Implication of ESR signals from ceruloplasmin (Cu(2+)) and transferrin (Fe(3+)) in pleural effusion of lung diseases.
Pleural effusions of seven lung cancer patients (mean age; 58) and seven non-cancer patients (mean age; 49) were examined and Cu(2+) was measured in ceruloplasmin and Fe(3+) in transferrin signals by electron spin resonance (ESR) method. The variations of total Fe and Cu ions, ceruloplasmin and transferrin, proteins, neutrophil cell counts, LDH and nitrite/nitrate were also examined. The Cu(2+) peak was decreased and the Fe(3+) peak was increased in the cancer group. The interrelationship among Cu(2+), total Cu and ceruloplasmin, and among Fe(3+), total Fe and transferrin clarified that Cu(2+) and Fe(3+) are not a representative of ceruloplasmin and transferrin, respectively. The ratio of Cu(2+)/Fe(3+) in pleural effusion distinguished lung cancer from benign inflammation as a cause. The ratio of total Cu/total Fe measured by the chemical analysis method also distinguished these, but the ratio of ceruloplasmin/transferrin was unable to distinguish the cancer. In conclusion, the simple and rapid measurement of Cu(2+)/Fe(3+) by ESR effectively abstracts the variation of total ion concentrations caused by malignant disease.