Moderate hyperhomocysteinemia and immune activation.

Area of Science:

• Biochemistry
• Immunology
• Pathology

Background:

• Moderate hyperhomocysteinemia increases risks for atherosclerosis, thrombosis, and neurodegenerative diseases.
• Homocysteine accumulation results from genetic factors and B-vitamin status, impacting disease pathogenesis.
• The precise role of homocysteine in disease, including oxidative stress and endothelial dysfunction, requires further clarification.

Purpose of the Study:

• To explore the mechanisms linking homocysteine to disease development.
• To investigate whether observed effects are due to homocysteine or B-vitamin deficiencies (folate and vitamin B12).
• To examine the association between homocysteine metabolism, oxidative stress, and immune activation in diseases like Alzheimer's, rheumatoid arthritis, and vascular diseases.

Main Methods:

• Review of proposed mechanisms of homocysteine action.
• Analysis of the interplay between genetic predisposition, B-vitamin status, and homocysteine levels.
• Investigation of the role of immune system activation, particularly Th1-type responses and interferon-gamma, in homocysteine metabolism.

Main Results:

• Hyperhomocysteinemia is frequently observed with B-vitamin deficiencies in patients with enhanced immune activation.
• Immune cell proliferation increases B-vitamin demand, leading to homocysteine accumulation.
• Activated macrophages produce reactive oxygen species (ROS), oxidizing antioxidants and B-vitamins, potentially contributing to hyperhomocysteinemia.

Conclusions:

• Th1-type immune responses may significantly contribute to hyperhomocysteinemia development.
• Immune activation is a potential key determinant in the progression of diseases associated with hyperhomocysteinemia.
• Distinguishing homocysteine's direct effects from those of B-vitamin deficiency is crucial for understanding disease pathogenesis.