adenosine deaminase activity in copd patients and healthy subjects

chronic obstructive pulmonary disease (copd) has been defined by the global initiative for chronic obstructive lung disease (gold), as a disease state characterized by airflow limitation which is not fully reversible. copd consists of emphysema which is the destruction and inflammation of the lung alveoli. adenosine deaminase (ada, e.c.3.5.4.4) converts adenosine to inosine. there are two isoenzymes of ada in serum; ada1 and ada2. it has been established that in copd patients the adenosine levels increase, which can contribute to decrease of ada activity. in this research we studied the ada and its isoenzyme activity in copd patients. this descriptive analytical case-control study was performed on thirty patients who were hospitalized in the pulmonary wards with an acute exacerbation of copd. ada activity was determined in 30 copd patients, 30 nonsmokers and 30 smokers controls. all subjects were male. we used colorimetric (giusti) method for measuring of ada activity. the data were analyzed using spss 13 software and kruskall-wallis and two-way anova tests. total ada activity in the copd and smoker control groups was significantly lower than in non smoker group (18.99 ± 7, 19.03 ± 9.1 and 22.95 ± 6.7 u/l, respectively). there was a significant difference for ada2 between the three groups. whereas the ada1 activity in the three groups had no significant difference. based on the obtained data, decrease of ada activity may play an important role in the formation of pulmonary injury in copd patients.