Increase in differentiated type of T lineage cells in the myasthenic thymus: two-color fluorocytometric analysis.

We made use of two-color flow cytometry to examine thymic lymphoid cells from patients with myasthenia gravis. The CD4+CD8- cells and the CD4-CD8+ cells were significantly increased in the thymus from the patients, compared with findings in the control samples. Conversely, the CD4+CD8+ cells were significantly decreased. Significant increases in CD1-CD3+ cells and significant decreases in CD1+CD3- cells were noted. The percentage of CD45R+ cells also increased. There were no increases in activated T lymphocytes, defined as CD4+DR+ cells, CD8+DR+ cells, or IL2R+ cells. We conclude that the proportion of T lineage lymphocytes that are differentiated is increased in the thymus of patients with myasthenia gravis, and could reflect accelerated differentiation.