than those (1.68 ± 0.17, 1.58 ± 0.31 and 0.54 ± 0.15, 1.36 ± 0.13) in BM-MSCs group, also which were significantly lower those (2.36 ± 0.17, 2.80 ± 0.14 and 0.64 ± 0.09, 1.84 ± 0.17) in model group (P0.05); On the 14th and 28th days after treatment, the TNF-α contents of pulmonary tissues in pcDNA3.1-HGF plus BM-MSCs group were 280.4 ± 23.11 and 249.78 ± 22.33 pg/mg, which were significantly lower than those (341.58 ± 35.34, 442.29 ± 36.76 pg/mg and 319.51 ± 17.84, 348.53 ± 33.95 pg/mg) in BM-MSCs and model groups (P0.05); On the 14th and 28th days after treatment, the HYP contents of pulmonary tissues in pcDNA3.1-HGF plus BM-MSCs group were 0.46 ± 0.04 and 0.65 ± 0.05 µg/mg, which were significantly lower than those (0.63 ± 0.04, 1.04 ± 0.07 µg/mg and 0.72 ± 0.60, 1.39 ± 0.60 µg/mg) in BM-MSCs and model groups (P0.05).The effects of BM-MSCs transfected by pcDNA3.1-HGF on suppressing pulmonary alveolitis and early fibrosis induced by SiO2 were better than those of BM-MSCs. The mechanism may be associated with the reduced pulmonary inflammation.

This study was purposed to evaluate the long-term outcome and the safety of autologous peripheral blood mononuclear cells (PBMNC) treated by interleukin 2 (IL-2) and granulocyte-macrophage colony stimulating factor (GM-CSF) in the therapy of patients with aplastic anemia (AA). The therapy of 49 patients admitted BG in hospital from April 2001 to December 2007 were analyzed retrospectively. PBMNC were isolated and cultured for 48 hours in presence of IL-2 and GM-CSF. Cells were collected, and 6 × 10(6) - 1 × 10(8) PBMNC were intravenously injected weekly for 4 - 22 months. Hematopoietic recovery was evaluated by examinations of peripheral blood, bone marrow aspirates and bone marrow biopsy. Flow cytometry was used to assess the peripheral T cell subsets before and after treatment. Polymerase chain reaction was performed to observe the clonal diversity of T cell receptor variable β-chain (TCR-Vβ) recombination. The results showed that 37 cases were cured and none of them relapsed during the follow-up, 5 cases were in partial remission, 3 cases got improvement, and 4 cases showed no response. The total efficiency reached up to 91.8%. The ratios of CD4(+)/CD8(+) subsets were abnormal in 39 patients prior to the treatment, and 31 cases restored to the normal range after cell transfusions. Analysis on the clonal diversity of TCR-Vβ recombination in 11 patients showed the transition from monoclonal or biclonal spectratype to polyclonal one. No long-term side effects were documented. It is concluded that the treatment with PBMNC treated by IL-2 and GM-CSF is generally safe and effective. The underlying mechanisms may be in relation to the restoration of cell immunity.

To analyze the changes in CD8(low) T lymphocyte subsets in patients with occupational chronic lead poisoning.Flow cytometric analysis was used to count the numbers of CD8+ cells. 23 patients with occupational chronic lead poisoning and 20 controls were examined.Compared with control group (8.21% ± 3.02%), the CD8(low) T lymphocyte (12.98% ± 5.62%) were significantly increased in patients with occupational chronic lead poisoning.Although the ratio of CD+ T lymphocyte is normal, the CD8 level is significantly decreased. The increase of CD8(low) T lymphocyte may be an important phenomenon of immuno-injury induced by lead. CD8(low) T lymphocyte could be an new direction for research of lead immuno-toxicity.

To observe the changes of T-lymphocyte subsets in workers with long-term benzene exposure, and further understand the benzene's lymphotoxicity.Blood was sampled from 44 patients with chronic benzene poisoning of different degrees, (mild 22 patients, moderate 14, severe 8) respectively. Twenty-two health benzene exposed workers, and 94 health unexposed workers served as normal control. A total of the phenotype (CD4, CD8) of T lymphocyte in peripheral blood was analyzed by indirect immunofluorescence assay.Lymphocyte subset analysis showed significantly decreased CD4(+) T lymphocytes, CD4(+)/CD8(+) ratio, except CD8(+) T lymphocytes in benzene exposed groups (P0.05). Among the four benzene-exposed groups, CD4(+) T lymphocytes and CD4(+)/CD8(+) ratio showed no difference (P0.05).The primary changes of T-lymphocyte subsets in workers following benzene long-term exposure are the decrease of CD4(+)%, but the changes are not correlated with haematopoietic injury.

We have developed a novel cell-based immunotherapy for treatment of some hematopoietic and blood deficient diseases such as aplastic anemia, chemotherapy-induced severe myelosuppression, idiopathic thrombocytopenia purpura and autoimmunity-induced cytopenia. Autologous and/or allogeneic peripheral blood mononuclear cells were cultured in vitro with a combination of cytokines and a calcium mobilizing agent for 2 days before given to patients via intravenous infusion. The immunotherapy has been shown to have potent activities in stimulating multi-lineage hematopoiesis and blood production including platelet production, which remains a major clinical problem to be solved. The immunotherapy is more effective for treatment of chronic and severe bone marrow failure and inefficient blood production than currently available growth factors of G-CSF, GM-CSF, Erythropoietin and IL-11. The mechanism of the immunotherapy is yet completely clear to us, however, some evidence suggests that in vitro activated immune cells produce and secrete multiple cytokines, working in concert, these cytokines released by the infused cells in organs important for hematopoiesis and blood production such as bone marrow, liver and spleen have remarkable effects on target cells, resulting in improved hematopoiesis, blood cell differentiation and maturation. In the preliminary clinical studies, more than 100 patients with aplastic anemia, severe chemotherapy-induced myelosuppression, systemic lupus erythematosus-associated cytopenia and idiopathic thrombocytopenia refractory to conventional therapies have been treated with the immunotherapy and the results have been encouraging. In severe idiopathic and benzene-induced aplastic anemia, 90% patients have complete or partial remission after the immunotherapy and one and half year survival is 90%. We have used 2–5x108in vitro activated allogeneic immune cells per infusion per day for 5 consecutive days, followed by small numbers of autologous infusions (1 to 10 million from approximately 50 ml of peripheral blood, depending on the severity of the disease, once a week for 4 weeks). This cycle of therapy is repeated till patient’s absolute neutrophil count is more than 0.5x109/L. The duration of the immunotherapy required for patients with AA to significantly improve ranges from two months to two years depending on the severity of the disease. Idiopathic thrombocytopenia is as difficult as aplastic anemia to treat for the immunotherapy and also requires relatively long time (several months to a year) for patients to respond to the therapy. Approximately 50% adult patients treated with the immunotherapy have complete or partial remission. In severe myelosuppression induced by chemotherapy in leukemia patients, the immunotherapy is highly effective and capable of reducing infection, bleeding and blood transfusion. The recovery of severe myelosuppression (from a few days to a month depending on the severity) after the immunotherapy is much quicker than that of aplastic anemia and idiopathic thrombocytopenia purpura. In conclusion, animal and preliminary human clinical studies suggest that the immunotherapy is highly effective for some bone marrow failure and blood deficient disorders, which are usually difficult to treat with the conventional therapies. The immunotherapy described here merits further investigation.