The determination in blood of haptoglobin (Hp) and immunoglobulin A2 (IgA2) levels is emerging as a useful tool for detecting subclinical atherosclerosis, functioning as diagnostic biomarkers, according to specialists from the Cardiovascular Diseases area of the Biomedical Research Network Center (CIBERCV) and the Health Research Institute-Jiménez Díaz Foundation-Autonomous University of Madrid (IIS-FJD-UAM).
"Atherosclerosis is the underlying mechanism of most cardiovascular diseases. These represent one of the biggest health problems worldwide, with a huge cost to our healthcare system. Therefore, it is very important to be able to identify the disease in its earliest stages, to prevent it before it develops," explained the first author of this study and researcher at CIBERCV and CNIC Ana García-Álvarez.
The work, published in the journal 'Journal of the American Heart Association' and carried out with the participation of the company The Binding Site and the financial support of the "la Caixa" Foundation, is based on previous research where it was already observed that high concentrations of Hp and IgA2 allowed for the identification of atherosclerosis in asymptomatic individuals belonging to three Spanish cohorts.
In this new phase, the authors have validated the diagnostic utility of these two markers after analyzing 5,328 asymptomatic American adults included in the 'BioImage' study. The analyzed population had an average age of 69 years and 56.9 percent were women.
Furthermore, the results confirm that these biomarkers also have prognostic value, as it was found that elevated levels of Hp and IgA2 are associated with approximately double the risk of experiencing cardiovascular events. The principal investigator at CIBERCV and CNIC Jesús Vázquez has pointed out that this implies that "their analysis can provide additional clues to understand risk stratification in these patients."
"The detection of Hp and IgA2 is a relatively simple, objective, reproducible, and feasible technique in most hospitals, which would facilitate its immediate implementation in the clinic," Vázquez has highlighted. However, the team emphasizes the need to continue expanding the knowledge base to "elucidate the exact role of Hp and IgA2 as diagnostic and prognostic biomarkers, as well as their contribution to the pathogenic mechanisms of atherosclerosis."
Clinical relevance of these biomarkers
Atherosclerosis consists of the gradual accumulation of fats, inflammatory cells, and fibrous tissue in the arterial wall. For long periods, even decades, this pathology can evolve without clinical manifestations.
When one of these plaques ruptures or erodes, a thrombus can originate that suddenly interrupts blood flow to essential organs, such as the heart or brain. This process is behind most acute coronary syndromes and ischemic strokes, making atherosclerosis the leading underlying cause of cardiovascular mortality.
For this reason, the authors insist that early detection of the disease is crucial, although they remind that it remains one of the most complex challenges in modern cardiology.
So far, the assessment of cardiovascular risk has been based mainly on classic factors such as hypertension, hypercholesterolemia, diabetes, tobacco use, or excess weight. While these parameters help calculate the probability of suffering cardiovascular disease in large population groups, they do not always allow for precise identification of which individuals are developing atherosclerosis in its early stages and without symptoms.
The presence of atherosclerosis can be revealed through non-invasive imaging techniques, such as vascular ultrasound, which improve risk stratification compared to traditional models. However, these tests are not universally available, which drives the search for alternative, rapid, and non-invasive methods, including the determination of plasma biomarkers such as Hp and IgA2.