Separation of lactoferrin and clinical application of its radioimmunoassay

A new method of separation and purification of lactoferrin (LF), its radioimmunoassay (LF-RIA), and application in the diagnosis of lung cancer are reported. The results showed that this method is much better than what were previously reported, with advantages of high yield, time-saving and economy. The results of the LF-RIA established were good. The coefficients of variation within a batch and between batches were 4.77% and 13.59% respectively and the recovery rate was 97.99%. There was no cross-reaction between lactoferrin and transferrin. The lactoferrin in the bronchial washing fluid (BLF) was determined in 36 lung cancer cases, 21 pulmonary infection cases and 4 normal controls. The results indicated that the BLF content in the lung cancer group was higher than that in the pulmonary infection group or the normal control group and the detection rate was the highest in lung adenocarcinoma. Pathological analysis indicated that the BLF was negatively related to the early and later tumor. (2 figs., 2 tabs.)