Importance of methodology in demonstrating depression of T-lymphocyte levels.

A comparison has been made of 3 methods of determining E rosettes in young, healthy people, women with breast cancer and an age-matched group of healthy women, in an attempt to explain the wide variations in T-cell levels in different disease states reported by different workers. The greatest difference in levels of E-rosetting cells between the different groups was seen in incubation of 1 1/2 h at 4 degrees C. Much of the difference seen in these comparisons disappeared after overnight incubation at 4 degrees C, which was associated with an increased T-cell level in all groups. Consequently, although maximal levels of T lymphocytes as determined by E rosetting are found using overnight incubation, a short incubation period may be superior for demonstrating subtle depressions in levels of T lymphocytes as seen in elderly people and cancer patients. This depression is not considered to be cancer specific, because of the findings in the age-matched control group and similar findings in benign disease states.