Depressed T cell colony growth in systemic lupus erythematosus.

Phytohemagglutinin-stimulated peripheral blood T lymphocytes, plated in agar, are capable of forming discrete lymphoid colonies. In 35 normal subjects, the average number of colonies was 6,020 +/- 351 (SEM). By contrast, in 39 patients with systemic lupus erythematosus (SLE), the mean colony number was 2,774 +/- 384, a value significantly less than controls (P less than 0.001). Normal responses were measured in 5 patients with progressive systemic sclerosis and in 7 of 8 patients with rheumatoid arthritis. Colony growth in SLE showed a strong correlation with disease activity but did not correlate with responses of blood lymphocytes to phytohemagglutinin in suspension cultures, the number of circulating T cells, or serologic abnormalities.