Abstract 4382

Objective

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.

Methods

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.

Results

(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.

Conclusion

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.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.

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