Treatment of heart failure in adults with thalassemia major: response in patients randomised to deferoxamine with or without deferiprone

Background

Established heart failure in thalassaemia major has a poor prognosis and optimal management remains unclear.

Methods

A 1 year prospective study comparing deferoxamine (DFO) monotherapy or when combined with deferiprone (DFP) for patients with left ventricular ejection fraction (LVEF) <56% was conducted by the Thalassemia Clinical Research Network (TCRN). All patients received DFO at 50–60 mg/kg 12–24 hr/day sc or iv 7 times weekly, combined with either DFP 75 at mg/kg/day (combination arm) or placebo (DFO monotherapy arm). The primary endpoint was the change in LVEF by CMR.

Results

Improvement in LVEF was significant in both study arms at 6 and 12 months (p = 0.04), normalizing ventricular function in 9/16 evaluable patients. With combination therapy, the LVEF increased from 49.9% to 55.2% (+5.3% p = 0.04; n = 10) at 6 months and to 58.3% at 12 months (+8.4% p = 0.04; n = 7). With DFO monotherapy, the LVEF increased from 52.8% to 55.7% (+2.9% p = 0.04; n = 6) at 6 months and to 56.9% at 12 months (+4.1% p = 0.04; n = 4). The LVEF trend did not reach statistical difference between study arms (p = 0.89). In 2 patients on DFO monotherapy during the study and in 1 patient on combined therapy during follow up, heart failure deteriorated fatally. The study was originally powered for 86 participants to determine a 5% difference in LVEF improvement between treatments. The study was prematurely terminated due to slow recruitment and with the achieved sample size of 20 patients there was 80% power to detect an 8.6% difference in EF, which was not demonstrated. Myocardial T2* improved in both arms (combination +1.9 ± 1.6 ms p = 0.04; and DFO monotherapy +1.9 ± 1.4 ms p = 0.04), but with no significant difference between treatments (p = 0.65). Liver iron (p = 0.03) and ferritin (p < 0.001) both decreased significantly in only the combination group.

Conclusions

Both treatments significantly improved LVEF and myocardial T2*. Although this is the largest and only randomized study in patients with LV decompensation, further prospective evaluation is needed to identify optimal chelation management in these high-risk patients.     

Effective Combination Therapy of Deferiprone and deferoxamine for the Rapid Clearance of Excess Cardiac IRON and the Prevention of Heart Disease in Thalassemia. The Protocol of the International Committee on Oral Chelators

The International Committee on Oral Chelators (ICOC) combination therapy protocol involving the administration of deferiprone (L1) during the day (80–110 mg/kg/day) and deferoxamine (DFO) (40–60 mg/kg at least 3 days/week) during the night for 8–12 hours using a pump, or the whole 24 hours using an elastomeric pump infuser, has been tested in 11 thalassemia patients (seven males, four females) over a period of 9–28 months. The patients had variable serum ferritin levels (0.54–4.6 mg/L) and cardiac iron load ranging from normal to severe siderosis levels (MRI T2*: 4.7–45 ms). There was a substantial overall reduction in serum ferritin levels (0.17–2.16 mg/L) and normalization of cardiac iron (MRI T2* >20 ms) in all patients. In two patients with severe and moderate cardiac iron load range levels, cardiac iron normalization was achieved within 9–10 months. Two patients on L1 monotherapy (80–120 mg/kg/day) maintained normal range MRI T2* cardiac iron levels over the same period. The ICOC combination therapy protocol appears to be the most effective and least cumbersome form of chelation treatment for the rapid clearance of excess iron from the heart.     

异基因外周血造血干细胞移植治疗重型β地中海贫血

目的　观察异基因外周血造血干细胞移植治疗重型 β地中海贫血 (简称 β地贫 )的疗效和副作用。方法　 1例 β地贫双重杂合子 (β17 IVS II 6 5 4突变点 )患儿经总量马利兰 2 0mg kg ,环磷酰胺 2 0 0mg kg、马法兰 90mg m2 和抗胸腺淋巴细胞球蛋白 90mg kg组成的方案预处理后 ,输入人类白细胞抗原 (HLA)相合的同胞供体外周血造血干细胞悬液 5 6ml。患儿获得的有核细胞数为 14.4× 10 8 kg,粒单系祖细胞 (CFU GM) 9.5× 10 5 kg,CD 3 4CD-3 8细胞数为 14.9× 10 6 kg。结果　患儿术后 13d时中性粒细胞绝对值 (ANC) >0 .5× 10 9 L ,40d时血小板 >2 0× 10 9 L ;术后 2 0d聚合酶链反向点杂交法(PCR RDB)检测患儿为供者型的 β17杂合子 ,性染色体核型从 46XX转变为 46XY(供者型 )。术后 2 0d起脱离红细胞输注 ,血红蛋白维持在 110g L以上 ,10 0d时复查骨髓细胞形态学正常 ,肝脾不大。 16d时出现急性移植物抗宿主病 (aGVHD)I度 ,经使用甲基强的松龙和泼尼松治疗 ,于 2 6d时aGVHD完全被控制。至今未发生慢性GVHD ,现已术后无病存活 475d。结论　异基因外周血造血干细胞移植治疗重型 β地贫患儿已获得成功。其出现的aGVHD可被药物控制     

双胎及三胎妊娠地中海贫血产前基因诊断研究

目的:探讨双胎妊娠和三胎妊娠地中海贫血的产前基因诊断情况。方法:对27例双胎妊娠和三胎妊娠患者进行绒毛膜穿刺或羊膜囊穿刺胎儿取样,采取裂隙聚合酶链反应以及聚合酶链反应结合反向点杂交方法进行产前基因诊断。结果:在进行α地中海贫血产前基因诊断的20例双胎妊娠及1例三胎妊娠中,共对43个胎儿进行取材,共检测出6例Bart's水肿胎,3例血红蛋白H病。在进行β地中海贫血产前基因诊断的6例双胎妊娠中,共对9个胎儿进行取材,共检测到3例中重型β地中海贫血。结论:地中海贫血的多胎妊娠孕妇产前基因诊断能较有效检出Bart's水肿胎和中重型β地中海贫血患儿,可预防重型地中海贫血患儿的出生。     

基于片段长度差异应用HPLC快速检测β-地中海贫血

目的 通过高效液相色谱检测β-地中海贫血常见的基因型.方法 通过多重引物延伸反应同时扩增β-地中海贫血常见的突变位点,基于长度区分不同位点野生型引物和突变型引物扩增产物,并将待检品与标准品检测结果 进行对比,以辨别待检样本的基因型.结果 建立了稳定的高效液相色谱检测点突变技术平台,实现了对β-地中海贫血常见基因型的快速检测,通过对质粒样本、临床病例样本的验证,完全符合质粒样本测序、患者基因组检测的结果.结论 高效液相色谱检测β-地中海贫血具有快速、简便、样品量少等优点,其为遗传病点突变提供了新的检测手段.     

基因测序确认一例新β地中海贫血基因突变CD112（T→A）

目的 报道1例中国人少见的β地中海贫血基因突变CD112（T→A）／N。方法 根据血常规平均红细胞体积（MCV）和平均血红蛋白含量（MCH）以及血红蛋白电泳的HbF和HbA2对婚检和产检患者筛查地中海贫血，对可疑β地中海贫血患者采用基因扩增反向点杂交法检测常见17个位点突变。对于未发现突变者采用基因测序。结果 患者携带一种中国人少见的B地贫基因突变CD112（T→A）。结论 β地贫基因CD112（T→A）突变的报道丰富了中国人β地贫突变谱。对于指导婚检、产检、遗传咨询具有重要价值。     

地中海贫血筛查实用技术的应用研究

目的通过对血常规的MCV（平均红细胞体积）、红细胞脆性试验、血红蛋白电泳分析三种方法筛查α及β地贫,比较其敏感性及特异性。方法全自动血细胞分析仪检测血常规及一管定量法检测RBC脆性,筛选出疑地贫者322例、正常者100例进行HB电泳分析（用美国Helena公司全自动快速电泳系统）和基因分析（GAP-PCR法检测α-THAL基因;反向点杂交-RDB法检测βTHAL基因）,以基因分析作为金标准。结果MCV,红细胞脆性试验,血红蛋白电泳分析三种方法对地中海贫血诊断的敏感性分别为98.8%、78.5%、98.4%,特异性分别为72.4%、83.8%、90.2%。经χ2检验前两种筛查方法敏感性之间差异有统计学意义（P〈0.01）。结论用血常规MCV筛查地贫较红细胞脆性试验筛查敏感性高,方法简便、经济、适用于条件有限的基层医院开展产前地贫筛查,可作为筛查的首选方法,若有条件配合血红蛋白电泳综合分析可提高其准确性。     

平均红细胞体积和平均红细胞血红蛋白含量筛查妊娠合并轻型地中海贫血的价值

目的探讨平均红细胞体积(MCV)、平均红细胞血红蛋白含量(MCH)检测在筛查妊娠合并轻型地中海贫血(地贫)中的价值。方法 1514例孕妇在首次产前检查时,同时检查外周血MCV、血红蛋白浓度(Hb)、MCH及血红蛋白电泳等指标,依据首次产前检查时血常规及血红蛋白电泳结果分3组:Ⅰ组127例:Hb<100g/L伴血红蛋白电泳异常;Ⅱ组69例:Hb<100g/L而血红蛋白电泳正常;对照组1318例:Hb>100g/L及血红蛋白电泳正常;以基因诊断作为地贫诊断金标准。结果Ⅰ组MCV及MCH最低,明显低于Ⅱ组和对照组(P<0.01),而Ⅱ组与对照组无显著性差异(P>0.05)。MCV及MCH检测筛查地贫与基因诊断结果比较:灵敏度(Se)98.06%、特异度(Sp)72.04%、假阳性率0.28、假阴性率0.02、准确度90.31%、阳性预测值79.53%、阴性预测值90.30%、阳性似然比3.50、阴性似然比0.028。结论轻型地贫者有MCV、MCH降低的特征,临床上检测MCV、MCH筛查妊娠合并轻型地贫,其灵敏度高,且特异度也较高,假阳性率和假阴性率低。方法简便、实用、经济。可作为基层医院轻型地贫的筛查指标。     

德宏州傣、景颇、德昂、阿昌族0-7岁儿童地中海贫血调查

目的了解云南省德宏州傣、景颇、德昂、阿昌族0-7岁地中海贫血的流行病学现状。方法对云南省德宏州傣、景颇、德昂、阿昌族7岁以下儿童共2171人,进行了血液分析、Hb电泳检测,并进行统计学分析。结果血常规各指标随年龄的增长阳性率降低,有非常显著差异;β-地贫,α-地贫均有民族差异和地区差异。结论 0～7岁儿童地中海贫血在云南德宏州少数民族中属高发,其发生率在所调查的不同的民族及地区有差异。该调查为德宏地区少数民族进行行地贫的遗传咨询及预防提供了有价值的基础资料。     

23809例育龄人群地中海贫血筛查与血液学分析

目的了解育龄人群中地中海贫血（地贫）携带情况及其血液学特点,为地贫出生干预及筛查方法的完善提供依据。方法 23 809例育龄人群进行地贫初筛,对红细胞脆性或（和）平均容积低于正常值者进行血红蛋白电泳分析,根据初筛及电泳结果进行基因诊断。结果 23 809例育龄人群中,地贫初筛阳性5147例,血红蛋白分析筛出可疑α地贫3523例、β地贫1624例。地贫基因检测确诊α地贫2435例,包括合并β地贫103,1877例α地贫-1,462例α地贫-2,96例HbH病;β地贫1492例,包括HbE61例,249对夫妇可能生育中、重型地贫儿。少数地贫者血红蛋白水平正常,部分HbH和HbCS病血红蛋白电泳无特殊区带,β地贫合并α地贫双重杂合子表现为β地贫特点,各类地贫间血红蛋白水平、MCV、血红蛋白电泳结果及RBC脆性比较差异均有统计学意义（P〈0.05）。结论掌握地贫患者血液学特点,选择合理的筛查模式对育龄人群进行常规筛查,对高危者进行基因检测是干预重症地中海贫血患儿出生的有效措施。