[Immunity tests for respiratory diseases--SP-A, SP-D, KL-6]

We present the measurement methods, physiological means and clinical utilities of surfactant protein-A (SP-A), surfactant protein-D and KL-6 of current immunity tests for pulmonary diseases in Japan. The measurement methods of SP-A and SP-D are Enzyme Immunoassays(EIA), and SP-D cannot be measured automatically. KL-6 can be measured directly by the Sandwich method, developed in 1985 by our co-researcher Professor Kohno. SP-A and SP-D, proteins in pulmonary surfactants (phosphoric lipids), can kill many causative bacteria of respiratory infectious diseases by the activation of natural immune defective functions of macrophages. KL-6 is MUC-1, which responded to sixth antibodies extracted from lung cancer cells by Professor Kohno's monoclonal antibody method. SP-A, SP D and KL-6 are very used in the clinical field as injury markers of the lungs, because they have been proved to increase abnormity in difficult pulmonary fibrotic diseases such as idiopathic interstitial pulmonitis (IIP), etc. In particular, we could prove that KL-6 increased the movement and volume of pulmonary fibroblastic cells and decreased the apoptosis of pulmonary fibroblastic cells. In the near future, we are planning to develop new therapeutic drugs for pulmonary fibrotic diseases, as the target the fibrotic mechanism of the lungs by KL-6.