Myeloperoxidase in Nasal Secretion as a Cell-Activation Marker in Acute Sinusitis

Abstract

Acute bacterial infections of the upper respiratory tract, including the nasal sinuses, lead to an activation of neutrophil granulocytes. The protein myeloperoxidase (MPO) is released by this cell type only and therefore can act as a marker for activity of inflammation. In a prospective multicenter study, 45 patients with acute bacterial sinusitis (diagnosed by clinical examination, ultrasonography, and X ray or computed tomography scan) were treated with two different antibiotics (Cefditoren or Cefuroxim twice a day for 10 days). Nasal secretions were collected with absorbing foam-rubber samplers and a concentration of MPO was evaluated before the therapy and after 7 +/- 1 days and 14 +/- 2 days of antibiotic treatment. The concentrations of MPO were measured by a radioimmunoassay method and the dilution factors were determined by the lithium method. Significant differences in the MPO concentration in nasal secretions between the first and third visit could be found in both groups (p < 0.01 each). No significant difference was seen within the two different antibiotics used. Measurement of MPO concentration in nasal secretions showed a significant change after antibiotic treatment of acute bacterial rhinosinusitis. The reduction of MPO levels correlated with the observed clinical and radiological improvement of the disease. Additional investigations are needed to achieve more knowledge about basal concentrations of MPO in healthy persons and different activation patterns before it can be determined whether the MPO measurement could be a suitable method for monitoring the success of an antibiotic treatment in acute bacterial sinusitis.