Vitamin D in hematological disorders and malignancies

Commonly known for its critical role in calcium homeostasis and bone mineralization, more recently vitamin D has been implicated in hematological cancer pathogenesis and shows promise as an anti‐cancer therapy. Serum levels of 25(OH)D₃, the precursor to the active form of vitamin D, calcitriol, are frequently lower in patients with hematological disease compared to healthy individuals. This often correlates with worse disease outcome. Furthermore, diseased cells typically highly express the vitamin D receptor, which is required for many of the anti‐cancer effects observed in multiple in vivo and in vitro cancer models. In abnormal hematological cells, vitamin D supplementation promotes apoptosis, induces differentiation, inhibits proliferation, sensitizes tumor cells to other anti‐cancer therapies, and reduces the production of pro‐inflammatory cytokines. Although the dosage of vitamin D required to achieve these effects may induce hypercalcemia in humans, analogs and combinatorial treatments have been developed to circumvent this side effect. Vitamin D and its analogs are well tolerated in clinical trials, and thus, further investigation into the use of these agents in the clinic is warranted. Here, we review the current literature in this field.     

儿童重型再生障碍性贫血并发毛细血管渗漏综合征诊治探讨（附2例报告）

目的探讨联合免疫抑制治疗重型再生障碍性贫血（SAA）并发毛细血管渗漏综合征（CLS）儿童的临床特征、发病机制及诊治方法。方法总结2011年我科行联合免疫抑制治疗SAA并发CLS病儿2例的临床特点及诊治过程,并结合相关文献进行分析。结果 2例病儿分别于连续5d应用抗胸腺细胞免疫球蛋白（ATG）结束后38d和1d发生CLS,临床特征有体质量增加、腹围增加、双下肢轻度凹陷性水肿、胸腔积液、心包积液、腹水、非感染性腹泻、低清蛋白血症,单纯输注清蛋白无效,以及无明显低血容量性低血压。经糖皮质激素＋羟乙基淀粉＋呋塞米＋清蛋白治疗后,症状及体征均逐渐消失。结论 CLS是联合免疫抑制治疗SAA过程中的一种罕见并发症,早期诊断和治疗可治愈。     

CD8+T细胞及其分泌的细胞因子在再生障碍性贫血发病机制中的作用

再生障碍性贫血（aplasticanemia,AA）是由多种因素引起的骨髓造血干细胞严重受损,造成骨髓造血功能降低或衰竭,以全血细胞减少为主要表现的一组综合征。AA发病机理复杂,尚未完全明了,故对其病理机制的深入研究有利于提高其诊疗水平。目前AA发病机制的研究主要集中在异常免疫,而异常免疫的研究热点为CD8＋T细胞及其分泌的细胞因子。本文就近年来CD8＋T细胞及其分泌的相关细胞因子在AA发病机制中的作用作一综述。     

Changes in bone marrow and peripheral blood lymphocyte subset findings with onset of hepatitis-associated aplastic anemia

Rationale:Hepatitis-associated aplastic anemia (HAAA) is a rare illness that results in bone marrow failure following hepatitis development. The etiological agent remains unknown in most HAAA cases. However, clinical features of the disease and immunotherapy response indicate that immune-mediated factors play a central role in the pathogenesis of HAAA. Activation of cytotoxic T cells and increase in CD8 cells could exert cytotoxic effects on the myelopoietic cells in the bone marrow.Patient concerns:A 15-month-old boy was brought to our hospital with complaints of generalized petechiae and purpura observed a week prior to hospitalization. His liver was palpated 3 cm below the costal margin, platelet count was 0 × 10⁴/μL, and alanine aminotransferase level was 1346 IU/L. A blood test indicated cytomegalovirus infection, and 3 bone marrow examinations revealed progressive HAAA. As the disease progressed to the 3^rd, 6^th, and 9^th week after onset, CD4⁺ T cells were markedly decreased, CD8⁺ T cells were markedly increased, and the CD4/CD8 ratio was significantly decreased. The number of B cells and natural killer cells decreased with time, eventually reaching 0.0%.Diagnosis:HAAA.Interventions:Rabbit antithymocyte globulin and eltrombopag olamine (a thrombopoietin receptor agonist) were administered.Outcomes:The patient''s platelet count returned to normal, and bone marrow transplantation was avoided. The peripheral blood lymphocytes (PBLs) improved as the patient''s general condition recovered.Lessons:This case demonstrates that HAAA induced by cytomegalovirus infection features decreasing CD4⁺ and increasing CD8⁺ PBLs as the bone marrow hypoplasia progresses. The PBLs return to their normal levels with the recovery from the disease. Our case findings thus support the involvement of immunological abnormality in HAAA.     

儿童非重型再生障碍性贫血中医证候分布研究

目的 探索儿童非重型再生障碍性贫血（NSAA）的中医证候分布规律,为临床辨证治疗提供参考。方法 收集2019年1月—2021年12月期间确诊的NSAA患儿,制定证素调查问卷并进行临床信息采集,采用因子分析、聚类分析的方法,探索NSAA患儿中医证候分布规律。结果 共纳入NSAA患儿368例,收集频率>15%的中医证候共54个。因子分析获得公因子16个,NSAA患儿主要病位证素分布在脾、肾、肝,主要病性证素为气虚、血虚、阴虚、阳虚、痰湿。对16个公因子进一步进行聚类分析,最终归纳为5个中医证型,分别为脾气亏虚证、气血两虚证、肾阴虚证、肾阳虚证、肾阴阳两虚证。结论 儿童NSAA病位主要在脾、肾、肝,中医主要证型为脾气亏虚证、气血两虚证、肾阴虚证、肾阳虚证和肾阴阳两虚证。     

重型再生障碍性贫血患者外周血自然杀伤细胞亚群百分比及功能变化

目的 分析重型再生障碍性贫血(SAA)患者免疫抑制治疗(IST)前、后外周血自然杀伤(NK)细胞亚群占淋巴细胞百分比、功能变化及其与造血功能相关性,探讨NK细胞在SAA发病机制中的作用.方法 用流式细胞术检测2010年4月至2010年12月天津医科大学总医院收治的12例初治(初治组)、30例IST后恢复(恢复组)的SAA患者的外周血NK细胞(CD3-CD56+/CD16+)及其亚群[CD3-CD56brightCD16-(CD56bright)、CD3-CD56dimCD16+(CD56dim)、CD3-CD56-CD16+]占淋巴细胞百分比、活化性受体(NKG2D和NKp46)、穿孔素、颗粒酶β表达,并与13名健康对照(对照组)比较;分析上述变化与外周血中性粒细胞比例(ANC%)、淋巴细胞比例、网织红细胞计数及骨髓造血功能(增生程度、粒系百分比、红系百分比、巨核细胞数量、淋系百分比)的相关性.结果 (1)初治组NK细胞、CD56bright细胞百分比(10.30%±6.08%、0.11%)均显著低于恢复组(16.47%±8.29%、0.68%,P＜0.05)和对照组(19.45%±6.88%、0.53%,均P＜0.05);初治组CD56dim细胞百分比(9.62%±6.04%)明显低于对照组(18.21%±7.16%,P＜0.05);恢复组CD3-CD56-CD16+细胞百分比(0.79%)显著高于初治组及对照组(0.37%、0.41%,均P＜0.05).(2)初治组与恢复组NK细胞NKp46、穿孔素表达[初治组(88.23%、64.97%±21.61%),恢复组(82.97%、66.14%±20.73%)]显著高于对照组(40.99%、42.11%±27.25%,均P＜0.05).(3)NK、CD56bright及CD3-CD56-CD16+细胞的百分比与SAA患者ANC%呈正相关(r分别为0.423、0.609、0.468,均P＜0.05),与骨髓粒系百分比呈正相关(r分别为0.357、0.517、0.434,均P＜0.05);NK、CD56bright、CD56dim和CD3-CD56-CD16+细胞的百分比与SAA患者骨髓增生程度呈正相关(r分别为0.455、0.412、0.404、0.451,均P＜0.05),与骨髓淋系百分比呈负相关(r分别为-0.522、-0.435、-0.411、-0.547,均P＜0.05);NK细胞NKG2D、NKp46、穿孔素、颗粒酶β表达与各造血指标无相关性(均P＞0.05).结论 SAA患者外周血NK细胞、CD56bright、CD56dim亚群占淋巴细胞百分比降低及穿孔素途径增强可能引起免疫耐受被破坏、T细胞功能亢进而导致造血功能衰竭.

Abstract：

Objective To analyze the percentage and functional changes of natural killer(NK)cell subsets in peripheral blood of severe aplastic anemia(SAA)patients before and after immunosuppressive therapy(IST)so as to evaluate the relationships between these changes and hematopoietic functions and explore the role of NK cells in the pathogenesis of SAA.Methods By flow cytometry,the percentages of NK cells(CD3-CD56+/CD16+)and its subsets[CD3-CD56brightCD16-(CD56bright),CD3-CD56dimCD16+(CD56dim),CD3-CD56-CD16+]in peripheral blood lymphocytes were detected in 12 untreated patients,30 recovered patients and 13 normal controls respectively from April 2010 to December 2010 in our hospital.NK cells activating receptors(NKG2D and NKp46),pofforin and granzyme-β of patients and normal controls were also detected.The correlation between these changes and hematopoietic functions,including the percentages of neutrophil granulocyte(ANC%),lymphocyte and reticulocyte absolute value in peripheral blood,and hyperplasia degree,percentage of granulocytes,erythrocytes,lymphocytes and megakaryocytes absolute value in bone marrow were evaluated.Results (1)The percentages of NK cells (10.30% ± 6.08%)and CD56 bright cells(0.11%)in untreated patients were significantly lower than those of recovered patients(16.47% ± 8.29%,0.68%,both P ＜0.05)or normal controls(19.45% ±6.88%,0.53%,both P ＜0.05).The percentage of CD56dim cells in untreated patients was significantly lower than that of normal controls(9.62% ±6.04% vs 18.21% ±7.16%,P ＜0.05).The percentage of CD3 CD56 CD16 + cells was significantly higher in recovered patients than that of untreated patients or normal controls(0.79% vs 0.37%,0.41%,both P＜0.05).(2)The expression of NKp46 and pefforin of NK cells in untreated(88.23%,64.97% ± 21.61%)and recovered patients(82.97%,66.14% ±20.73%)were significantly higher than those of healthy controls(40.99%,42.11% ±27.25%,all P ＜0.05).(3)The percentage of NK CD56bright and CD3-CD56-CD16+ cells of patients was positively correlated with ANC%(r=0.423,0.609,0.468 respectively,all P＜0.05)and the percentage of granulocytes in bone marrow(r=0.357,0.517,0.434 respectively,all P＜0.05).The percentages of NK,CD56bight,CD56dim and CD3-CD56-CD16+ cells were positively correlated with the hyperplasic degree of bone marrow(r=0.455,0.412,0.404,0.451 respectively,all P＜0.05),but they were negatively correlated with the percentage of lymphocytes in bone marrow(r =-0.522,-0.435,-0.411,-0.547 respectively,all P ＜0.05).The expression of NKG2D,NKp46,pefforin and granzyme-β of NK cells had no correlation with hematopoiesis(all P＞0.05).Conclusion The lowered percentage of NK CD56bright,CD56dim cells and a higher expression of pefforin may cause the over-function of T lymphocytes and thus lead to hematopoietic failure in SAA.     

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.     

误诊为特发性血小板减少性紫癜的儿童再生障碍性贫血临床分析

目的通过对误诊为特发性血小板减少性紫癜(ITP)的再生障碍性贫血(再障)患儿临床特点和误诊原因的分析,提高临床医师对儿童再障的认识,减少早期误诊。方法收集我院1992年1月-2010年8月收治的曾误诊为ITP、入院后确诊为再障的20例患儿的临床资料,分别按照实验室检查、疗效及误诊原因进行回顾性分析。结果在所有再障患儿中,误诊为ITP者占16%,在被诊断为ITP时:(1)多数患儿已经出现明显的外周血二系或三系下降,而并非单纯血小板减少。(2)5例患儿行骨髓检查,但结果并不符合ITP骨髓象。(3)绝大部分患儿未进行必要的血小板抗体检查,或检查结果并不典型。(4)按ITP进行糖皮质激素和大剂量免疫球蛋白治疗,疗效欠佳,未能进一步检查以核实诊断。(5)所有患儿均不符合ITP诊断标准,经过进一步检查均符合再障诊断标准。经抗胸腺细胞免疫球蛋白、环胞素A和雄性激素等治疗后,参照再障疗效标准,总有效率和显效率分别为75%和62%。结论再障和ITP均存在明显的血小板减少和出血倾向,ITP发病率明显高于再障,临床容易发生误诊。因此,临床上发现血小板降低,在考虑ITP诊断时,必须同时考虑可导致血小板减少的其他疾病的可能性,严格参照中华医学会制定的"再生障碍性贫血诊断标准"和"特发性血小板减少性紫癜诊断标准",以明确诊断和进行必要的鉴别诊断。