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*

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 investigate the clinical characteristics, laboratorial and bone marrow pathological features of primary thrombocytopenia (ET) patients with different mutations of CALR, JAK2 and MPL genes. METHODS: The chinical data of 120 cases of ET in Jiangsu provincial people's hospital/ The First Affiliated Hospital of Nanjing Medical University from January 2015 to December 2017 were collected and analyzed, including 76 cases with JAK2 gene mutation, 40 cases with CALR gene mutation, 2 cases with MPL gene mutations, 2 cases without gene mutation. RESULTS: Among the ET patients, compared with the JAK2 gene mutation, CALR gene mutation showed statistically significant deareament of white blood cells and hemoglobin (P=0.001, P=0.01) and the male platelets in CALR group showed significant increament (P=0.04). Fourthermore, the average number of megakaryocytes and its cluster numbers in each hight power field of vision showed statistically significant decreament in CALR group as compared with JAK2 group (P=0.001, P=0.001), and thrombotic events in CALR group were signicantly lower than those in JAK2 group (7.5% vs 18.4%) (P=0.03). CONCLUSION Mutations of CALR, JAK2 have different clinical characteristics and blood pathological changes of Chinese ET patients, and their clinical significance is worth to explore.
Bone Marrow ; Calreticulin ; genetics ; China ; Humans ; Janus Kinase 2 ; genetics ; Male ; Mutation ; Receptors, Thrombopoietin ; genetics ; Thrombocythemia, Essential

OBJECTIVE: To explore the potential pathogenetic mutations of primary hypereosinophilia（HEN）by sequencing FGFR1 FLT3, MPL and JAK2 genes, and to clarify their effect on clinical manifestation and prognosis of HEN patients. METHODS: The direct DNA sequencing was employed to detect the gene mutations of FGFR1, FLT3, MPL and JAK2 in HEN patients. RESULTS: One deletion mutation (2654_2753del) within tyrosine kinase domain of FLT3 gene was found in a patient suffered from severe symptoms and ended with dismal outcome, which induced a premature stop codon (G885fsX888). For FGFR1, a new variation described as 1014_1019del AACAGT for nucleotide change was found in 19 cases, resulting in T339_V340del at the protein level. CONCLUSION The deletion of 6 bases in the FGFR1 gene (1014_1019del AACAGT) is first reported as non-synonymous SNP (nsSNP) site in the patients with primary hypereosinophilia. Deletion mutations in the FLT3 gene may be related with malignant clinical features and poor prognosis.
Base Sequence ; Humans ; Hypereosinophilic Syndrome ; genetics ; Mutation ; Receptors, Thrombopoietin ; Sequence Deletion ; fms-Like Tyrosine Kinase 3

OBJECTIVE: Interlukin-6 (IL-6) increases platelet count during inflammation and may act in a manner similar to thrombopoietin. Tocilizumab is a monoclonal antibody of the IL-6 receptor and widely used in the treatment of rheumatoid arthritis (RA). Here, we evaluated the incidence of tocilizumab-induced thrombocytopenia and clinical factors associated with the development of thrombocytopenia. METHODS: Patients with RA, who were treated with tocilizumab and had exposed to other biologics previously in a tertiary hospital between January 2014 and December 2017, were retrospectively evaluated. We compared occurrence of thrombocytopenia between tocilizumab and previous biologics. Furthermore, the factors associated with thrombocytopenia were analyzed using logistic regression analysis. RESULTS: In total, 114 patients with RA were treated with tocilizumab for mean 90.5 weeks (interquartile range, 30.9~174.9). Thrombocytopenia was reported in 14 patients (12.3%) and it was higher rate compared with previous biologics. Most cases were grade 1 thrombocytopenia. Multivariate analysis showed that patient age (odds ratio [OR], 2.170; 95% confidence interval [CI], 1.118~4.211; p=0.022) and platelet count prior to treatment with tocilizumab (OR, 0.972; 95% CI, 0.954~0.990; p=0.002) were significantly associated with the development of thrombocytopenia. CONCLUSION: Old age is risk factor for developing tocilizumab-induced thrombocytopenia and higher platelet count prior to treatment is associated with lowering risk of development of thrombocytopenia. However, thrombocytopenia was tolerable.
Antibodies ; Arthritis, Rheumatoid ; Biological Products ; Humans ; Incidence ; Inflammation ; Interleukin-6 ; Logistic Models ; Multivariate Analysis ; Platelet Count ; Receptors, Interleukin-6 ; Retrospective Studies ; Risk Factors ; Tertiary Care Centers ; Thrombocytopenia ; Thrombopoietin

BACKGROUNDEssential thrombocythemia is a subgroup of myeloproliferative neoplasms. Previous studies identified mutations of JAK2, CALR, and MPL that are closely related with the pathogenesis of myeloproliferative neoplasms. All these mutations contribute to the hyperactivation of JAK2/STAT pathway. However, a small proportion of essential thrombocythemia patients does not display such mutations. The pathogenesis of "triple-negative" form of essential thrombocythemia remains unknown.

OBJECTIVETo investigate the clinical characteristics of triple-negative essential thrombocythemia and related mutation genes.

METHODSTo identify the mutations associated with triple-negative essential thrombocythemia, next-generation sequencing was used to conduct targeted sequencing of 360 genes in samples from 68 patients.

RESULTSAt least one missense mutation was detected in all the patients and all the detected genes. After screening the data, it was observed that 10 genes with the 10 highest mutation were follows: FLT3, SH2B3, ASXL1, ADAMTS1, TET2, TP53, EGFR, CUX1, GATA2, and MPL.When only rare genes (i.e., with a frequency in Asian populations lower than 5%, as estimated by the 1000 Genomes Project) were analyzed, the most frequently mutated genes in the patients were TET2 (33.82%), SH2B3(29.41%), and ASXL1 (23.53%). Our study identified some mutations that did not previously reported. Although all these mutations need further validation, high incidence rates may indicate relevance of the respective mutations to essential thrombocythemia pathogenesis. Some of the detected mutations have been previously reported; these mutations were also found in a large proportion of our subjects.

CONCLUSIONwhole-exon sequencing can provide a higher level of accuracy for gene mutation analysis and assist in identifying mutations that contribute to illustrate the pathogenesis of essential thrombocythemia.

OBJECTIVETo detect the JAK2, CALR and MPL gene mutations in patients with BCR/ABL1 negative chronic myeloproliferative diseases（BCR/ABL1-CMPD）and to evaluate their diagnostic value.

METHODSTwo hundred and eight cases of BCR/ABL1-CMPD comprising of 146 cases of essential thrombocythemia（ET）, 37 cases of polycythemia vera（PV）and 25 cases of primary myelofibrosis（PMF）from March 2012 to December 2015 were enrolled in the BCR/ABL1-CMPD, while 124 cases of secondary thrombocythemia and 73 cases of secondary polycythemia were enrolled in the control group. The genomic DNA and total RNA Were isolated from bone marrow or peripheral blood, then the exons 12 to 20 of JAK2 gene, exon 10 of MPL gene and exons 3 to 9 of CALR gene were analyzed by using DNA sequencing.

RESULTSamong 146 ET patients, the JAK2, CALR or MPL mutations were found in: 138 cases（94.5%）including 86 cases with JAK2V617F mutation（58.9%）and 2 cases（1.4%）with exon 12 of JAK2 mutations. CALR mutations were detected in 41 cases（28.1%）, among them type 1（c.1092_1143del）in 22 cases, type 2（c.1154_1155insTTGTC）in 11 cases, and type 5（c. 1091_1142del）, type 8（c.1104_1137del）, type 41(c.1107_1137del）, type 42(c.1125_1125del）in one case respectively. In addition, 4 cases were detected withother mutations of the CALR gene（c.1107_1115del, c.1111_1144 del, c.1101 A>C, c.1112_1117del）. Moreover, 9 cases harbored MPL mutations（6.2%）. Secondly, 31 patients were detected with JAK2V617F mutation（83.8%）in 37 cases of PV, and JAK2 exon 12 mutations were found in 2 cases（5.4%）. Besides, CALR mutations were detected in 2 cases（5.4%）, including 1 case of type I, the other of novel mutation of CALR. Thirdly, 19 in 25 cases of PMF were detected with JAK2V617F mutation（76%）, 2 cases with CALR mutations（8%）. 4 patients（16%）, JAK2, CALR or MPL mutations were not detected, but among them 3 cases were found harboring other genetic abnormalities. Fourthly, no mutations of JAK2, MPL and CALR genes were detected in 124 patients with secondary thrombocytosis and 73 cases with secondary polycythemia.

CONCLUSIONCombined detection of JAK2, CALR and MPL gene mutations can cover the vast majority of patients with BCR/ABL1-negative myeloproliferative neoplasms. For higher frequencies of the mutations of CALR in ET patients, CALR mutation can be used as a new diagnostic marker in ET patients with JAK2 and MPL wild type.

OBJECTIVETo analyze the mutation rate and clinical characteristics of CALR, MPL W515K and JAK2 V617F genes in patients with primary thrombocythemia (PT).

METHODSFifty-six patients with PT were selected as the research objects in our hospital. The CALR and MPL W515K gene mutations were determined by genomic DNA-PCR direct sequencing of the PCR products, and the JAK2 V617F gene mutation was detected by allele specific PCR method.

RESULTSAmong the 56 patients with PT there were 14 cases of CALR gene mutation with the incidence rate of 25%, including 6 cases of type I, 5 cases of type II and 3 cases of type III. The sex, age, platelet(Plt) count, white blood cell (WBC) count and hemoglobin (Hb) level in the type I case of CALR gene mutation all were not significantly different from that in type II and III(all P>0.05); the WBC level in type III group significantly increased in comparison of type II group (P<0.05), while the sex, age, Hb and Plt levels showed no significant difference between the type III and type II groups (P>0.05). There were 3 cases of MPL W515K gene mutation with the incidence rate of 5.36%; 21 cases of JAK2 V617F gene mutation with the incidence rate of 37.50%. There were 13 cases of CALR gene mutation in negative patients with MPL W515K and JAK2 V617F (18 cases) with 72.22% incidence rate (13/18), and there was no cases of 1 or 2 gene mutations coexisted. The levels of Hb and WBC in peripheral blood of patients with CALR mutation were significantly lower than those of JAK2 V617F mutation (both P<0.05). In 56 cases, there were 3 cases of abnormal karyotype, with the incidence rate of 5.36%. The mutation rate of CALR gene in abnormal karyotypes (66.67%) was significantly higher than that of normal karyotypes (20.75%) (P<0.01).

CONCLUSIONThe incidence of JAK2 V617F gene mutation increases in the patients with primary thrombocythemia; CALR mutation rate is higher in the patients with negative MPL W515K and JAK2 V617F gene mutation, which may closely correlate with abnormal karyotype; the levels of peripheral Hb and WBC in PT the patients with CALR gene mutation are significantly lower than those in patients with JAK2 V617F mutation.

Objective: To investigate the safety and efficacy of eltrombopag for adult patients with chronic immune thrombocytopenia (cITP). Methods: It was a randomised, single-centre, 6 weeks, placebo-controlled study. Beginning in January 29(th), 2013, 35 patients were enrolled, and the trial was completed on May 16(th), 2014. 17 patients were assigned to receive eltrombopag (starting dose 25 mg/d) and 18 were assigned to receive placebo. Results: A total of 35 cases of adult cITP, 6 males and 29 females with a median age of 42(22-66) years were enrolled. One patient withdrew from eltrombopag treatment group for the adverse event (AE) and discontinued treatment. In first two weeks, 27.78% (5/18) of placebo-treated compared with 64.71%(11/17) of eltrombopag-treated patients achieved platelet counts ≥ 30×10(9)/L(P=0.031); Treatment 6 weeks, the proportion of platelet counts reached ≥50×10(9)/L and ≥ 30×10(9)/L in eltrombopag-treated were higher than placebo-treated ones with statistically significant differences in both groups [64.71%(11/17) vs 11.11% (2/18), P=0.001; 76.47% (13/17) vs 38.89% (7/18), P=0.028]; The study also indicated a statistically significant difference in favour of eltrombopag compared with placebo in the odds of achieving the outcome of a platelet count ≥ 50×10(9)/L at least once during 6-week treatment (94.11% vs 33.33%, P<0.001), and 70.59%(12/17) of patients with the platelet count continuously ≥ 50×10(9)/L in 50% of treatment time in eltrombopag-treated group was more than placebo-treated one [11.11%(2/18), P<0.001]. Proportions of patients who required rescue treatment were 44.44% in placebo group and none in eltrombopag-treated one, respectively (P=0.002); The odds of bleeding symptoms with the WHO bleeding scale had no difference in both groups after 6 weeks (P=0.066). Adverse events that occurred more frequently due to eltrombopag than placebo included increased transaminase (3/17) and blood bilirubin (5/17), cerebral infarction(1/17). Conclusions: The thrombopoietin receptor agonist eltrombopag was a suitable therapeutic option for Chinese adults with cITP.
Adult ; Aged ; Benzoates ; Female ; Humans ; Hydrazines ; Male ; Middle Aged ; Platelet Count ; Purpura, Thrombocytopenic, Idiopathic ; Pyrazoles ; Receptors, Thrombopoietin ; Treatment Outcome ; Young Adult