[Ultrastructural identifaction of human T lymphocytes using a peroxidase-conjugated anti-HTLA serum].

A horse antiserum rendered specific for human T lymphocytes was conjugated with peroxidase (PO) and used for identification of tonsilar T lymphocytes in electron microscopy. This conjugate stained nearly 50% of tonsilar lymphocytes, 96% of the T of the T cell-enriched population and 4% of the B cell-enriched population. The staining was only found on the cytoplasmic membrane as irregular small spots all over the cell surface. This conjugate was used for identification of the lymphocyte sub-populations extracted from skin infiltrates, and specially in Sezary's syndrome. PO-anti-HTLA serum stained all the cells showing morphological chracteristics of Sezary cells, which confirmed the thymus-derived origin of these cells.