Transient ischemic attack (TIA) is a predictor for cerebral infarction (CI), and early diagnosis of TIA is extremely important for the prevention of CI. We set out to identify novel antibody biomarkers for TIA and CI, and detected matrix metalloproteinase 1 (MMP1), chromobox homolog 1 (CBX1), and chromobox homolog 5 (CBX5) as candidate antigens using serological identification of antigens by recombinant cDNA expression cloning (SEREX) and Western blotting to confirm the presence of serum antibodies against the antigens. Amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) revealed that serum antibody levels were significantly higher in patients with TIA or acute-phase CI (aCI) compared with healthy donors (P < 0.01). Spearman’s correlation analysis and multivariate logistic regression analysis demonstrated that levels of anti-MMP1, anti-CBX1, and anti-CBX5 antibodies were associated with age, cigarette-smoking habits, and blood pressure. Thus, serum levels of antibodies against MMP1, CBX1, and CBX5 could potentially serve as useful tools for diagnosing TIA and predicting the onset of aCI.

Cerebral infarction (CI), cardiovascular disease (CVD), diabetes mellitus (DM) and chronic kidney disease (CKD) are atherosclerosis-related diseases, which are major causes of health damage. For early and sensitive diagnosis, development of novel biomarkers is expected and of significant practical importance. First screening was carried out by phage expression cloning to identify antigen proteins recognized by serum IgG antibodies in patients with atherosclerosis. RPA2, LRPAP1, EEF1A1, SPOCK1, LOC729260, tubulin beta 2C (TUBB2C) and KIAA0020 markers were identified. We then compared the serum antibody levels against the candidate proteins between healthy donors (HD) and patients with CI, CVD, DM, or CKD by Alpha (amplified luminescent proximity homogeneous assay)-LISA method. The results showed that the serum TUBB2C antibody levels were significantly higher in patients with CI, DM, or CKD than those in HD. Using the average + 2SD of HD as the cut-off value, the positive thresholds of TUBB2C antibody markers were 14.8% in CI, 25.8% in DM, and 18.3% in CKD. TUBB2C antibody levels were well correlated with artery stenosis degrees such as plaque score, maximum intima-media thickness and cardio ankle vascular index. Consequently, TUBB2C antibody markers are useful to diagnose atherosclerosis, DM, and CKD, and can be applied to the prediction of the onset of CI. The serum anti-TUBB2C antibody markers are useful for the diagnosis of DM and CKD.

BackgroundDisease specific autoantibodies have been detected in the sera of patients with atherosclerosis-related diseases, such as cerebral infarction, cardiovascular disease. In the present study, we aimed to identify novel autoantibodies responsible for transient ischemic attack (TIA), a prodromal condition for cerebral infarction.MethodsTo identify candidate antigens, we screened a human aortic endothelial cell cDNA library using sera from 20 patients with TIA. Serum antibody levels were measured using amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) in 2 independent patient/healthy donor (HD) cohorts (n = 192 and n = 906 in the second screening and validation cohort, respectively).ResultsFirst screening identified 3 candidate antigens. Of these, programmed cell death 11 (PDCD11) was determined to be associated with stroke (p < 0.0001), as evidenced from the second screening using AlphaLISA. The validation cohort revealed significantly higher antibody levels against PDCD11 (PDCD11-Ab levels) in patients with TIA than in HDs. Multivariate logistic regression analysis indicated that the predictive value of PDCD11-Ab levels for TIA [Odds ratio (OR): 2.44, 95% confidence interval (CI): 1.33-4.57, p = 0.0039] was not inferior to other known risk factors for ischemic stroke, including age (OR: 4.97, 95% CI: 2.67–9.48, p < 0.0001); hypertension (OR: 3.21, 95% CI: 1.76–5.86, p = 0.0001); and diabetes (OR: 4.31, 95% CI: 1.74–11.2, p = 0.0015).ConclusionSerum PDCD11-Ab level may serve as a potential biomarker for TIA.