A METHODOLOGICAL STUDY OF THE DIAGNOSIS OF CYSTIC FIBROSIS BY INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS OF SODIUM IN NAIL CLIPPINGS

Abstract

Abstract. Kollberg, H. and Landström, O. (Department of Paediatrics, University Hospital, Uppsala and AB Atomenergi, Studsvik, Sweden). A methodological study of the diagnosis of cystic fibrosis by instrumental neutron activation analysis of sodium in nail clippings. Acta Paediatr Scand, 63: 405, 1974.–Instrumental neutron activation analysis (INAA) of nail clippings was used in the development of a diagnostic method for cystic fibrosis (CF). From CF patients and controls more than three years old, nail clippings were sampled for tests of different errors. As a result of this study a precise collection routine was outlined. Sodium is easily washed out from nail clippings. The risk of sodium contamination of the nails seems to be small. The sodium distribution in the nail is inhomogeneous, and the sodium content varies also from nail to nail in the same person. There is good evidence that the increased sodium in the nails of CF patients comes from the sweat. There seems to be a basic “intrinsic” sodium level, which is about the same in the nails of CF patients as in controls. The precision and accuracy of INAA for determining sodium in nails is considered satisfactory. It is concluded that INAA of the sodium concentration in nail clippings is a suitable method as an aid in the diagnosis of CF if a precise collection routine is used.