Immunocytochemical analysis of the tissue location of cytokines (IL-2 and IL-12) in neuroendocrine lung cancer.

The study aimed at immunocytochemical evaluation of the cellular expression of two cytokines, IL-2 and IL-12 in lung carcinoids (n = 10), following the earlier demonstration of two markers of endocrine tumours (chromogranin A and NSE--neuron-specific enolase). In the immunocytochemical studies the classical avidin-biotinylated peroxidase (ABC) technique was used. Results of the tests were semiquantitatively appraised employing the IRS scale. In 9/10 cases intense reaction (score: 6-12 points) was noted for both lung neuroendocrine markers. In all cases of carcinoma co-expression of IL-2 and IL-12 was demonstrated in cells of the tumours. The cytokines showed a cytoplasmic localisation of mean (score: 3-4 points) or high (score: 6-12 points) intensity of reaction. Our studies point to a possible role of the two cytokines in the proliferation of lung neuroendocrine carcinomas but more detailed analysis is required on a broader material.