Reversible granulocyte killing defect in anorexia nervosa.

Area of Science:

• Immunology
• Nutritional Science
• Hematology

Background:

• Anorexia nervosa is an eating disorder often associated with malnutrition.
• Malnutrition can impact immune function, potentially increasing infection risk.

Observation:

• Three patients with anorexia nervosa presented with neutropenia and impaired granulocyte bactericidal function.
• Their granulocytes showed reduced killing of Staphylococcus aureus and E. coli in vitro.
• Serum opsonic activity was normal, suggesting the defect was intrinsic to the granulocytes.

Findings:

• Acquired deficiency in granulocyte bactericidal capacity was observed in malnourished patients with anorexia nervosa.
• Impaired bacterial killing correlated with the severity of malnutrition and neutropenia.
• In one patient, recurrent infections ceased after significant weight gain.

Implications:

• Granulocyte dysfunction in anorexia nervosa may contribute to increased susceptibility to infections.
• Nutritional rehabilitation and weight restoration can reverse this acquired immune defect.
• This highlights the critical role of nutrition in maintaining immune competence.