Iron and immunity

Area of Science:

• Immunology
• Nutritional Science
• Hematology

Background:

• Iron is crucial for immune function, but its precise impact remains debated.
• Human studies often lack control for confounding nutritional deficiencies.
• Clinical relevance of observed immune abnormalities in iron deficiency is uncertain.

Purpose of the Study:

• To review existing literature on iron deficiency and immune function.
• To clarify the relationship between iron status and immune responses.
• To assess the clinical significance of immune changes in iron deficiency.

Main Methods:

• Systematic review of animal and human studies.
• Analysis of immune parameters including T lymphocyte function, humoral immunity, and polymorphonuclear leucocyte activity.
• Evaluation of clinical outcomes related to infection.

Main Results:

• Evidence suggests iron deficiency may impair T lymphocyte function (DTH responses, proliferation).
• Humoral immunity (immunoglobulin production, complement) appears largely unaffected.
• Reduced bactericidal activity of polymorphonuclear leucocytes is consistently reported.

Conclusions:

• Iron deficiency may contribute to specific immune dysfunctions, primarily affecting T cells and neutrophil activity.
• Despite immune alterations, iron deficiency does not lead to severe infections characteristic of primary immunodeficiencies.
• Humans exhibit resilience to iron deficiency, maintaining overall health despite potential immune compromise.