A PILOT TRIAL FOR SEVERE ,REFRACTORY SYSTEMIC AUTOIMMUNE DISEASE WITH STEM CELL TRANSPLANTATION

Objective To evaluate the feasibility, efficacy, and safety of high dose immunosuppressive therapy （HDIT） and autolognus hemopoietic stem cell transplantation （HSCT） with CD^34＋ cell selection in patients with severe, refractory autoim mune diseases. Methods Twenty-six patients with persistent systemic lupus erythematosus （SLE）, rheumatoid arthritis （RA）, primary Sjogren＇s syndrome （pSS）, or systemic sclerosis （SSc） who had been treated unsuccessfully with conventional treatment were enrolled in the trial in Peking Union Medical College Hospital from September 1999 to June 2004. The patients received HDIT with 200 mg/kg cyclophosphamide followed by an infusion of autologous stem cells that were CD34 selected. Disease acti- vity, adverse effect, hemopoietic and immune reconstitution, and time to recurrence of disease were monitored. Overall treatment related mortality was 7.7% （2/26） with 1 patient died of cytomegalovirus infection and an other of severe pneumonia. Relapse occurred in 3 SLE patients （17.6%） in 37, 26, and 19 months posttransplantation respectively, and 1 RA patient in 15 months posttransplantation. SLE Disease Activity Index （SLEDAI） scores of SLE survivors decreased significantly （P 〈 0.01）. RA patients recorded a drop of Disease Activity Score 28 （DAS 28）. The pSS patient remained symptoms free up to now, more than 50 months aider the transplantation. Conclusion HSCT can be performed relative safely in patients with severe autoimmune disease. Short-term effect of HSCT is promising. However treatment related mortality and relapse were observed in a subset of patients.

REARRANGEMENT AND EXPRESSION OF T CELL RECEPTOR β GENE IN HUMAN HEMOPOIETIC CELL LINES AND PRIMARY CELLS FROM ACUTE LYMPHOCYTIC LEUKEMIAS

Using Southern blot, Northern blot and Quick blot methods, we examined the rearrangement and expression of TCR βgene in four early differentiation stage cell lines from human hemopoietic system, namely HL-60, Jurkat, Daudi and Raji cells as well as lymphocytes from 17 acute lymphocytic leukemia （ALL） patients. The results showed. Ⅰ) Rearrangement of TCR βgene was seen in Jurkat cells. A germline pattern was observed in HL-60, Daudi and Raji cells. 2) Eight of 9 patients with T-ALL had cells with rearranged TCR βgene. But two of 3 patients with B-ALL and three of 5 patients with nonT, nonB-ALL also had cells with rearranged TCR βgene. 3) A 1.3 kb full-length transcript and a 1.0 kb truncated transcript were detected in Jurkat cells by probing with 32P-TCR βcDNA. But some leukemic B cells also expressed an incompleted transcript. 4) TCR βmRNA was detected in six of 8 patients with T-ALL, four of 5 patients with nonT, nonB-ALL and one of 3 patients with B-ALL. But the level of expression was quite differ ent. The dual-rearrangement and the abnormal expression may give us a new clue for researching leukemogenesis.

Differential susceptibility of murine hemopoietic cells and lymphocytes to freezing－thawing process

The susceptibility was compared between murine bone marr ow hemopoietic cells and splenic lymphocytes to four major factors of cryopreservation process: toxicity of dimethyl sulfoxide (DMSO), cooling rate,Tris-NH4Cl treatment, and dilution after thawing. When the concentration of DMSO was over 20%, the proliferative function or viability of both kinds of cells decreased markedly. Injury to hemopoietic stem cells and lymphoeytes was found more severe in rapid cooling than in slow cooling, and the intensity of iujury seemed alike under the same fast cooling condition. Pretreatment of bone marrow cells with Tris-NH4Cl did not significantly accentuate the injury of frozen-thawed hemopoietic stem cells. Dilution of the frozen-thawed cells in ice bath or at a fast rate was harmful to both cells. No significant differential susceptibilities of the two kinds of cells to each factor were found. These results indicate that selective destruction or inactivation of lymphocytes by cold treatment among bone marrow cells may be impossible.

ULTRASTRUCTURAL STUDY OF THE HEMOPOIETIC MICROENVIRONMENT IN HUMAN FETAL SPLEEN

Reciprocal interactions between hemopoietic stromal cells and immature hemopoietic cells in human spleens obtained from 20 fetuses of 10-28 weeks gestation were observed by transmission electron microscopy and scanning electron microscopy. The close association of stromal cells with immature hemopoietic cells was confirmed under the electron microscope and a presumptive HIM (Hemopoietic inductive microenvironment) was visualized. In regions of immature hemopoietic cell-reticular cell, endothelial cell, macrophage and interdigitating cell contact,some communicating structures were found between the plasma membranes of adjacent cells; moreover, the cytoplasm of these four stromal cells were full of various kinds of organelles. These results suggest that reticular cells,endothelial cells, macrophages and interdigitating cells are component parts of the HIM of human fetal spleen and that these cells have a nurturing function in relation to hemopoietic cells.

Impact of COVID-19 in patients with lymphoid malignancies

The first cases of coronavirus disease 2019(COVID-19)were detected in Wuhan,China,in December 2019.Since this time a concerted global effort of research and observational data gathering has meant that a great deal has been learnt about the impact of COVID-19 in patients with lymphoid malignancies.Approximately onethird of patients with lymphoid malignancies who acquire COVID-19 and have it severely enough to require hospital assessment will die from this infection.Major risk factors for a poor outcome are age and co-morbidities,but when these are taken into account lymphoma patients have a slightly greater than 2-fold increased risk compared to the general population.Notably,despite early concerns regarding the particular vulnerability of lymphoma patients due to the immunosuppressive effects of therapy,active treatment,including B-cell depleting agents such as rituximab,do not appear to be associated with an increased risk of a poorer outcome.Indeed,some treatments such as ibrutinib may be beneficial due to their modulation of the potential fatal hyperinflammatory phase of infection.There are risks associated with hemopoietic stem cell transplantation,but the collective experience is that these can be minimized by preventive strategies and that the majority of transplant recipients with COVID-19 infection will survive.Many questions remain including those regarding the outcome of COVID-19 infection in the rarer lymphoid malignancies and the efficacy of COVID-19 vaccines in lymphoma patients.This review aims to discuss these issues and present a summary of the current knowledge of the impact of COVID-19 in lymphoid malignancies.

Post-transcriptional regulation of DEAD-box RNA helicases in hematopoietic malignancies

Hematopoiesis represents a meticulously regulated and dynamic biological process.Genetic aberrations affecting blood cells,induced by various factors,frequently give rise to hematological tumors.These instances are often accompanied by a multitude of abnormal post-transcriptional regulatory events,including RNA alternative splicing,RNA localization,RNA degradation,and storage.Notably,post-transcriptional regulation plays a pivotal role in preserving hematopoietic homeostasis.The DEAD-Box RNA helicase genes emerge as crucial post-transcriptional regulatory factors,intricately involved in sustaining normal hematopoiesis through diverse mechanisms such as RNA alternative splicing,RNA modification,and ribosome assembly.This review consolidates the existing knowledge on the role of DEAD-box RNA helicases in regulating normal hematopoiesis and underscores the pathogenicity of mutant DEADBox RNA helicases in malignant hematopoiesis.Emphasis is placed on elucidating both the positive and negative contributions of DEAD-box RNA helicases within the hematopoietic system.

Low incidence of severe aGVHD and accelerating hemopoietic reconstitution in allo-BMT using lenograstim stimulated BM cells

Objectives To investigate the efficacy of accelerating hemopoietic reconstraction and reducing a graft versus host disease (GVHD) in Allo-BMT receiving lenograstim stimulated donor marrow and to assess the preliminary biological mechanism .Methods The donors for thirty patients (study group) with leukemia were given lenograstim 3-4?μg*kg-1*d-1 for seven days prior to marrow harvest. The results of subsequent engraftment in the recipients was compared with fifteen donors without G-CSF (control group). Five donors themselves were studied to assess the effects of lenograstion on hematopoietic progenitor cells and lymphocyte subsets in BM.Results The stimulated bone marrow contained a higher number of nucleated cells, CFU-GM and CD34+ cells (P<0.01). The hematopoetic reconstitution was accelerated. Until granulocyte counts exceeded 0.5×109/L and plalete counts exceeded 20×109/L, the days were 16.7±3.2 and 18.4±3.0 days as compared with those of the control group (22.5±5.1 and 26.3±5.9 days respectively, P<0.01). The incidence of grade Ⅱ-Ⅳ aGVHD was very low, only one case with grade Ⅱ aGVHD on the skin in the study group. Four out of fifteen patients (26.7%) in the control group had grade Ⅱ-Ⅳ aGVHD (P<0.05). The number of T lymphocyte subsets in the harvested BM stimulated by G-CSF changed. In comparison with the control group, CD4+ decreased and CD8+ increased significantly (P<0.01). The changes of progenitor cells and T lymphocyte subsets in BM from pre- to post- G-CSF stimulation indicated that the percentage of CD4+ cells reduced (P<0.05), that of CD8+ cells, and that of CD34+ increased (P<0.01). The incidence of chronic GVHD and relapse of leukemia were not different significantly between both groups.Conclusions Allogenic bone marrow transplant (Allo-BMT) donors given G-CSF can accelerate engraftment and minimize the incidence of severe aGVHD. There is a trend in favour of improved transplant-related complicatians.

Development of Dendritic Cell System

The dendritic cell system contains conventional dendritic cells(DCs)and plasmacytoid pre-dendritic cells (pDCs).Both DCs and pDCs are bone marrow derived cells.Although the common functions of DCs are antigen-processing and T-lymphocyte activation,they differ in surface markers,migratory patterns,and cytokine output.These differences can determine the fate of the T cells they activate.Several subsets of mature DCs have been described in both mouse and human and the developmental processes of these specialized DC subsets have been studied extensively.The original concept that all DCs were of myeloid origin was questioned by several recent studies,which demonstrated that in addition to the DCs derived from myeloid precursors, some DCs could also be efficiently generated from lymphoid-restricted precursors.Moreover,it has been shown recently that both conventional DCs and pDCs can be generated by the Flt3 expressing hemopoietic pro- genitors regardless of their myeloid-or lymphoid-origin.These findings suggest an early developmental flexibility of precursors for DCs and pDCs.This review summarizes some recent observations on the deve- lopment of DC system in both human and mouse.Cellular & Molecular Immunology.2004;1(2):112-118.

Allogeneic peripheral blood stem cell transplantation in the treatment of severe aplastic anemia and severe infection

Objective To investigate the efficacy of allogeneic peripheral blood stem cell transplantation (PBSCT) in the treatment of severe aplastic anemia (SAA) and severe infection. Methods A patient with SAA and pseudomonas aeruginosa septicemia was treated with PBSCT from an HLA-identical sibling with cyclophosphamide (CY) and total body irradiation (TBI) for conditioning. The patient was infused with 20.3×108/kg mononuclear cells including 61.0×106/kg CD34+cells following the conditioning regimen. Results Twelve days after PBSCT, the absolute neutrophil count (ANC) of 1.0×109/L was achieved, with platelet count >50×109/L at twenty days. The donor origin of engraftment was confirmed by polymerase chain reaction (PCR) analysis of short tandem repeats at the end of the first, sixth and twelfth month. The patient’s body temperature dropped to normal level when her ANC reached 0.5×109/L on day 10, and the bacterial culture of blood sample became negative subsequently. Symptoms and signs of acute or chronic graft versus host disease (GVHD) were not observed in 30 months after PBSCT. Conclusions Hematopoiesis was reconstituted shortly after PBSCT. The combination of CY and TBI and the infusion of sufficient peripheral blood stem cells may contribute to the successful engraftment. PBSCT may be considered as the first choice when hematopoietic stem cell transplantation is needed for SAA patients complicated with severe infection.

Comparative Study of Tiaoxue Yisui Recipe with SSL Regimen in Treating Infantile Chronic Aplastic Anemia

Objective: To find the effective method in treating infantile chronic aplastic anemia (ICAA) by using traditional Chinese medicine (TCM). Methods: Seventy-eight cases of ICAA were observed, 48 in the treated group were treated with Tiaoxue Yisui recipe, and 30 cases in the control group with SSL regimen. Results: The remission rate and total effective rate in the treated group were 52. 08% and 81. 25% respectively,which were higher than those in the control group (P < 0. 05). After one year's treatment the ratio of hemopoietic and non-hemopoietic cells in the treated group was higher than that in the control group (P< 0. 05). Conclusion: Tiaoxue Yisui recipe could improve the living quality of ICAA patients. The therapeutical mechanism of the recipe might be related to its promoting the proliferation of hemopoietic stem cells and regulating the immune function.