Active T-rosette-forming cells in the peripheral blood of cancer patients

We studied a subpopulation of the thymus-dependent rosette-forming lymphocytes from the peripheral blood of normal individuals and of untreated patients with solid tumors or hematological cancers. This subpopulation of the thymus-dependent rosette-forming cells (T-RFC), termed the "active T-RFC," may be relatively more immunocompetent than the total thymus-dependent population. The mean percentages and absolute numbers of active T-RFC of 40 healthy adult controls were 25.8 +/- 4.3 and 626 +/- 213, respectively. There was no difference in the percentage of active T-RFC between the controls (smokers and nonsmokers) and the 102 untreated patients with solid (localized or metastasized) tumors, 4 patients with Hodgkin's disease, or the 10 patients with non-Hodgkin's lymphomas. However, the absolute number of active T-RFC was significantly less in the cancer patients than in the controls. Eight patients with chronic lymphocytic leukemia had lower percentages but higher absolute numbers of active T-RFC, whereas 6 patients with multiple myeloma had higher percentage and lower absolute numbers than the controls. Following radiation therapy, 61 patients with solid tumors showed no difference in the percentage of active T-RFC, but the corresponding absolute numbers declined significantly. A good correlation was seen with patients having positive microbial skin test responses and normal percentage of active T-RFC. The significance of both the percentages and absolute numbers of active T-RFC and their relationship to patient status are discussed.