OBJECTIVE: To investigate the effect and relative mechanism of Recombinant Human Thrombopoietin (rhTPO) on long-term hematopoietic recovery in mice with acute radiation sickness. METHODS: Mice were intramuscularly injected with rhTPO (100 μg/kg) 2 hours after total body irradiation with ⁶⁰Co γ-rays (6.5 Gy). Moreover, six months after irradiation, peripheral blood, hematopoietic stem cells (HSC) ratio, competitive transplantation survival rate and chimerization rate, senescence rate of c-kit⁺ HSC, and p16 and p38 mRNA expression of c-kit⁺ HSC were detected. RESULTS: Six months after 6.5 Gy γ-ray irradiation, there were no differences in peripheral blood white blood cells, red blood cells, platelets, neutrophils and bone marrow nucleated cells in normal group, irradiated group and rhTPO group (P>0.05). The proportion of hematopoietic stem cells and multipotent progenitor cells in mice of irradiated group was significantly decreased after irradiation (P<0.05), but there was no significant changes in rhTPO group (P>0.05). The counts of CFU-MK and BFU-E in irradiated group were significantly lower than that in normal group, and rhTPO group was higher than that of the irradiated group(P<0.05). The 70 day survival rate of recipient mice in normal group and rhTPO group was 100%, and all mice died in irradiation group. The senescence positive rates of c-kit⁺ HSC in normal group, irradiation group and rhTPO group were 6.11%, 9.54% and 6.01%, respectively (P<0.01). Compared with the normal group, the p16 and p38 mRNA expression of c-kit⁺ HSC in the irradiated mice were significantly increased (P<0.01), and it was markedly decreased after rhTPO administration (P<0.01). CONCLUSION The hematopoietic function of mice is still decreased 6 months after 6.5 Gy γ-ray irradiation, suggesting that there may be long-term damage. High-dose administration of rhTPO in the treatment of acute radiation sickness can reduce the senescence of HSC through p38-p16 pathway and improve the long-term damage of hematopoietic function in mice with acute radiation sickness.
Humans ; Mice ; Animals ; Thrombopoietin/metabolism* ; Hematopoietic Stem Cells ; Blood Platelets ; Recombinant Proteins/therapeutic use* ; Radiation Injuries ; RNA, Messenger/metabolism*

SARS-CoV-2-induced immune thrombocytopenia (SARS-CoV-2-induced ITP) is an autoimmune disease secondary to virus infections. Its diagnosis is often based on exclusion of other possible causes of thrombocytopenia in COVID-19 patients. Common laboratory examinations include coagulation function, thrombopoietin and drug-dependent antibodies. Since both bleeding and thrombosis risks are seen in SARS-CoV-2-induced ITP patients, individual remedy is essential for the treatment of this disease. Because thrombopoietin receptor agonist(TPO-RA) has the side effect of accelerating thrombosis and may aggravate the pulmonary embolism symptoms of patients, it should be used for refractory SARS-CoV-2-induced ITP patients only. This review briefly summarizes the recent research progress in the pathogenesis, diagnosis and treatment of SARS-CoV-2-induced ITP.
Humans ; Purpura, Thrombocytopenic, Idiopathic/drug therapy* ; SARS-CoV-2 ; COVID-19/complications* ; Thrombocytopenia ; Thrombosis/drug therapy* ; Thrombopoietin/therapeutic use* ; Recombinant Fusion Proteins/therapeutic use*

OBJECTIVE: To explore the effect of recombinant human thrombopoietin (rhTPO) on hematopoietic reconstruction in allogeneic hematopoietic stem cell transplantation (allo-HSCT) model. METHODS: The C57BL/6 mice were employed as the donors, and BALB/c mice as recipients. The bone marrow mononuclear cells of the donor mice were extracted and pretreated, which then were injected with 5×10⁶ per mouse through the tail vein of the recipient to establish an allo-HSCT model. The implantation of hematopoietic stem cells in the recipient mice was detected by flow cytometry on the 28^th day after transplantation. Next, the successfully modeled recipient mice were randomly divided into experimental group and control group. The rhTPO was injected into mice in the experimental group on the first day after transplantation, while the saline was injected into mice in the control group. Both groups were injected for 14 consecutive days. The peripheral blood and bone marrow hematopoiesis of the two groups were observed on day 1, 3, 7, 14, and 21 after transplantation. RESULTS: The expression rate of H-2K^b in the bone marrow of recipient mice was 43.85% (>20%) on the 28^th day after transplantation, which indicated that the recipient mice were successfully chimerized. Meanwhile, counts of PLTs on the day 3, 7, 14, and 21 after transplantation in the experimental group were higher than those in the control group with statistical significances (P<0.05). In addition, hematopoietic function of bone marrow was suppressed in both groups on day 1, 3 and 7 after transplantation, but hematopoietic bone marrow hyperplasia was better in the experimental group than in the control group. On day 14 and 21 after transplantation, the hematopoietic function of bone marrow in the two groups was recovered, and the experimental group showed more obvious than the control group. CONCLUSION rhTPO can effectively stimulate the production of PLTs and facilitate the recovery of white blood cells and hemoglobin after allo-HSCT, and promote hematopoietic recovery and reconstitution of bone marrow.
Humans ; Animals ; Mice ; Thrombopoietin ; Mice, Inbred C57BL ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; Bone Marrow ; Recombinant Proteins ; Mice, Inbred BALB C

BACKGROUND: Recombinant human thrombopoietin (rh-TPO) and eltrombopag are two distinct TPO receptor agonists (TPO-RAs) with different mechanisms. During the pandemic, when immunosuppressive medications are controversial, switching to another TPO-RA may be worth exploring in patients who do not benefit from their first TPO-RA. We investigated the outcomes of switching from rh-TPO to eltrombopag or vice versa in immune thrombocytopenia (ITP) patients. METHODS: This prospective, open-label, observational investigation included 96 adult ITP patients who needed to switch between rh-TPO and eltrombopag between January 2020 and January 2021 at Peking University People's Hospital in China. The study evaluated response rates and platelet counts at different time points after the switch, bleeding events, time to response, duration of response, and adverse events. RESULTS: At 6 weeks after switching, response was observed in 21/49 patients (43%) who switched for inefficacy and 34/47 patients (72%) who switched for non-efficacy-related issues. In the inefficacy group, 9/27 patients (33%) responded to eltrombopag, and 12/22 patients (55%) responded to rh-TPO. In the non-efficacy-related group, 21/26 (81%) and 13/21 (62%) patients in the eltrombopag and rh-TPO groups maintained their response rates at 6 weeks after switching, respectively. Response at 6 months was achieved in 24/49 patients (49%) switching for inefficacy and 37/47 patients (79%) switching for non-efficacy issues. In the inefficacy group, 13/27 patients (48%) responded to eltrombopag, and 11/22 patients (50%) responded to rh-TPO. In the non-efficacy-related group, 22/26 patients (85%) and 15/21 patients (71%) in the eltrombopag and rh-TPO groups maintained their response rates at 6 months after switching, respectively. Both eltrombopag and rh-TPO were well tolerated. CONCLUSIONS: Our study confirmed the safety and effectiveness of switching between rh-TPO and eltrombopag for ITP patients who had no response to or experienced adverse events with their first TPO-RA. When the switch was motivated by other reasons, including patient preference and platelet count fluctuations, the probability of response was high. REGISTRATION ClinicalTrials.gov, NCT04214951.
Adult ; Humans ; Purpura, Thrombocytopenic, Idiopathic ; Thrombopoietin/adverse effects* ; Prospective Studies ; Recombinant Fusion Proteins ; Receptors, Fc/therapeutic use* ; Receptors, Thrombopoietin/therapeutic use* ; Thrombocytopenia/chemically induced* ; Benzoates/adverse effects* ; Hydrazines/adverse effects*

OBJECTIVE: To compare the effects of artificial liver treatment with double plasma molecular adsorption system(DPMAS) mode and traditional plasma exchange (PE) mode on platelets in patients, and to evaluate the clinical efficacy of recombinent human thrombopoietin (rhTPO) in the treatment of thrombocytopenia. METHODS: A total of fifteen patients undergoing artificial liver with DPMAS model admitted to the Fifth Affiliated Hospital of Guangzhou Medical University from January 2018 to November 2020 were selected and included in the DPMAS group, and another 15 patients receiving PE were selected and included in the PE group. The improvement of clinical symptoms, such as fatigue, jaundice, oliguria, edema, etc. before and after artificial liver treatment was compared between the two groups, and the trend of blood routine (especially platelet), coagulation function and other indexes before and after treatment were compared between the two groups. The use of rhTPO and the number of platelets were recorded during treatment. RESULTS: The improvement rate of clinical symptoms in DPMAS group was 86.67%, which was higher than that in PE group, but the difference was not statistically significant (P>0.05). There was no statistical significance in the outcome of the two groups within 90 days (P>0.05). There was no significant difference in white blood cell (WBC) and hemoglobin (HB) between the two groups after treatment (P>0.05). However, the level of platelet(PLT) in DPMAS group was significantly lower than that before treatment (P < 0.05), and was significantly lower than that in PE group (P < 0.05). After treatment, the international normalized ratio (INR) level in PE group was significantly improved (P < 0.05), but there was no significant difference in the INR level in DPMAS group (P>0.05). The patients in the DPMAS group received an average of (8.2±3.1) doses of rhTPO and (1.5±0.3) IU of platelet transfusions during hospitalization. In DMPAS group, platelets increased significantly after infusion of terbium. CONCLUSION Compared with PE mode, the artificial liver with DPMAS mode can reduce platelet levels in patients, but the application of rhTPO can stimulate platelet regeneration and increase platelet levels in the patients, thereby reducing the risk of bleeding due to platelet hypoplasia.
Blood Platelets ; Humans ; Liver, Artificial ; Plasma Exchange ; Recombinant Proteins ; Thrombocytopenia/therapy* ; Thrombopoietin

OBJECTIVE: To analyze and compare the efficacy of recombinant human thrombopoietin (rhTPO) and recombinant human interleukin-11 (rhIL-11) in the treatment of thrombocytopenia after chemotherapy in acute leukemia patients. METHODS: 180 patients with acute leukemia complicated with thrombocytopenia after chemotherapy in the First Affiliated Hospital of Anhui Medical University were analyzed retrospectively. Among them, 50 patients who treated with rhTPO and did not receive platelet transfusion were set as group A, 50 patients treated with rhTPO and receive platelet transfusion were set as group B, Forty patients treated with rhIL-11 without platelet transfusion were set as group C, Forty patients who treated with rhIL-11 and received platelet transfusion were set as group D. The duration of PLT below 20×10⁹/L, the days it takes for PLT to recover to more than 100×10⁹/L, and the incidence of different bleeding degrees were compared among several groups. RESULTS: The duration of PLT<20×10⁹/L in group A(3.72±1.14 d) was significantly shorter than that in group C(4.93±1.33 d) (P<0.001), and there was no significant difference from group B (P>0.05). The duration of PLT<20×10⁹/L in group B(3.06±0.91 d) was significantly shorter than that in group D(4.65±0.98 d) (P<0.001), while the difference in duration of days between group C and D was not statistically significant (P>0.05). The times for PLT to recover to 100×10⁹/L in group A(13.46±1.67 d) were significantly shorter than that in group C(16.85±2.13 d) (P<0.05), but there was no significant difference from group B (P>0.05). The time required for PLT to recover to 100×10⁹/L in group B(13.36±1.49 d) were significantly shorter than that in group D(16.18±1.78 d) (P<0.05), while the difference in the days required for group C and group D was not statistically significant (P>0.05). The incidence of high bleeding risk in group B was significantly lower than that in group A (22% vs 44%, P<0.05), the incidence of high bleeding risk in group D was significantly lower than that in group C (32% vs 65%, P<0.05), and the incidence of high bleeding risk in group A was significantly lower than that in group C (44% vs 65%, P<0.05). The incidence of high bleeding risk in group B(22%) was lower than that in group D(32.5%), and the difference was not statistically significant (P>0.05). CONCLUSION In the treatment of acute leukemia patients with thrombocytopenia after chemotherapy, compared with rhIL-11, rhTPO can significantly shorten the duration for patients in a status with extremely low levels of PLT and the recovery time of PLT to normal range. In addition, PLT transfusion cannot speed up the time for patients to raise platelets to a safe range, nor can it shorten the duration of low PLT levels, but it can reduce the incidence of high bleeding risk events.
Humans ; Interleukin-11 ; Leukemia, Myeloid, Acute/drug therapy* ; Platelet Count ; Recombinant Proteins/therapeutic use* ; Retrospective Studies ; Thrombocytopenia ; Thrombopoietin/therapeutic use*

OBJECTIVE: To evaluate the efficacy and safety of recombinant human thrombopoietin (rhTPO) combined with glucocorticoid in treatment of newly diagnosed adult primary immune thrombocytopenia (ITP). METHODS: Eleven male and 23 female patients with the diagnosis of primary ITP in our hospital from November 2018 to October 2019 were enrolled and randomly divided into test group (17 cases) and control group (17 cases), the median age was 52 years old (range: 20-76 years old). The patients in test group were treated with rhTPO 300 IU/(kg·d) combined with glucocorticoid , while the patients in control group were treated with rhTPO (15 000 IU/d) combined with glucocorticoid. Platelet count, platelet increase, as well as the overall response rate were compared. At the same time, the drug tolerance and any adverse drug reactions were observed. RESULTS: The platelet counts and platelet increase of the patients in the test group were significantly higher than those in control group (P<0.05). There was no significant difference in platelet counts and platelet increase between the patients in the test group and control group at day 3, 7 after treatment. There was no significant difference in overall response rates and complete response rates at day 7, 14 between the two groups either. In test group, there were 13 cases received platelet transfusion, while 12 cases in control group. The muscle aches occurred in one patient, and mild aminotransferase increased in another patient in test group which was self-recovery without treatment. CONCLUSION RhTPO 300 U/(kg·d) combined with glucocorticoid could rapidly increase the platelet count with a low incidence of tolerable adverse events compared with conventional dose rhTPO with glucocorticoid.
Adult ; Aged ; Female ; Glucocorticoids/therapeutic use* ; Humans ; Male ; Middle Aged ; Platelet Count ; Platelet Transfusion ; Purpura, Thrombocytopenic, Idiopathic/drug therapy* ; Recombinant Proteins/therapeutic use* ; Thrombopoietin/therapeutic use* ; Young Adult

Thrombopoietin (TPO) can activate hematopoietic cell proliferation by its receptor c-MPL mediated downstream pathways and induce the generation of megakaryocyte. In recent years, domestic and foreign researches have confirmed that TPO/ c-MPL pathway also plays an important role in the self-renewal and quiescence of leukemia stem cell, and its expression in acute myeloid leukemia (AML) also indicates the chemotherapy resistance and poor prognosis. In this article, the research progress of the roles of TPO/c-MPL pathway in chemotherapy resistance, prognosis of AML patients, and the application of TPO/ c-MPL receptor agonists in AML were summarized briefly.
Humans ; Leukemia, Myeloid, Acute ; Neoplasm Proteins ; Proto-Oncogene Proteins/metabolism* ; Receptors, Cytokine ; Receptors, Thrombopoietin ; Signal Transduction ; Thrombopoietin

OBJECTIVE: To investigate the effects of recombinant human thrombopoietin (rhTPO) to proliferation and apoptosis of acute myeloid leukemia (AML) cell lines. METHODS: After the treatment of different concentrations of rhTPO (0, 50, 100 ng/ml) for different time (24,48,72 h)，the cell proliferation rates of the AML cell lines (Kasumi-1, Skno-1, HEL, HL-60, THP-1) were determined by CCK-8 method. Apoptosis rate of each cell line cocultured with rhTPO was detected by Annexin V/PI method. The relative expression of TPO receptor c-MPL (myeloproliferative clonal antibody) mRNA in AML cell lines was detected by Q-PCR. The expression of c-MPL protein in each cell line was detected by Western blot. The expression of c-MPL antigen in HL-60 cells treated by different concentrations of rhTPO was detected by Flow cytometry. RESULTS: RhTPO showed no promotion to the proliferation of Kasumi-1, Skno-1, HEL, HL-60, THP-1 cell lines，however，it showed inhibitory effect to cell proliferation (72 h 0 ng/ml vs 100 ng/ml, P= 0.029) and pro-apoptotic (48 h 0 ng/ml vs 50 ng/ml, P=0.0143) in HL-60 cells. In Kasumi-1, Skno-1, HEL and THP-1 cells, there showed no statistically significant differences in apoptosis rate among each groups treated by different concentrations of rhTPO. Each AML cell line showed different levels of c-MPL gene and c-MPL protein expression, but HEL cells showed the highest expression in both of them. After HL-60 cells were treated by different concentrations of rhTPO for 48 hours, there showed no statistical difference in c-MPL antigen expression among each groups. CONCLUSION RhTPO can not promote the proliferation of Kasumi-1, Skno-1, HEL, HL-60 and THP-1 leukemia cell lines. On the contrary, rhTPO can inhibit HL-60 cell proliferation and promote its apoptosis, and this effect is not related to c-MPL gene expression or protein expression.
Apoptosis ; Cell Proliferation ; Humans ; Leukemia, Myeloid, Acute ; Neoplasm Proteins ; Proto-Oncogene Proteins ; Receptors, Cytokine ; Thrombopoietin

OBJECTIVE: To explore whether thrombopoietin (TPO) can rescue megakaryopoiesis by protecting bone marrowderived endothelial progenitor cells (BM-EPCs) in patients receiving chemotherapy for hematological malignancies. METHODS: Bone marrow samples were collected from 23 patients with hematological malignancies 30 days after chemotherapy and from 10 healthy volunteers. BM-EPCs isolated from the samples were identified by staining for CD34, CD309 and CD133, and their proliferation in response to treatment with TPO was assessed using CCK8 assay. DiL-Ac-LDL uptake and FITC-UEA-I binding assay were performed to evaluate the amount of BM-EPCs from the subjects. Tube-formation and migration experiments were used for functional assessment of the BM-EPCs. The BM-EPCs with or without TPO treatment were co-cultured with human megakaryocytes, and the proliferation of the megakaryocytes was detected with flow cytometry. RESULTS: Flow cytometry indicated that the TPO-treated cells had high expressions of CD34, CD133, and CD309. CCK8 assay demonstrated that TPO treatment enhanced the proliferation of the BM-EPCs, and the optimal concentration of TPO was 100 μg/L. Double immunofluorescence assay indicated that the number of BM-EPC was significantly higher in TPO-treated group than in the control group. The TPO-treated BM-EPCs exhibited stronger tube-formation and migration abilities ( < 0.05) and more significantly enhanced the proliferation of co-cultured human megakaryocytes than the control cells ( < 0.05). CONCLUSIONS TPO can directly stimulate megakaryopoiesis and reduce hemorrhage via protecting the function of BM-EPCs in patients following chemotherapy for hematological malignancies.
Bone Marrow ; Bone Marrow Cells ; Cells, Cultured ; Hematologic Neoplasms ; Humans ; Megakaryocytes ; Thrombopoietin