Objective:To investigate alterations in the immune lineage of T-cell large granular lymphocytic leukemia (T-LGLL) at the single-cell transcriptome level and to elucidate its pathogenic mechanisms.Methods:Peripheral blood samples were collected from 5 T-LGLL patients before and after treatment (from June 2019 to December 2020) and 3 healthy controls at the Institute of Hematology & Blood Diseases Hospital, CAMS & PUMC. Single-cell transcriptome sequencing libraries were prepared and sequenced using 10× Genomics technology. Differentially expressed genes in immune cells were compared between patients and healthy donors, followed by pathway enrichment analyses.Results:Profiling 67,237 immune cells revealed that, in T-LGLL: 1) Effector CD8+ T cells exhibited increased numbers, enhanced cytotoxicity, and greater proliferative capacity. Following effective immunosuppressive therapy, both the proliferative capacity and effector functions of these cells significantly decreased ( P<0.05). 2) The proportion of regulatory T (Treg) cells was reduced, accompanied by increased apoptosis. After effective immunosuppressive therapy leading to remission, Treg cell proportions increased, and apoptotic pathways were downregulated ( P<0.05). 3) Antigen-presenting cells (APCs) showed enhanced functionality. Monocytes and dendritic cells were enriched in antigen synthesis and presentation pathways, while B cells displayed increased antigen-binding capacity and were enriched in pathways related to T-cell activation ( P<0.05). 4) Natural killer (NK) cells exhibited attenuated cytotoxic function but demonstrated an enhanced regulatory capacity over T cells ( P<0.05) . Conclusions:T-LGLL patients present a characteristic immunological profile marked by an imbalance in immune homeostasis. This profile includes abnormal activation and expansion of effector CD8 + T cells, and a reduction in Treg cell numbers accompanied by functional impairment. Furthermore, APCs and NK cells were found to positively regulate T-lymphocyte activation, differentiation, and proliferation.

Objective:To evaluate the efficacy of cyclophosphamide in patients with T-cell large granular lymphocytic leukemia (T-LGLL) and the maintenance of treatment-free remission (TFR) following drug discontinuation.Methods:Clinical data were collected from 37 patients with T-LGLL who received oral cyclophosphamide at the Regenerative Medicine Clinic of the Institute of Hematology and Blood Diseases Hospital between June 2019 and March 2024. Patient clinical characteristics, treatment efficacy, and long-term TFR were analyzed.Results:The median age of the 37 patients was 60 years (range: 37-86), and 22 (59.5%) were male. Anemia was observed in 30 patients (81.1%), and 28 (75.7%) met the diagnostic criteria for secondary pure red cell aplasia. Neutropenia occurred in 15 patients (40.5%), lymphocytosis in 11 (29.7%), and thrombocytopenia in three (8.1%). Sixteen patients (43.2%) had not received prior immunosuppressive therapy (treatment-naive group), while 21 patients (56.8%) were refractory to or had relapsed after immunosuppressive treatment (refractory/relapsed group). All patients met the treatment criteria and received oral cyclophosphamide at doses of 50-100 mg/day. Among the 36 evaluable patients, hematologic remission was achieved in 25 (69.4%), with a median time of 2.0 months (range: 0.7-7.0). There was no statistically significant difference in remission rates between the treatment-naive and refractory/relapsed groups (68.5% vs. 66.7%, P=0.589). Among the 25 patients who achieved hematologic remission, 24 discontinued cyclophosphamide. With a median follow-up of 39.0 months (range: 8.0-56.0), the median TFR duration was not reached. The estimated TFR rates were (90.87± 6.16) % at 12 months and (75.72±11.04) % at 36 months. No significant difference in TFR was observed between the treatment-naive and refractory/relapsed groups ( P=0.451) . Conclusion:Oral cyclophosphamide is effective in the treatment of T-LGLL, and patients may maintain long-term TFR following drug discontinuation.

Objective:To investigate alterations in the immune lineage of T-cell large granular lymphocytic leukemia (T-LGLL) at the single-cell transcriptome level and to elucidate its pathogenic mechanisms.Methods:Peripheral blood samples were collected from 5 T-LGLL patients before and after treatment (from June 2019 to December 2020) and 3 healthy controls at the Institute of Hematology & Blood Diseases Hospital, CAMS & PUMC. Single-cell transcriptome sequencing libraries were prepared and sequenced using 10× Genomics technology. Differentially expressed genes in immune cells were compared between patients and healthy donors, followed by pathway enrichment analyses.Results:Profiling 67,237 immune cells revealed that, in T-LGLL: 1) Effector CD8+ T cells exhibited increased numbers, enhanced cytotoxicity, and greater proliferative capacity. Following effective immunosuppressive therapy, both the proliferative capacity and effector functions of these cells significantly decreased ( P<0.05). 2) The proportion of regulatory T (Treg) cells was reduced, accompanied by increased apoptosis. After effective immunosuppressive therapy leading to remission, Treg cell proportions increased, and apoptotic pathways were downregulated ( P<0.05). 3) Antigen-presenting cells (APCs) showed enhanced functionality. Monocytes and dendritic cells were enriched in antigen synthesis and presentation pathways, while B cells displayed increased antigen-binding capacity and were enriched in pathways related to T-cell activation ( P<0.05). 4) Natural killer (NK) cells exhibited attenuated cytotoxic function but demonstrated an enhanced regulatory capacity over T cells ( P<0.05) . Conclusions:T-LGLL patients present a characteristic immunological profile marked by an imbalance in immune homeostasis. This profile includes abnormal activation and expansion of effector CD8 + T cells, and a reduction in Treg cell numbers accompanied by functional impairment. Furthermore, APCs and NK cells were found to positively regulate T-lymphocyte activation, differentiation, and proliferation.

Objective:To evaluate the efficacy of cyclophosphamide in patients with T-cell large granular lymphocytic leukemia (T-LGLL) and the maintenance of treatment-free remission (TFR) following drug discontinuation.Methods:Clinical data were collected from 37 patients with T-LGLL who received oral cyclophosphamide at the Regenerative Medicine Clinic of the Institute of Hematology and Blood Diseases Hospital between June 2019 and March 2024. Patient clinical characteristics, treatment efficacy, and long-term TFR were analyzed.Results:The median age of the 37 patients was 60 years (range: 37-86), and 22 (59.5%) were male. Anemia was observed in 30 patients (81.1%), and 28 (75.7%) met the diagnostic criteria for secondary pure red cell aplasia. Neutropenia occurred in 15 patients (40.5%), lymphocytosis in 11 (29.7%), and thrombocytopenia in three (8.1%). Sixteen patients (43.2%) had not received prior immunosuppressive therapy (treatment-naive group), while 21 patients (56.8%) were refractory to or had relapsed after immunosuppressive treatment (refractory/relapsed group). All patients met the treatment criteria and received oral cyclophosphamide at doses of 50-100 mg/day. Among the 36 evaluable patients, hematologic remission was achieved in 25 (69.4%), with a median time of 2.0 months (range: 0.7-7.0). There was no statistically significant difference in remission rates between the treatment-naive and refractory/relapsed groups (68.5% vs. 66.7%, P=0.589). Among the 25 patients who achieved hematologic remission, 24 discontinued cyclophosphamide. With a median follow-up of 39.0 months (range: 8.0-56.0), the median TFR duration was not reached. The estimated TFR rates were (90.87± 6.16) % at 12 months and (75.72±11.04) % at 36 months. No significant difference in TFR was observed between the treatment-naive and refractory/relapsed groups ( P=0.451) . Conclusion:Oral cyclophosphamide is effective in the treatment of T-LGLL, and patients may maintain long-term TFR following drug discontinuation.

Objective To establish F0 generation chimeric rabbits with FOXN1 gene knockout and explore method for the in vivo conservation of immunodeficient rabbits in a conventional housing environment.Methods Initially,CRISPR/Cas9 technology was employed to inject constructed sgRNA and Cas9 protein into a single cell from rabbit two-cell stage embryos to obtain chimeric embryos with FOXN1 gene editing.The embryos were subsequently transferred into surrogate does.Finally,the F0 generation offsprings were genotyped using PCR and Sanger sequencing,and their growth and development in a conventional housing environment were observed.Results The PCR and Sanger sequencing result confirmed the successful establishment of himeric rabbits with FOXN1 gene knockout.On observation,the chimeras exhibited normal growth and development in a conventional environment without any immunodeficient phenotypes.Conclusions This study established a preliminary chimeric rabbit model with FOXN1 gene knockout that grows and develops normally in standard laboratory environments.This lays the foundation for the further breeding of FOXN1 immunodeficient rabbits in the future.

Objective:To investigate the efficacy and feasibility of mechanical thrombectomy (MT) via carotid artery salvage puncture in patients with acute anterior circulation large vessel occlusive stroke. Methods:A retrospective analysis was performed. Eight patients with acute anterior circulation large vessel occlusive stroke underwent MT via carotid artery salvage puncture in Departments of Neurology, First People's Hospital of Xianyang, Xi'an Ninth Hospital, Xi'an Daxing Hospital and XD Group Hospital from June 2021 to September 2023 were enrolled. Occlusion location, time from onset to femoral artery puncture, causes of carotid artery salvage puncture, time from femoral artery puncture to carotid artery salvage puncture, time from successful carotid artery puncture to vascular recanalization, modified thrombolysis in cerebral infarction (mTICI) score immediately after MT, and scores of National Institutes of Health Stroke Scale (NIHSS) 24 h after MT and modified Rankin Scale (mRS) 90 d after MT were analyzed. Results:Of the 8 patients, 7 had M1 segment occlusion and 1 patient had M2 segment occlusion. Direct thrombectomy was not possible resulting from type III aortic arch in 3 patients, aortic arch replacement in 1 patient, right common carotid artery twisting angle in 1 patient, left common carotid artery twisting angle in 2 patients, and bilateral femoral artery occlusion in 1 patient. All 8 patients had successful carotid artery puncture under local anesthesia, including 7 with mTICI 3 and 1 patient with mTICI 2b. Average time from successful carotid artery puncture to vascular recanalization was about 35 min, ranged 10-90 min. All patients had decreased NIHSS score 24 h after MT compared with before MT, and no complications such as hematoma or airway compression occurred in carotid artery puncture site. Six patients had mRS scores of 0-2 and 2 had scores of 6 (death cause: pulmonary infection) 90 d after surgery.Conclusion:For patients with patients with acute anterior circulation large vessel occlusive stroke, MT via carotid artery salvage puncture is a safe and feasible method in cases of difficulty in establishing thrombectomy route via femoral artery such as type III aortic arch, common carotid artery twisting angle, abdominal aorta occlusion.

Objective:To explore the dynamic changes of donor derived T cells at different time points in the aplastic anemia mouse model.Methods:The aplastic anemia mouse model was induced and then the proportion of infiltrated donor derived T cells in spleen and bone marrow, expression of activation molecular markers, cell cycle and functional subsets were measured by flow cytometry at different time points to evaluate the functional status of T cells in different periods.Results:①T cell immune-mediated aplastic anemia mouse model was successfully established by half lethal dose irradiation combined with major histocompatibility antigen (MHC) haploidentical lymph node cells infusion. ②The donor derived T cells began to infiltrate significantly in the spleen of aplastic anemia mouse from the 3rd day after transplantation and the ratio of CD4 +/CD8 + gradually inverted. After the 5th day, they gradually entered the bone marrow, predominated by CD8 + cells. ③The expression peak of CD69 in donor CD4 + cells was later than that in CD8 + cells. The trend of CD25 expression in CD4 + cells was the same as that in CD8 + cells, but the expression level in CD8 + cells was higher than CD4 + cells. ④The proportion of donor CD4 + cells in S/G 2/M phase reached the peak in spleen, about 12%, within 3 days after transplantation, while a higher level in CD8 + cells, which was about 20%. And the proportion of both CD4 + and CD8 + cells in S/G 2/M phase increased again after entering bone marrow, which was continued to be higher in CD8 + cells than that in CD4 + cells after 3 days of transplantation. ⑤Immune activated T cells in the spleen rapidly differentiated into effector memory T cells (T EM) after a short central memory T cell (T CM) stage. After entering the bone marrow, some T EM differentiated into effector cells to further function. Conclusion:In the aplastic anemia mouse model, donor derived T cells activated rapidly after entering the allogenic recipient, reached its proliferation booming period and differentiated into T EM cells within 5 days. After 5 days, they began to enter the bone marrow to continue proliferate and damage hematopoiesis.

Klebsiella pneumoniae (KP) is a common conditional pathogen, and also one of the common pathogens causing infection in immunocompromised patients, with its infection rate increasing year by year. Carbapenem antibiotics are effective drugs to control KP infection. But with the widespread use of carbapenem antibiotics, carbapenemresistant Klebsiella pneumoniae (CRKP) appears and increases year by year. Organ transplant recipients are at high risk of CRKP infection due to the suppressed immune system. Once drug-resistant bacteria infection occurs, it is often difficult to control and the survival rate of transplant organs is reduced, which brings great challenges to clinical treatment. In this article, the current status and treatment progress of CRKP infection in organ transplantation are summarized.

Objective: To determine the valuable hemolytic characteristics in differential diagnosis of paroxysmal nocturnal hemoglobinuria (PNH), autoimmune hemolytic anemia (AIHA) and hereditary spherocytosis (HS). Method: The clinical and hemolytic characteristics of 108 PNH patients, 127 AIHA patients and 172 HS patients diagnosed from January 1998 to April 2017 were compared. Results: ①Reticulocyte percentage (Ret%) of PNH patients [6.70% (0.14%-22.82%)] was significantly lower than that of AIHA [14.00%(0.10%-55.95%), P<0.001] and HS patients [11.83%(0.60%-57.39%), P<0.001]. The Ret% in PNH patients were significantly lower than those in AIHA and HS patients at the same levels of anemia, except for in mild anemia between PNH and AIHA patients. However, when comparing the Ret% between AIHA and HS patients, there was significant difference only in mild anemia [7.63%(1.87%-29.20%)% vs 11.20%(3.31%-22.44%), z=-2.165, P=0.030]. ②The level of TBIL in HS patients was significantly higher than that in AIHA and PNH patients [79.3 (11.2-244.0) μmol/L vs 57.6 (7.6-265.0) μmol/L, z=5.469, P<0.001; 79.3(11.2-244.0) μmol/L vs 26.2(4.6-217.7) μmol/L, z=-2.165, P<0.001], and the proportion of HS patients with TBIL more than 4 times the upper limit of normal (ULN) (64.1%) was significantly higher than that of AIHA (37.7%, χ²=19.896, P<0.001) and PNH patients (4.6%, P<0.001). ③The LDH level of PNH patients was significantly higher than that of AIHA and HS [1 500 (216-5 144) U/L vs 487 (29-3 516) U/L, z=-9.556, P<0.001; 1 500 (216-5 144) U/L vs 252 (132-663) U/L, z=-11.518, P<0.001], and the proportion of PNH patients with LDH more than 1 000 U/L (79.1%) was significantly higher than that of AIHA patients (13.0%, χ²=93.748, P<0.001) and HS patients (0, P<0.001). ④Splenomegaly occurred in 43.5% of PNH patients, including 16.0% with severe splenomegaly. In contrast, the occurrence of splenomegaly was 98.6% in AIHA patients and 100.0% in HS patients (P<0.001), and 63.0% of AIHA patients (P<0.001) and 90.4% of HS patients (P<0.001) were with severe splenomegaly. ⑤The prevalence of cholelithiasis in HS patients was up to 43.1%, significantly higher than that in AIHA patients (10.5%, P<0.001) and PNH patients (2.9%, P<0.001). Conclusion The comprehensive assessment of the five hemolytic characteristics is simplified, practical and efficient, with great clinical significance, providing specific indicators for differential diagnosis and efficient approach for making further work-up.

Objective To simulate the process of hypoxic?ischemic brain injury at high altitude in a simulated cabin with plateau low pressure environment, and to prepare a rat model of cerebral injuries at different high altitudes. Method Thirty?two 0?day?old neonatal SD rats were divided into four groups, namely group A ( control group) and three test groups:group B (2000 m group), group C (4000 m group), and group D (6000 m group). The rats of control group were reared in a barrier environment. The rats of test groups were placed in a simulated cabin with plateau low pressure environment, and to prepare neonatal cerebral ischemia?hypoxia model by sport activities. The sport movements were carried out in the cabin in a swimming groove 60 min/d, and not less than 20 hours a day at high altitude low pressure environment. Zea Longa 5 point scale standard was used to determine the behavioral scores at the 3 th 7 th 11 th 15 th days, and samples were collected on the 15th day to observe red blood cell morphology using HE and 2, 3, 5?triphenyltetrazolium chloride ( TTC ) staining and ultrastructure by scanning electron microscopy. Result ( 1 ) The neurological scores of the test groups A, B, C were significantly different from that of the control group (P<0?05), and the scores of test group D and control group were very significantly different ( P <0?01 ) . ( 2 ) The histopathological examination using HE staining showed inflammatory cell infiltration in all rats of the test groups, and the extent of inflammatory cell infiltration was positively correlated with the increase of altitude. ( 3 ) The histopathology with TTC staining revealed prominent ischemia in the cerebral cortex of rats in the plateau hypoxic environment. ( 4 ) Scanning electron microscopy showed that the rat erythrocytes were cap?like in the group B, irregular in the group C, and zigzag shape in the group D. Conclusions In this study, a rat model of neonatal hypoxic?ischemic encephalopathy ( HIE) is successfully established by hypoxic cabin combined with sport activity. This model is stable, reliable, more closely mimicking the pathogenesis and clinical manifestation of neonatal HIE than models prepared with other methods, therefore, may be used in related research.