Disciplina de Reumatologia, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, Brazil.
Instituto da Criança, Hospital das Clinicas HCMFUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil.
Adv Rheumatol. 2018 Oct 26;58(1):37. doi: 10.1186/s42358-018-0037-5.
Different inflammatory cells (i.e., CD4, CD8, CD20 and CD68) are involved in pathogenesis of DM muscle. In this context, the aim of this study was to assess and compare these inflammatory cell phenotyping in muscle samples of treatment naive juvenile and adult patients with dermatomyositis.
This is a cross-sectional study, in which 28 untreated juvenile and 28 adult untreated dermatomyositis patients were included. Immunohistochemical analysis was performed on serial frozen muscle sections. Inflammatory cell phenotyping was analyzed quantitatively in endomysium, perimysium, and perivascular (endomysium and perimysium) area.
Mean age at disease onset was 7.3 and 42.0 years in juvenile and adult dermatomyositis, respectively. Both groups had comparable time duration from symptom's onset to biopsy performance. CD4 and CD8 positive cells distributions were similar in both groups in all analyzed area, except for more predominance of CD4 in perimysium at juvenile muscle biopsies. The CD20 and CD68 positive cells were predominantly observed in adult muscle biopsy sections, when compared to juvenile samples, except for similar distribution of CD20 in perivascular endomysium, and CD68 in perimysium.
These data show that the differences between juvenile and adult dermatomyositis may be restricted not only to patients' age, but also to different inflammatory cell distribution, particularly, in new-onset disease. Further studies are necessary to confirm the present study data and to analyze meaning of the different inflammatory cell phenotyping distribution finding in these both diseases.
不同的炎症细胞（如 CD4、CD8、CD20 和 CD68）参与了皮肌炎的发病机制。在此背景下，本研究旨在评估和比较初治的青少年和成年皮肌炎患者肌肉样本中的这些炎症细胞表型。
这是一项横断面研究，纳入了 28 例未经治疗的青少年皮肌炎患者和 28 例未经治疗的成年皮肌炎患者。对连续的冷冻肌肉切片进行免疫组织化学分析。在肌内膜、肌束膜和血管周围（肌内膜和肌束膜）区域定量分析炎症细胞表型。
青少年皮肌炎的发病年龄平均为 7.3 岁，成年皮肌炎为 42.0 岁。两组从症状出现到活检的时间间隔相似。在所有分析区域，除了在青少年肌肉活检中肌束膜中 CD4 更为优势外，两组的 CD4 和 CD8 阳性细胞分布相似。与青少年样本相比，CD20 和 CD68 阳性细胞主要见于成年肌肉活检切片，除了在血管周围肌内膜中 CD20 分布相似和肌束膜中 CD68 分布相似外。
这些数据表明，青少年皮肌炎和成年皮肌炎之间的差异不仅限于患者的年龄，还可能与不同的炎症细胞分布有关，尤其是在新发疾病中。需要进一步的研究来证实本研究的数据，并分析在这两种疾病中发现的不同炎症细胞表型分布的意义。
