The role of argyrophilic nucleolar organizing region-associated proteins in clinical exacerbation of chronic obstructive pulmonary disease

Objective To investigate whether argyrophilic nucleolar organizing region-associated protein (AgNOR) parameters can be used as a biomarker that could potentially help with the management and clinical prognosis of chronic obstructive pulmonary disease (COPD) exacerbation. Methods This case–control study enrolled patients with COPD who were admitted to the Emergency Department and healthy sex- and age-matched control subjects. Peripheral blood samples were collected at hospital admission and the peripheral lymphocytes were silver-stained to investigate the quantity and distribution of AgNOR proteins. Fifty nuclei per patient were viewed and the total AgNOR area/total nuclear area (TAA/TNA) ratio and the mean AgNOR number for each patient were calculated. Results A total of 20 patients with COPD exacerbation and 17 healthy control subjects were recruited to the study. The TAA/TNA ratio and the mean AgNOR number were significantly higher in the patients with COPD exacerbation compared with the healthy control subjects. The mean AgNOR number showed a positive correlation with the pCO2 levels on admission. Conclusion AgNOR protein levels were elevated during a COPD exacerbation compared with healthy control subjects and there was a positive correlation between pCO2 levels and mean AgNOR number.