Estimation o latent iron binding capacity using Fe
Mehta, B.C.; Doctor, R.G.; Patel, J.C.
Journal of Postgraduate Medicine 16(4): 190-192
1970
ISSN/ISBN: 0022-3859 PMID: 5497697 Document Number: 26362
The latent iron-binding capacity (LIBC) of serum was estimated colorimetrically by the method of Rath and Finch (Abst. 2415, Vol. 19) or with 59Fe by the following method, using the Irosorb-59 kit (Abbott Laboratories, Chicago). Serum 1 ml mixed in a plastic tube with buffer solution of ferric ammonium citrate including Fe 6.5 micro g with a specific activity of 0.1 mCi or less from 59Fe was left 10 min at room temperature. Next, polyether sponge with Amberlite IRA-400 ion exchange resin was put into the tube and compressed with a plunger to expel air, then left 1 h during which the radioactivity of the tube was counted. The solution was aspirated from tube and sponge and the sponge was washed. Then the LIBC in micro g per 100 ml was /(net original count). The 1.05 corrects for the fact that the sponge takes up only 95% of the Fe not bound to transferrin. There was a close relation between the values for LIBC estimated with the 2 methods for 31 persons with Fe-deficiency anaemia and Hb 4.0 to 9.0 g%. For 9 persons thought to be normal, with Hb 12-0 to 15.0, the LIBC was normal in fasting venous serum by the first method but with 59Fe it was high in 5 of the 9 persons, indicating latent Fe deficiency. Nine anaemic persons were studied 24 h after treatment with iron-dextran; LIBC by the first method indicated saturation but the 59 Fe method showed LIBC in all 9. The method with 59Fe was considered the better of the two.