[Analysis of gene mutation spectrum and pharmacokinetics of fibrinogen infusion in 146 cases of congenital fibrinogen disorders]

Objective: To investigate the clinical type and gene mutations, clinical manifestations, laboratory tests, diagnosis, and fibrinogen replacement therapy of congenital fibrinogen disorders. Methods: Clinical data of 146 patients with congenital fibrinogen disorders diagnosed from April 2000 to November 2020 were retrospectively analyzed. Results: Among the 146 patients, 61 (41.8%) men and 85 (58.2%) women had a median age of 33.5 years at the time of consultation. 34 patients (34.7%) were found to suffer from the disease due to bleeding symptoms, 33 patients (33.7%) due to preoperative examination. 55 patients (56.1%) had at least one bleeding symptom, and 42 patients (42.9%) had no bleeding symptoms. There is a negative correlation between fibrinogen activity concentration and bleeding ISTH-BAT score (rs=-0.412, P=0.001) . A total of 34 gene mutations were detected in 56 patients, of which 84.1% were missense mutations, and 16 new mutations were found. FGA Exon2 and FGG Exon8 mutations accounted for 71.4% of all mutation sites. Patients with afibrinogenemia were younger, with a median age of 2 (1-12) years, an ISTH-BAT score of 4, and patients with dysfibrinogenemia had significantly longer thrombin time (TT) , with a median of 28.5 (19.2-36.6) s. The 1 hour in vivo recovery (IVR) after fibrinogen infusion was (127.19±44.03) %, and the 24 hour IVR was (101.78±43.98) %. In addition to the obvious increase in the concentration of fibrinogen activity, the TT and the prothrombin time (PT) both decreased significantly, and the TT decreased more significantly, with an average decrease of 15.2% compared to the baseline after 24 hours of infusion. Conclusion: Most patients with congenital fibrinogen disorders have mild or no bleeding symptoms. Patients with afibrinogenemia have more severe symptoms. There is a negative correlation between the fibrinogen and the degree of bleeding. Genetic testing is helpful for the diagnosis of disease classification. FIB∶C/FIB∶Ag<0.7 can be used as a basis for clinical diagnosis. The TT can be used as the basis for the diagnosis of dysfibrinogenemia and the effectiveness of fibrinogen infusion.

[Clinical and genetic analyses of hereditary factor Ⅴ deficiency cases]

Objective: To analyze the clinical phenotype and molecular pathogenesis of nine patients with hereditary factor Ⅴ (FⅤ) deficiency. Methods: Nine patients with hereditary FⅤ deficiency who were admitted to the Institute of Hematology and Blood Diseases Hospital from April 1999 to September 2019 were analyzed. The activated partial thromboplastin time, prothrombin time, and FⅤ procoagulant activity (FⅤ∶C) were measured for phenotypic diagnosis. High-throughput sequencing was employed for the F5 gene mutation screening, Sanger sequencing was adopted to confirm candidate variants and parental carrying status, Swiss-model was used for three-dimensional structure analysis, and ClustalX v.2.1 was used for homologous analysis. Results: The FⅤ∶C of the nine patients ranged from 0.1 to 10.6. Among them, eight had a hemorrhage history, with kin/mucosal bleeding as the most common symptom (three cases, 37.5%) , whereas one case had no bleeding symptom. There were five homozygotes and four compound heterozygotes. A total of 12 pathogenic or likely pathogenic mutations were detected, of which c.6100C>A/p.Pro2034Thr, c.6575T>C/p.Phe2192Ser, c.1600_1601delinsTG/p. Gln534*, c.4713C>A/p.Tyr1571*, and c.952+5G>C were reported for the first time. Conclusion: The newly discovered gene mutations enriched the F5 gene mutation spectrum associated with hereditary FⅤ deficiency. High-throughput sequencing could be an effective method to detect F5 gene mutations.

[Congenital factor Ⅶ deficiency: a retrospective analysis of 43 cases]

Objective: To explore the pathogenesis, clinical characteristics, laboratory findings, diagnosis, treatment, and prognosis of congenital factor Ⅶ (FⅦ) deficiency. Methods: Clinical data of 43 patients with congenital FⅦ deficiency diagnosed from April 1999 to September 2019 were retrospectively analyzed. Results: There were 27 females and 16 males. Median age was 16 (1-70) years. Family history was found in 6 cases. There were 29 (67.4%) cases with bleeding symptoms, most common of which were mucocutaneous bleeding (13 cases, 30.2%) , oral bleeding (13 cases, 30.2%) , and epistaxis (9 cases, 20.9%) . Menorrhagia occurred in 11 cases (47.6% of female patients who were in fertile age) . Laboratory findings were characterized by significantly prolonged prothrombin time (PT) , normal partial thromboplastin time (APTT) , and decreased FⅦ activity (FⅦ∶C) . Ten cases received gene mutation analysis and 3 new mutations were found. Fourteen cases (32.6%) were treated with prothrombin complex concentrates (PCC) , 12 (27.9%) with fresh frozen plasma (FFP) , and 3 (7.0%) with human recombinant activated FⅦ (rFⅦa) . Twenty cases (46.5%) with no or mild bleeding symptoms did not receive any replacement therapy. Previous bleeding symptoms recurred in 5 patients (11.6%) , 8 females still had heavy menstrual bleeding, and 9 patients (20.9%) were lost to follow-up. Conclusion: Most patients with congenital FⅦ deficiency have mild or no bleeding symptoms, but have a tendency to excessive bleeding after surgery or trauma. There is no significant correlation between FⅦ∶C and severity of bleeding symptoms. Prophylaxis should be applied in patients with severe bleeding symptoms and rFⅦa is the first choice. Gene mutation test is significant for screening, diagnosis, and prognosis prediction of the disease.

Distinguishing Extravascular from Intravascular Ferumoxytol Pools within the Brain: Proof of Concept in Patients with Treated Glioblastoma

BACKGROUND AND PURPOSE

Glioblastoma-associated macrophages are a major constituent of the immune response to therapy and are known to engulf the iron-based MR imaging contrast agent, ferumoxytol. Current ferumoxytol MR imaging techniques for localizing macrophages are confounded by contaminating intravascular signal. The aim of this study was to assess the utility of a newly developed MR imaging technique, segregation and extravascular localization of ferumoxytol imaging, for differentiating extravascular-from-intravascular ferumoxytol contrast signal at a delayed 24-hour imaging time point.

MATERIALS AND METHODS

Twenty-three patients with suspected post-chemoradiotherapy glioblastoma progression underwent ferumoxytol-enhanced SWI. Segregation and extravascular localization of ferumoxytol imaging maps were generated as the voxelwise difference of the delayed (24 hours) from the early (immediately after administration) time point SWI maps. Continuous segregation and extravascular localization of ferumoxytol imaging map values were separated into positive and negative components. Image-guided biologic correlation was performed.

RESULTS

Negative segregation and extravascular localization of ferumoxytol imaging values correlated with early and delayed time point SWI values, demonstrating that intravascular signal detected in the early time point persists into the delayed time point. Positive segregation and extravascular localization of ferumoxytol imaging values correlated only with delayed time point SWI values, suggesting successful detection of the newly developed extravascular signal.

CONCLUSIONS

Segregation and extravascular localization of ferumoxytol MR imaging improves on current techniques by eliminating intrinsic tissue and intravascular ferumoxytol signal and may inform glioblastoma outcomes by serving as a more specific metric of macrophage content compared with uncorrected T1 and SWI techniques.

[Clinical characteristics of 83 patients with thrombotic thrombocytopenic purpura]

Objective: To analyze the clinical characteristics, treatment and prognosis of patients with thrombotic thrombocytopenic purpura (TTP) . Methods: 83 patients with TTP from May 1998 to May 2019 were analyzed retrospectively. Results: Among the 83 patients, there were 27 males and 56 females, with a median age of 39 (10-68) years. 41 cases (49.4%) showed pentalogy syndrome and 79 cases (95.2%) showed triad syndrome. 78.0% (46/59) of the patients had a PLASMIC score of 6 or higher. TTP gene mutations was detected in 5 of 10 patients. The activity of von Willebrand factor-cleaving protease (ADAMTS13) , which was detected in 10 patients before plasma exchange (PEX) , was less than 10% in 9 patients. 83 patients were treated with PEX/plasma infusion and glucocorticoid, 35 of which were treated combined with rituximab and/or immunosuppressant. The median follow-up was 34 (1-167) months, the effective rate was 81.9%, the remission rate was 63.9%, the relapse rate was (35.7 ±7.1) %, and the 3-year overall survival (OS) rate was (78.6 ±4.6) %. The effective rate (72.9%vs 94.3%, P=0.019) and OS rate[ (63.8±7.5) %vs (94.3±3.9) %, χ(2)=8.450, P=0.004] in the group treated with PEX/PI and glucocorticoid alone were lower than those in the group treated combined with rituximab and/or immunosuppressant. COX multivariate analysis showed that age (HR=1.111, 95%CI 1.044-1.184, P=0.001) and alanine transaminase (ALT) /aspartate aminotransferase (AST) (HR=1.353, 95%CI 1.072-1.708, P=0.011) were independent risk factors for OS. Conclusion: Most patients with TTP have triad syndrome, accompanied by a decrease in ADAMTS13 activity. Plasma infusion and glucocorticoid combined with rituximab, immunosuppressive therapy could improve overall survival. The prognosis of patients with older age and high ALT/AST ratio is poor.

[Eltrombopag for the treatment of primary immune thrombocytopenia in 23 pediatric patients]

目的

评估艾曲泊帕治疗儿童原发免疫性血小板减少症（ITP）的疗效和不良反应。

方法

回顾性分析2015年5月至2019年3月接受艾曲泊帕治疗的23例儿童ITP患者临床资料。

结果

23例患者中，男11例，女12例，中位年龄11（2~17）岁。新诊断ITP 4例（17.39%），持续性ITP 8例（34.78%），慢性ITP 11例（47.83%）。艾曲泊帕中位起始剂量为25.0（12.5~50.0）mg/d。基线中位血小板计数为14（2~82）×10⁹/L，治疗后第2周（23例）、第4周（23例）、第3个月（16例）、第6个月（11例）的中位血小板计数分别为40（4~170）×10⁹/L、20（4~130）×10⁹/L、60（4~110）×10⁹/L、70（18~160）×10⁹/L，均高于基线水平（z=-3.440，P=0.001；z=-1.964，P=0.049；z=-4.339，P<0.001；z=-5.794，P<0.001）。7例（30.43%）患者的起效时间≤7 d，10例（43.48%）患者的起效时间≤2周，总有效率为60.87%（14/23）。<6岁（6例）、6~12岁（10例）、13~17岁（7例）组的总有效率分别为33.33%（2/6）、60.00%（6/10）、85.71%（6/7），组间比较差异均无统计学意义（P>0.05）。23例患者基线WHO出血评分0、1、2级分别有4、12、7例，治疗后分别为13、7、3例，出血症状得到明显改善（χ²=7.558，P=0.006）。治疗过程中发生转氨酶、胆红素增高各4例，轻度恶心、呕吐及头晕各1例，对治疗均未造成影响。

结论

艾曲泊帕作为二线用药治疗儿童ITP疗效及耐受性均较好。

[Gene mutation spectrum and clinical characteristics analysis of 178 patients with essential thrombocytosis]

目的

分析原发性血小板增多症（ET）患者基因突变谱及临床特征。

方法

对2009年2月1日至2018年11月1日收治的178例初诊ET患者进行回顾性分析。

结果

全部178例患者中，男89例，女89例，中位初诊年龄为49.5（3~86）岁。JAK2V617F基因突变频率为16.45%（1.67%~43.90%），CALR基因突变频率为40.00%（10.00%~49.15%），MPL基因突变频率为25.10%（25.00%~40.00%）。与CALR基因突变的患者相比，JAK2V617F基因突变患者具有较高的发病年龄（P=0.035）、初诊白细胞计数（P=0.040）、初诊血红蛋白浓度（P=0.001）和较低的初诊血小板计数（P=0.002）。47例（27.01%）患者诊断ET前发生血栓事件，3例（1.72%）诊断ET后发生血栓事件。多因素分析结果显示，年龄>60岁（P=0.013，OR=4.595，95%CI1.382~15.282）、心血管危险因素（P<0.001，OR=8.873，95%CI2.921~26.955）为血栓事件的危险因素，CALR基因突变（P=0.032，OR=0.126，95%CI0.019~0.838）为血栓事件的保护性因素。年龄>60岁（P=0.042，OR=4.045，95%CI1.053~15.534）是影响ET患者总生存时间的危险因素。年龄≤60岁、年龄>60岁患者的OS时间分别为（115.231±1.899）、（83.291±4.991）个月（χ²=6.406，P=0.011）。

结论

心血管危险因素、年龄>60岁为ET患者血栓事件的危险因素，CALR基因突变为血栓事件的保护性因素。年龄>60岁是影响ET患者总生存的危险因素。

[The incidence and risk factors for thrombosis in primary immune thrombocytopenia]

目的

探讨原发免疫性血小板减少症（ITP）患者血栓发生情况及相关危险因素。

方法

对2005年12月至2017年12月在中国医学科学院血液病医院血栓止血中心住院治疗的3 225例ITP患者进行回顾性分析。

结果

共46例患者（1.43%）发生血栓事件，中位发病年龄为54（26~83）岁，成人患者中>40岁人群血栓发生率明显高于40岁以下人群[3.37%（40/1 187）对0.58%（6/1 030），P=0.000]。男、女性患者血栓发生率差异无统计学意义[1.53%（20/1309）对1.36%（26/1 916），P=0.187]。动脉血栓的发生率高于静脉血栓[1.12%（36/3 225）对0.22%（7/3 225），P=0.000]。82.61%（38/46例）患者发生血栓时PLT<100×10⁹/L。吸烟、高血压病、糖尿病及脾切除是ITP患者发生血栓的危险因素（P值分别为0.232、0.531）；糖皮质激素、TPO治疗患者治疗在有无血栓事件的两组间比较差异无统计学意义（P值分别为0.064、0.075、0.531）。

结论

对于中国人群，ITP疾病本身可能也是一种可伴发血栓的免疫性疾病，即使血小板水平低下仍可发生血栓事件；且具有明显的年龄分布特点；吸烟史、高血压病、糖尿病史及脾切除是发生血栓的危险因素。

[Immune tolerance induction in a case of hemophilia B with inhibitor with prothrombin complex concentrate and rituximab]

目的

探讨血友病B伴抑制物的免疫耐受诱导（ITI）治疗，提高血友病B伴抑制物的诊疗水平。

方法

应用基于APTT标准曲线的一期法测定重型血友病B患者凝血因子Ⅸ（FⅨ）活性，应用Bethesda法进行FⅨ抑制物定量测定；利用凝血酶原复合物（PCC）进行ITI并联合利妥昔单抗清除患者抑制物。

结果

患儿既往PCC暴露日为20 d，抑制物滴度峰值为56 BU/ml。在2015年11月患儿抑制物滴度降至10.4 BU/ml时开始ITI治疗，单用PCC一段时间无效，给予PCC联合利妥昔单抗治疗，17个月后成功清除患者体内FⅨ抑制物，未发生过敏反应及肾病综合征等并发症。ITI过程中患者年化出血率有所改善。

结论

该患者是国内首例报道的采用ITI联合利妥昔单抗成功治疗血友病B伴抑制物的病例。PCC联合利妥昔单抗ITI治疗是目前有希望清除血友病B抑制物的方法。

[A phase Ⅲ multi-center clinical trial on safety and efficacy of a domestic plasma derived factor Ⅸ for the treatment of patients with hemophilia B]

Objective: To evaluate the efficacy and safety of a domestic human plasma derived coagulation Factor Ⅸ concentrate (pd-FⅨ) in patients with hemophilia B. Methods: The study was a multicenter, open-label and single-arm study. The efficacy of pd-F Ⅸ was evaluated by objective performance criteria. The doses of pd-FⅨ were calculated according to the bleeding symptom and disease severity. The infusion efficiency of pd-FⅨ and improvement of bleeding symptoms were measured at 30 minutes and (24±4) h after the first infusion, respectively. Adverse events were recorded. Viral infection and FⅨ inhibitor were detected 90 d after the first infusion. Results: All 36 subjects with hemophilia B were enrolled in the study. The median age of these patients was 31 years old and the median injection doses were 4 (1-17) times. The hemostatic effect of 27/36 (75.00%) and 9/36 (25.00%) acute bleeding events were rated as "excellent" and "better" , respectively. The recovery rate was 111.92% (65.55%-194.28%) at 30 minutes after infusion of FⅨ. There was no adverse event related to FⅨ. No reactivation of HBV, HCV or HIV and FⅨ inhibitor was detected at 90-104 d after the first FⅨ infusion. Conclusion: This domestically made human plasma derived FⅨ concentrate is safe and effective in the treatment of acute bleeding in patients with hemophilia B. Clinical trial registration: China food and Durg Administration, 2016L08027.

[Clinical evaluation of the revised International Prognostic Score of Thrombosis for essential thrombocythemia (IPSET-thrombosis) in a cohort of 746 Chinese adult patients]

Objective: To evaluate the role of the revised International Prognostic Score of Thrombosis (IPSET-thrombosis) in predicting the occurrence of thrombotic events in Chinese patients with essential thrombocythemia (ET) and to develop a thrombosis predicting model more applicable to Chinese ET patients. Methods: Medical records of 746 adult patients with an initial diagnosis of ET were retrospectively analyzed. Results: The median age at diagnosis was 52 (18-87) years, with 305 males and 441 females. According to the revised IPSET-thrombosis model, the number of very low-, low-, intermediate-, and high-risk patients were 271 (36.3%) , 223 (29.9%) , 63 (8.4%) and 189 (25.3%) , respectively. The four groups exhibited significantly different thrombosis-free survival (χ(2)=72.301, P<0.001) . Thirty-six patients were reclassified as intermediate-risk according to the revised IPSET-thrombosis instead of low-risk as per the original IPSET-thrombosis. Nineteen intermediate-risk patients as per the original IPSET-thrombosis were upgraded to high-risk according to the revised IPSET-thrombosis. Fifty-one high-risk patients as per the original IPSET-thrombosis were reclassified as low-risk in the revised IPSET-thrombosis. It suggests that the revised IPSET-thrombosis potentially avoids over- or under-treatment. In low-risk patients as per the revised IPSET-thrombosis, the rate of thrombosis in patients with cardiovascular risk factors (CVF) was higher than that in those without (16.3% vs 5.2%, χ(2)=5.264, P=0.022) , and comparable with intermediate-risk patients as per the revised IPSET-thrombosis (16.3% vs 14.3%, χ(2)=0.089, P=0.765) . As a result, a new revised IPSET-thrombosis model more applicable to Chinese ET patients was developed in which patients with CVF in the low-risk group as per the revised IPSET-thrombosis were reclassified as intermediate-risk group. Conclusion: For predicting the occurrence of thrombotic events, the revised IPSET-thrombosis model was better than the original IPSET-thrombosis model. The revised IPSET-thrombosis was optimized and a new revised IPSET-thrombosis model more applicable to Chinese ET patients was developed, and the new evidence for risk stratification and treatment of ET in Chinese was provided.