DNA Damage Induced by Radiation Exposure from Cardiac Catheterization

Area of Science:

• Cardiology
• Radiation Biology
• Molecular Biology

Background:

• Medical radiation exposure, particularly from cardiac imaging and interventions, constitutes a significant portion of total exposure.
• The biological impacts of low-dose radiation from medical imaging procedures are not well understood.
• Cardiac catheterization involves ionizing radiation, raising concerns about potential genomic and inflammatory effects.

Purpose of the Study:

• To investigate the effects of ionizing radiation from cardiac catheterization on genomic DNA integrity.
• To evaluate the impact of this radiation on inflammatory cytokine expression in patients and healthcare operators.
• To assess DNA damage markers and inflammatory responses following coronary angiography and/or percutaneous coronary intervention.

Main Methods:

• Isolation of peripheral mononuclear cells (MNCs) from patients (n=51) and operators (n=35) before and after procedures.
• Measurement of gamma-H2AX foci (DNA double-strand breaks marker) via immunofluorescence.
• Assay of dicentric chromosomes (DICs) using fluorescent in situ hybridization.
• Quantification of mRNA expression for inflammatory cytokines (IL-1α, IL-1β, LIF, caspase-1) and IκBα protein.

Main Results:

• Significant increases in γH2AX foci (4.5-fold) and DICs (71%) were observed in patient MNCs post-procedure.
• Elevated mRNA expression of IL-1α, IL-1β, leukemia inhibitory factor, and caspase-1 occurred in patients.
• While operators showed no change in γH2AX or DICs, their IL-1β mRNA levels increased significantly.
• Decreased IκBα protein expression was noted in both patient and operator groups, suggesting NF-κB activation.

Conclusions:

• Cardiac catheterization induces DNA damage in patients' MNCs, but not in operators'.
• Inflammatory cytokine levels rise in both patients and operators, likely via NF-κB pathway activation.
• Reducing radiation exposure during cardiac catheterization is crucial for the safety of both patients and operators.