Cell surface expression of FcgammaRI (CD64) on neutrophils and monocytes in patients with influenza A, with and without complications

• The expression of the Fcgamma-receptor I (FcgammaRI), CD64 on normal neutrophils is up-regulated during bacterial infections. CD64 is a promising diagnostic tool in the diagnosis of acute infections. The aim was to study surface expressions of CD64 on neutrophils and monocytes in patients with influenza A with and without complications and evaluate these as diagnostic tools in comparison with serum levels of HNL (human neutrophil lipocalin). CD64 expression on neutrophils and monocytes was evaluated by flow cytometry. HNL was assayed by a specific radioimmunoassay. 22 patients with influenza A with or without complications were included and the results compared with those of 29 patients with acute bacterial infections and 29 healthy subjects. Neutrophil expression of CD64 was increased in influenza A with raised proportion expressing CD64 in complicated compared to uncomplicated influenza. The expression was significantly higher in bacterial infections compared to both influenza groups. Serum levels of HNL were raised in all infection groups, but significantly more so in the group with bacterial infection. ROC-curve analysis showed that neutrophil expression of CD64 and the serum levels of HNL had similar diagnostic power in the discrimination between acute bacterial infections and influenza A. Monocyte expression of CD64 was raised in all infections with no differences between subgroups. We conclude that neutrophil expression of CD64 and serum levels of HNL are both promising assays in the distinction between infections caused by bacteria or influenza A, whereas CD64 could identify patients with complications of their influenza A infection.

Nyckelord

Acute-Phase Proteins

Adult

Aged

Aged; 80 and over

Bacterial Infections/complications/diagnosis/immunology

C-Reactive Protein/metabolism

Case-Control Studies

Humans

Influenza A virus

Influenza; Human/complications/diagnosis/*immunology

Middle Aged

Monocytes/immunology

Neutrophils/immunology

Pneumonia/complications/immunology

Proto-Oncogene Proteins/blood

Receptors; IgG/*metabolism

MEDICINE

MEDICIN

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)