Department of Pathology, University of Otago, Dunedin School of Medicine, Dunedin, New Zealand.
Pathology. 2010 Feb;42(2):160-4. doi: 10.3109/00313020903494953.
Pregnancy-related and idiopathic adult polymyositis are inflammatory myopathies of unknown aetiology in which CD8 positive T cells are found in close association with the up-regulation of human leukocyte antigen (HLA) class I on affected muscle cells. A similar polymyositis can also occur in patients with chronic graft versus host disease, wherein graft lymphocytes may be involved in the myositis. We investigated whether polymyositis that was temporally related to pregnancy, contained Y chromosome-bearing cells or signals using polymerase chain reaction (PCR) in biopsies of lesional muscle from two women who had given birth to sons. Furthermore, if Y chromosome material was present, we investigated whether it was contained in the intact inflammatory cells (CD8 positive lymphocytes for example), fetal macrophages, or differentiated fetal stem cells engrafted in the lesional skeletal muscle, and thus whether fetal cells played a role in the pathogenesis of the myositis.
PCR analysis was used for the Y chromosome in lesional tissue and fluorescence in situ hybridisation (FISH) for intact cells carrying the Y chromosome.
Small amounts of Y chromosome material were detected on second round PCR in fresh frozen tissue. No Y chromosome-bearing intact cells of lymphocytic, macrophage or muscle lineage were detected.
Our results suggest that microchimeric fetal cells are not found in the lesional tissue of pregnancy-related polymyositis.
妊娠相关性和特发性成人多发性肌炎是病因不明的炎症性肌病，其中 CD8 阳性 T 细胞与受影响的肌肉细胞上 HLA Ⅰ类人类白细胞抗原的上调密切相关。在慢性移植物抗宿主病患者中也可能发生类似的多发性肌炎，其中移植物淋巴细胞可能参与肌炎。我们通过对两名生育儿子的女性的皮损肌肉活检进行聚合酶链反应（PCR），来研究是否存在与妊娠时间相关的、携带 Y 染色体的细胞或信号。此外，如果存在 Y 染色体物质，我们还研究了其是否存在于完整的炎症细胞（例如 CD8 阳性淋巴细胞）、胎儿巨噬细胞或移植到皮损骨骼肌中的分化胎儿干细胞中，从而研究胎儿细胞是否在肌炎发病机制中发挥作用。
PCR 分析用于检测皮损组织中的 Y 染色体，荧光原位杂交（FISH）用于检测携带 Y 染色体的完整细胞。
在新鲜冷冻组织的第二轮 PCR 中检测到少量的 Y 染色体物质。未检测到具有淋巴细胞、巨噬细胞或肌肉谱系的携带 Y 染色体的完整细胞。
我们的结果表明，妊娠相关性多发性肌炎的皮损组织中未发现微嵌合胎儿细胞。
