Is autoimmunity a common denominator in immune complex diseases?

Area of Science:

• Immunology
• Molecular Biology
• Pathology

Background:

• Antibodies to native DNA are present in plasma during inflammatory conditions.
• These antibodies are produced in response to DNA released from nucleated cells.
• DNA/anti-DNA immune complexes are found in the plasma of patients with inflammatory diseases.

Purpose of the Study:

• To investigate the formation and characteristics of DNA/anti-DNA immune complexes in inflammatory diseases.
• To understand the role of plasma DNAase in the generation of these complexes.
• To elucidate the mechanism by which these complexes contribute to immune-mediated inflammation.

Main Methods:

• Analysis of plasma samples from patients with inflammatory diseases.
• Detection and characterization of DNA/anti-DNA complexes and polynucleotide antigens.
• Assessment of the impact of plasma DNAase activity on immune complex formation and clearance.

Main Results:

• A significant proportion of immune complexes contain low-molecular-weight polynucleotide antigens derived from DNA degraded by plasma DNAase.
• Low-molecular-weight complexes are cleared more slowly by the reticuloendothelial system compared to large complexes.
• Plasma DNAase action leads to a predominance of small, soluble polynucleotide/anti-DNA complexes.

Conclusions:

• Soluble polynucleotide/anti-DNA complexes can deposit in vessel walls under conditions of increased vascular permeability.
• These complexes can trigger immune-mediated inflammatory phenomena in various disease states, irrespective of the initial trigger.
• The study highlights a common pathway for immune-mediated inflammation involving DNA/anti-DNA complexes.