Demonstration of calcitonin and calmodulin by immunoperoxidase in the cystic fibrosis lung.

In this investigation, the presence of calcitonin and calmodulin has been demonstrated in immunoperoxidase formalin-fixed, paraffin-embedded sections of lung from autopsy tissues of four patients who died as a result of complications resulting from their cystic fibrosis disease. Immunoreactive calcitonin has been stained and quantitated in solitary endocrine cells which are increased in number and staining intensity in cystic fibrosis lung when compared to COPD and normal lungs. Immunoreactive calmodulin has been demonstrated to be increased in cystic fibrosis lung when compared to COPD and normal lungs. Previously, increased calcitonin and calmodulin were identified in sputum from cystic fibrosis patients utilizing radioimmunoassay. The calcitonin and calmodulin may be associated with increased calcium in pulmonary secretions leading to selective colonization of the lung by a limited number of pathogenic bacteria and enhanced pulmonary infection.