T gamma cells in sarcoidosis: E rosetting monocytes suppress lymphocyte transformation.

Increased suppressor T gamma lymphocytes have been described in sarcoidosis. We have shown that a proportion of these cells are esterase-positive, phagocytic, adherent to plastic and stain with an anti-monocyte serum. Removal of these cells or the addition of indomethacin increases the lymphocyte transformation to Con A. Transformation was still reduced in spite of preincubation with plastic and the addition of indomethacin suggesting that a further abnormality exists. Thus, within the increased number of T gamma cells there exists a population of activated monocytes which rosette with sheep red blood cells and could therefore be mistaken for T cells.