儿童原发性免疫缺陷病的免疫学改变及分析

The characteristics of laboratory analysis for primary immunodeficiency diseases in children

目的了解儿童原发性免疫缺陷病(PID)患儿的实验室免疫检查特点,为临床早期诊断PID提供依据。方法对76例PID患儿的免疫学检查包括细胞免疫和体液免疫指标进行回顾性总结及分析。结果体液免疫检查中,普通变异型免疫缺陷病(CVID)及联合免疫缺陷病的IgG均降低,尤以CVID降低更为明显,且伴IgA及CD19+B细胞明显降低;IgA降低主要见于CVID、选择性IgA缺乏症(IgAD)及共济失调毛细血管扩张症(AT);低丙种球蛋白血症患儿IgG、IgA及CD19+B细胞均降低。细胞免疫功能中CD3+、CD4+T细胞降低主要见于细胞免疫缺陷病、联合免疫缺陷病及DiGeorge综合征(DGS);AT患儿的CD4+/CD8+比例也降低。8例CVID患儿检测T细胞功能亚群及活化指标,其中5例患儿的CD4+/CD8+比例倒置(CD4+/CD8+<0.9);与对照组相比,CVID患儿的CD4+HLA-DR+和CD8+CD45RO+T细胞比例明显升高,CD4+CD45RA+T细胞比例明显降低(P均<0.01)。结论儿童原发性免疫缺陷病免疫学改变各异。CVID患者体内T细胞过度活化,可能是CVID患者容易罹患自身免疫性疾病的原因之一。

Objective To characterized the laboratory analyses in primary immunodeficiency diseases（PID）in children,to provide better approach to early diagnosis.Methods Cellular and humoral immune functions were measured among 76 patients with PID.Results In aspects of humoral immune function tests,the level of IgG was lower in patients with common variable immunodeficiency（CVID）or severe combined immunodeficiency disease（SCID）,especially in patients with CVID accompanying by low level of IgA and decreased count of CD19＋ B cells.Low level of IgA were also observed in patients with CVID,selective IgA deficiency or AT.Patients with hypogammaglobulinemia had low level of IgG,IgA and decreased count of CD19＋B cells.In aspects of cellular immune function,decreased count of CD3＋ and CD4＋ T was seen in SCID and DGS.Low ratio of CD4＋/CD8＋ was found in AT.The subset of T cells and activation cell marker in T cells were evaluated in eight patients with CVID,among whom five patients had inversed CD4＋/CD8＋ ratio（CD4＋/CD8＋ 〈 0.9）.Furthermore,the percentage of CD4＋HLA-DR＋ and CD8＋CD45RO＋ T cells in patients with CVID were higher than normal control while the percentage of CD4＋CD45RA＋ T was lower than normal control（P 〈 0.01）.Conclusions Different kind of PID showed different laboratory characteristics.Over-activation of T cells may be a cause of autoimmune disorder in CVID.