The expression of small cell lung cancer related antigens in foetal lung and kidney.

The presence and distribution of antigens recognised by the antibodies submitted to the Second International Workshop on Small Cell Lung Cancer Antigens has been mapped on human foetal lung and kidney using a streptavidin immunoperoxidase technique on frozen tissue sections. Thirteen of the antibodies showed no staining at all on these tissues and five showed staining of all structures in all tissues of equal intensity. The staining patterns of the remaining antibodies could be divided into several groups. All the cluster 1 antibodies recognising the neural cell adhesion molecule (NCAM) gave a distinctive staining pattern in both tissues. The cluster 2 antibodies and several groups of unclustered antibodies gave varying pure epithelial patterns of staining. The cluster w4 and 5 antibodies gave an interesting staining pattern which included some of the distinctive features of the cluster 1 pattern plus some epithelial expression. Various less distinctive patterns were also observed. Serial sections of foetal lung which had been stained with NCC-LU-246 (cluster 1), anti-desmin, and anti-neurofilament antibodies were also studied to attempt to determine the nature of the cells expressing NCAM in the foetal lung.