The activity of cytochrome oxidase is increased in circulating lymphocytes of patients with chronic obstructive pulmonary disease, asthma, and chronic arthritis

Am J Respir Crit Care Med. 2000 Jan;161(1):32-5. doi: 10.1164/ajrccm.161.1.9807079.


We have previously shown that the activity of cytochrome oxidase (CytOx) in skeletal muscle of patients with chronic obstructive pulmonary disease (COPD) was higher than in healthy control subjects. The mechanisms and implications of this observation were unclear. In particular, it was not known if this abnormality can occur also in: (1) cell types other than muscle cells, and (2) other chronic inflammatory diseases. To obtain further insight into these questions, we measured the activity of CytOx in circulating lymphocytes in patients with stable COPD (n = 17), bronchial asthma (n = 6), or chronic arthritis (n = 5), and in healthy control subjects (n = 8). We found that, compared with healthy subjects (280 +/- 117 nKat/microg protein), patients with COPD showed increased CytOx activity (430 +/- 150 nKat/microg protein, p = 0.01) in lymphocytes. Further, this activity was negatively related to the degree of airflow obstruction present in these patients (r = -0.53, p < 0.05). We also found that the activity of CytOx in circulating lymphocytes was higher than normal in patients with chronic arthritis (411 +/- 130 nKat/microg protein, p < 0.05) and, particularly, in patients with bronchial asthma (1,667 +/- 1,027 nKat/microg protein, p < 0.001). These results show that the increased CytOx activity previously reported in skeletal muscle of patients with COPD is also detected in other cell types (such as circulating lymphocytes) and in other chronic inflammatory diseases (such as bronchial asthma and chronic arthritis). The mechanisms and implications of these findings deserve further investigation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arthritis / blood*
  • Arthritis / physiopathology
  • Asthma / blood*
  • Asthma / physiopathology
  • Biomarkers / blood
  • Chronic Disease
  • Electron Transport Complex IV / blood*
  • Humans
  • Lung Diseases, Obstructive / blood*
  • Lung Diseases, Obstructive / physiopathology
  • Lymphocytes / enzymology*
  • Male
  • Middle Aged
  • Respiratory Function Tests
  • Smoking / adverse effects


  • Biomarkers
  • Electron Transport Complex IV