ALDOA and FH4 Antibodies Associated with Cerebrovascular Disease

Ischemic stroke, including transient ischemic attack (TIA) and cerebral infarction (CI), is the most globally recognized cerebrovascular disorder, and is a serious health problem in the aging society. CI is an episode of neurological dysfunction caused by focal brain infarction, often resulting in fatality and disability. Patients with TIA are at a high risk of CI.

Endogenous antigens cause autoimmune responses that significantly influence the development of atherosclerosis, ultimately leading to the stenosis or blockage of the offending artery. These antigens induce autoantibodies that have been detected in the serum of patients with atherosclerosis-related diseases, such as CI, coronary heart disease (CHD), and diabetes mellitus (DM).

Clinical Biochemists and Geneticists at Chiba University (Chiba, Japan) collected serum samples from healthy donors (HDs) and patients diagnosed with TIA or CI caused by the development of atherosclerotic vulnerable plaque. In comparing the serum antibody levels, they set up four independent groups, which included 621 patients and 285 HDs. Of the 621 patients, 92, suffered from TIA, 464, from acute-phase cerebral infarction (aCI), and, 65, from old (chronic-phase) cerebral infarction (oCI). The serological identification of antigens by recombinant cDNA expression cloning (SEREX) is an established method for identifying endogenous antigenic proteins, combining molecular cloning and serological typing by using phage expression libraries.

In 19 patients with TIA, candidate antigens recognized by serum IgG autoantibodies were screened using a human aortic endothelial cell cDNA library. Through amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA, Perkin Elmer, Waltham, MA, USA), serum antibody levels against the candidate antigens were examined in the HDs, 92 TIA, and aCI, cohorts The plasma antibody levels in the Japan Public Health Center-based Prospective Cohort Study (1991–1993) were also examined. Glutathione-S-transferase (GST), GST–aldolase A (ALDOA), and GST–fumarate hydratase (FH) proteins were electrophoresed through SDS–polyacrylamide gel and analyzed by western blotting.

The team reported that in AlphaLISA, patients with TIA or aCI had significantly higher anti-ALDOA antibody (ALDOA-Ab) and anti-FH antibody (FH-Ab) levels than the HDs. In a multivariate logistic regression analysis, the ALDOA-Ab (odds ratio [OR]: 2.46) and FH-Ab (OR: 2.49) levels were independent predictors of TIA. According to the case–control study, the ALDOA-Ab (OR: 2.50) and FH-Ab (OR: 2.60) levels were associated with aCI risk. In a correlation analysis, both ALDOA-Abs and FH-Abs were well associated with hypertension, coronary heart disease, and habitual smoking. These antibody levels also correlated well with maximum intima–media thickness, which reflects atherosclerotic stenosis.

The authors concluded that the levels of antibodies against ALDOA and FH were significantly higher in patients with TIA or aCI than in HDs. These antibody markers can be novel predictors of TIA and pre-onset aCI, which are induced by atherosclerosis. The study was published on July 9, 2021 in the journal BMC Neurology.

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