Preliminary Study of the Relationship Between EPO Receptor and Autoantibody on the Membrane of Erythropoietic Cells of the Patients with BMMNC- Coomb's Test(+) Hemocytopenia

To observe the relationship between EPO receptor (EPOR) and autoantibody(IgG) on the membrane of erythropoietic cells of the patients with bone marrow mononuclear cell Coomb's(BMMNC-Coomb's) test(+) immuno-related pancytopenia(IRP),and then explore the probable autoantigens of autoantibodies in IRP.

42 newly diagnosed IRP patients (14 with IgG autoantibody on erythropoietic cells and 28 without this autoantibody) and 11 healthy donors as controls were enrolled in this study. EPOR on their nuclear erythrocyte were tested with flow cytometry. Their clinical data were also analyzed.

(1) The level of EPOR of IgG(+) arm(1.59±0.87)% was significantly lower than that of IgG(-) arm (4.58±4.09)%(P<0.01), and the level of EPOR of IgG(-) arm was significantly higher than that of normal controls(2.27±1.76)%(P<0.05) G The level of EPOR of IRP patients was negatively correlated with their IgG autoantibody(r=-0.543,P=0.000) and its regression equation was Y(EPOR)=0.040-0.335X(IgG); (2) Reticulocyte percentage of IgG(+) arm (1.55±0.64)% was significantly lower than that of IgG(-) arm (2.41±1.42)%(P<0.05). The level of EPOR of IRP patients was positively correlated with reticulocyte percentage(r=0.346,P=0.029); (3)The serum level of indirect bilirubin(IDBIL) of IgG(+) arm was normal. While there were six patients (21.4%) whose serum level of IDBIL were higher than those of normal controls in IgG(-) arm.

The autoantibody(IgG) of some IRP patients might block or competitively inhibit the EPOR on the membrane of erythropoietic cells. It could inhibit the proliferation and differentiation of erythropoiesis in early phase.

No relevant conflicts of interest to declare.