Paroxysmal nocturnal haemoglobinuria: Nature's gene therapy?

The development of paroxysmal nocturnal haemoglobinuria (PNH) requires two coincident factors: somatic mutation of the PIG-A gene in one or more haemopoietic stem cells and an abnormal, hypoplastic bone marrow environment. When both of these conditions are met, the fledgling PNH clone may flourish. This review will discuss the pathophysiology of this disease, which has recently been elucidated in some detail.     

骨髓间充质干细胞对再生障碍性贫血患者T细胞的免疫抑制

背景：骨髓间充质干细胞对再生障碍性贫血患者T细胞增殖的影响国内报道较少,而骨髓间充质干细胞是否通过抑制T细胞增殖实现对再生障碍性贫血患者的免疫调节目前尚无定论。 目的：观察人骨髓间充质干细胞对再生障碍性贫血患者T细胞的免疫调节作用。 方法：体外分离培养、扩增人骨髓间充质干细胞并通过形态学特征以及流式细胞术进行表面标志鉴定,将骨髓间充质干细胞分别与正常人和再生障碍性贫血患者外周血提取的T淋巴细胞共培养7 d。应用ELISA法检测各培养上清液中T淋巴细胞分泌的白细胞介素2、γ-干扰素、白细胞介素4及白细胞介素10水平。 结果与结论：再生障碍性贫血组患者培养上清液中T淋巴细胞分泌的白细胞介素2、γ-干扰素水平明显高于正常人(P < 0.05),白细胞介素4、白细胞介素10低于正常人(P < 0.05)。骨髓间充质干细胞可下调白细胞介素2、γ-干扰素表达,同时上调白细胞介素4、白细胞介素10表达,从而调节再生障碍性贫血患者的免疫紊乱。     

Acetazolamide-associated aplastic anaemia

Eleven cases of acetazolamide-associated aplastic anaemia were reported in Sweden during a 17-year period. There were six women and five men with a median age of 71 years (range 63-85 years). The median dose of acetazolamide was 500 mg, and the median duration of treatment was 3 months (range 2-71 months). Ten of the eleven patients died, all within 8 weeks after detection of their aplastic anaemia. The relative risk of developing aplastic anaemia when taking acetazolamide was 13.3 (95% confidence limits (CL); 6.8-25.3). The estimated incidence of reported acetazolamide-associated aplastic anaemia is approximately one in 18,000 patient years. The results strongly indicate that acetazolamide treatment is associated with a substantial increase in the risk of developing aplastic anaemia.     

First‐line choice for severe aplastic anemia in children: Transplantation from a haploidentical donor vs immunosuppressive therapy

We retrospectively compared the outcomes of children with severe aplastic anemia (SAA) who received immunosuppressive therapy (IST) or who underwent hematopoietic stem cell transplantation (HSCT) from a haploidentical donor (HID), between 2007 and 2016. A total of 52 children with SAA under the age of 17 years were initially treated with IST (n = 24) or haploidentical HSCT (n = 28) as first‐line treatment. The estimated 10‐year overall survival was 73.4 ± 12.6% and 89.3 ± 5.8% in patients treated with IST or HID‐HSCT (P = .806). The failure‐free survival was significantly inferior in patients receiving IST than in those undergoing transplantation from an HID (52.6 ± 10.5% vs 89.3 ± 5.8, P = .008). In univariate and multivariate analysis, the choice of first‐line immunosuppressive therapy was the only adverse predictor for failure‐free survival. At the last follow‐up, completely normal blood count was observed in 11 of 20 (55.0%) and 24 of 25 (96.0%) live cases in IST and HID‐HSCT cohort (P = .003). These suggest that HSCT from a haploidentical donor could be considered as first‐line treatment in children who lack a matched related donor, especially in experienced transplantation centers.     

Diagnostic criteria to distinguish hypocellular acute myeloid leukemia from hypocellular myelodysplastic syndromes and aplastic anemia: recommendations for a standardized approach

Members of the French-American-British Cooperative Leukemia Working Group met to review cases of aplastic anemia, hypocellular myelodysplastic syndrome and hypocellular acute myeloid leukemia. Criteria were proposed and modified following three workshops. Additional input was obtained from another hematopathologist with a special interest in bone marrow histology and immunohistochemistry. Guidelines were recommended based on the workshop results as well as additional studies including selective immunohistochemistry, flow cytometry and cytogenetics.     

Trilineage Response to rhG-CSF with Subsequent Clonal Hematopoiesis in a Patient with Severe Bone Marrow Aplasia

We treated a patient with severe aplastic anemia with long-term administration of recombinant human granulocyte-colony stimulating factor (rhG-CSF). When a trilineage response of hematopoiesis was obtained after the first treatment, a chromosomal change [45XX, -7] was observed in 20 of the 20 metaphases examined. Later, we were able to show a monoclonal X inactivation pattern in the phosphoglycerate kinase (PGK) gene in the peripheral blood polymorphonuclear leukocytes and mononuclear cells, indicating the presence of clonal hematopoiesis regardless of the disappearance of the karyotype abnormality. We suggest that it is important to pay close attention to the appearance of clonal hematopoiesis during the administration of G-CSF to patients with idiopathic severe bone marrow aplasia.     

Plasma thrombopoietin levels in patients with aplastic anemia and idiopathic t hrombocytopenic purpura

目的　为了研究血小板生成素 (TPO)在慢性血小板减少性疾病中的病理变化。方法　我们用敏感的双抗体夹心法酶联免疫吸附试验 (ELISA)检测了 4 0例再生障碍性贫血 (AA)和 32例特发性血小板减少性紫癜 (ITP)病人的血浆TPO的浓度。结果　AA患者血浆TPO浓度 (774± 393pg/ml)明显高于正常人 (5 5± 34pg/ml,P <0 0 0 1) ,并且与血小板计数呈负相关 ;ITP患者血浆TPO水平正常或仅轻度增高 (73± 36pg/ml) ,与正常人相比无显著性差异 (P >0 0 5 ) ,其血浆TPO浓度与血小板计数间也无相关性。结论　AA和ITP患者血浆TPO含量不仅受到外周血血小板同时也受到骨髓巨核细胞的调节。血浆TPO含量的检测有助于血小板减少性疾病的诊断及病理研究。