Impaired granulocyte formylpeptide-induced superoxide generation in chronically ill, malnourished, elderly patients.

Objective: Protein-energy malnutrition (PEM), often occurring in patients with chronic disease, is associated with a decreased capacity to combat infections. In this study we assessed polymorphonuclear neutrophil (PMN) superoxide anion (*O2-) formation in elderly PEM patients with various chronic diseases.

Design And Subjects: Nineteen patients (75+/-1 years), with body mass index 17.1+/-0.4, and 19 age-matched healthy controls were included. Fourteen patients and 14 controls were re-examined in a 3 month follow-up.

Setting: A service of internal medicine at a university-affiliated hospital.

Interventions: Eight patients were prescribed a dietary liquid supplementation during the observation period.

Main Outcome Measures: Superoxide production in PMN induced by fMLP (a receptor ligand) and phorbol myristate acetate (PMA), which acts directly on protein kinase C.

Results: fMLP-induced superoxide generation in the malnourished patients was 55+/-5% of that of the controls. However, the patients retained their capacity, 108+/-6% of control PMN generation, to respond to PMA. In those who received formula supplementation, fMLP-generated *O2- production levels were 48+/-8 and 73+/-13% (P = 0.12) of those of controls at the start and after 3 months, respectively. Corresponding figures in those who were not prescribed supplementation were 57+/-8 and 64+/-4% (P = 0.55).

Conclusion: Possibly contributing to reduced host defence, receptor ligand-induced PMN generation of *O2 is significantly lower in chronically ill, elderly patients with PEM than in age-matched healthy controls.