Wang Yi-Hao, Fu Rong, Dong Shu-Wen, Liu Hui, Shao Zong-Hong
Department of Hematology, Tianjin Medical University General Hospital, Tianjin, China.
PLoS One. 2014 Apr 16;9(4):e95143. doi: 10.1371/journal.pone.0095143. eCollection 2014.
Immune-related pancytopenia (IRP) is characterized by pancytopenia caused by autoantibody-mediated bone marrow destruction or suppression. The bone marrows of IRP patients have remarkably increased erythroblastic islands (EIs).
We determined the immunoglobulin G (IgG) autoantibodies in some parts of EIs of IRP patients using immunofluorescence to investigate the biological function of EIs with IgG in the pathophysiology of IRP. The dominant class of autoantibodies detected in mononuclear cells was IgG (CD34 IgG, CD15 IgG, and GlycoA IgG), specifically IgG on GlycoA-positive cells (GlycoA IgG). Results show that extravascular hemolysis occurred in IRP through IgG autoantibodies in the EIs. These data included a high percentage of reticulocytes in the peripheral blood, hypererythrocytosis in the bone marrow, and high serum bilirubin. Furthermore, we examined the macrophages in the bone marrow of IRP patients. The results show that the number of activated macrophages relatively increased, and the phagocytic activity of macrophages significantly increased.
Increased EIs with IgG were the sites of erythroblast phagocytosis by the activated macrophages, rather than erythropoietic niches. The IgG autoantibodies in the EIs possibly functioned as adhesion molecules for a ring of erythroblasts around the macrophages, thereby forming morphologic EIs.
免疫相关性全血细胞减少症（IRP）的特征是由自身抗体介导的骨髓破坏或抑制引起的全血细胞减少。IRP患者的骨髓中红细胞岛（EIs）明显增加。
我们使用免疫荧光法测定了IRP患者EIs某些部分的免疫球蛋白G（IgG）自身抗体，以研究EIs中IgG在IRP病理生理学中的生物学功能。在单核细胞中检测到的主要自身抗体类别是IgG（CD34 IgG、CD15 IgG和GlycoA IgG），特别是GlycoA阳性细胞上的IgG（GlycoA IgG）。结果表明，IRP中通过EIs中的IgG自身抗体发生血管外溶血。这些数据包括外周血中网织红细胞百分比高、骨髓中红细胞增多以及血清胆红素高。此外，我们检查了IRP患者骨髓中的巨噬细胞。结果表明，活化巨噬细胞的数量相对增加，巨噬细胞的吞噬活性显著增加。
含有IgG的EIs增加是活化巨噬细胞吞噬成红细胞的部位，而不是造血龛。EIs中的IgG自身抗体可能作为巨噬细胞周围一圈成红细胞的黏附分子发挥作用，从而形成形态学上的EIs。
