Peripheral blood T and B lymphocytes in patients with thyrotoxicosis and Hashimoto's thyroiditis and in normal subjects. A comparison of lymphocyte separation methods.

Lymphocytes were separated from the peripheral blood of three groups of subjects (normal controls, untreated thyrotoxicosis and confirmed Hashimoto's thyroiditis) by two separation methods: dextran sedimentation and Ficoll–Triosil gradient centrifugation. It has been shown that there is a selective loss of T lymphocytes (as measured by sheep red cell rosettes) with relative enrichment of B lymphocytes (as measured by surface immunoglobulins) in the Ficoll–Triosil-separated suspensions. This distortion of the T/B ratio was seen to a similar extent in each of the three groups of subjects. Furthermore, the mean percentage T and B lymphocytes of both patient groups were not significantly different from those of the controls when separated by the same method. Optimal E-rosette formation occurred after prolonged incubation at 4°C and in the absence of serum. Direct counts using Toluidine Blue were superior to indirect counts with unstained rosette suspensions.