Preliminary Study of the Autoantigens on the Membrane of Erythropoietic Cells of the Patients with BMMNC- Coomb’s Test(+) Hemocytopenia

To observe the relationship between EPO receptor(EPOR) and autoantibodies-IgG/IgM(auto-Ab) on the membrane of erythropoietic cells of the patients with IRP and then explore the probable autoantigens of auto-Ab in IRP.

46 newly diagnosed IRP patients(15 with auto-Ab on erythropoietic cells and 31 without auto-Ab on erythropoietic cells) and 18 healthy controls were enrolled in this study. EPOR expression on their nuclear erythrocytes were tested with FCM to observe the relationship between EPOR and auto-Ab; EPOR mRNA were tested by RT-PCR; Stat5 and P-Stat5 proteins in nucleared erythrocytes were measured by Western blot; EPOR expression on the nucleared erythrocytes membrane were tested again after stripping autoantibodies with glycine buffer.

(1)EPOR of auto-Ab(+) arm(1.59±0.87)% was significantly lower than that of auto-Ab (−) arm(4.58±4.09)%(P<0.01)and the latter was significantly higher than that of normal controls(2.27±1.76)%(P<0.05); GEPOR of IRP patients was inversely correlated with their auto-Ab (r=−0.543,P=0.000).(2) EPOR mRNA of auto-Ab(+) arm(0.685±0.136)was significiantly higher than that of auto-Ab (−) arm(0.554±0.116)(P<0.01)and normal controls(0.580±0.119)(P<0.05);(3) Protein Stat5 of auto-Ab(+) arm(1.45±0.94) was significantly higher than that of normal controls(0.54±0.36)(P<0.05). While P-Stat5 of auto-Ab(+) arm(0.42±0.18) was significantly lower than that of normal controls(0.85±0.38)(P<0.05). (4) EPOR expression increased significantly after auto-Ab stripped from nucleared erythrocytes with glycine buffer.

The auto-Ab of some IRP patients might block or competitively inhibit the EPOR on the membrane of erythropoietic cells. EPOR might be one of autoantigens in IRP.

No relevant conflicts of interest to declare.