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. 