Analysis of primary immunodeficiency syndrome with low levels of antibody: diagnosis and treatment

为了产生抗体，需要将B细胞分化为分泌抗体的细胞，即浆细胞。CD27属于肿瘤坏死因子受体(TNFR)家族，是B细胞的记忆标记物，结合CD27可产生关键信号，积极控制B细胞进入浆细胞的途径。在这一发现的基础上，我们研究了血清免疫球蛋白水平低的原发免疫缺陷患者的B细胞功能，并对原发免疫缺陷的诊断和治疗进行了新的探索。我们描述了一种新的Artemis基因外显子3缺失突变，导致Artemis基因外显子3和4m RNA跳跃，在4个无血缘关系的严重联合免疫缺陷伴免疫球蛋白缺乏和细胞放射敏感性增加的日本患者中发现。在被研究的父母中也发现了杂合性外显子3缺失。这份报告I…S等在东亚地区首次对青蒿素缺乏症进行了研究，认为青蒿素基因突变是日本人所特有的。在共同变量免疫缺陷方面，共同变量免疫缺陷的分子基础尚不清楚。为了评估CVID患者的体液免疫功能，我们选择了24名起病早或晚的患者。根据临床表型、免疫反应、单核细胞或血小板中存在Bruton‘s酪氨酸激酶(BTK)、活化T细胞CD40配体表达正常，排除X连锁无丙种球蛋白血症(XLA)、X连锁高IgM综合征(XHIM)和非XHIM。外周血B细胞数量在正常范围或减少。24例患者IGD^-CD27+记忆B细胞均明显减少或消失，8例患者IGD^+CD27+B细胞减少。所有6例患者的循环B细胞，包括具有IGD^+CD27^+细胞的CVID患者，均未发生与脐带血B细胞类似的免疫球蛋白可变区基因的体细胞超突变。CVID患者的B细胞在IL-2和IL-10存在的情况下，通过Ig受体和CD40的结合产生IgM和Ig G，但不产生Ig A。除5例患者外，其余患者的B细胞在有JL-4存在的情况下，经CD40交联剂刺激后均可分泌IgE。对细胞标志物表达和功能异常的记忆缺陷B细胞的观察表明，幼稚的CVID B细胞，包括那些表达IGD^+CD27^+的细胞，类似于脐带血和高IgM综合征B细胞，可能是它们不能分化为浆细胞并产生不同类型的高亲和力抗体的原因。在X-连锁高IgM综合征(XHIM)患者中，大多数患者的单个核细胞共刺激诱导NO向低水平的类转换，从IgM到IgG和IgA与金黄色葡萄球菌考文菌株(SAC)加IL-2或抗CD40单抗(抗CD40)加IL-10。部分患者经抗CD40+IL-4刺激后，可检测到IgE分泌水平。SAC+IL-2+抗CD40+IL-10共刺激后，除产生IgM外，还能分泌大量的免疫球蛋白G，但不能分泌免疫球蛋白A。最显著的发现是6例患者外周血B细胞仅由IGD+CD27-和IGD+CD27+B细胞组成，IGD-CD27+记忆性B细胞明显减少。1例XHIM患者的IGD+CD27+B细胞主要产生IgM。我们的数据表明，XHIM患者免疫球蛋白产生的低应答率是由于IGD-CD27+记忆B细胞数量减少所致。但在体外，免疫球蛋白受体和CD40可与IL-2、IL-10等细胞因子协同刺激产生免疫球蛋白G。较少

To produce antibodies, the differentiation of B cells into antibody-secreting cells, plasma cells, is required. We describe that a ligation of CD27, which belongs to the tumor necrosis factor receptor (TNFR) family and is memory marker of B cells, is memory B-cell marker and yields crucial signals that positively control the entry of B cells into the pathway to plasma cells. On the basis of this finding, we investigated B-cell functions in primary immunodeficiencies with low levels of immunoglobulins in the serum, and performed new approach about the diagnosis and the treatment in primary immunodeficiencies.we describe a novel mutation of genomic exon 3 deletion, resulting in exon 3 and 4 m RNA skipping, of Artemis gene found in 4 Japanese patients of 4 unrelated families with severe combined immunodeficiency with absence of immunoglobulin and increased cellular radiosensitivity (RS-SCID) . The heterozygous genornic exon 3 deletion was also found in their parents studied. This report i … More s the first study of Artemis deficiency in East Asia and suggests that the Artemis gene mutation is peculiar to Japanese.In regarding common variable immunodeficiency, The molecular basis of common variable immunodeficiency (CVID) is unknown. To assess humoral immunity in CVID, we selected 24 patients with early or late onset of disease. X-linked agammaglobulinemia (XLA), X-linked hyper-IgM syndrome (XHIM) and non-XHIM were excluded based on clinical phenotype, assessment of the immune response, presence of Bruton's tyrosine kinase (Btk) in monocytes or platelets and normal expression of CD40 ligand by activated T cells. The number of circulating B cells was within normal range or reduced. IgD^- CD27^+ memory B-cells were markedly reduced or absent in all 24 patients and IgD^+ CD27^+ B cells were diminished in 8 patients. Circulating B cells from all six patients examined, including CVID patients with IgD^+ CD27^+ cells, failed to undergo somatic hypermutation in immunoglobulin variable (V)-region genes, similar to cord blood B cells. B cells from CVID patients produced IgM and IgG, but not IgA upon the engagement of Ig receptor and CD40 in the presence of IL-2 and IL-10. B cells from all but 5 patients secreted IgE when stimulated by CD40 crosslinking in the presence of JL-4. The observation of defective memory B cells with abnormal cell marker expression and function demonstrates that naive CVID B cells including those expressing IgD^+ CD27^+, in analogy to cord blood and hyper IgM syndrome B cells, may be responsible for their failure to differentiate into plasma cells and to produce high affinity antibodies of different isotypes.In the patients with X-linked hyper-IgM syndrome (XHIM), costimulation of mononuclear cells from most of the patients induced no to low levels of class switching from IgM to IgG and IgA with Staphylococcus aureus Cowan strain (SAC) plus IL-2 or anti-CD40 mAb (anti-CD40) plus IL-10. Measurable levels of IgE were secreted in some of the patients after stimulation with anti-CD40 plus IL-4. Costimulation with SAC plus IL-2 plus anti-CD40 plus IL-10 yielded secretion of significant levels of IgG in addition to IgM, but not IgA. The most striking finding was that peripheral blood B cells from all of the six patients were composed of only IgD+ CD27- and IgD+ CD27+ B cells; IgD- CD27+ memory B cells were greatly decreased. IgD+ CD27+ B cells from an XHIM patient produced IgM predominantly. Our data indicate that the low response of IgG production in XHIM patients is due to reduced numbers of IgD- CD27+ memory B cells . However, the IgG production can be induced by stimulation of immunoglobulin receptors and CD40 in cooperation with such cytokines as IL-2 and IL-10 in vitro. Less