Imbalance in Tγ and Tμ lymphocyte subpopulations in patients with sarcoidosis

The percentage and the absolute numbers of T lymphocytes bearing Fc receptors for IgG and IgM (Tγ and Tμ lymphocytes, respectively) were evaluated in fourteen patients with active sarcoidosis and in a group of controls. A marked increase in the percentage of Tγ cells and a net decrease of Tμ cells were found. Although sarcoidosis patients present a T lymphopenia, the absolute number of Tγ lymphocytes was still increased whereas the Tμ decrease was even more pronounced. The possible causes of this imbalance in view of the recent interpretations of T suppressor and T helper lymphocytes are discussed.