Electrolytes in nails analysed by X-ray microanalysis in electron microscopy. Considerations on a new method for the diagnosis of cystic fibrosis.

Patients with cystic fibrosis (CF) have an increased concentration of sodium in their nails. Hitherto, only neutron activation analysis has been considered for the diagnosis of cystic fibrosis by analysis of electrolytes in nails. It has been thoroughly tested methodologically and clinically. However, the intrinsic advantages of X-ray microanalysis and the results obtained in this study suggest that this method, after further testing, may be a useful diagnostic acid for cystic fibrosis. In comparison with neutron activation analysis, X-ray microanalysis has the advantage of simultaneously giving the concentrations of several elements and may be accessible at any hospital with an electron microscope fitted with the necessary equipment. Nails of CF-patients are here shown to have increased concentrations of Na, K and Cl, which will make the diagnosis of cystic fibrosis more reliable. The possibility of using sulphur as a reference element may eliminate the weighing procedure necessary in neutron activation analysis.