[Studies of the mechanism of disorders of the natural killer cell activity in patients with systemic scleroderma].

The NK activity of peripheral blood mononuclear cells (PBMC) was evaluated in 90 patients with various subsets of systemic scleroderma (SSc). The NK activity, as performed with K-562 as target cell, was found to be significantly lowered in patients with diffuse scleroderma, but did not differ from the healthy control in patients with acrosclerosis. The lowest values in the NK activity assay were obtained in patients with most extensive skin involvement and severe internal organ changes. The NK activity of healthy donors' PBMC was significantly decreased by addition of SSc patients PBMC (50:1) to the cytotoxicity assay, but was not influenced by the patients sera.