Abstract
The percentages of T and B lymphocytes in 13 patients with chronic lymphocytic leukemia were determined at two-week intervals. One patient with "B-cell predominant" disease showed a decrease from 77 to 49 in the percentage of circulating B cells, which bind heat-aggregated immunoglobulin and anti-human immunoglobulin. This patient had a comparable increase in T cells, which form rosettes with sheep erythrocytes. The lymphocytes of three other patients, who originally had equal percentages of cells that bound heat-aggregated immunoglobulin and anti-human immunoglobulin, lost Ig determinants from 47 to 63 per cent of cells without changing the proportion of cells with receptors for heat-aggregated immunoglobulin or for sheep erythrocytes.