The self-nonself concept as a basis for immune complex to replace "autoimmune diseases"

Area of Science:

• Immunology
• Oncology
• Genetics

Background:

• Gastric adenocarcinoma presents a unique case for understanding immune responses.
• The self-non-self concept is crucial in distinguishing host tissues from foreign antigens like glycolipid (GL) antigens and Forssman (Fs) antigen.
• Autoimmune diseases share similarities with cancer in immune complex (IC) deposition and tissue damage.

Observation:

• A 1951 patient with gastric adenocarcinoma survived 22 years post-surgery without metastasis after induced anti-P1 IgG antibodies.
• Anti-P1 antibodies likely target the galactose sugar on cancer cells, initiating a cytotoxic cellular immune response.
• Reduced anti-Forssman (Fs) antibodies were observed in cancer patients and the elderly, suggesting age-related immune changes.

Findings:

• Induced anti-P1 IgG antibodies demonstrated a two-stage cytotoxic effect against gastric adenocarcinoma cells.
• The presence of GL and Fs antigens in cancer and autoimmune conditions supports the self-non-self hypothesis.
• Normal serum contains antibodies against missing GL antigens, with anti-Fs prevalence decreasing with age.

Implications:

• The anti-P1 immune mechanism may be relevant for treating gastric cancer and understanding pregnancy loss.
• Understanding immune responses to foreign antigens is key to addressing autoimmune diseases like rheumatoid arthritis and lupus.
• Plasma exchange therapy is suggested to replenish IgG antibodies and complement in autoimmune conditions.