Lambert Nathalie C, Erickson Timothy D, Yan Zhen, Pang Jennifer M, Guthrie Katherine A, Furst Daniel E, Nelson J Lee
Immunogenetics, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
Arthritis Rheum. 2004 Mar;50(3):906-14. doi: 10.1002/art.20200.
Microchimerism (Mc), originating from bidirectional fetal-maternal cell traffic during pregnancy, has recently been identified in healthy adults and in patients with scleroderma (systemic sclerosis [SSc]). This study was undertaken to investigate the frequency and quantitative levels of maternal Mc (MMc) in healthy women and women with SSc.
HLA-specific primers and fluorogenic probes were used in real-time quantitative polymerase chain reaction assays to detect and quantify MMc by targeting noninherited, nonshared HLA sequences. DNA-based HLA typing was conducted in 67 proband-mother pairs and in all children if the proband was parous. Statistical analysis was limited to 50 proband-mother pairs (including 32 healthy women and 18 women with SSc) in whom MMc could be distinguished from potential fetal Mc.
MMc in peripheral blood mononuclear cells was more frequent among women with SSc (72%) than healthy women (22%) (odds ratio 9.3, P = 0.001). However, levels of MMc, expressed as the genome equivalent of maternal cells per million (gEq/mil), were not significantly different (0-68.6 gEq/mil in SSc patients, 0-54.5 in healthy women). In additional studies, positivity for MMc was demonstrated in a bone marrow aspirate from an SSc patient in whom peripheral blood had been found to be negative for MMc on 4 occasions, and tissue from a subsequent autopsy of this patient had MMc levels of 757 and 1,489 gEq/mil in the lung and heart, respectively.
MMc is not uncommon in the peripheral blood of healthy adults, is increased in frequency in patients with SSc, and may be present in bone marrow and disease-affected tissues although absent in the peripheral blood.
微嵌合体（Mc）源于孕期母婴细胞的双向交换，最近在健康成年人及硬皮病（系统性硬化症[SSc]）患者中被发现。本研究旨在调查健康女性和SSc女性中母体微嵌合体（MMc）的频率及定量水平。
采用实时定量聚合酶链反应检测法，使用HLA特异性引物和荧光探针，通过靶向非遗传、非共享的HLA序列来检测和定量MMc。对67对先证者 - 母亲对进行基于DNA的HLA分型，若先证者已生育，则对其所有子女也进行分型。统计分析限于50对先证者 - 母亲对（包括32名健康女性和18名SSc女性），在这些样本中MMc可与潜在的胎儿微嵌合体区分开来。
SSc女性外周血单个核细胞中的MMc出现频率（72%）高于健康女性（22%）（优势比9.3，P = 0.001）。然而，以每百万母体细胞的基因组当量（gEq/mil）表示的MMc水平无显著差异（SSc患者为0 - 68.6 gEq/mil，健康女性为0 - 54.5 gEq/mil）。在其他研究中，一名SSc患者的骨髓穿刺液显示MMc阳性，而该患者外周血在4次检测中均为MMc阴性，该患者后续尸检的肺组织和心脏组织中MMc水平分别为757和1489 gEq/mil。
MMc在健康成年人外周血中并不罕见，在SSc患者中出现频率增加，可能存在于骨髓和疾病累及组织中，尽管在外周血中不存在。
