Proteomics-based Identification Of Autoantibodies In Sera Of Acute Leukemia Patients And Healthy Chinese Individuals

Autoantibodies have long been used as diagnosis markers in autoimmune disease, and are thought to be the key point of the pathogenesis. There is substantial evidence for a humoral immune response to cancer in humans as demonstrated by the identification of antibodies against a number of intracellular and surface antigens in patients with various tumor types. The identification of panels of tumor antigens that elicit an antibody response may have utility in cancer screening or diagnosis or in establishing prognosis.Until now, autoimmunity in cancer has been mainly revealed in solid tumors. This study was to apply the proteomic approach to the identification of proteins that commonly elicit a humoral response in acute leukemia (AL). Sera from 21 newly diagnosed patients with AL, 20 patients with solid tumors, and 22 noncancer controls were analyzed for antibody-based reactivity against AL proteins resolved by two-dimensional PAGE. As a result, autoantibodies against a protein identified by mass spectrometry as Rho-GDI2 were detected in sera from 15 of 21 patients with AL (71%). By contrast, such antibodies were detected in sera from 1 of 20 patients with solid tumors (5%), and 1 of 22 noncancer controls (4.5%). Other four protein autoantibodies were also found in AL patients with a high frequency and constituted the major target antigens of the AL autoimmune response. The findings of autoantibodies against and others in serum of patients with AL suggest that the proteomic approach we have implemented may have utility for the development of serum-based assay for AL screening and diagnosis.However, autoantibodies normally exist in sera of healthy individuals and are enormously diversified. To explore the reservoir of autoantibody in healthy population, we performed a proteomics investigation of autoantibody profiles in the sera of 36 Chinese healthy individuals, which may provide valuable reference information to the identification of disease-specific autoantibodies. The results showed that autoantibody profiles varied individually, but some autoantibodies were identified at a high frequency in healthy population. The autoantibodies against α-enolase and those against...