Protein concentrations in sputa from asthmatic children. Albumin, lactoferrin, gamma A and gamma G.

Abstract

Abstract Concentrations of human serum albumin (HSA), lactoferrin (Lfn), and immunoglobulins G (γG) and A (γA) were investigated in sputum from children with asthma by radial immunodiffusion in specific antibody-containing agar. All proteins were bound to sputum gel such that homogenization was required to yield maximum values. Lfn values were depressed even by the presence of homogenized sputum, making its accurate measurement in sputum impossible by this method. γA concentrations were best approximated by reference to exocrine, 11 S γA standards. Determination of HSA, γG, and γA concentrations failed to indicate the probable presence of bronchopulmonary infection. Variability of such values was so great as to restrict severely their clinical significance. However, knowledge of a protein's concentration and partition between the phases of exocrine fluids are suggested to be essential for comparisons of protein-dependent activities between sputum and other exocrine secretions or serum.