Proliferative capacity of mononuclear cells in the human lung.

In pulmonary sarcoidosis, a chronic granulomatous disorder with different stages of activity, the proliferative capacity of the alveolar mononuclear cells is unknown. To get a closer look at this proliferation we combined pulse labeling (by means of tritium thymidine incorporation and autoradiography) with an immunocytochemical staining assay. This assay revealed on one single slide simultaneously blue CD4+ lymphocytes, brown CD8+ lymphocytes and red macrophages. We were able to show that CD4+ as well as CD8+ lymphocytes were radiolabeled only in the active state of the disease. But macrophage proliferation occurred independently of the activity of the disease. In other words with this combination of techniques, it is possible to differentiate, on a single slide, three subsets of mononuclear cells, in combination with their proliferative behavior.