老年人再生障碍性贫血68例临床分析

目的探讨老年人再生障碍性贫血（ＡＡ）的临床特点。方法分析同期收治的老年人及非老年人ＡＡ各６８例，对照比较其临床特点及疗效。结果老年患者发病前有致病因素接触史者占４４．１％，临床上贫血、感染及出血症状多见且严重，并存症多，骨髓增生程度低下更为显著，治疗效果差，随访１～９年，老年人慢性ＡＡ（ＣＡＡ）及严重型ＡＡ（ＳＡＡ）１年及５年生存率分别为７９．６％、５７．９％及２０．４％、５．３％，与非老年患者（分别为９４．０％、７２．２％及７６．０％、１６．７％）比较差异有显著性。结论老年人ＡＡ预后不佳，除加强支持治疗和并存症治疗外，对于其骨髓衰竭的治疗应采取更加积极的措施。     

Telomere length changes in patients with aplastic anaemia

To investigate telomere changes in patients with aplastic anaemia (AA) and clinical factors influencing the telomere dynamics, telomere length (TL) was measured in peripheral blood mononuclear cells using Southern blot analysis of 42 patients with AA and 39 healthy normal controls. Nineteen patients received supportive treatment only, while the remaining 23 patients received immunosuppressive therapy with anti-thymocyte globulin or anti-lymphocyte globulin +/- cyclosporin A. In AA patients, TL was on average 1.41 kb shorter than that of age-matched normal controls (P < 0.001). In patients treated with immunosuppression, the mean TL of non-responders was significantly shorter than that of age-matched normal controls (P < 0.001), while no difference in TL was detected in responders compared with controls. Positive correlation was observed between the extent of telomere shortening, the severity of neutropenia (P = 0.05) and the degree of mean corpuscular volume elevation (P = 0.005) at the time of the study. However, there was no correlation with time elapsed since diagnosis (P = 0.214). These findings suggest that haematopoietic stem cells in patients with AA rapidly lose TL at the onset of the disease. The TL shortening may reflect the severity of impairment of haematopoiesis.     

Abnormal immunomodulatory ability on memory T cells in humans with severe aplastic anemia

Severe aplastic anemia (SAA) is a bone marrow failure disease induced by hyperfunctional autoimmunic Th1 lymphocytes. Memory T cells (TM) are a component of the adaptive immune system. They ensure the host of more aggressive and faster immune response to efficiently eliminate the specific antigens after re-exposure and thus play a key role in T-cell functions. In this study we investigate the quantities and functions of memory T cells in SAA patients before and after immunosuppressive therapy (IST) to further clarify the mechanism of SAA apoptosis of bone marrow hematopoietic cells. Results showed that the percentage of CD4+ effector T cells in peripheral blood and bone marrow lymphocytes was decreased in SAA patients. The ratio of CD4+ memory T lymphocytes to CD8+ memory T subsets (CD4+/CD8+TM) in SAA patients was also lower. The percentage of CD8+ effector T cells in peripheral blood and CD8+ central memory T cells in the bone marrow lymphocytes was significantly higher in newly diagnosed patients. Furthermore, the median expressions of perforin and granzyme B on memory T cells were higher in SAA patients compared to those in normal controls. After IST, the quantities and functions of memory T cells return to normal level. Therefore, we concluded that the abnormal immunomodulatory ability on memory T cells may contribute to the imbalance of Th1/Th2 subsets and thus lead to over-function of T lymphocytes and hematopoiesis failure in SAA.     

Paroxysmal nocturnal haemoglobinuria phenotype cells and leucocyte subset telomere length in childhood acquired aplastic anaemia

The significance of paroxysmal nocturnal haemoglobinuria (PNH^pos) cells and leucocyte subset telomere lengths in paediatric aplastic anaemia (AA) is unknown. Among 22 children receiving immunosuppressive therapy (IST) for AA, 73% (16/22) were PNH^pos, of whom 94% achieved at least a partial response (PR) to IST; 11/16 (69%) achieved complete response (CR). Only 2/6 (33%) PNH^neg patients achieved PR. PNH^pos patients were less likely to fail IST compared to PNH^neg patients (odds ratio 0·033; 95% confidence interval 0·002–0·468; P = 0·012). Children with AA had short granulocyte (P = 7·8 × 10^?9), natural killer cell (P = 6·0 × 10^?4), naïve T lymphocyte (P = 0·002) and B lymphocyte (P = 0·005) telomeres compared to age‐matched normative data.     

Excellent outcome of matched unrelated donor transplantation in paediatric aplastic anaemia following failure with immunosuppressive therapy: a United Kingdom multicentre retrospective experience

We retrospectively analysed the outcome of consecutive children with idiopathic severe aplastic anaemia in the United Kingdom who received immunosuppressive therapy (IST) or matched unrelated donor (MUD) haematopoietic stem cell transplantation (HSCT). The 6-month cumulative response rate following rabbit antithymocyte globulin (ATG)/ciclosporin (IST) was 32·5% (95% CI 19·3-46·6) (n = 43). The 5-year estimated failure-free survival (FFS) following IST was 13·3% (95% confidence interval [CI] 4·0-27·8). In contrast, in 44 successive children who received a 10-antigen (HLA-A, -B, -C, -DRB1, -DQB1) MUD HSCT there was an excellent estimated 5-year FFS of 95·01% (95% CI 81·38-98·74). Forty of these children had failed IST previously. HSCT conditioning was a fludarabine, cyclophosphamide and alemtuzumab (FCC) regimen and did not include radiotherapy. There were no cases of graft failure. Median donor chimerism was 100% (range 88-100%). A conditioning regimen, such as FCC that avoids total body irradiation is ideally suited in children. Our data suggest that MUD HSCT following IST failure offers an excellent outcome and furthermore, if a suitable MUD can be found quickly, MUD HSCT may be a reasonable alternative to IST.     

Success of allogeneic marrow transplantation for children with severe aplastic anaemia

Allogeneic marrow transplantation offers curative therapy for children with severe aplastic anaemia (SAA). We report the outcomes of 148 children with SAA who received human leucocyte antigen (HLA)-matched related marrow grafts between 1971 and 2010. Patients were divided into three groups, reflecting changes in conditioning and graft-versus-host disease (GVHD) prophylaxis regimens that occurred over time. Patients in Group 1 were conditioned with cyclophosphamide (CY; 200 mg/kg) followed by 'long' (102 d) methotrexate (MTX). Patients in Groups 2 and 3 received CY alone (Group 2) or combined with anti-thymocyte globulin (Group 3) followed by 'short' (days 1, 3, 6, and 11) MTX and ciclosporin (until day 180). With a median follow-up of 25 years, the 5-year survivals were 66%, 95%, and 100% for Groups 1, 2, and 3, respectively (overall P < 0·0001). The 3-year estimates of graft rejection were 22%, 32%, and 7%, respectively. The probabilities of grades III-IV acute and 2-year chronic GVHD were 15%, 0%, and 3%, and 21%, 21%, and 10%, respectively. Advances in preparative and GVHD prophylaxis regimens, and supportive care during the past 40 years have led to improved outcomes for children with SAA. These results confirm the use of allogeneic marrow transplantation for children with SAA who have HLA-matched related donors.     

再生障碍性贫血感染的研究进展

再生障碍性贫血是一种外周全血细胞减少的骨髓衰竭综合征。感染是再生障碍性贫血患者死亡的主要原因。再生障碍性贫血患者的免疫妥协状态与化疗导致的中性粒细胞减少的免疫妥协状态不同,其导致的感染也有所不同。长期粒细胞减少是发生侵袭性真菌病和细菌感染的最大危险因素。中性粒细胞减少的恢复能明显提高生存率,粒细胞减少期间的支持治疗可起到很大的保护作用。再生障碍性贫血患者合并侵袭性真菌病最常见的致病菌为曲霉菌属、假丝酵母菌属、接合菌属和镰刀菌属。合并细菌感染的致病菌包括：革兰阳性菌如凝固酶阴性的葡萄球菌属、肠球菌、凝固酶阳性的金黄色葡萄球菌、梭状芽胞杆菌、微球菌甲型溶血性链球菌、单核细胞增生李斯特菌、蜡样芽胞杆菌;革兰阴性菌如大肠埃希杆菌、沙门菌、脆弱拟杆菌、肺炎克雷伯杆菌、亲水性气单胞菌属、铜绿假单胞菌。再生障碍性贫血患者合并病毒感染相对少见,但可出现疱疹病毒科、社区获得性呼吸道病毒感染和甲型、乙型、丙型病毒性肝炎。     

Comparable survival outcome between transplantation from haploidentical donor and matched related donor or unrelated donor for severe aplastic anemia patients aged 40 years and older: A retrospective multicenter cohort study

This retrospective multicenter cohort study aimed to compare the outcome of haploidentical hematopoietic stem cell transplantation (HID-HSCT) with matched sibling donor (MSD) and unrelated donor (URD) transplantation in severe aplastic anemia (SAA) patients 40 years of age and older. With a median follow-up time of 17.6 months, 85 consecutive patients were enrolled in the study, and the median patient age was 45 years (40, 58). The cumulative engraftment rates of neutrophil and platelet were 98.8 ± 0.0% and 92.9 ± 0.1%. The cumulative incidences of Grade 2-4 acute graft-versus-host disease (aGvHD) and chronic graft-versus-host disease (cGvHD) at 3 years were 14.1 ± 0.1% and 17.3 ± 0.2%. The 3-year estimated overall survival (OS) and failure-free survival (FFS) were 91.2 ± 3.2% and 89.7 ± 3.5%. In multivariate analysis, the only factor associated with inferior survival was an ECOG score ≥2. HID-HSCT was associated with a higher incidence of GvHD, but the difference of 3-year estimated OS between HID group and the other two cohorts was not significant (86.7 ± 6.4% for HID vs 92.1% ± 4.4% for MSD and 100% for URD, P = .481). HID-HSCT might be a feasible alternative option for selected SAA patients aged 40 years and older without a matched donor.     

肿瘤坏死因子相关凋亡诱导配体在再生障碍性贫血患者中的表达及意义

目的通过检测再生障碍性贫血(AA)患者骨髓单个核细胞表面肿瘤坏死因子相关凋亡诱导配体(TRAIL)的表达,探讨TRAIL在AA造血干细胞凋亡中的作用。方法采用流式细胞术对12例AA患者(AA组)、11例AA治疗后缓解患者(缓解组)、12例正常对照者(对照组)骨髓单个核细胞表面TRAIL的表达进行检测。结果 AA组、缓解组、对照组TRAIL均有表达;AA组TRAIL的阳性表达率(5.8±3.3)%高于缓解组(2.4±2.0)%和对照组(3.2±2.2)%(P<0.05);缓解组与对照组间差异无统计学意义(P>0.05)。结论 TRAIL在AA患者骨髓单个核细胞表面的表达阳性率增高,提示TRAIL介导的细胞凋亡可能在AA的发病机制中发挥一定的作用。     

Bone marrow transplantation for acquired aplastic anemia: What's new

Bone marrow transplantation is a major therapeutic option for patients with acquired severe aplastic anaemia: improved survival has been achieved in younger patients, thanks to better donor selection, conditioning regimens and graft versus host disease prophylaxis, together with improved supportive care, including diagnosis and treatment of opportunistic infections. This has not been the case for older patients over the age of 40 years.We will discuss transplantation platforms as used for different donor types and we will analyse major breakthroughs of the last years: the combination of Fludarabine and cyclophosphamide as a conditioning regimen, the use of alternative donors including HLA haploidentical related donors and new strategies to prevent acute and chronic graft versus host disease, including post transplantation Cyclophosphamide. These changes extend the option of a bone marrow transplantation for patients who lack an HLA matched donor and appear to improve engraftment and reduce graft versus host disease: whether this will be true for all age groups is currently being investigated.